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Vocapedia > Health > Genetics

 

Cells, DNA, Genes, Human genome,

 

Genetic engineering, Gene therapy

 

 

 

 

 

Genetics 101        Video        National Geographic        12 July 2018

 

What is a genome,

and how are traits passed from generation to generation?

 

Learn how pea plants helped launch the study of genetics

and how the field of genetics research has evolved over time.

 

YouTube

https://www.youtube.com/watch?v=v8tJGlicgp8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How DNA Changed the World of Forensics        NYT        19 May 2014

 

 

 

 

How DNA Changed the World of Forensics        Video        Retro Report        The New York Times        19 May 2014

 

Before DNA testing,

prosecutors relied

on less sophisticated forensic techniques,

including microscopic hair analysis,

to put criminals behind bars.

 

But how reliable was hair analysis?

 

 

Related

How DNA Changed the World of Forensics        By Retro Report        NYT

http://www.nytimes.com/video/us/100000002886783/how-dna-changed-the-world-of-forensics.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

human cell

 

What are Cells?

 

Before we can understand genes,

we need to talk about cells !

 

Cells are the basic building blocks

of all living things.

 

Human cells are too tiny

to see with the naked eye,

but your body is made

of 1,000,000,000,000s of them.

 

Your cells work together to make your body work.

 

You have hundreds of different kinds of cells in the body,

each specially adapted to do different jobs.

 

For example,

red blood cells carry the oxygen you breathe

around your body.

 

(...)

 

What is a Gene?

 

Your genes

are an instruction manual for your body.

 

Hidden inside almost every cell in your body

is a chemical called DNA.

 

A gene is a short section of DNA.

 

Your genes contain instructions

that tell your cells to make molecules

called proteins.

 

Proteins perform various functions in your body

to keep you healthy.

 

Each gene carries instructions

that determine your features,

such as eye colour, hair colour and height.

 

There are different versions of genes

for each feature.

 

For example

one version (a variant) of a gene for eye colour

contains instructions for blue eyes,

another type contains instructions for brown eyes.

http://www.genesandhealth.org/genes-your-health/genes-made-easy - Nov. 13, 2020

 

 

https://www.nytimes.com/2020/03/24/
science/aging-dna-epigenetics-cells.html

 

https://www.nytimes.com/interactive/2020/03/11/
science/how-coronavirus-hijacks-your-cells.html

 

https://www.npr.org/sections/health-shots/2018/05/09/
609361688/artificial-intelligence-takes-scientists-inside-living-human-cells

 

 

 

 

 

 

 

immune cells        USA

 

https://www.nytimes.com/2020/09/08/
health/covid-aging-immune-system.html

 

 

 

 

 

 

 

rejuvenate human cells        USA

 

https://www.nytimes.com/2020/03/24/
science/aging-dna-epigenetics-cells.html

 

 

 

 

 

 

 

cell nucleus

 

 

 

 

 

chromosome

 

 

 

 

 

Y-chromosome

 

 

 

 

 

gene

 

 

 

 

isolate and patent human genes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

deoxyribonucleic acid    DNA        UK

 

https://www.theguardian.com/science/2020/may/13/
coronavirus-patient-dna-study-could-tell-us-why-some-fare-worse

 

https://www.theguardian.com/science/2016/jun/08/
doctors-edge-closer-to-creating-babies-with-dna-from-three-people

https://www.theguardian.com/uk-news/2016/jun/07/
killer-dna-evidence-genetic-profiling-criminal-investigation

 

http://www.bbc.co.uk/schools/gcsebitesize/science/
edexcel_pre_2011/genes/dnarev1.shtml

 

http://www.guardian.co.uk/science/2013/apr/21/
using-genetics-to-fight-disease

 

https://www.theguardian.com/science/2000/jun/27/
genetics.uknews

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

deoxyribonucleic acid    DNA        USA

 

https://en.wikipedia.org/wiki/DNA

 

 

https://www.npr.org/2021/06/12/
1005690930/detectives-just-used-dna-to-solve-a-1956-double-homicide-they-may-have-made-hist

 

 

 

 

https://www.npr.org/sections/health-shots/2019/10/16/
769462793/a-boys-mysterious-illness-leads-his-family-on-a-diagnostic-odyssey

 

https://www.npr.org/2019/01/08/
682925589/using-genetic-genealogy-to-identify-unknown-crime-victims-sometimes-decades-late

 

 

 

 

https://www.nytimes.com/2018/09/04/
health/synthetic-biology-pku.html

 

https://www.theguardian.com/science/2018/jul/03/
nhs-routine-dna-tests-precision-cancer-tumour-screening

 

https://www.npr.org/sections/health-shots/2018/06/21/
621511949/some-dna-dismissed-as-junk-is-crucial-to-embryo-development

 

https://www.npr.org/sections/health-shots/2018/06/06/
616334508/her-son-is-one-of-the-few-children-to-have-3-parents

 

https://www.npr.org/sections/health-shots/2018/06/06/
615909572/inside-the-ukrainian-clinic-making-3-parent-babies-for-women-who-are-infertile

 

 

 

 

https://www.npr.org/2017/11/24/
565771508/30-years-of-criminal-justice-reporting-from-robert-siegel 

 

http://www.npr.org/sections/codeswitch/2017/08/10/
541921634/when-where-are-you-from-takes-you-someplace-unexpected

 

 

 

 

https://www.npr.org/sections/goatsandsoda/2016/12/08/
504618235/a-mummys-dna-may-help-solve-the-mystery-of-the-origins-of-smallpox

 

 

 

 

http://www.npr.org/sections/health-shots/2015/11/05/
451216596/powerful-gene-drive-can-quickly-change-an-entire-species

 

http://www.npr.org/sections/health-shots/2015/09/18/
441408880/british-scientists-seek-permission-to-edit-dna-in-human-embryos

 

https://www.npr.org/sections/health-shots/2015/02/19/
387088596/just-a-bit-of-dna-helps-explain-humans-big-brains

 

 

 

 

http://www.npr.org/sections/health-shots/2014/10/13/
354934248/in-hopes-of-fixing-faulty-genes-one-scientist-starts-with-the-basics

http://www.nytimes.com/2014/05/08/
business/researchers-report-breakthrough-in-creating-artificial-genetic-code.html

http://www.nytimes.com/2014/03/04/
health/a-powerful-new-way-to-edit-dna.html

http://www.npr.org/2014/02/04/
271120630/exonerations-on-the-rise-and-not-just-because-of-dna

http://www.nature.com/nsu/DNA50

http://www.time.com/time/time100/scientist/profile/
watsoncrick.html

 

http://www.nytimes.com/2013/06/04/us/
supreme-court-says-police-can-take-dna-samples.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

gene sequencing        USA

 

https://www.npr.org/sections/health-shots/2019/07/08/
738528989/the-promises-and-pitfalls-of-gene-sequencing-for-newborns

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DNA sequencing        USA

 

Advances in technology

have made it much easier,

faster and less expensive

to do whole genome sequencing

— to spell out all three billion letters

in a person's genetic code.

 

Falling costs

have given rise to speculation

that it could soon become

a routine part of medical care,

perhaps as routine

as checking your blood pressure.

http://www.npr.org/sections/health-shots/2017/06/26/
534338576/routine-dna-sequencing-may-be-helpful-and-not-as-scary-as-feared

 

http://www.npr.org/sections/health-shots/2017/06/26/
534338576/routine-dna-sequencing-may-be-helpful-and-not-as-scary-as-feared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DNA heritage

http://www.npr.org/sections/codeswitch/2017/08/10/
541921634/when-where-are-you-from-takes-you-someplace-unexpected

 

 

 

 

Doctors edge closer

to creating babies with DNA from three people        G        UK        8 June 2016

https://www.theguardian.com/science/2016/jun/08/
doctors-edge-closer-to-creating-babies-with-dna-from-three-people

 

 

 

 

a strand of DNA        UK

http://www.theguardian.com/science/2015/sep/02/
genome-editing-how-to-modify-genetic-faults-and-the-human-germline

 

http://www.guardian.co.uk/science/2013/apr/21/
using-genetics-to-fight-disease

 

 

 

 

DNA sequence        UK

http://www.guardian.co.uk/commentisfree/2013/mar/13/
know-your-genome-personal-genetics

 

 

 

 

DNA fingerprinting        USA

https://www.theguardian.com/uk-news/2016/jun/07/
killer-dna-evidence-genetic-profiling-criminal-investigation

 

 

 

 

mutant DNA / mutations in DNA        UK

http://www.guardian.co.uk/science/2011/jun/15/
genetics-technique-genes-mutations-dna

 

 

 

 

DNA test

 

 

 

 

routine DNA tests        UK

https://www.theguardian.com/science/2018/jul/03/
nhs-routine-dna-tests-precision-cancer-tumour-screening

 

 

 

 

manipulate DNA        USA

https://www.nytimes.com/2018/09/04/
health/synthetic-biology-pku.html

 

 

 

 

repair DNA        USA

http://www.npr.org/sections/thetwo-way/2015/10/07/
446532519/dna-repair-research-nets-chemistry-nobel-for-3-scientists

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rosalind Elsie Franklin        1920-1958

 

In 1951

the young British scientist

began one of the key

scientific investigations

of the century.

 

Rosalind Franklin

produced an x-ray photograph

that helped show the structure of DNA,

the molecule that holds the genetic code

that underpins all life.

 

The discovery was integral

to the transformation

of modern medicine

and has been described

as one of the greatest

scientific achievements ever.

http://www.bbc.co.uk/programmes/p04r7h7k - Mon. 6 February 2017

 

http://www.bbc.co.uk/programmes/p04r7h7k - Mon. 6 February 2017

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DNA analysis

for diseases such as cancer and Alzheimer's        UK

http://www.guardian.co.uk/lifeandstyle/2008/dec/09/
healthandwellbeing-medicalresearch

 

 

 

 

cancer genetics > gene markers > cancers        USA

http://www.npr.org/sections/health-shots/2013/03/27/
175471264/catalogue-of-gene-markers-for-some-cancers-doubles-in-size

 

 

 

 

New laws on body tissue ban secret DNA testing        UK

http://www.theguardian.com/science/2006/aug/31/
humanrights.politics

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DNA - What is DNA? - Basics of DNA        Plethrons        15 January 2014

 

 

 

 

DNA - What is DNA? - Basics of DNA        Video        Plethrons        15 January 2014

 

Here's an animated video

on the basics of DNA, genes, and heredity.

 

DNA, or deoxyribonucleic acid,

is the hereditary material

in humans and almost all other organisms.

 

Nearly every cell in a person's body has the same DNA.

Most DNA is located in the cell nucleus (where it is called nuclear DNA),

but a small amount of DNA can also be found in the mitochondria

(where it is called mitochondrial DNA or mtDNA).

 

Here is an animated video

on the basics of DNA, genes, and heredity.

 

YouTube

https://www.youtube.com/watch?v=uXdzuz5Q-hs

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

biology

 

 

 

 

biological

 

 

 

 

What is a chromosome?

 

Chromosomes are X-shaped objects

found in the nucleus of most cells.

 

They consist

of long strands of a substance

called deoxyribonucleic acid,

or DNA for short.

 

A section of DNA

that has the genetic code

for making a particular protein

is called a gene.

 

The gene is the unit of inheritance,

and each chromosome may have

several thousand genes.

 

We inherit particular chromosomes

through the egg of our mother

and sperm of our father.

 

The genes on those chromosomes

carry the code that determines

our physical characteristics,

which are a combination

of those of our two parents.

http://www.bbc.co.uk/schools/gcsebitesize/science/
edexcel_pre_2011/genes/dnarev1.shtml

 

http://www.bbc.co.uk/schools/gcsebitesize/science/
edexcel_pre_2011/genes/dnarev1.shtml 

http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/
celldivision/celldivision1.shtml 

 

 

 

 

proteins > protein folding

 

how proteins change shape

during cell division to carry out genetic functions        USA

http://www.nytimes.com/2016/10/30/
science/susan-lindquist-scientist-who-made-genetic-discoveries-using-yeast-
dies-at-67.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

chromosome        UK

 

http://www.theguardian.com/uk/2005/mar/17/
science.science

 

 

 

 

 

 

 

rare chromosome disorder        USA

 

https://www.nytimes.com/2017/10/14/
us/union-jobs-mexico-rexnord.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fragile X syndrome

 

be born with a genetic disorder

that affects brain development - Fragile X

 

It makes it hard to learn language and basic daily tasks

and often is accompanied by a host of other disorders.

 

https://www.npr.org/2021/05/05/
993838102/a-fragile-x-treatment-may-be-on-the-horizon

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

gene        UK

 

https://www.theguardian.com/news/audio/2019/apr/22/
hope-for-those-with-huntingtons-podcast

 

http://www.guardian.co.uk/science/2013/jun/23/
rational-heroes-edith-heard-epigenetics

http://www.guardian.co.uk/science/2013/may/12/
how-to-spot-a-murderers-brain

 

http://www.theguardian.com/society/2007/may/28/
cancercare.health 

https://www.theguardian.com/science/2007/apr/13/
genetics.frontpagenews 

https://www.theguardian.com/science/2007/mar/08/
genetics.medicineandhealth

 

 

 

 

 

 

 

gene        USA

 

http://www.npr.org/sections/health-shots/2017/02/01/
512859830/which-genes-make-you-taller-a-whole-lot-it-turns-out

 

http://www.npr.org/sections/health-shots/2016/12/27/
506720771/early-alzheimer-s-gene-spells-tragedy-for-patients-opportunity-for-science

http://www.npr.org/sections/health-shots/2016/10/27/
499651062/would-you-want-to-know-the-secrets-hidden-in-your-babys-genes

http://www.npr.org/sections/health-shots/2016/06/08/
481234642/new-genetic-engineering-method-called-promising-and-perilous

 

http://www.npr.org/sections/health-shots/2015/11/05/
451216596/powerful-gene-drive-can-quickly-change-an-entire-species

 

http://www.nytimes.com/2014/06/19/health/
scientists-identify-mutations-that-protect-against-heart-attacks.html

http://www.nytimes.com/2014/04/29/
science/the-continuing-evolution-of-genes.html

 

http://www.nytimes.com/2010/10/30/
business/30drug.html

 

https://www.nytimes.com/2009/06/17/
science/17depress.html

 

http://www.usatoday.com/news/world/2006-10-02-
nobel-medicine_x.htm

 

 

 

 

virus genes        USA

http://www.npr.org/sections/health-shots/2017/04/06/
522478901/in-giant-virus-genes-hints-about-their-mysterious-origin

 

 

 

 

early Alzheimer's gene        USA

http://www.npr.org/sections/health-shots/2016/12/27/
506720771/early-alzheimer-s-gene-spells-tragedy-for-patients-opportunity-for-science

 

 

 

 

gene > a gene that codes for a protein called elastin        USA

http://www.npr.org/sections/health-shots/2016/10/27/
499651062/would-you-want-to-know-the-secrets-hidden-in-your-babys-genes

 

 

 

 

faulty genes        USA

http://www.npr.org/sections/health-shots/2014/10/13/
354934248/in-hopes-of-fixing-faulty-genes-one-scientist-starts-with-the-basics

 

 

 

 

malfunctioning gene        USA

https://www.npr.org/sections/health-shots/2019/05/09/
721788348/experimental-drug-for-huntingtons-disease-jams-malfunctioning-gene

 

 

 

 

lethal gene        USA

https://www.nytimes.com/2007/03/18/
health/18huntington.html

 

 

 

 

cancer genes        UK

https://www.theguardian.com/society/2007/may/28/
cancercare.health

 

 

 

 

cancer > gene patterns        USA

http://www.nytimes.com/2013/05/02/
health/dna-research-points-to-new-insight-into-cancers.html

 

 

 

 

gene > mutation        USA

http://www.npr.org/sections/health-shots/2016/10/27/
499651062/would-you-want-to-know-the-secrets-hidden-in-your-babys-genes

 

 

 

 

gene > rare mutation

that protects even fat people

from getting Type 2 diabetes        USA

http://www.nytimes.com/2014/03/03/
health/rare-gene-protects-against-type-2-diabetes-even-in-obese-people.html

 

 

 

 

 gene sequencing        USA

http://www.npr.org/sections/health-shots/2016/10/27/
499651062/would-you-want-to-know-the-secrets-hidden-in-your-babys-genes

 

 

 

 

genetic information > life insurers        USA

http://www.npr.org/sections/health-shots/2016/10/27/
499651062/would-you-want-to-know-the-secrets-hidden-in-your-babys-genes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

eugenics        UK

 

https://www.theguardian.com/commentisfree/2017/sep/19/
white-supremacist-statues-must-fall-scientists

 

 

 

 

 

 

 

eugenics        USA

 

http://www.npr.org/sections/health-shots/2017/08/14/
543362834/poet-imagines-life-inside-a-1910-institution-that-eugenics-built

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

gene therapy for cancer and leukemia / cell-based gene therapy        USA

 

https://www.npr.org/sections/health-shots/2018/08/16/
636749192/scientists-race-to-improve-living-drugs-to-fight-cancer

 

http://www.npr.org/sections/health-shots/2017/08/30/
547293551/fda-approves-first-gene-therapy-treatment-for-cancer

https://www.nytimes.com/2017/07/23/
health/gene-therapy-cancer.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

genetic material > RNA

https://www.nytimes.com/interactive/2020/03/11/
science/how-coronavirus-hijacks-your-cells.html

 

 

 

 

genetic testing

 

 

 

 

genetic screening

 

 

 

 

genetic fingerprinting

 

 

 

 

genetic engineer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

cancer gene        UK

 

http://www.theguardian.com/science/2007/mar/08/
genetics.medicineandhealth 

 

 

 

 

 

 

 

rogue genes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

virus > SARS-CoV-2 > virus genome        USA

 

https://www.nytimes.com/interactive/2021/03/25/
magazine/genome-sequencing-covid-variants.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

hunam genome / genome        UK / USA

 

Our genome

is over 3 billion genetic “letters” long

https://www.nytimes.com/interactive/2020/03/11/
science/how-coronavirus-hijacks-your-cells.html

 

 

https://www.nytimes.com/interactive/2020/03/11/
science/how-coronavirus-hijacks-your-cells.html

 

http://www.nytimes.com/2015/03/20/
science/biologists-call-for-halt-to-gene-editing-technique-in-humans.html

 

http://www.guardian.co.uk/commentisfree/2013/mar/13/
know-your-genome-personal-genetics

http://www.nytimes.com/2013/04/16/
science/the-human-genome-project-then-and-now.html

 

http://www.nytimes.com/2010/06/20/
opinion/l20genome.html

http://www.nytimes.com/2010/06/15/
business/15genome.html

http://www.nytimes.com/2010/06/13/
health/research/13genome.html

 

https://www.theguardian.com/science/2007/mar/08/
genetics.medicineandhealth 

 

 

 

 

 

 

 

decode the human genome / human genome project        UK / USA

 

the Human Genome Project (...) was completed in 2003

and funded mainly by the National Institutes of Health.

 

The project showed that the human genome

— “nature’s complete genetic blueprint

for building a human being,” as the N.I.H. describes it —

is composed of a sequence

of about three billion “base pairs.”

 

These are bonded chemicals

coded as A, C, G and T,

where A stands for adenine, C for cytosine,

G for guanine and T for thymine.

 

The chemical pairs are frequently

grouped together on our chromosomes,

in about 30,000 information-dense strings, or clumps.

 

The clumps are our genes.

 

The Human Genome Project required 13 years of work

and cost more than $3 billion.

https://www.nytimes.com/interactive/2021/03/25/
magazine/genome-sequencing-covid-variants.html

 

 

https://www.theguardian.com/science/human-genome-project 

 

 

https://www.nytimes.com/interactive/2021/03/25/
magazine/genome-sequencing-covid-variants.html

 

http://www.guardian.co.uk/science/2013/mar/29/
genome-research-adventure

 

https://www.theguardian.com/science/2000/jun/27/
genetics.uknews

http://www.guardian.co.uk/science/2000/jun/26/
genetics.drugs

 

http://www.nytimes.com/1999/10/26/
science/rivals-reach-milestones-in-genome-race.html

 

 

 

 

 

 

 

Human code fully cracked        UK        2003

 

Cambridge scientists in global consortium

spell out the 3bn letters of the genome,

50 years on from Crick and Watson's

model of DNA

 

http://www.guardian.co.uk/science/2003/apr/14/
genetics.research

 

 

 

 

 

 

 

Genome facts        USA

 

A rough draft of the human genome

was completed in June 2000.

 

http://www.pbs.org/wgbh/nova/genome/facts.html

 

 

 

 

 

 

 

Human Genome Project    1990s-2000s

 

The Human Genome Project

is an international research effort

to decode the human genome,

the complete genetic instructions

for a human being.

https://www.pbs.org/wgbh/nova/genome/her_gen.html 

 

http://www.guardian.co.uk/science/2000/jun/26/genetics.forensicscience

 

 

 

 

gene > glossary        USA

http://www.pbs.org/wgbh/nova/genome/glossary.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

genetics        UK

 

https://www.theguardian.com/science/genetics 

 

 

http://www.guardian.co.uk/commentisfree/2013/mar/13/
know-your-genome-personal-genetics

 

 

 

 

 

 

 

genetics        USA

 

https://www.nytimes.com/2018/01/29/
obituaries/arno-motulsky-dies-medical-genetics-founder.html

 

http://www.npr.org/sections/health-shots/2016/06/16/
482189322/will-baby-making-move-from-the-bedroom-to-the-lab

 

http://www.npr.org/sections/health-shots/2015/11/05/
451216596/powerful-gene-drive-can-quickly-change-an-entire-species

http://www.nytimes.com/2015/02/07/
opinion/using-genetics-to-improve-medicine.html

http://www.nytimes.com/2015/01/29/
opinion/moonshot-medicine-will-let-us-down.html

 

 

 

 

 

 

 

medical genetics        USA

 

https://www.nytimes.com/2018/01/29/
obituaries/arno-motulsky-dies-medical-genetics-founder.html

 

 

 

 

pharmacogenetics        USA

https://www.nytimes.com/2018/01/29/
obituaries/arno-motulsky-dies-medical-genetics-founder.html

 

 

 

 

heredity        USA

https://www.nytimes.com/2018/01/29/
obituaries/arno-motulsky-dies-medical-genetics-founder.html

 

 

 

 

epigenetics        UK

http://www.guardian.co.uk/science/2013/jun/23/
rational-heroes-edith-heard-epigenetics

 

 

 

 

geneticists        USA

http://www.npr.org/sections/health-shots/2016/03/24/
471307905/scientists-build-live-no-frills-cell-that-could-have-a-big-future

 

 

 

 

genetic entrepreneur

J. Craig Venter’s Synthetic Genomics > Company > Human Longevity       USA

http://www.nytimes.com/2014/03/05/
business/in-pursuit-of-longevity-a-plan-to-harness-dna-sequencing.html

 

 

 

 

genetic fingerprint        USA

http://www.nytimes.com/2013/05/02/
health/dna-research-points-to-new-insight-into-cancers.html

 

 

 

 

genetically

 

 

 

 

produce genetically modified human beings /

genetically modified babies        USA

http://www.nytimes.com/2014/02/24/
opinion/genetically-modified-babies.html

 

 

 

genetically engineer        USA

http://www.npr.org/sections/health-shots/2015/11/05/
451216596/powerful-gene-drive-can-quickly-change-an-entire-species

 

 

 

 

genetic engineering        USA

http://www.npr.org/sections/health-shots/2016/06/08/
481234642/new-genetic-engineering-method-called-promising-and-perilous

 

http://www.npr.org/sections/health-shots/2015/11/05/
451216596/powerful-gene-drive-can-quickly-change-an-entire-species

 

 

 

 

genetic enhancements        UK

https://www.theguardian.com/commentisfree/2016/aug/28/
ideology-liberal-democracy-technology-bioscience-yuval-harari-artificial-intelligence

 

 

 

 

gene therapy        UK

http://www.guardian.co.uk/science/2013/apr/30/
gene-therapy-trials-heart-patients

 

http://www.guardian.co.uk/science/2000/jun/26/
genetics.drugs

 

 

 

 

gene therapy        USA

http://www.npr.org/sections/health-shots/2015/07/08/
421204204/genetic-tweaks-are-restoring-hearing-in-animals-raising-hopes-for-people

 

http://www.npr.org/blogs/health/2013/12/07/
249335960/gene-therapy-keeps-bubble-boy-disease-at-bay-in-8-children

 

 

 

 

pioneering treatment > replacement gene        UK

http://www.guardian.co.uk/science/2013/apr/30/
gene-therapy-trials-heart-patients

 

 

 

 

genetics        UK

http://www.guardian.co.uk/science/video/2013/apr/26/
young-engineer-year-genetics-lab-video

 

 

 

 

deoxyribo-nucleic-acid        DNA

 

The DNA of humans (...)

is composed of approximately 3 billion base pairs,

making up a total of almost a meter-long stretch of DNA

in every cell in our bodies.

https://educationalgames.nobelprize.org/educational/medicine/
dna_double_helix/readmore.html

 

 

 

 

understand heredity        USA

https://www.pbs.org/wgbh/nova/genome/her_cri.html

 

 

 

 

genetic test        USA

http://www.npr.org/sections/health-shots/2015/04/15/
399821134/personalizing-cancer-treatment-with-genetic-tests-can-be-tricky

 

 

 

 

consumer genetic tests        USA

http://www.npr.org/sections/health-shots/2017/04/07/
522897473/fda-approves-marketing-of-consumer-genetic-tests-for-some-conditions

 

 

 

 

You can now order genetic tests off the Internet

and get your child's genome sequenced

for less than the cost of a new car        USA

http://www.npr.org/sections/health-shots/2015/07/02/
419460424/dont-get-your-kids-genes-sequenced-just-to-keep-up

 

 

 

 

genetic testing        USA

http://www.npr.org/sections/health-shots/2016/04/18/
473066953/more-people-seek-genetic-testing-but-there-arent-enough-counselors

 

 

 

 

genetic testing dilemmas        USA

http://www.pbs.org/wgbh/nova/body/genetic-testing-dilemmas-intro.html

 

 

 

 

gene therapy > Parkinson's disease

http://www.theguardian.com/uk/2006/oct/18/
genetics.science 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Down Syndrome        USA

 

Down syndrome is a genetic condition

in which a person has 47 chromosomes

instead of the usual 46.

http://health.nytimes.com/health/guides/disease/down-syndrome/overview.html

 

 

https://www.nytimes.com/2021/06/16/
us/cheerleader-down-syndrome.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

mouse egg

 

 

 

 

divide

 

 

 

 

cell        USA

http://www.nytimes.com/2013/11/11/us/
leonard-herzenberg-immunologist-who-revolutionized-research-dies-at-81.html

 

 

 

 

 senescent cells        USA

http://www.npr.org/sections/health-shots/2016/02/03/
465354874/boosting-lifespan-by-clearing-out-cellular-clutter

 

 

 

 

immunologist        USA

http://www.nytimes.com/2013/11/11/us/
leonard-herzenberg-immunologist-who-revolutionized-research-dies-at-81.html

 

 

 

 

immunologist > Leonard Arthur Herzenberg        USA        1931-2013

http://www.nytimes.com/2013/11/11/us/
leonard-herzenberg-immunologist-who-revolutionized-research-dies-at-81.html

 

 

 

 

hematologist        USA

http://www.nytimes.com/2010/04/15/us/
15ranney.html

 

 

 

 

Skin from heart attack patients

transformed into beating heart cells        UK        23 May 2012

 

The heart cells created from patients' skin

were at the same stage of development

as those of a newborn baby

http://www.guardian.co.uk/science/2012/may/23/
skin-heart-attack-beating-heart-cells

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Researchers Say They Created a ‘Synthetic Cell’        2010

 

http://www.nytimes.com/2010/05/21/science/21cell.html

http://www.guardian.co.uk/science/2010/may/20/craig-venter-synthetic-life-form

http://www.guardian.co.uk/science/2010/may/20/craig-venter-synthetic-life-genome

http://www.guardian.co.uk/science/video/2010/may/20/craig-venter-new-life-form

http://www.guardian.co.uk/commentisfree/andrewbrown/2010/may/20/craig-venter-life-god

http://www.guardian.co.uk/science/gallery/2010/may/20/first-synthetic-cell

http://www.guardian.co.uk/science/2010/may/20/creation-bacterial-cell-craig-venter

 

http://www.independent.co.uk/news/science/
synthetic-cell-is-a-giant-leap-for-science-and-could-be-bigger-still-for-mankind-1978869.html

http://www.independent.co.uk/news/people/profiles/
dr-craig-venter-so-doctor-how-does-it-feel-to-have-created-artificial-life-1978873.html

http://www.independent.co.uk/opinion/commentators/
dr-tom-wakeford-a-thrilling-breakthrough-but-also-a-frightening-one-1978870.html

 

 

 

 

play God        USA

http://www.npr.org/sections/health-shots/2016/05/18/
478212837/in-search-for-cures-scientists-create-embryos-that-are-both-animal-and-human

 

 

 

 

 

 

 

J. Craig Venter

 

https://www.theguardian.com/science/venter

https://www.nytimes.com/topic/person/craig-venter 

 

 

https://www.theguardian.com/science/2010/may/20/
craig-venter-synthetic-life-form 

http://www.guardian.co.uk/science/2010/may/20/craig-venter-synthetic-life-genome

http://www.guardian.co.uk/science/video/2010/may/20/craig-venter-new-life-form

http://www.guardian.co.uk/commentisfree/andrewbrown/2010/may/20/craig-venter-life-god

http://www.guardian.co.uk/science/gallery/2010/may/20/first-synthetic-cell

http://www.guardian.co.uk/science/2010/may/20/creation-bacterial-cell-craig-venter

http://www.independent.co.uk/news/people/profiles/
dr-craig-venter-so-doctor-how-does-it-feel-to-have-created-artificial-life-1978873.html

 

 

 

 

biotech company        UK

http://www.guardian.co.uk/science/2013/apr/21/
using-genetics-to-fight-disease

 

 

 

 

Scientists turn dead cells into live tissue        UK        2006

http://www.theguardian.com/science/2006/sep/24/
highereducation.research 

 

 

 

 

converts a patient's skin cell into embryonic cells

and then new tissues to repair the body        USA

http://www.nytimes.com/2005/10/17/
health/17stem.html

 

 

 

 

break open the embryo

before it implants in the uterus,

a stage at which it is called a blastocyst,

and take out the inner cell mass,

whose cells form all the tissues

in a human body

 

 

 

 

let a fertilized mouse egg divide three times

until it contained eight cells,

a stage just before

the embryo becomes a blastocyst

 

 

 

 

seven-cell embryo

 

 

 

 

be implanted in the mouse uterus

 

 

 

 

grow successfully to term

 

 

 

 

remove

 

 

 

 

grow

 

 

 

 

tissue

 

 

 

 

glassware

 

 

 

 

embryo

 

 

 

 

product of a clinic embryo

 

 

 

 

test-tube babies

 

 

 

 

 

 

 

 

 

Corpus of news articles

 

Cells, DNA, Genes, Human genome,

 

Genetic engineering, Gene therapy
 

 

 

 

Lynn Margulis,

Evolution Theorist,

Dies at 73

 

November 24, 2011

The New York Times

By BRUCE WEBER

 

Lynn Margulis, a biologist whose work on the origin of cells helped transform the study of evolution, died on Tuesday at her home in Amherst, Mass. She was 73.

She died five days after suffering a hemorrhagic stroke, said Dorion Sagan, a son she had with her first husband, the cosmologist Carl Sagan.

Dr. Margulis, who had the title of distinguished university professor of geosciences at the University of Massachusetts, Amherst, since 1988, drew upon earlier, ridiculed ideas when she first promulgated her theory, in the late 1960s, that cells with nuclei, which are known as eukaryotes and include all the cells in the human body, evolved as a result of symbiotic relationships among bacteria.

The hypothesis was a direct challenge to the prevailing neo-Darwinist belief that the primary evolutionary mechanism was random mutation.

Rather, Dr. Margulis argued that a more important mechanism was symbiosis; that is, evolution is a function of organisms that are mutually beneficial growing together to become one and reproducing. The theory undermined significant precepts of the study of evolution, underscoring the idea that evolution began at the level of micro-organisms long before it would be visible at the level of species.

“She talked a lot about the importance of micro-organisms,” said her daughter, Jennifer Margulis. “She called herself a spokesperson for the microcosm.”

The manuscript in which Dr. Margulis first presented her findings was rejected by 15 journals before being published in 1967 by the Journal of Theoretical Biology. An expanded version, with additional evidence to support the theory — which was known as the serial endosymbiotic theory — became her first book, “Origin of Eukaryotic Cells.”

A revised version, “Symbiosis in Cell Evolution,” followed in 1981, and though it challenged the presumptions of many prominent scientists, it has since become accepted evolutionary doctrine.

“Evolutionists have been preoccupied with the history of animal life in the last 500 million years,” Dr. Margulis wrote in 1995. “But we now know that life itself evolved much earlier than that. The fossil record begins nearly 4,000 million years ago! Until the 1960s, scientists ignored fossil evidence for the evolution of life, because it was uninterpretable.

“I work in evolutionary biology, but with cells and micro-organisms. Richard Dawkins, John Maynard Smith, George Williams, Richard Lewontin, Niles Eldredge and Stephen Jay Gould all come out of the zoological tradition, which suggests to me that, in the words of our colleague Simon Robson, they deal with a data set some three billion years out of date.”

Lynn Petra Alexander was born on March 5, 1938, in Chicago, where she grew up in a tough neighborhood on the South Side. Her father was a lawyer and a businessman. Precocious, she graduated at 18 from the University of Chicago, where she met Dr. Sagan as they passed each other on a stairway.

She earned a master’s degree in genetics and zoology from the University of Wisconsin and a Ph.D. in genetics from the University of California, Berkeley. Before joining the faculty at Massachusetts, she taught for 22 years at Boston University.

Dr. Margulis was also known, somewhat controversially, as a collaborator with and supporter of James E. Lovelock, whose Gaia theory states that Earth itself — its atmosphere, the geology and the organisms that inhabit it — is a self-regulating system, maintaining the conditions that allow its perpetuation. In other words, it is something of a living organism in and of itself.

Dr. Margulis’s marriage to Dr. Sagan ended in divorce, as did a marriage to Thomas N. Margulis, a chemist. Dr. Sagan died in 1996.

In addition to her daughter and her son Dorion, a science writer with whom she sometimes collaborated, she is survived by two other sons, Jeremy Sagan and Zachary Margulis-Ohnuma; three sisters, Joan Glashow, Sharon Kleitman and Diane Alexander; two half-brothers, Robert and Mark Alexander; a half-sister, Sara Alexander; and nine grandchildren.

“More than 99.99 percent of the species that have ever existed have become extinct,” Dr. Margulis and Dorion Sagan wrote in “Microcosmos,” a 1986 book that traced, in readable language, the history of evolution over four billion years, “but the planetary patina, with its army of cells, has continued for more than three billion years. And the basis of the patina, past, present and future, is the microcosm — trillions of communicating, evolving microbes.”

Lynn Margulis, Evolution Theorist, Dies at 73,
NYT,
24.11.2011,
http://www.nytimes.com/2011/11/25/
science/lynn-margulis-trailblazing-theorist-on-evolution-dies-at-73.html

 

 

 

 

 

Researchers Say

They Created a ‘Synthetic Cell’

 

May 20, 2010

The New York Times

By NICHOLAS WADE

 

The genome pioneer J. Craig Venter has taken another step in his quest to create synthetic life, by synthesizing an entire bacterial genome and using it to take over a cell.

Dr. Venter calls the result a “synthetic cell” and is presenting the research as a landmark achievement that will open the way to creating useful microbes from scratch to make products like vaccines and biofuels. At a press conference Thursday, Dr. Venter described the converted cell as “the first self-replicating species we’ve had on the planet whose parent is a computer.”

“This is a philosophical advance as much as a technical advance,” he said, suggesting that the “synthetic cell” raised new questions about the nature of life

Other scientists agree that he has achieved a technical feat in synthesizing the largest piece of DNA so far — a million units in length — and in making it accurate enough to substitute for the cell’s own DNA.

But some regard this approach as unpromising because it will take years to design new organisms, and meanwhile progress toward making biofuels is already being achieved with conventional genetic engineering approaches in which existing organisms are modified a few genes at a time.

Dr. Venter’s aim is to achieve total control over a bacterium’s genome, first by synthesizing its DNA in a laboratory and then by designing a new genome stripped of many natural functions and equipped with new genes that govern production of useful chemicals.

“It’s very powerful to be able to reconstruct and own every letter in a genome because that means you can put in different genes,” said Gerald Joyce, a biologist at the Scripps Research Institute in La Jolla, Calif.

In response to the scientific report, President Obama asked the White House bioethics commission on Thursday to complete a study of the issues raised by synthetic biology within six months and report back to him on its findings. He said the new development raised “genuine concerns,” though he did not specify them further.

Dr. Venter took a first step toward this goal three years ago, showing that the natural DNA from one bacterium could be inserted into another and that it would take over the host cell’s operation. Last year, his team synthesized a piece of DNA with 1,080,000 bases, the chemical units of which DNA is composed.

In a final step, a team led by Daniel G. Gibson, Hamilton O. Smith and Dr. Venter report in Thursday’s issue of the journal Science that the synthetic DNA takes over a bacterial cell just as the natural DNA did, making the cell generate the proteins specified by the new DNA’s genetic information in preference to those of its own genome.

The team ordered pieces of DNA 1,000 units in length from Blue Heron, a company that specializes in synthesizing DNA, and developed a technique for assembling the shorter lengths into a complete genome. The cost of the project was $40 million, most of it paid for by Synthetic Genomics, a company Dr. Venter founded.

But the bacterium used by the Venter group is unsuitable for biofuel production, and Dr. Venter said he would move to different organisms. Synthetic Genomics has a contract from Exxon to generate biofuels from algae. Exxon is prepared to spend up to $600 million if all its milestones are met. Dr. Venter said he would try to build “an entire algae genome so we can vary the 50 to 60 different parameters for algae growth to make superproductive organisms.”

On his yacht trips round the world, Dr. Venter has analyzed the DNA of the many microbes in seawater and now has a library of about 40 million genes, mostly from algae. These genes will be a resource to make captive algae produce useful chemicals, he said.

Some other scientists said that aside from assembling a large piece of DNA, Dr. Venter has not broken new ground. “To my mind Craig has somewhat overplayed the importance of this,” said David Baltimore, a geneticist at Caltech. He described the result as “a technical tour de force,” a matter of scale rather than a scientific breakthrough.

“He has not created life, only mimicked it,” Dr. Baltimore said.

Dr. Venter’s approach “is not necessarily on the path” to produce useful microorganisms, said George Church, a genome researcher at Harvard Medical School. Leroy Hood, of the Institute for Systems Biology in Seattle, described Dr. Venter’s report as “glitzy” but said lower-level genes and networks had to be understood first before it would be worth trying to design whole organisms from scratch.

In 2002 Eckard Wimmer, of the State University of New York at Stony Brook, synthesized the genome of the polio virus. The genome constructed a live polio virus that infected and killed mice. Dr. Venter’s work on the bacterium is similar in principle, except that the polio virus genome is only 7,500 units in length, and the bacteria’s genome is more than 100 times longer.

Friends of the Earth, an environmental group, denounced the synthetic genome as “dangerous new technology,” saying that “Mr. Venter should stop all further research until sufficient regulations are in place.”

The genome Dr. Venter synthesized is copied from a natural bacterium that infects goats. He said that before copying the DNA, he excised 14 genes likely to be pathogenic, so the new bacterium, even if it escaped, would be unlikely to cause goats harm.

Dr. Venter’s assertion that he has created a “synthetic cell” has alarmed people who think that means he has created a new life form or an artificial cell. “Of course that’s not right — its ancestor is a biological life form,” said Dr. Joyce of Scripps.

Dr. Venter copied the DNA from one species of bacteria and inserted it into another. The second bacteria made all the proteins and organelles in the so-called “synthetic cell,” by following the specifications implicit in the structure of the inserted DNA.

“My worry is that some people are going to draw the conclusion that they have created a new life form,” said Jim Collins, a bioengineer at Boston University. “What they have created is an organism with a synthesized natural genome. But it doesn’t represent the creation of life from scratch or the creation of a new life form,” he said.

Researchers Say They Created a ‘Synthetic Cell’,
NYT,
20.5.2010,
http://www.nytimes.com/2010/05/21/science/21cell.html

 

 

 

 

 

Man freed by DNA testing

after 27 years

 

29 April 2008

USA Today

 

DALLAS (AP) — A Dallas man who spent more than 27 years in prison for a murder he didn't commit was freed Tuesday, after being incarcerated longer than any other wrongfully convicted U.S. inmate cleared by DNA testing.

James Lee Woodard stepped out of the courtroom and raised his arms to a throng of photographers. Supporters and other people gathered outside the court erupted in applause.

"No words can express what a tragic story yours is," state District Judge Mark Stoltz told Woodard at a brief hearing before his release.

Woodard, cleared of the 1980 murder of his girlfriend, became the 18th person in Dallas County to have his conviction cast aside. That's a figure unmatched by any county nationally, according to the Innocence Project, a New York-based legal center that specializes in overturning wrongful convictions.

"I thank God for the existence of the Innocence Project," Woodard, 55, told the court. "Without that, I wouldn't be here today. I would be wasting away in prison."

Overall, 31 people have been formally exonerated through DNA testing in Texas, also a national high. That does not include Woodard and at least three others whose exonerations will not become official until Gov. Rick Perry grants pardons or the Texas Court of Criminal Appeals formally accepts the ruling of lower courts that have already recommended exoneration.

Woodard was sentenced to life in prison in July 1981 for the murder of a 21-year-old Dallas woman found raped and strangled near the banks of the Trinity River.

He was convicted primarily on the basis of testimony from two eyewitnesses, said Natalie Roetzel, the executive director of the Innocence Project of Texas. One has since recanted in an affidavit. As for the other, "we don't believe her testimony was accurate," Roetzel said.

Like nearly all the exonorees, Woodard has maintained his innocence throughout his time in prison. But after filing six writs with an appeals court, plus two requests for DNA testing, his pleas of innocence became so repetitive and routine that "the courthouse doors were eventually closed to him and he was labeled a writ abuser," Roetzel said.

"On the first day he was arrested, he told the world he was innocent ... and nobody listened," Jeff Blackburn, chief counsel for the Innocence Project of Texas, said during Tuesday's hearing.

He even stopped attending his parole hearings because gaining his release would have meant confessing to a crime he didn't do.

"It says a lot about your character that you were more interested in the truth than your freedom," the judge told Woodard after making his ruling.

Blackburn and prosecutors hailed Tuesday's hearing as a landmark moment of frequent adversaries working together.

Since the DNA evidence was tied to rape and Woodard was convicted of murder, Innocence Project attorneys had to prove that the same person committed both crimes. They said they couldn't have done that without access to evidence provided by Dallas County District Attorney Craig Watkins' office.

"You've got to have very good lawyers with a lot of experience and skill ... working on both ends of this case, hard," Blackburn said. "And you've also got to have government power behind what you do."

Under Watkins, Dallas County has a program supervised by the Innocence Project of Texas that is reviewing hundreds of cases of convicts who have requested DNA testing to prove their innocence.

While the number of exonerations on Watkins' watch continues to grow, he said this one was a little different.

"I saw the human side of it, and seeing the human said of it just gives you more courage to advocate for issues like this," said Watkins, who had breakfast with Woodard on Tuesday morning. "It gives me that resolve to go even further to find out who (the killer) is so that we can get him into custody."

Woodard said his family was "small and scattered," although he pointed out a niece in the courtroom. He said his biggest regret was not being with his mother when she died.

"I can tell you what I'd like to do first: breathe fresh, free air," Woodard said during a news conference in the courtroom after the hearing. "I don't know what to expect. I haven't been in Dallas since buses were blue."

Man freed by DNA testing after 27 years,
UT, 29.4.2008,
http://www.usatoday.com/news/nation/2008-04-29-dallas-dna_N.htm

 

 

 

 

 

Basics

Sleek, Fast and Focused:

The Cells That Make Dad Dad

 

June 12, 2007

The New York Times

By NATALIE ANGIER

 

We are fast approaching Father’s Day, the festive occasion on which we plague Dad with yet another necktie or collect phone call and just generally strive to remind the big guy of the central verity of paternity — that it’s a lot more fun to become a father than to be one. “I won’t lie to you,” said the great Homer Simpson. “Fatherhood isn’t easy like motherhood.” Yet in our insistence that men are more than elaborately engineered gamete vectors, we neglect the marvels of their elaborately engineered gametes. As the scientists who study male germ cells will readily attest, sperm are some of the most extraordinary cells of the body, a triumph of efficient packaging, sleek design and superspecialization. Human sperm are extremely compact, and they’ve been stripped of a normal cell’s protein-making machinery; but when cast into the forbidding environment of the female reproductive tract, they will learn on the job and change their search strategies and swim strokes as needed.

Sperm are also fast and as cute as tadpoles. They have chubby teardrop heads and stylish, tapering tails, and they glide, slither, bumble and do figure-eights. So while a father may not be entitled to take the same pride in his sperm as he does in his kids, it’s fair to celebrate the single-minded cellular commas that helped give those children their start.

Sperm are pretty much the tiniest cells in the human body. The head of a mature, semen-ready sperm cell spans about 5 microns, or two-thousandths of an inch, less than half the width of a white blood cell or a skin cell. And a sperm cell is absurdly dwarfed by its female counterpart, the egg, which, fittingly or not, is among the biggest cells in the body. At 30 times the width of a sperm, the egg is massive enough to be seen with the naked eye.

But men have the overwhelming quantitative edge in the gamete games. Whereas current evidence suggests that a human female is born with all the eggs she will have, and that only about 500 of her natal stock of one million will ever ripen and have a shot at fertilization, a male from puberty onward is pretty much a nonstop sperm bakery. Each testicle generates more than 4 million new sperm per hour, for a lifetime total of maybe 12 trillion sperm per man (although the numbers vary with the day and generally slope downward with age).

The average ejaculation consists mostly of a teaspoon’s worth of nonspermic seminal fluid, a viscous mix of sugars, citric acid and other ingredients designed to pamper and power the sperm cells and prepare them for difficult times ahead; the sperm proper account for only about 1 percent of the semen mass. Yet in that 1 percent may be found 150 million sperm, 150 million human aspirants yearning to meet their mammoth other halves.

To which one can crack, dream on. Not only are there far too few eggs to go around, but also the majority of sperm couldn’t fertilize an ovum if it were plunked down in front of them. “Only a perfectly normal sperm can penetrate an egg,” said Dr. Harry Fisch, a urologist at Columbia University Medical Center, “and the majority of sperm are abnormally shaped.” Some may have pinheads, others have two heads, some lack tails, a third don’t move at all. As a rule, Dr. Fisch said, a man is lucky if 15 percent of his sperm are serviceable. “One guy I saw had 22 percent,” he said, “but that’s rare.”

Creating sperm is a complex, multistep operation in which immature cells spend one or two months wending through a labyrinth of tubules coiled in the testes, at each stage losing a bit more of the blobby contours and yolky contents of standard cells and assuming the streamlined profile of sperm cells. The operation is a delicate one that must be performed at temperatures some 2 degrees below that of the body, which is why the testicles hang outside the body, where breezes can keep them cool; why a man hoping to become a father is advised to skip the hot baths and saunas; and why a bout of high fever can disrupt fertility for months.

The model sperm that emerges at tubule’s end has, like an insect, three basic body segments. Of crowning importance is the head, which is taken up largely by a supercondensed tangle of 23 chromosomes, half the complement of DNA found in a normal body cell and thus the right number to merge with an egg’s 23 chromosomes and begin tapping out a whole new body. At the tip of the sperm head is the acrosome, a specialized sack of enzymes that help the sperm penetrate through what Joseph S. Tash, a male fertility expert at the University of Kansas Medical Center, calls the “forest” of ancillary cells and connective tissue that surrounds the ripe, ready egg.

Below the head is the midpiece, which is packed with the tiny engines called mitochondria that lend the sperm its motility, and below the midpiece is the tail, a bundle of 11 entwined filaments that thrashes and propels a sperm forward at the estimable pace of one-twelfth of an inch per minute, the equivalent of a human striding at four miles an hour.

Sperm do not really hit their stride until they are deposited in the female reproductive tract, at which point chemical signals from the vaginal and cervical mucus seem to spark them to life. Released from the buffering folds of their seminal delivery blanket, they at first swim straight ahead, torpedo-style, “with very little back and forth of the head,” Dr. Tash said. They may linger in the cervical mucus for a couple of days, or cross the cervix and enter the uterus.

If an egg has burst from its ovarian follicle and been plucked by a fallopian tube, sperm can sense its signature, a telltale shift in calcium ions. The sperm become “hyperactivated,” said Moira O’Bryan, a sperm expert at Monash University in Australia, switching to “a crazed figure-eight motion” ideal for boring through barriers. The ovum eggs them on, signaling some to play the sacrificial kamikaze and explode their enzyme sacks prematurely, loosening the corridor for other, shapelier sperm to pass through intact. A few dozen fine-figured sperm find their way to the final barrier, the egg’s plasma membrane, where they waggle with all their crazy-eight might and beg to be chosen — but only one will be taken, will fuse with the egg and be absorbed into its rich inner sanctum.

In a fraction of a second, an electrical, ionic jolt dramatically changes the egg’s outer coat, to forestall the lethal intrusion of additional sperm.

The wheels are in motion. How do you like your new tie?

Sleek, Fast and Focused: The Cells That Make Dad Dad,
NYT,
12.6.2007,
http://www.nytimes.com/2007/06/12/science/12angi.html

 

 

 

 

 

 

 

 

 

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