Genetics & Molecular Biology

Why are we forked creatures instead of tumbling beach balls of undifferentiated cells?

An embryo begins by dividing into identical cells, but within hours these cells begin to make genetic decisions, turning off some genes and turning on others. So the ball of cells acquires a front end and a back end, a top and a bottom, nerve cells and muscles cells, all still carrying the same DNA, but DNA now packaged in such a way that some genes are shrink wrapped and silent but others are spread-eagled for easy access and active.

There once was a time when the parts you had were all you were going to get; when something went wrong that was that.    As science and medicine progressed in leaps during the 20th century replacement parts became available, like artificial joints, and state-of-the-art metal or ceramic implants eliminated pain and gave many relief from arthritic knees, shoulders and hips.

But what once was the future is now old tech and, instead, the goal is to take a patient's own cells and create replacement joints.   A team of  researchers have found a way to create these biological joints in animals, and they believe biological joint replacements for humans aren't far away.
While hundreds of millions of dollars are spent on masking and treating male pattern baldness, surprisingly little is known about its cause at the cellular level.

A Journal of Clinical Investigation study has found that stem cells play an unexpected role in explaining what happens in bald scalps.   Using cell samples from men undergoing hair transplants, researchers compared follicles from bald scalps and non-bald scalps and found that bald areas had the same number of stem cells as normal areas in the same person but noted that another, more mature cell type called a progenitor cell was markedly depleted in the follicles of bald scalps. 
Scientists writing in Nature Genetics have produced the full genome of a wild strawberry plant. 

The woodland strawberry - Fragaria vesca - is closely related to garden-variety cultivated strawberry and this berry contains large amounts of anti-oxidants (mainly tannins, the substances that give wine their astringency), as well as vitamins A, C and B12 and minerals – potassium, calcium and magnesium. In addition, the strawberry fruit is rich in substances for flavor and aroma.

The production of high quality chocolate will benefit from the recent sequencing and assembly of the chocolate tree genome - Theobroma cacao - considered by chocolate experts to produce the world's finest chocolate. The Maya domesticated this variety of Theobroma cacao, 'Criollo', about 3,000 years ago in Central America and it is among the oldest domesticated tree crops, though today many growers prefer to grow hybrid cacao trees ('Trinitario') that produce chocolate of lower quality but are more resistant to disease.
In the 1989 holiday classic "Scrooged", the chairman of the television network predicts that because there were so many pets in America they would become steady viewers in 20 years - which would be 2009.    So he asks network executive Bill Murray to introduce Door Mice instead of Door Men in their live Christmas Eve version of Dickens' "A Christmas Carol", in order to get a head start on appealing to television-watching pets.

Far fetched?   Perhaps, though singing mice are sure to get everyone's attention, not just your cat.
A million years is a blink of an eye in evolution but that doesn't mean newer genes matter less in life itself.    
"My two dads" is no longer just a lousy TV show.  Using induced pluripotent stem cell technology (controversy-free!) scientists have produced male and female mice from two fathers.

It isn't part of any cultural agenda, the intent was to preserve endangered species, but obviously it opens up the possibility of same-sex couples having their own genetic children.  The authors caution that the "generation of human iPS cells still requires significant refinements prior to their use for therapeutic purposes."
Does science really need to give Tiger Woods/Brett Favre an excuse?

"Sorry, sweetheart, I didn't mean to bang anything with a hole and a heart beat that came my way/text that chick pictures of my junk. But you have to forgive me because it's in my DNA. Oh look, it's tee time/game time again."
A new study was released today in JAMA which looked at, in part, mitochondrial DNA overreplication in a sample of ten autistic children between the ages of 2 and 5 and ten matched controls.  Giulivi et al. found that 5 of the 10 autistic children and 2 of the control children had mitchondrial DNA overreplication.

In the comments section of a previous post, the question was raised of how autism is diagnosed in the samples being studied. This new study allows an opportunity to look at how carefully the sample is selected and controls matched to the sample.