Genetics & Molecular Biology
Researchers conducting genome-wide association studies say they have discovered 30 new genes determine the age of sexual maturation in women - and many of those genes also act on body weight regulation or biological pathways related to fat metabolism.
Menarche, the onset of first menstruation in girls, indicates the attainment of reproductive capacity and is a widely used marker of pubertal timing. Age of menarche varies widely and is highly dependent on nutritional status and early menarche is associated with many adverse health outcomes later in life, including breast cancer, endometrial cancer, obesity, type 2 diabetes and cardiovascular disease, as well as shorter adult stature.
Not having had any serious biological training I have to go to Wikipedia and Google to learn the basics. And I’m often surprised to find that concepts everyone uses don’t have good consensus amongst scientists. When reading the Wikipedia entry for “gene”, it occurs to me that if the concept didn’t predate the discovery of DNA, it would not exist.
At the very least, it would look much different than “a locatable region of genomic sequence, corresponding to a unit of inheritance” (call this the “standard definition”).
The ethical issues surrounding unchecked human embryonic stem cell research are not going away any time soon, regardless of which political party occupies Congress or the White House.
Given that, researchers have devised various alternatives and now scientists at the Max Planck Institute for Molecular Genetics in Berlin have added one more. They have managed to convert amniotic fluid cells into induced pluripotent stem cells (iPS cells). These amniotic fluid-derived iPS cells are hardly distinguishable from embryonic stem cells - however, they 'remember' where they came from.
Oxytocin, dubbed the "cuddle hormone" because of its importance in bonding , is best known for its role in childbirth and breastfeeding, and animal studies have shown that it may also be important in monogamous social relationships. Recently, economic research in humans implicated oxytocin in trust and empathy.
Additional animal research shows that oxytocin may relieve stress and anxiety in social settings and may be more rewarding than cocaine to new mothers.
Proteins are the indispensable catalytic workhorses, carrying out the processes essential to life in today's sophisticated organisms, but long ago ribonucleic acid (RNA) reigned supreme.
Researchers have produced an atomic picture that shows how two of these very old molecules interact with each other and it provides a rare glimpse into the transition from an ancient, RNA-based world to our present, protein-catalyst dominated world.
'Agouti' is a family of genes previously identified in humans and the first two members are responsible for skin and hair color. I
dentified by Vanderbilt scientists, AgRP2 the newest member of the family, exclusively found in bony fishes and is claimed to be responsible for the ability of fish to rapidly change color!
Can there be a genetic difference between progressives and conservatives? Certainly we have had the discussion many times
about studies, both sociological and biological, seeking to make the case that politics might be nature as well as nurture.
The jokes write themselves, really:"Ozzy Osbourne's Genome Reveals Some Neandertal Lineage
The idea itself is fascinating
, though, and I am interested to see what more they can mine from the PoD (Prince of Darkness, to the uninitiated). I nominate the full contingent of Mötley Crüe as the next genetic guinea pigs, testing for why people who should by all accounts be dead are still alive and shouting at the devil.
Is alcoholism genetic as well as behavioral? Studies have suggested it in the past and scientists at Brookhaven National Lab say they have the first experimental evidence of it.
Their study compared the brain's response to long-term alcohol drinking in two genetic variants of mice. One strain lacked the gene for a specific brain receptor dopamine D2, which responds to dopamine, the brain's "feel good" chemical, to produce feelings of pleasure and reward. The other strain was genetically normal.
In the dopamine-receptor-deficient mice (but not the genetically normal strain), long-term alcohol drinking resulted in significant biochemical changes in areas of the brain well know to be involved in alcoholism and addiction.
'Copy Number Variants' (CNVs) are hot. A CNV is a sizeable chunk of DNA that's either missing from your genome or present in extra copies. Chunks of DNA get copied or deleted on a surprisingly frequent basis. We've all got CNVs, most cases they are probably benign, but CNVs are becoming an increasingly appreciated as a significant source of medically important genetic variation. 'Recently appreciated' because we now have the technology to detect CVNVs reliably.