genetics
clock | May 7, 2008The genome of the Platypus has been sequenced:
The first analysis of the genome sequence of the duck-billed platypus was published today by an international team of scientists, revealing clues about how genomes were organized during the early evolution of mammals. The research was supported in part by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH).
Fans of TV nature shows will remember that the duck-billed platypus, native to Australia, is one of the few mammals that lay eggs. However, platypus peculiarity does not end there. For example…
clock | May 7, 2008Considering this I am kinda baffled by this. There is tons of microbial metagenomics and genomics in PLoS journals.
gregladen | May 6, 2008A recent study of dog genetics, published in PLoS, seeks to improve the quality of genetic research by better understanding the underlying patterns of genetic variation at the level of specific dog breeds.
Sometimes we are interested in the evolutionary relationship between two "species" or populations, and genetics can be helpful. The more different the genetic sequence between two populations, the more distantly related they are (on average) and thus we can construct phylogenies ("family trees" of species or groups).
Sometimes we are interested in finding genes that are linked to…
pharyngula | May 5, 2008That's the sound you should hear when Joe Felsenstein takes on an idiotic claim by Sal Cordova. Would you believe that Cordova claims that Kimura and Ohta's classic 1971 paper "shatters the modern synthesis"? That's what he claims, on the basis of his poor understanding of the mathematics of population genetics, which is ridiculous on the face of it. So it's very satisfying to see one of the big guns of population genetics take him down with one brief explanation: contrary to Cordova, the principle he's describing confirms the effectiveness of natural selection.
Just to help everyone follow…
edyong | May 4, 2008This is a quick follow-up to my other post on fat cells, which as it happens, isn't the only obesity-related story out today. Another paper found a common genetic variant that increases the risk of obesity in its carriers.
A huge team of researchers scoured the genomes of almost 17,000 European people for genetic variations that are linked to obesity. Until now, only one has been found and it sits within a gene called FTO. This new study confirmed that FTO variants have the strongest association with obesity, but in the runner-up position is another variant near a gene called melanocortin-4…
grrlscientist | May 2, 2008tags: Elizabeth Blackburn, Joan Steitz, Albany Medical Center Prize
I learned this afternoon that America's highest prize in medicine, the Albany Medical Prize in Medicine and Biomedical Research, was awarded to two women for the first time in its history. The recipients, Elizabeth Blackburn of the University of California, San Francisco, and Joan Steitz of Yale University will share the $500,000 prize, which is second only to the $1.4 million Nobel Prize. The two medical scientists, who work independently of each other, study proteins associated with DNA and RNA, and their work will likely…
razib | April 30, 2008From The evolution of human skin coloration, page 12:
The main reason I post is that I don't think that intuitively people have a good idea of how far north the north of Europe is, and the fact that "temperate" East Asia is at the latitude of the Mediterranean (as is most of the United States).
edyong | April 28, 2008
They say that size doesn't matter, but try telling that to bacteria. Most are very small, for they rely heavily on passive diffusion to ferry important nutrients and molecules across their membranes. To ensure that this happens quickly enough, bacteria need to ensure that their surface area is large enough relative to their volume - become too big and they won't be able to import enough nutrients to support their extra size.
These constraints greatly limit the size of bacteria. The larger ones solve the problem by being extremely long and slender, or by using an internal compartment called…
razib | April 26, 2008Welcome to the 30th Gene Genie!
Indulge in the fascinating world of Radiology and Nuclear Medicine has a "genetics lifestyle" post, Home Improvement For Geneticists. Not quite Tim Allen. Fellow ScienceBlogger Sandra illustrates Mapping polymorphisms in 16S ribosomal RNA. Definitely worth checking out, anyone interested in biology should be down with ribosomes, and rRNA has also been critical in taxonomy. Biotech Weblog notes that Gene Therapy May Treat Cocaine Addiction. 'nuf said. Migraines affect about 1 out of 6 people in the world; so pay attention when Genetics and Health suggest…
razib | April 24, 2008Genetic variation in human NPY expression affects stress response and emotion:
Understanding inter-individual differences in stress response requires the explanation of genetic influences at multiple phenotypic levels, including complex behaviours and the metabolic responses of brain regions to emotional stimuli. Neuropeptide Y (NPY) is anxiolytic...and its release is induced by stress...NPY is abundantly expressed in regions of the limbic system that are implicated in arousal and in the assignment of emotional valences to stimuli and memories...Here we show that haplotype-driven NPY…
razib | April 23, 2008Is it necessary to assume an apartheid-like social structure in Early Anglo-Saxon England? :
It has recently been argued that there was an apartheid-like social structure operating in Early Anglo-Saxon England. This was proposed in order to explain the relatively high degree of similarity between Germanic-speaking areas of northwest Europe and England. Opinions vary as to whether there was a substantial Germanic invasion or only a relatively small number arrived in Britain during this period. Contrary to the assumption of limited intermarriage made in the apartheid simulation, there is…
razib | April 22, 2008Mother's Diet Influences Infant Sex: High Energy Intake Linked To Conception Of Sons:
...The study shows a clear link between higher energy intake around the time of conception and the birth of sons. The findings may help explain the falling birth-rate of boys in industrialised countries, including the UK and US.
The study focused on 740 first-time pregnant mothers in the UK, who did not know the sex of their fetus. They were asked to provide records of their eating habits before and during the early stages of pregnancy. They were then split into three groups according to the number of…
razib | April 21, 2008History and Geography of Human Genes is one of my favorite books; it might rank up there in my "top 10" if I ever wished to enumerate one. But in both Human Evolutionary Genetics, a textbook, and A Genetic and Cultural Odyssey, a biography of L. L. Cavalli-Sforza, it was noted that the PCA maps pioneered in History and Geography of Human Genes have never really caught on. There might be a reason...Interpreting principal component analyses of spatial population genetic variation:
Nearly 30 years ago, Cavalli-Sforza et al. pioneered the use of principal component analysis (PCA) in population…
pharyngula | April 21, 2008There in the foaming welter of email constantly flooding my in-box was an actual, real, good, sincere question from someone who didn't understand how chromosome numbers could change over time — and he also asked with enough detail that I could actually see where his thinking was going awry. This is great! How could I not take time to answer?
So here's the question:
How did life evolve from one (I suspect) chromosome to... 64 in horses, or whatever organism you want to pick. How is it possible for a sexually reproducing population of organisms to change chromosome numbers over time?
Firstly:…
razib | April 20, 2008If you don't like the word "racial," just substitute "population." In any case, Many African-Americans Have A Gene That Prolongs Life After Heart Failure:
About 40 percent of African-Americans have a genetic variant that can protect them after heart failure and prolong their lives, according to research conducted at Washington University School of Medicine in St. Louis and collaborating institutions.
...
"By mimicking the effect of beta blockers, the genetic variant makes it appear as if beta blockers aren't effective in these patients," he explains. "But although beta blockers have no…
mikethemadbiologist | April 20, 2008What? You thought I was serious? I'm Mad, not crazy. But the release of Expelled gives me an opportunity to note one facet of creationist stupidity.
A while ago, in response to Michael Egnor, who features prominently in the movie Expelled, I discussed how creationists party like it's 1859. As the movie Expelled inadvertently demonstrates, they fail to recognize that we biologists have done a little work since Darwin's Origin of Species. Specifically, creationists never discuss either population genetics or phylogenetics because, if they did, they would get their asses handed to them (and…
edyong | April 16, 2008
Of the different types of flu virus, influenza A poses the greatest threat to human health and at any point in time, about 5-15% of the world's entire population are infected with these strains. Together, they kill up to half a million people every year and the death toll rises sharply when pandemics sweep the globe.
Today, two papers published in Nature and Science shed new light on the origins of these epidemics. By prying into the private lives of flu viruses, the studies provide fresh clues about the birthplaces of new strains, their flight plans around the world and the locations…
razib | April 15, 2008Sheril pointed me to this data rich release of Science and Engineering Indicators. I was interested to see this table:
Table 7-12
Perceptions of scientific nature of various fields: 2006
(Percent)
Field
Very scientific
Pretty scientific
Not too scientific
Not at all scientific
Haven't heard of field
Don't know
Medicine
81
16
1
--
--
1
Biology
70
24
2
1
--
2
Physics
69
21
3
1
2
4
Engineering
45
32
11
7
--
4
Economics
16
35
31
13
1
3
Sociology…
razib | April 14, 2008Effect of Variation in CHI3L1 on Serum YKL-40 Level, Risk of Asthma, and Lung Function:
Background The chitinase-like protein YKL-40 is involved in inflammation and tissue remodeling. We recently showed that serum YKL-40 levels were elevated in patients with asthma and were correlated with severity, thickening of the subepithelial basement membrane, and pulmonary function. We hypothesized that single-nucleotide polymorphisms (SNPs) that affect YKL-40 levels also influence asthma status and lung function.
...
Results A promoter SNP (–131C→G) in CHI3L1, the chitinase 3–like 1 gene encoding…