Posts Tagged ‘genetics’
Students are often faced with with some very contradictory decisions. Liberal arts or natural sciences? English literature or chemistry? The classical educational framework forces students to choose early on which path they will take and, as a result, students with a penchant for history will rarely be exposed to the intricacies of biology. However, a new study out of Columbia University’s School of Engineering and Applied Sciences, may give those who are ready to trade-in their biology textbooks for lessons in history a reason for second-thought.
In a study published in the November 2012 issue of The American Journal of Human Genetics (AJHG), Columbia scientists describe a new approach used to analyze genetic data to learn more about the history of populations. The authors are the first to develop a method that can describe in detail events in recent history, over the past 2,000 years. They demonstrate this method in two populations, the Ashkenazi Jews and the Masai people of Kenya, who represent two kinds of histories and relationships with neighboring populations: one that remained isolated from surrounding groups, and one that grew from frequent cross-migration across nearby villages.
Over the past decade, research in the field of epigenetics has revealed that chemically modified bases are abundant components of the human genome and has forced us to abandon the notion we’ve had since high school genetics that DNA consists of only four bases.
Now, researchers at Weill Cornell Medical College have made a discovery that once again forces us to rewrite our textbooks. This time, however, the findings pertain to RNA, which like DNA carries information about our genes and how they are expressed. The researchers have identified a novel base modification in RNA which they say will revolutionize our understanding of gene expression.
Their report, published May 17 in the journal Cell, shows that messenger RNA (mRNA), long thought to be a simple blueprint for protein production, is often chemically modified by addition of a methyl group to one of its bases, adenine. Although mRNA was thought to contain only four nucleobases, their discovery shows that a fifth base, N6-methyladenosine (m6A), pervades the transcriptome. The researchers found that up to 20 percent of human mRNA is routinely methylated. Over 5,000 different mRNA molecules contain m6A, which means that this modification is likely to have widespread effects on how genes are expressed.
What do you get when you cross a yeast and first year biology students?
Apparently, a very cool undergraduate course and significant scientific innovation!
UC Berkeley students who are lucky enough to be enrolled in the university’s entry-level biology course are being exposed to a discovery-based learning curriculum that gives them hands-on bench experience and has resulted in the discovery of a novel technique published in the current issue of Genetics.
Under the mentorship of University of Massachusetts Amherst geneticist Jacob Mayfield, students devised a technique for testing the consequence of variant human gene alleles by moving them into yeast cells. Once swapped into yeast, colony growth was be compared to reveal functional differences.
The technique was used to compare allelic differences in the Cystathionine-beta-synthase (CBS) gene, created by site-directed mutagenesis. Deficiencies in the gene causes homocystinuria which can be rescued by vitamin B6 treatments. However, only some individuals respond to vitamin B6 treatment while others do not. Using the yeast metabolic profiling technique, researchers were able to ascertain which individuals, (based on their CBS sequence), would respond to the B6 treatment and which would not.
Sounds like a winning program to me!
Citation: Mayfield JA, Davies MW, Dimster-Denk D, Pleskac N, McCarthy S, Boydston EA, Fink L, Lin XX, Narain AS, Meighan M, & Rine J (2012). Surrogate genetics and metabolic profiling for characterization of human disease alleles. Genetics, 190 (4), 1309-23 PMID: 22267502
In recent years, there have been an increasing amount of media reports of bullying in our schools. Studies have shown that negative effects associated with bullying including loneliness, depression, anxiety, low self-esteem and increased susceptibility to illness. In a new report published in the journal of Molecular Psychiatry, researchers from Duke University have shown that bullying may have a much deeper impact on its victim than previously thought. According to the study, children who experience bullying have been found to have shortened telomeres, which in essence means that its impact reaches deep down into the DNA of its victims.
CITATION: “Exposure to Violence During Childhood is Associated with Telomere Erosion from 5 to 10 Years of Age: A Longitudinal Study,” Idan Shalev, Terrie Moffitt et al. Molecular Psychiatry, April 24th. doi:10.1038/mp.2012.32