Charles Criscione at Texas A&M University was first author on a study appearing this week in Genome Biology that created a genetic linkage map for the blood fluke, Schistosoma mansoni, in order to enable more research on this "neglected pathogen," says the abstract. He and his team genotyped grandparents, parents, and 88 progeny to construct a linkage map of 243 microsatellites positioned on 203 of the biggest scaffolds in the genome sequence. "Marker segregation reveals higher female recombination, confirms ZW inheritance patterns, and identifies recombination hotspots and regions of segregation distortion," they write. A mini-review adds insight.
Also published this week, French scientists led by Yvan Zivanovic have sequenced the genome of Thermococcus gammatolerans, the most radioresistant archaeon, and performed both comparative genomic and proteomic analysis. They found that T. gammatolerans has a circular chromosome of 2.045 Mbp, encoding 2,157 proteins. Shotgun LC-MS/MS identified 10,931 unique peptides corresponding to 951 proteins. Their proteogenomic study, they say, "indicates that the high radiotolerance of T. gammatolerans is probably due to proteins that remain to be characterized rather than a larger arsenal of known DNA repair enzymes."
The University of Pennsylvania's Maja Bucan was senior author on a study that checked into the regulatory network controlling gene expression in pre- and post-synaptic neurons. Using unbiased in vivo and in vitro screens, says the abstract, they were able to characterize the cis elements regulating the Rab3A gene, much expressed in pre-synaptic neurons, as well as find that 16 transcription factor binding motifs were over-represented in intergenic multi-species conserved elements near nine pre-synaptic genes, including Rab3A.
Last week, Andrew Paterson at the University of Georgia, Athens, led research that used comparative genomics to study the evolution of photosynthesis to create C4 plants, of which sorghum is the first with a full genome sequence available. Comparing key photosynthetic enzyme genes in sorghum, maize (C4), and rice (C3), the scientists showed that both whole-genome and individual gene duplication have contributed to the evolution of C4 photosynthesis. Interestingly, they write, sorghum and maize carbonic anhydrase genes "display a novel mode of new gene formation, with recursive tandem duplication and gene fusion accompanied by adaptive evolution to produce C4 genes with 1-3 functional units."