This week, a team led by investigators at the Broad Institute reports a genome sequence for the North American green anole lizard, Anolis carolinensis, making it the first non-avian member of the reptile lineage to have been sequenced. "We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes," the authors write. In its paper, the Broad-led team also compares the lizard genomes to those of mammals and birds. Our sister publication GenomeWeb Daily News has more on the lizard genome study.
In another paper published online in advance in Nature this week, Weill Cornell Medical College in Qatar's Karsten Suhre and his colleagues discuss the effects of "human metabolic individuality in biomedical and pharmaceutical research," reporting their analysis of genotype-dependent metabolic phenotypes via a genome-wide association study with non-targeted metabolomics. "We identified 37 genetic loci associated with blood metabolite concentrations, of which 25 show effect sizes that are unusually high for GWAS and account for 10 percent to 60 percent differences in metabolite levels per allele copy," Suhre et al. write, adding their their study "advances our knowledge of the genetic basis of metabolic individuality in humans."
An international team led by investigators in Switzerland shows that the hemizygosity of an approximately 600-kb region on the short arm of chromosome 16, which is known to cause "a highly penetrant form of obesity," has a "corresponding reciprocal duplication is associated with being underweight." The researchers characterized 138 duplication carriers who showed "significantly reduced postnatal weight and BMI." The affected individuals presented "with an unusually high frequency of selective and restrictive eating behaviours and a significant reduction in head circumference," the authors write in Nature, adding that "each of the observed phenotypes is the converse of one reported in carriers of deletions at this locus."
Over in Nature Genetics, members of the Brassica rapa Genome Sequencing Project Consortium report their annotation and analysis of a draft genome sequence for accession Chiifu-401-42 of the Chinese cabbage. Using Arabidopsis thaliana as an outgroup to investigate the consequences of genome triplication, the team found that the "extent of gene loss … among triplicated genome segments varies, with one of the three copies consistently retaining a disproportionately large fraction of the genes expected to have been present in its ancestor." Overall, the authors say "the B. rapa genome sequence provides an important resource for studying the evolution of polyploid genomes and underpins the genetic improvement of Brassica oil and vegetable crops."