In PLoS Genetics this week, researchers at the Baylor College of Medicine and elsewhere propose a "connection between the epigenome, selective mutability, evolution, and human disease" based on the findings of their study on associations of structural mutability with germline DNA methylation and with non-allelic homologous recombination mediated by low-copy repeats. "Combined evidence from four human sperm methylome maps, human genome evolution, structural polymorphisms in the human population, and previous genomic and disease studies consistently points to a strong association of germline hypomethylation and genomic instability," the Baylor-led team writes.
In the same journal, investigators at the Stowers Institute for Medical Research suggest, based on their studies on budding yeast, that "the capacity for accurate chromosome segregation by the mitotic system does not scale continuously with an increasing number of chromosomes, but may occur via discrete steps each time a full set of chromosomes is added to the genome." In addition, the Stowers team shows that "on top of such general ploidy-related effect, [chromosome instability] is also associated with the presence of specific aneuploid chromosomes as well as dosage imbalance between specific chromosome pairs."
Over in PLoS One, researchers at the Chinese Academy of Sciences' Kunming Institute of Botany report on their analysis of DNA sequence variation in three gene markers in samples of the wild gourmet mushroom Boletus edulis. "Our results revealed 15 novel phylogenetic species ... and a newly identified lineage represented by Boletus sp. HKAS71346 from tropical Asia," the authors write, adding that their "phylogenetic analyses support eastern Asia as the center of diversity for the porcini sensu stricto clade," of which B. edulis is the only known holarctic species.