In the early, online edition of PNAS this week, National Institutes of Health researchers examine the epigenetic changes associated with different red blood cell invasion strategies in a strain of the malarial parasite Plasmodium falciparum that can be coaxed to switch from sialic acid-dependent to -independent invasion. The researchers focused on the transcription start site of a gene called RH4 that's up-regulated during this switch, showing that sialic acid-independent invasion by the parasite is accomplished through histone H3K9 trimethylation silencing in this region.
Researchers from Harvard Medical School and Boston's Brigham and Women's Hospital report that they have integrated copy number, messenger RNA, microRNA, and DNA methylation data to find targets of miR-26a in a Cancer Genome Atlas glioblastoma sample. In the process, the team uncovered an ocomir/oncogene DNA cluster involving hsa-miR-26a, CDK4, and CENTG1 that is linked to aggressive cancer.
In a paper stemming from the Evolution in Health and Medicine Sackler Colloquium last spring, Baylor College of Medicine and Texas Children's Hospital researcher James Lupski and his team discuss how studying genomic disorders can offer insights into human genes, genome evolution, and architecture. "The same mechanisms implicated in the origin of genomic disorders may also play a role in the emergence of segmental duplications and the evolution of new genes by means of genomic and gene duplication and triplication, exon shuffling, exon accretion, and fusion/fission events," they write.
And a paper scheduled to appear online this week describes the use of information on mobile elements in modern human genomes for estimating ancient population size. As Nicholas Wade reports in the New York Times, Lynn Jorde and company examined genetic variants around Alu insertions in the haploid reference genome and the diploid Venter genome, finding evidence to suggest a human population size of just 18,500 about 1.2 million years ago.