In this week's Nature, a multi-institute team reports the genome of the seagrass Zostera marina, marking the first time a marine angiosperm has been fully sequenced. The work provides new insights into the genomic losses and gains involved in the flowering plant's shift to a marine lifestyle, including the loss of an entire repertoire of stomatal genes and genes involved in ultraviolet light protection. The genome is expected to prove valuable in a variety of research areas including the adaptation of marine ecosystems under pressure from climate warming and the mechanisms of osmoregulation under high salinity, the authors say. GenomeWeb has more on this here.
Also in Nature, a Harvard Medical School-led team presents the fine mapping of genetic variations strongly associated with schizophrenia. The investigators analyzed 255 post-mortem brain samples, including ones from 50 people diagnosed with schizophrenia, to better understand two forms of a gene called complement component 4 (C4), which can vary structurally between individuals. They then analyzed DNA from nearly 65,000 individuals with and without schizophrenia and found that risk for the disease is very closely associated with a genetic variation that increases expression of one form of C4 in the brain. Although C4 is known as a player in the immune system, the researchers show that it is present at neuronal synapses and that it can control the elimination of synapses during brain development in mice. GenomeWeb also covers this and a similar JAMA Psychiatry paper here.
Finally, in Nature Neuroscience, a team of European scientists describes the epigenomic annotation of gene regulatory alterations during evolution of the primate brain. They annotated cis-regulatory elements (CREs) in the human, rhesus macaque, and chimpanzee genomes using ChIP-seq in various anatomical region of the adult brain. They found high similarity in the genomic positioning of macaque and human CREs, suggesting that many of these elements were already present in a common ancestor 25 million years ago. "Most of the observed regulatory changes between humans and rhesus macaques occurred before the ancestral separation of humans and chimpanzees, leaving a modest set of regulatory elements with predicted human specificity." More on this from GenomeWeb can be found here.