Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies

To identify loci for age at menarche, we performed a meta-analysis of 32 genome-wide association studies in 87,802 women of European descent, with replication in up to 14,731 women. In addition to the known loci at LIN28B (P = 5.4 × 10???) and 9q31.2 (P = 2.2 × 10?33), we identified 30 new menarche loci (all P < 5 × 10??) and found suggestive evidence for a further 10 loci (P < 1.9 × 10??). The new loci included four previously associated with body mass index (in or near FTO, SEC16B, TRA2B and TMEM18), three in or near other genes implicated in energy homeostasis (BSX, CRTC1 and MCHR2) and three in or near genes implicated in hormonal regulation (INHBA, PCSK2 and RXRG). Ingenuity and gene-set enrichment pathway analyses identified coenzyme A and fatty acid biosynthesis as biological processes related to menarche timing.     

The systematics of Microtus (Terricola) savii group: an odonthometrical perspective (Mammalia,Rodentia, Cricetidae)

ABSTRACT

The morphology of the first lower molar of Microtus savii group (M. brachycercus, M. nebrodensis, M. savii) is complex and highly variable. A morphometrical analysis done by grouping the samples into large geographical sets reveals the differentiation between northern, central and southern populations. The specific status of M. nebrodensis is confirmed while it is not possible to separate M. brachycercus. The subspecies M. savii tolfetanus and M. brachycercus niethammericus are, respectively, not well and moderate distinguished from the other populations. Finally, the distinction of M. savii group from other species of European voles is also confirmed.     

Deciphering the evolution and metabolism of an anammox bacterium from a community genome

Anaerobic ammonium oxidation (anammox) has become a main focus in oceanography and wastewater treatment. It is also the nitrogen cycle's major remaining biochemical enigma. Among its features, the occurrence of hydrazine as a free intermediate of catabolism, the biosynthesis of ladderane lipids and the role of cytoplasm differentiation are unique in biology. Here we use environmental genomics--the reconstruction of genomic data directly from the environment--to assemble the genome of the uncultured anammox bacterium Kuenenia stuttgartiensis from a complex bioreactor community. The genome data illuminate the evolutionary history of the Planctomycetes and allow us to expose the genetic blueprint of the organism's special properties. Most significantly, we identified candidate genes responsible for ladderane biosynthesis and biological hydrazine metabolism, and discovered unexpected metabolic versatility.     

Sub1A is an ethylene-response-factor-like gene that confers submergence tolerance to rice

Most Oryza sativa cultivars die within a week of complete submergence--a major constraint to rice production in south and southeast Asia that causes annual losses of over US 1 billion dollars and affects disproportionately the poorest farmers in the world. A few cultivars, such as the O. sativa ssp. indica cultivar FR13A, are highly tolerant and survive up to two weeks of complete submergence owing to a major quantitative trait locus designated Submergence 1 (Sub1) near the centromere of chromosome 9 (refs 3, 4, 5-6). Here we describe the identification of a cluster of three genes at the Sub1 locus, encoding putative ethylene response factors. Two of these genes, Sub1B and Sub1C, are invariably present in the Sub1 region of all rice accessions analysed. In contrast, the presence of Sub1A is variable. A survey identified two alleles within those indica varieties that possess this gene: a tolerance-specific allele named Sub1A-1 and an intolerance-specific allele named Sub1A-2. Overexpression of Sub1A-1 in a submergence-intolerant O. sativa ssp. japonica conferred enhanced tolerance to the plants, downregulation of Sub1C and upregulation of Alcohol dehydrogenase 1 (Adh1), indicating that Sub1A-1 is a primary determinant of submergence tolerance. The FR13A Sub1 locus was introgressed into a widely grown Asian rice cultivar using marker-assisted selection. The new variety maintains the high yield and other agronomic properties of the recurrent parent and is tolerant to submergence. Cultivation of this variety is expected to provide protection against damaging floods and increase crop security for farmers.     

Anhedonia requires MC4R-mediated synaptic adaptations in nucleus accumbens

Chronic stress is a strong diathesis for depression in humans and is used to generate animal models of depression. It commonly leads to several major symptoms of depression, including dysregulated feeding behaviour, anhedonia and behavioural despair. Although hypotheses defining the neural pathophysiology of depression have been proposed, the critical synaptic adaptations in key brain circuits that mediate stress-induced depressive symptoms remain poorly understood. Here we show that chronic stress in mice decreases the strength of excitatory synapses on D1 dopamine receptor-expressing nucleus accumbens medium spiny neurons owing to activation of the melanocortin 4 receptor. Stress-elicited increases in behavioural measurements of anhedonia, but not increases in measurements of behavioural despair, are prevented by blocking these melanocortin 4 receptor-mediated synaptic changes in vivo. These results establish that stress-elicited anhedonia requires a neuropeptide-triggered, cell-type-specific synaptic adaptation in the nucleus accumbens and that distinct circuit adaptations mediate other major symptoms of stress-elicited depression.