The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Diabetes mellitus: pathophysiological changes and therap

Notes on the collection of Zingiberaceae

Since the time of Linnaeus taxonomists have said that Zingiberaceae need to be studied from living plants, and as though to emphasize this, too many collectors have thrust leafy shoots and inflorescences into the press, jotted down a few rather obvious field notes (or none) and left the taxonomist to do his worst. At first the trouble experienced was simply that of understanding the structure of a flower in which most of the petaloid parts are staminodal in origin. Individual flowers of many Zingiberaceae are soft and watery and often surrounded by mucilage. Roughly pressed, especially if pressed in the inflorescence, their structure is lost beyond recall. As time went on the basic structural problems were elucidated. But the number of known Zingiberaceae has been constantly rising and with it the taxonomist’s cry that material is still too often inadequate. Now it is not only floral form that is so often lost; the structure of the inflorescence, or of the cincinni making up the compound inflorescence, cannot be easily elucidated in the herbarium, and in more recent classifications (Valeton, Bull. Jard. Bot. Btzg ii 17, 1918; Holttum, Gard. Bull. 13, 1950) this has come to play a more and more important part

The benefits of bathing buds: water calyces protect flowers from a microlepidopteran herbivore

Protective floral structures may evolve in response to the negative effects of floral herbivores. For example, water calyces—liquid-filled, cup-like structures resulting from the fusion of sepals—may reduce floral herbivory by submerging buds during their development. Our observations of a water-calyx plant, Chrysothemis friedrichsthaliana (Gesneriaceae), revealed that buds were frequently attacked by ovipositing moths (Alucitidae), whose larvae consumed anthers and stigmas before corollas opened. Almost 25% of per-plant flower production was destroyed by alucitid larvae over two seasons, far exceeding the losses to all other floral herbivores combined. Experimental manipulation of water levels in calyces showed that a liquid barrier over buds halved per-flower alucitid egg deposition and subsequent herbivory, relative to buds in calyces without water. Thus, C. friedrichsthaliana's water calyx helps protect buds from a highly detrimental floral herbivore. Our findings support claims that sepal morphology is largely influenced by selection to reduce floral herbivory, and that these pressures can result in novel morphological adaptations