Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive error.

Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects on eye elongation. Implicated genes are involved in extracellular matrix organization, developmental process for body and eye, connective tissue cartilage and glycosylation protein activities. Our study provides insights into population-specific novel genes for corneal curvature, and their pleiotropic effect in regulating eye size or conferring susceptibility to myopia

Multi-trait genome-wide association study identifies new loci associated with optic disc parameters

A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH

Chitin in Meloidogyne javanica

La gangue gélatineuse extrudée par les femelles vivantes de #Meloidogyne javanica$ et formant avec les oeufs la masse d'oeufs, a été analysée en vue de la présence de chitine. A 22°C, la gelée fraîchement extrudée se dissout rapidement lorsque du KOH à 5 % est ajouté à une lame de perfusion contenant le nématode. La gelée des masses d'oeufs est plus dure mais se dissout en 24h dans la potasse à 5 % portée à 105°C. Les coques des oeufs résistent à ce traitement et produisent un spectre de diffraction électronique de type chitine lorsque examinées en microscopie électronique. La présence de chitine n'a pas été détectée dans la gelée et sa signalisation est probablement due à des hyphes de champignons contaminants, lesquels peuvent être détectés en lumière ultra-violette à l'aide de fluorochromes, tel le Calcofluor White. (Résumé d'auteur

Sub-marine palaeoenvironments during Emeishan flood basalt volcanism, SW China: implications for plume-lithosphere interaction during the Capitanian (‘end Guadalupian’) extinction event.

Plume-induced lithospheric uplift and erosion are widely regarded as key features of large igneous province (LIP) emplacement, as is the coincidence of LIP eruption with major extinction and oceanic anoxic events (OAE). The Emeishan LIP, which erupted during the Capitanian (formally ‘end Guadalupian’) extinction event, has provided the most celebrated example where advocates argue that in excess of 500 m of axisymmetric uplift occurred over >30 000 km2 causing extensive radially-distributed erosion and alluvial fan formation. However, the recognition of submarine and phreatomagmatic-style volcanism, as well as syn-volcanic marine sediments interbedded in the eruptive succession, now requires further examination to this simple plume – uplift model. Here we present data from newly-discovered sections from the center of the putative uplifted area (around Lake Er Hai, SW Yunnan Province,) that provide a more complete history of the Emeishan volcanism. These reveal that platform carbonate deposition was terminated by rapid subsidence, followed quickly by the onset of volcanism. For at least the lower two thirds of the 4-5 km thick lava pile, eruptions continued at or below sea level, as testified by the presence of voluminous mafic volcaniclastic deposits, pillow lavas and development of syn-volcanic reefal limestones in the Emeishan inner zone. Only in the later stages of eruption did terrestrial lava flows become widely developed. This onset of volcanism in a submarine setting and the consequent violent, phreatomagmatic-style eruptions may have exacerbated the cooling effects of volcanism during the Capitanian. The late Permian of SW China at the time of the Emeishan was an extended area of thinned lithosphere with epeiric seas, which appear to have been sustained through the onset of LIP emplacement. Therefore, whilst there remains substantial geochemical support of a plume origin for Emeishan volcanism, LIP emplacement cannot be ubiquitously associated with regional pre-eruption uplift particularly where complex lithospheric structure exists above a plume