Biology subjects

Vogel, H.

Publications and source records attributed to Vogel, H..

4 recordsLinked to original sources

bioRxiv2018

Expansion of the fatty acyl reductase gene family shaped pheromone communication in Hymenoptera

The conserved fatty acyl reductase (FAR) family is involved in biosynthesis of fatty alcohols that serve a range of biological roles. In moths, butterflies (Lepidoptera), and bees (Hymenoptera), FARs biosynthesize fatty alcohol pheromones participating in mate-finding strategies. Using a combination of next-generation sequencing, analysis of transposable elements (TE) in the genomic environment of FAR genes, and functional characterization of FARs from Bombus lucorum, B. lapidarius, and B. terrestris, we uncovered a massive expansion of the FAR gene family in Hymenoptera, presumably facilitated by TEs. Expansion occurred in the common ancestor of bumblebees (Bombini) and stingless bees (Meliponini) after their divergence from the honeybee lineage. We found that FARs from the expanded FAR-A orthology group contributed to the species-specific male marking pheromone composition. Our results indicate that TE-mediated expansion and functional diversification of the FAR gene family played a key role in the evolution of pheromone communication in the crown group of Hymenoptera.\n\nAbbreviationsMMP: male marking pheromone, FA: fatty acid, FAME: fatty acid methyl ester, FAR: fatty acyl reductase, LG: labial gland, FB: fat body, TE: transposable element.

evolutionary biology↗

bioRxiv2018

The genomic basis of colour pattern polymorphism in the harlequin ladybird

Many animal species are comprised of discrete phenotypic forms. Understanding the genetic mechanisms generating and maintaining such phenotypic variation within species is essential to comprehending morphological diversity. A common and conspicuous example of discrete phenotypic variation in natural populations of insects is the occurrence of different colour patterns, which has motivated a rich body of ecological and genetic research1-6. The occurrence of dark, i.e. melanic, forms, displaying discrete colour patterns, is found across multiple taxa, but the underlying genomic basis remains poorly characterized. In numerous ladybird species (Coccinellidae), the spatial arrangement of black and orange patches on adult elytra varies wildly within species, forming strikingly different complex colour patterns7,8. In the harlequin ladybird Harmonia axyridis, more than 200 distinct colour forms have been described, which classic genetic studies suggest result from allelic variation at a single, unknown, locus9,10. Here, we combined whole-genome sequencing, population genomics, gene expression and functional analyses, to establish that the gene pannier controls melanic pattern polymorphism in H. axyridis. We show that pannier, which encodes an evolutionary conserved transcription factor, is necessary for the formation of melanic elements on the elytra. Allelic variation in pannier leads to protein expression in distinct domains on the elytra, and thus determines the distinct colour patterns in H. axyridis. Recombination between pannier alleles may be reduced by a highly divergent sequence of ca. 170 kb in the cis-regulatory regions of pannier with a 50 kb inversion between colour forms. This likely helps maintaining the distinct alleles found in natural populations. Thus we propose that highly variable discrete colour forms can arise in natural populations through cis-regulatory allelic variation of a single gene.

evolutionary biology↗

bioRxiv2018

High-resolution wide-field human brain tumor margin detection and in vivo murine neuroimaging

Current in vivo neuroimaging techniques provide limited field of view or spatial resolution and often require exogenous contrast. These limitations prohibit detailed structural imaging across wide fields of view and hinder intraoperative tumor margin detection. Here we present a novel neuroimaging technique, speckle-modulating optical coherence tomography (SM-OCT), which allows us to image the brains of live mice and ex vivo human samples with unprecedented resolution and wide field of view using only endogenous contrast. The increased effective resolution provided by speckle elimination reveals white matter fascicles and cortical layer architecture in the brains of live mice. To our knowledge, the data reported herein represents the highest resolution imaging of murine white matter structure achieved in vivo across a wide field of view of several millimeters. When applied to an orthotopic murine glioblastoma xenograft model, SM-OCT readily identifies brain tumor margins with near single-cell resolution. SM-OCT of ex vivo human temporal lobe tissue reveals fine structures including cortical layers and myelinated axons. Finally, when applied to an ex vivo sample of a low-grade glioma resection margin, SM-OCT is able to resolve the brain tumor margin. Based on these findings, SM-OCT represents a novel approach for intraoperative tumor margin detection and in vivo neuroimaging.

bioengineering↗

bioRxiv2017

A butterfly chromonome reveals selection dynamics during extensive and cryptic chromosomal reshuffling

Chromosome evolution, an important component of mico- and macroevolutionary dynamics 1-5, presents an enigma in the mega-diverse Lepidoptera6. While most species exhibit constrained chromosome evolution, with nearly identical haploid chromosome counts and chromosome-level shared gene content and collinearity among species despite more than 140 Million years of divergence7, a small fraction of species independently exhibit dramatic changes in chromosomal count due to extensive fission and fusion events that are facilitated by their holocentric chromosomes7-9. Here we address this enigma of simultaneous conservation and dynamism in chromosome evolution in our analysis of the chromonome (chromosome level assembly10) of the green-veined white butterfly, Pieris napi (Pieridae, Linnaeus, 1758). We report an unprecedented reorganization of the standard Lepidopteran chromosome structure via more than 90 fission and fusion events that are cryptic at other scales, as the haploid chromosome number is identical to related genera and gene collinearity within the large rearranged segments matches other Lepidoptera. Furthermore, these rearranged segments are significantly enriched for clusters of functionally related genes and the maintenance of ancient telomeric ends. These results suggest an unexpected role for selection in shaping chromosomal evolution when the structural constraints of monocentricq chromosomes are relaxed.

evolutionary biology↗