Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:While retaining ancestral morphological and genomic traits, skates evolved a novel body plan with remarkably enlarged wing-like fins that allowed skates to thrive in benthic environments, but their molecular underpinnings remain elusive. Here we investigate the origin of this phenotypical innovation by assembling a high-quality chromosome-scale genome sequence for the little skate Leucoraja erinacea and by generating extensive regulatory profiling datasets in developing fins (gene expression, chromatin occupancy and conformation). We show that despite their derived morphology, the skate genome retains multiple features of the ancestral jawed vertebrate genome.
Project description:The synarcual is a specialized adaptation of the anterior axial skeleton comprising a putatively fused array of vertebral elements characteristic of jawed vertebrate (gnathostome) clades such as batoid and chimaeroid chondrichthyans, as well as a fossil group known as the placoderms. Placoderms represent the phylogenetically most basal jawed vertebrates and the presence of a synarcual in these and chondrichthyans may suggest a conserved vertebral type for jawed vertebrates, predating the divergence of stem and crown gnathostomes. Alternatively, synarcuals may have evolved independently in these lineages, exhibiting a remarkable case of morphological convergence. We investigated the early development of the cervicothoracic synarcual of an emerging model chondrichthyan, the Little skate Leucoraja erinacea, by combining x-ray computed tomography, classical histology, and a de novo transcriptome assembly for two developmental stages of the skate synarcual and post-synarcual axial skeletal elements.
Project description:Gene expression profiling of pooled late stage embryos from Leucoraja erinacea, Scyliorhinus canicula and Callorhinchus milii show that HOXC cluster genes are not expressed in the two elasmobranch fishes, L. erinacea and S. canicula. This finding supports the observations that these genes are not found in whole genome shotgun sequencing of L. erinacea or genomic clones from S. canicula. Profile gene expression in pooled late stage embryos from three species (L. erinacea, S. canicula and C. milii)
Project description:Gene expression profiling of pooled late stage embryos from Leucoraja erinacea, Scyliorhinus canicula and Callorhinchus milii show that HOXC cluster genes are not expressed in the two elasmobranch fishes, L. erinacea and S. canicula. This finding supports the observations that these genes are not found in whole genome shotgun sequencing of L. erinacea or genomic clones from S. canicula.
Project description:Elasmobranch fishes, including sharks, rays, and skates, use specialized electrosensory organs called Ampullae of Lorenzini to detect extremely small changes in environmental electric fields. Electrosensory cells within these ampullae are able to discriminate and respond to minute changes in environmental voltage gradients through an as-yet unknown mechanism. Here we show that the voltage-gated calcium channel CaV1.3 and big conductance calcium-activated potassium (BK) channel are preferentially expressed by electrosensory cells in little skate (Leucoraja erinacea) and functionally couple to mediate electrosensory cell membrane voltage oscillations, which are important in the detection of specific, weak electrical signals. Both channels exhibit unique properties compared with their mammalian orthologues to support electrosensory functions: structural adaptations in CaV1.3 mediate a low voltage threshold for activation, while alterations in BK support specifically tuned voltage oscillations. These findings reveal a molecular basis of electroreception and demonstrate how discrete evolutionary changes in ion channel structure facilitate sensory adaptation.