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: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:RNA-seq of ventricles from 6 Scyliorhinus canicula juveniles (~5 months old) that underwent embryogenesis at 15C or 20C and were held at 15C post-hatching.
Project description:Transcriptional profiling from adult Scyliorhinus retifer from electrosensory cells of the ampullae of Lorenzini, forebrain, skin, and skeletal muscle shows differential gene expression of voltage-activated ion channels related to sensory transduction.
Project description:The origin of extracellular digestion in metazoans was accompanied by structural and physiological alterations of the gut. These adaptations culminated in the differentiation of a novel digestive structure in jawed vertebrates, the stomach. Specific endoderm/mesenchyme signalling is required for stomach differentiation, involving the growth and transcription factors: 1) Shh and Bmp4, required for stomach outgrowth; 2) Barx1, Sfrps and Sox2, required for gastric epithelium development and 3) Cdx1 and Cdx2, involved in intestinal versus gastric identity. Thus, modulation of endoderm/mesenchyme signalling emerges as a plausible mechanism linked to the origin of the stomach. In order to gain insight into the ancient mechanisms capable of generating this structure in jawed vertebrates, we characterised the development of the gut in the catshark Scyliorhinus canicula. As chondrichthyans, these animals retained plesiomorphic features of jawed vertebrates, including a well-differentiated stomach. We identified a clear molecular regionalization of their embryonic gut, characterised by the expression of barx1 and sox2 in the prospective stomach region and expression of cdx1 and cdx2 in the prospective intestine. Furthermore, we show that gastric gland development occurs close to hatching, accompanied by the onset of gastric proton pump activity. Our findings favour a scenario in which the developmental mechanisms involved in the origin of the stomach were present in the common ancestor of chondrichthyans and osteichthyans.