Project description:Vampire bats and snakes have taken thermosensation to the extreme by developing specialized systems for detecting infrared radiation. As such, these creatures provide a window into the molecular and genetic mechanisms underlying evolutionary tuning of thermoreceptors in a species or cell type specific manner. In each case, robust thermal sensitivity likely reflects specialized anatomical features of infrared sensing pit organs, as well as intrinsic heat sensitivity of trigeminal nerve fibers that innervate these structures. Here we show that vampire bats use a molecular strategy involving alternative splicing of the TRPV1 gene to generate a channel specifically within trigeminal ganglia that has a reduced thermal activation threshold. Selective expression of splicing factors in trigeminal, but not dorsal root ganglia, together with unique organization of the vampire bat TRPV1 gene underlies this mechanism of sensory adaptation. Comparative genomic analysis of the TRPV1 locus supports phylogenetic relationships within the proposed Pegasoferae clade of mammals. Gene expression measurements implicate a TRPV1 splice isoform as the heat-sensitive channel in vampire bats
Project description:Bats are the only mammals capable of self-powered flying. Many bat species hibernate in winter. A reversible control of cerebral activities is critical for bats to accommodate a repeated torpor-arousal cycle during hibernation. Little is known about the molecular mechanism that regulates neuronal activities in torpid bats. In this study, brain proteins were fractionated and compared between torpid and active Rhinolophus ferrumequinum bats.
Project description:As the only truly flying mammals, bats use their unique wing formed from elongated digits connected by membranes to power their flight. The forelimb of bats consists of four elongated digits (digits II-V) and one shorter digit (digit I) that is morphologically similar to the hindlimb digits. Elongation of bat forelimb digits is thought to results from changes in the temporal and spatial expression of a number of developmental genes. As a result, comparing gene expression profiles between short and elongated digit morphologies of the fore- and hindlimbs may elucidate the molecular mechanisms underlying digit elongation in bats. Here, we performed a large-scale analysis of gene expression of forelimb digit I, forelimb digits II-V, and all five hindlimb digits in Myotis ricketti using digital gene expression tag profiling approach. Results of this study not only implicate several developmental genes as robust candidates underlying digit elongation in bats, but also provide a better understanding of the genes involved in autopodial development in general. A large-scale analysis of gene expression of 3 different parts of autopods in Myotis ricketti using digital gene expression tag profiling approach.
Project description:Vesper bats (family Vespertilionidae) experienced a rapid adaptive radiation beginning around 36 mya that resulted in the second most species rich mammalian family. Coincident with that radiation was an initial burst of DNA transposon activity that has continued into the present. Deep sequencing of small RNAs from the vespertilionid, Eptesicus fuscus, as well as dog and horse revealed that substantial numbers of novel bat miRNAs are derived from DNA transposons unique to vespertilionids. In fact, 35.9% of Eptesicus-specific miRNAs derive from DNA transposons compared to 2.2 and 5.9% of dog- and horse-specific miRNAs, respectively and targets of several miRNAs are identifiable. Timing of the DNA transposon expansion and the introduction of novel miRNAs coincides remarkably well with the rapid diversification of the family Vespertilionidae. We suggest that the rapid and repeated perturbation of regulatory networks by the introduction of many novel miRNA loci was a factor in the rapid radiation.
Project description:Vesper bats (family Vespertilionidae) experienced a rapid adaptive radiation beginning around 36 mya that resulted in the second most species rich mammalian family. Coincident with that radiation was an initial burst of DNA transposon activity that has continued into the present. Deep sequencing of small RNAs from the vespertilionid, Eptesicus fuscus, as well as dog and horse revealed that substantial numbers of novel bat miRNAs are derived from DNA transposons unique to vespertilionids. In fact, 35.9% of Eptesicus-specific miRNAs derive from DNA transposons compared to 2.2 and 5.9% of dog- and horse-specific miRNAs, respectively and targets of several miRNAs are identifiable. Timing of the DNA transposon expansion and the introduction of novel miRNAs coincides remarkably well with the rapid diversification of the family Vespertilionidae. We suggest that the rapid and repeated perturbation of regulatory networks by the introduction of many novel miRNA loci was a factor in the rapid radiation. A testicular tissue sample from dog, horse, and two different Eptesicus fuscus individuals. Four samples total.
Project description:As the only truly flying mammals, bats use their unique wing formed from elongated digits connected by membranes to power their flight. The forelimb of bats consists of four elongated digits (digits II-V) and one shorter digit (digit I) that is morphologically similar to the hindlimb digits. Elongation of bat forelimb digits is thought to results from changes in the temporal and spatial expression of a number of developmental genes. As a result, comparing gene expression profiles between short and elongated digit morphologies of the fore- and hindlimbs may elucidate the molecular mechanisms underlying digit elongation in bats. Here, we performed a large-scale analysis of gene expression of forelimb digit I, forelimb digits II-V, and all five hindlimb digits in Myotis ricketti using digital gene expression tag profiling approach. Results of this study not only implicate several developmental genes as robust candidates underlying digit elongation in bats, but also provide a better understanding of the genes involved in autopodial development in general.
Project description:Vampire bats and snakes have taken thermosensation to the extreme by developing specialized systems for detecting infrared radiation. As such, these creatures provide a window into the molecular and genetic mechanisms underlying evolutionary tuning of thermoreceptors in a species or cell type specific manner. In each case, robust thermal sensitivity likely reflects specialized anatomical features of infrared sensing pit organs, as well as intrinsic heat sensitivity of trigeminal nerve fibers that innervate these structures. Here we show that vampire bats use a molecular strategy involving alternative splicing of the TRPV1 gene to generate a channel specifically within trigeminal ganglia that has a reduced thermal activation threshold. Selective expression of splicing factors in trigeminal, but not dorsal root ganglia, together with unique organization of the vampire bat TRPV1 gene underlies this mechanism of sensory adaptation. Comparative genomic analysis of the TRPV1 locus supports phylogenetic relationships within the proposed Pegasoferae clade of mammals.