Project description:Mammals and reptiles possess a sophisticated somatosensory system for precise tactile discrimination via mechanosensory end-organs, such as Meissner and Pacinian corpuscles, and others. These structures detect sustained pressure, velocity, and vibrations, thereby facilitating nuanced environmental interactions. Whether the ancestral anamniotic somatosensory system, typically lacking such structures, provides comparable tactile discrimination, is unknown. Here, we investigate the Schnauzenorgan, a specialized foraging chin appendage in Mormyrid fish Gnathonemus petersii and show that it detects touch via functionally distinct myelinated mechanosensory afferents. Although these afferents terminate in the skin as seemingly free nerve endings, they detect sustained pressure, transient touch, velocity, low- and high-frequency vibrations. Thus, despite lacking typical end-organs, the Schnauzenorgan enables tactile discrimination rivaling that of amniotic extremities. Our findings reveal a previously unrecognized functional complexity in the ancestral piscine somatosensory system, suggesting that the nuanced mechanosensory capacity of amniotes was inherited from anamniote predecessors.
Project description:This study aims to investigate the DNA methylation patterns at transcription factor binding regions and their evolutionary conservation with respect to binding activity divergence. We combined newly generated bisulfite-sequencing experiments in livers of five mammals (human, macaque, mouse, rat and dog) and matched publicly available ChIP-sequencing data for five transcription factors (CEBPA, HNF4a, CTCF, ONECUT1 and FOXA1). To study the chromatin contexts of TF binding subjected to distinct evolutionary pressures, we integrated publicly available active promoter, active enhancer and primed enhancer calls determined by profiling genome wide patterns of H3K27ac, H3K4me3 and H3K4me1.
Project description:Whole genome sequencing of the Arabidopsis thaliana dot5-1 transposon insertion line described in Petricka et al 2008 The Plant Journal 56(2): 251-263.