(776.1) Conservation of Kidney Development in the Red-eared Slider, Trachemys scripta

Poster Board Number: C13
Introduction: AAA has separate poster presentation times for odd and even posters.
Odd poster #s – 10:15 am – 11:15 am
Even poster #s – 11:15 am – 12:15 pm

Hannah Boehler (New York Institute of Technology College of Osteopathic Medicine at Arkansas State University), James Donohue (New York Institute of Technology College of Osteopathic Medicine at Arkansas State University), Jessica Hiley (Arkansas State University), Kasen Lisonbee (New York Institute of Technology College of Osteopathic Medicine at Arkansas State University), Troy Camarata (New York Institute of Technology College of Osteopathic Medicine at Arkansas State University)

Mammals, birds, and reptiles all possess a metanephric kidney in adult animals. The process of kidney development, or nephrogenesis, ceases in mammals prior to or immediately after birth. Termination of mammalian nephrogenesis is due to kidney progenitor cell populations halting self-renewal and undergoing terminal differentiation. Our previous studies have shown in several reptile species the presence of post-embryonic nephrogenesis accompanying embryonic-like adult progenitor cells. It is unknown how or why kidney progenitor cell populations are lost during mammalian development but persist in reptiles. To better understand the persistence of kidney progenitor cells in reptiles, we have set out to characterize kidney development to determine if adult progenitor cell populations are a continuation of embryonic processes. We have chosen to use the red-eared slider turtle, Trachemys scripta, as a model for reptile metanephric kidney development as this species showed the highest number of nephrogenic zones in adults. While the embryonic development of external morphology (such as head, limbs, shell) in this species has been documented, organogenesis has not been studied as thoroughly. We have utilized gross observations of morphology, histology, whole-mount immunohistochemistry and in situ hybridization to characterize and assess the conservation of kidney development in this species. The embryonic kidney progenitor cell marker, Six2, was detected as early as stage-15 as a linear group of metanephric mesenchyme. Little to no cytokeratin positive epithelium was detected at this stage of kidney development. As kidney development proceeds, the progenitor mesenchyme cells and adjacent ureteric bud epithelium are found in highly organized rows. Several genes known to play roles within mammalian kidney development displayed conserved expression domains in the developing T. scripta kidney. The embryonically expressed Six2 transcription factor was also detected in progenitor cells of adult kidneys. Future investigation will continue to assess kidney ontogeny in reptiles.