OSR1

OSR1, short for odd-skipped related transcription factor 1, is a protein-coding gene in vertebrates that encodes a transcription factor of the OSR family. The OSR family includes OSR1 and OSR2, both characterized by C2H2-type zinc finger domains toward their C-termini and by roles in regulating embryonic development. In humans, OSR1 is expressed during early development, with notable activity in the intermediate mesoderm and tissues that form the kidney, as well as in developing heart and vasculature.

Functionally, OSR1 participates in specifying renal progenitors and in the patterning and morphogenesis of the nephron fleet, contributing to organogenesis of the kidney and related structures. As a transcription factor, it is believed to regulate networks of target genes in conjunction with other transcription factors to influence cell fate decisions during embryogenesis.

Clinical and research relevance points to a conserved role for OSR1 in kidney development. Studies in model organisms show that loss of OSR1 function can lead to defective kidney development and abnormal nephron formation, underscoring its importance in renal organogenesis. In humans, variation or altered expression of OSR1 has been investigated in relation to congenital anomalies of the kidney and urinary tract (CAKUT), though the precise contribution and mechanisms remain under study. OSR1 has a paralog, OSR2, which shares overlapping and distinct roles in development.

Discovery and naming: OSR1 was identified as the vertebrate homolog of the Drosophila odd-skipped gene family and is studied in mouse and other vertebrates to understand conservation and diversification of organogenesis programs.