Evidence that Mothers-against-dpp-related 1 (Madr1) plays a role in the initiation and maintenance of spermatogenesis in the mouse.
We have cloned a mouse cDNA encoding a Mothers-against-dpp (MAD)-related protein, MADR1. Madr1 is ubiquitously expressed in the mouse embryo, indicating a broad function in a variety of tissue during embryogenesis, potentially relaying signals of numerous BMPs. However, its expression in the testis is strictly germ cell-specific and developmentally regulated. Testicular Madr1 expression starts in some seminiferous tubules at 2 weeks of age. After mid-puberty, a stage-specific Madr1 expression is established. During the cycling of the seminiferous epithelium, Madr1 expression initiates in the pachytene spermatocytes of stage V seminiferous tubules, peaks at stage X, then decreases as pachytene spermatocytes differentiate into secondary spermatocytes and then round spermatids. In the testis of adult Bmp8b homozygous mutant males, the Madr1- expressing pachytene spermatocytes are the first cell population to show increased apoptosis. These data suggest that MADR1 serves as a downstream component of the BMP8 signaling pathway during the differentiation of meiotic male germ cells.
Zhao
G Q
GQ
Howard Hughes Medical Institute, Vanderbilt University Medical School, Nashville, TN 37232-2175, USA.
Hogan
B L
BL
D000818:Animals; D001483:Base Sequence; D019485:Bone Morphogenetic Proteins / Q000235:genetics; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D051785:Smad Proteins; D051898:Smad1 Protein; D013087:Spermatids / Q000166:cytology / Q000378:metabolism; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism; D013091:Spermatogenesis; D013093:Spermatogonia / Q000166:cytology / Q000378:metabolism; D013737:Testis / Q000254:growth & development; D015534:Trans-Activators
D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D051785:Smad Proteins; D051898:Smad1 Protein; C497401:Smad1 protein, mouse; D015534:Trans-Activators