Mouse Polycomb M33 is required for splenic vascular and adrenal gland formation through regulating Ad4BP/SF1 expression.
Mice with disrupted mammalian PcG (Polycomb group) genes commonly show skeletal transformation of anterior-posterior identities. Disruption of the murine M33 gene, a PcG member, displayed posterior transformation of the vertebral columns and sternal ribs. In addition, failure of T-cell expansion and hypoplasia and sex-reversal of the gonads, have been observed. In the present study, we identified defects in the splenic and adrenal formation of M33-knock-out (KO) mice on a C57BL/6 genetic background. The spleen in these animals was smaller than in the wild-type mice and was spotted red because of nonuniform distribution of blood cells. Histologic examination revealed disorganization of the vascular endothelium and its surrounding structures, and immunohistochemistry demonstrated disturbances in vascular formation and colonization of immature hematopoietic cells. These splenic phenotypes observed in the M33-KO mice were quite similar to those seen in Ad4BP/SF1 (Nr5a1) knock-outs. Moreover, the adrenal glands of M33-KO and Ad4BP/SF1 heterozygous KO mice were smaller than those of the wild-type mice. Western blot, immunohistochemistry, and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses of the M33 knock-outs all indicated significantly low expression of adrenal 4 binding protein/steroidogenic factor-1 (Ad4BP/SF-1), indicating that M33 is an essential upstream regulator of Ad4BP/SF1. In agreement with these observations, chromatin immunoprecipitation assays with adrenocortical Y-1 cells revealed direct binding of the M33-containing PcG to the Ad4BP/SF1 gene locus.
Katoh-Fukui
Yuko
Y
Division for Sex Differentiation, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan. yfukui@nibb.ac.jp
Owaki
Akiko
A
Toyama
Yoshiro
Y
Kusaka
Masatomo
M
Shinohara
Yuko
Y
Maekawa
Mamiko
M
Toshimori
Kiyotaka
K
Morohashi
Ken-Ichirou
K
D000311:Adrenal Glands / Q000254:growth & development / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D018398:Homeodomain Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D063150:Polycomb Repressive Complex 1; D063146:Polycomb-Group Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013154:Spleen / Q000098:blood supply / Q000378:metabolism* / Q000648:ultrastructure; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D015415:Biomarkers; C570426:Cbx2 protein, mouse; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D063146:Polycomb-Group Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D063150:Polycomb Repressive Complex 1