RESUMEN
Inhibin-betaC is a recently described TGF-beta family member most homologous to inhibin-betaA and inhibin-betaB. By Northern analysis, inhibin-betaC mRNA was detected exclusively in the liver among a large number of adult mouse tissues surveyed. The expression of inhibin-betaC mRNA in adult liver dropped sharply and transiently following partial hepatectomy. At 6 and 12 hours following partial hepatectomy, the levels of inhibin-betaC mRNA were at least 8-fold lower than in control animals. The liver specificity of inhibin-betaC expression and its down-regulation following partial hepatectomy suggest that inhibin-betaC may function as a negative regulator of liver growth.
Asunto(s)
Regulación Enzimológica de la Expresión Génica , Hepatectomía , Hígado/metabolismo , Biosíntesis de Péptidos , Proteínas de Secreción Prostática , Animales , Femenino , Inhibinas/biosíntesis , Cinética , Masculino , Ratones , Ratones Endogámicos , Especificidad de ÓrganosRESUMEN
Growth/differentiation factor-9 (GDF-9) is a previously described member of the transforming growth factor-beta superfamily expressed specifically in the ovary in adult mice. Using in situ hybridization methods, we have localized the expression of GDF-9 messenger RNA (mRNA) exclusively to oocytes. GDF-9 mRNA was detected in oocytes at all stages of follicular development, except in primordial follicles, in both neonatal and adult ovaries. GDF-9 mRNA continued to be expressed in oocytes after ovulation, but disappeared by 1.5 days after fertilization. Based on Western analysis of ovarian extracts using antibodies raised against recombinant GDF-9 protein, GDF-9 mRNA expressed by oocytes appears to be translated. A human homolog of GDF-9 was isolated from a complementary DNA library prepared from adult ovary mRNA. The predicted human protein is 90% identical to murine GDF-9 in the mature portion of the molecule. These results are significant because no other growth factor-like molecules have been shown to be expressed specifically by oocytes and, together with results of previous studies, suggest that ovarian development and function are regulated by factors produced by both oocytes and support cells of the ovary.