DEVELOPMENTAL-CHANGES IN MULLERIAN-INHIBITING SUBSTANCE IN THE CYNOMOLGUS MONKEY, MACACA-FASCICULARIS

Mullerian inhibiting substance (MIS) is a glycoprotein hormone produce d in Sertoli cells of the fetal and postnatal testis, and granulosa ce lls of the pubertal ovary. We examined MIS expression in a nonhuman pr imate, the cynomolgus macaque monkey (Macaca fascicularis), to define an animal model for studying MIS gene regulation. Changes in testicula r MIS mRNA with age were assessed by in situ hybridization of prepuber tal to adult testes, Northern analysis of pubertal and adult specimens , and determination of serum MIS concentrations from infancy to adulth ood. We found that MIS expression was highest in the youngest animals and decreased progressively with increasing age. Serum MIS concentrati ons correlated inversely with increasing age (r = -0.74), body weight (r = -0.79), and testicular volume (r = -0.73), but not with testoster one levels (r = -0.35). The mean MIS concentrations +/- SEM for the fo ur developmental age groups were 270.6 +/- 23.8 (infants), 195.5 +/- 1 8.5 (juveniles), 102.7 +/- 28.4 (peripubertals), and 51.6 +/- 7.1 (adu lts). This study confirms that nonhuman primate and human MIS are high ly homologous and have similar developmental patterns. The normative d ata for serum MIS concentrations in cynomolgus monkeys at different ag es and developmental stages will be invaluable for further work examin ing MIS regulation.