PHENOGENETIC ANALYSIS OF PRENATAL DEVELOP MENT OF THE GLUCOCORTICOID FUNCTION OF ADRENALS IN SILVER FOXES AFTER LONG-TERM SELECTION FOR DOMESTIC BEHAVIOR

The level of cortisol in serum and adrenals and its production by adre nals in vitro was studied by the radioimmune method in male and female silver fox embryos, starting from day 30 of pregnancy every five days . Pregnant females from a commercial population and an experimental po pulation, which had been selected for domestic behavior, was used. It was shown that, at the end of the prenatal developmental stage, all in vestigated parameters of the glucocorticoid function of adrenals were significantly lower in embryos from selected mothers as compared to th e unselected control group. The addition of adrenocorticotropic hormon e into the incubation medium increased cortisol biosynthesis at all em bryogenesis stages, but in the selected population the increase was le ss than that in the control group.