Effects of long-term selection for behaviour on the level of progesterone in blood and its content in the adrenals of silver fox embryos.

摘要

Pregnant silver foxes from a population that had undergone long-term selection for tameness, and from an unselected, control population, were slaughtered at 35 days of pregnancy or at intervals of 5 days thereafter throughout pregnancy. The contentof progesterone in the blood and adrenals of the fetuses of the slaughtered females was determined. At 45 and 50 days of pregnancy, the content of progesterone in the adrenals was significantly lower in the selected than in the control population. Therewas no significant difference in respect of serum progesterone concentration.