Download Effect of extra prenatal testosterone on rabbit offspring at birth

Effect of extra prenatal testosterone on rabbit offspring at birth
OXÁNA BÁNSZEGI 1, VIKTÓRIA SZETEI, VILMOS ALTBÄCKER,
ISTVÁN NÉMETH and ÁGNES BILKÓ 2
1, 2
Eötvös Loránd University, Department of Ethology, Jávorka Sándor u. 14., 2131 Göd, Hungary
E−mail: 1 [email protected], 2 [email protected]
ÁLLATTANI KÖZLEMÉNYEK (2007) 92(1): 77–86.
Abstract. In several rodent species, the sexual differentiation of offspring is known to be affected prenatally, by the
testosterone reaches the foetuses at a critical time. The aim of our present study was to investigate, whether this process exists
also in domestic rabbit. For this, 2 different amounts of testosterone (3μg and 3mg) were administered daily to groups of
pregnant females, on days 19−25 of pregnancy. A non-injected group, and to control for possible effect of injenction, a
sesame group was also conducted. The following measures were taken in the offspring at birth: anogenital-distance (AGD),
body weight (BW), litter size, and sex ratio. To avoid possible seasonal (sequential) effect, all of these measures were
compared to the given does’ previous litters. As a result, male offspring had longer AGD, both in the low, and the high
testosterone groups. However, sesame-oil alone also had some effect, possibly because of the stress caused by injection. In
females, the effect of testosterone was in correlation with its amount. BW at birth increased in case of males, in each of the
treated groups, in case of females however, only the small amount was effective. Our results suggest, that prenatal hormonal
environment affects sexual differentiation in lots of different ways.
Keywords: hormonal imprinting, testosterone, sexual differentiation, ano-genital distance, birth weight.