Uteroglobin levels at day 6 of gestation in two lines of rabbits divergently selected for uterine capacity.

The aim of this work was to study the expression of uteroglobin in uterine fluid from two lines of rabbits divergently selected for uterine capacity during ten generations. In addition, the relation between embryo survival and uteroglobin expression and between progesterone levels in uterine flushings and uteroglobin expression were studied. Females from the 12 generation were used. Nineteen females from High line and fifteen females from Low line were slaughtered at day 6 of gestation. The genital tracts were removed and uterine flushings were obtained to measure uteroglobin expression and progesterone concentration. Number of recovered embryos (RE), ovulation rate (OR) and embryo survival (ES=RE/OR) were counted. The uteroglobin expression and progesterone concentration in uterine fluid was 2.44±1.29 and 15.48±5.88 ng/ml, respectively. Progesterone concentration and uteroglobin expression in uterine fluid were similar in both lines. Uteroglobin was slightly correlated with levels of progesterone in uterine fluid (r=0.29; P 0.05) or to embryo survival (r=-0.13; P>0.05). Thus, differences in embryo survival between lines do not seem to be caused by differences in uteroglobin expression at day 6 of gestation.