Differential expression and regulation of PNA and UEA‐1 bindings in rabbit uterus during preimplantation period

Abstract

Peanut agglutinin (PNA) and Ulex europaeus agglutinin-1 (UEA-1) were used as probes to study the distribution of β-gal (1→3) ga1Nac and α-L-Fucose in rabbit uterus during early pregnancy. PNA binding was mainly localized on the surface of uterine glandular and luminal epithelium. There were no positive signals on day 1 of pregnancy. PNA binding gradually increased from day 2 and reached its highest level on days 3 and 4. The distribution of PNA binding gradually declined from day 5 and reached a low level on day 7. However, UEA-1 binding was only localized on the luminal epithelial during early pregnancy. A high level of UEA-1 binding had been found on the luminal epithelium on day 1 of pregnancy and low level of positive signals had been found in the uterus on days 2 and 3. UEA-1 binding increased gradually and reached its highest level on day 4. Then the distribution of UEA-1 binding sharply declined and no positive signals were found on days 5-7. The distribution of PNA and UEA-1 bindings in pseudopregnant uterus was similar to that in normal pregnant uterus. During estrus cycle, there was no detectable PNA binding signal in uterus. But, a high level of UEA-1 binding was found in the luminal epithelium of estrus uterus. In ovariectomized rabbit uterus, progesterone significantly induced the expression of PNA binding, while estrogen stimulated UEA-1 binding expression. These results suggested that the distribution of PNA and UEA-1 bindings in rabbit uterus may be related to rabbit implantation.