F. Gandolfi et al., SIMILARITY OF AN OVIDUCT-SPECIFIC GLYCOPROTEIN BETWEEN DIFFERENT SPECIES, Reproduction, fertility and development, 5(4), 1993, pp. 433-443
The oviduct provides the best environment in which a zygote can grow a
nd it can also support the development of embryos from a different spe
cies. However, there is no clear explanation of its embryotrophic prop
erties at present. In several species, oviduct epithelial cells synthe
size and secrete glycosylated proteins that become associated with dev
eloping embryos. Although these macromolecules may have a functional r
ole at the time of fertilization and early embryonic development, the
nature of such a role remains to be elucidated. The aim of this work w
as to perform a comparative analysis of oviduct-specific glycoproteins
in search of molecules common to different species since their phylog
enetic conservation would imply biological significance. In previous s
tudies, sheep oviduct-specific proteins were characterized and a monoc
lonal antibody (AFRC MAC 264) specific for the sheep oviduct protein 9
2 (sOP 92) was produced; hence, sheep was taken as the reference speci
es. The degree of similarity between sheep glycoproteins and those of
the cow, goat, pig, rabbit and mouse was determined on the basis of: t
he presence of carbohydrate sidechains, cross-reactivity with AFRC MAC
264, correspondence of molecular weight between crossreacting molecul
es, and similarity of immunohistochemical localization. On this basis,
proteins similar to sOP 92 were present in cow and goat oviduct. A mo
re limited similarity was also observed in pigs. This indicates a cert
ain degree of phylogenetic conservation and suggests that these molecu
les may play an important physiological role; however, their function
remains to be determined.