Immunohistochemical localization of beta-Tubulin in the unincubated avian germ and in the peri-, para- and subgerminal ooplasm: Homology with meroblastic teleost embryos

beta-Tubulin was immunohistochemically localized in the unincubated avian germ and in the peri-, para- and subgerminal ooplasm. Numerous immunostained threads were found surrounding the clusters of mitotic figures seen in the peripheral subgerminal ooplasm. In the Rauber's sickle this method enabled clear discrimination to be made between unstained ooplasmic areas and the immunostained surrounding blastoderm cells. A vast, superficial, extra-embryonic ring-shaped area of paragerminal ooplasm (forming a white halo, seen on the surface of the intact living yolk) presenting a dense immunoreactivity on sections, encircles the clear perigerminal ooplasm and the rim of the blastoderm at some distance.