Differential expression of activin β_A and β_B genes in female allotriploid and diploid red crucian carp Carassius auratus red var

Abstract

activin β A and β B from diploid and allotriploid crucian carp were cloned.The differential expression of activin β A and β B genes in female allotriploid and diploid red crucian carp Carassius auratus red var. were studied and found to be expressed in all the tested tissues; particularly, the expression of activin β A and β B was elevated in the ovaries of allotriploids and differential expression in pituitaries during the nonbreeding season and the breeding season period. The immunohistochemistry indicated that the abnormal triploid ovaries were dominated by small oogonium-like cells with dense signals and that the elevated expression of activin β A and β B in the ovaries of allotriploids may be related to allotriploid sterility. K E Y W O R D Sactivin β A , activin β B , allotriploid, Carassius auratus red. var., differential expression, sterility Activin is a member of the transforming growth factor-β (TGF-β) family of growth and differentiation factors (Vale et al., 1988). Activin was first isolated from gonadal fluids (Mathews, 1994) and commonly consists of three types: activin A, activin B and activin AB. Homodimerisation of the β A subunit generates activin A and the β B subunit generates activin B. The β A and β B subunits can also heterodimerise and form activin AB. In addition to the β A and β B subunits, β C and β E have been identified in mammals (Fang et al., 1996;Hotten et al., 1995) and a β D subunit has been described in the Africa clawed frog Xenopus laevis (Oda et al., 1995), but the β A and β B subunits have been researched more frequently (Woodruff, 1998).