Figure 2. Different states of gametogenesis in cultured white sturgeon female. Paraffin sections stained by PAS: a-early phase of
oogenesis, oogonia and oocytes initiating meiosis, b -differentiated ovarian follicles with the oocytes in the late primary growth phase, c-
previtellogenic follicle with differentiated granulosa layer and vitelline envelope. d-mid-vitellogenesis, deposition of yolk bodies, e-
ripe follicle with polarized oocyte near completion of vitellogenic growth, f-ovarian tissue after ovulation, containing post-ovulatory
follicles, atretic follicles. and new generation of oocytes (BL = basal lamina. GR = granulosa cells, ZR = zona radiata, YP = yolk platelets,
MP=micropyle, GC=gelatinous coat, ZRE=zona radiata externa, ZRI = zona radiata interna, CG = cortical granules, ML = melanin
granules, PF=post-ovulatory follicle,AF=atretic follicle).
described by Moberg et al. (1991b, 1995). Briefly, the
RIA’S were based on specific polyclonal antibodies
to purified stGTH’s fractions. The cross-reactivity
of stGTH I antibody with stGTH II was 2%, andthat of stGTH II antibody with stGTH I was 9.3%.
Minimum detectable concentrations for the stGTH
I and stGTH II were 0.84 ng ml–1and1.25ng ml–1
respectively. Inter- and intra-assay variability was