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Female-specific protein (vitellogenin) was purified from mature
female hemolymph of the freshwater prawn, Macrobrachium
rosenbergii by DEAE, hydroxylapatite and another DEAE
chromatographic columns. A purified vitellogenin with an
apparent molecular weight of 700 kDa was obtained on the basis
of by PAGE. The purified vitellogenin was considered as a lipo-
glyco-protein on the basis of staining data. Three subunits (170
kDa, 100 kDa and 89 kDa) in purified vitellogenin and two
subunits (100 kDa and 89 kDa ) in vitellin were detected with
SDS-PAGE. Non-disulfide bonds were found in the binding of
polypeptide subunits. Only the 89 kDa subunit was a
glycopolypeptide. Eight amino acid sequences from N-terminal end
of 89 kDa and 100 kDa subunits were determined and they were
identical between vitellogenin and vitellin. Purified
vitellogenin was more susceptible to the precipitation in a
solution with low ionic strength than vitellin. The closely
relationship in biochemical characteristics between vitellogenin
and vitellin in M. rosenbergii was suggested. The ovarian
development of M. rosenbergii was classified into five
developmental stages (Stage A-E). Vitellogenin concentrations
increased in the hemolymph of prawns in the early stages of
ovarian development (Stage A and B) and were maintained at high
levels until Stage E. There was no close association between
ovarian development and the concentrations of circulating
vitellogenin. Concentrations of protein in hemolymph and
hepatopancreas remained constant during various stages of
ovarian development. The ovarian stages losely correlated with
the gonadosomatic index, the concentrations of ovarian vitellin
and protein, respectively.Vitellogenin levels in the
hepatopancreas remained very low in different stages of the
prawn although the highest levels were observed in Stage D. The
increase of vitellogenin concentration in the hemolymph occurred
earlier than vitellin content in ovary. Vitellin and its
subunits (100 kDa and 89 kDa) were observed in the ovary of each
ovarian stage by Westeular blotting although those
concentrations were very low in Stage A. The 170 kDa subunit of
vitellogenin was also observed in the ovaries of late stage
(Stage C,D and E). Vitellogenin in the hepatopancreas of each
stage could be observed by Western blotting. The subunits of
vitellogenin were not observed in the hepatopancreas of each
stage by Western blotting because the subunits of vitellogenin
were easily digested in the hepatopancreas extracts. Yolk
protein was observed in the vitellogenic oocyte and
hepatopancreas but not in the follicular cells with
immunocytochemistry staining. Radioactive vitellogenin was
synthesised in the vitellogenic hepatopancreas after incubated
with C14 amino acid in vitro. Free progesterone was the major
form of progesterone in hemolymph. In hemolymph, progesterone
and estradiol-17β levels were not different in each ovarian
stage. Ecdysone level in the hemolymph was highest at Stage E.
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