Dynamics of vitellogenin mRNA expression and changes in hemolymph vitellogenin levels during ovarian maturation in the giant freshwater prawn Macrobrachium rosenbergii.
The dynamics of vitellogenin mRNA expression during ovarian maturation in Macrobrachium rosenbergii were examined by measuring hemolymph vitellogenin (Vg) levels and Vg mRNA expression in the hepatopancreas and ovary at differing reproductive stages in both intact and eyestalk ablated animals. Vg mRNA was quantified using real-time RT-PCR and hemolymph Vg was measured by enzyme immunoassay. In intact animals, Vg mRNA levels in the hepatopancreas and hemolymph Vg levels showed a gradual increase during the molt cycle concomitant with increasing gonadosomatic index (GSI), with Vg levels decreasing prior to ecdysis although GSI continued to increase. Eyestalk ablation was seen to accelerate Vg synthesis as well as ovarian maturation, although it did not alter the overall pattern of Vg expression. Vg mRNA expression was negligible in the ovary of both intact and eyestalk ablated animals, confirming that the hepatopancreas is the principal site of Vg synthesis in M. rosenbergii with the ovary being only a minor contributor. This study has shown that Vg synthesis is correlated to ovarian maturation and the molt cycle in M. rosenbergii.
Jayasankar
Vidya
V
Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
Tsutsui
Naoaki
N
Jasmani
Safiah
S
Saido-Sakanaka
Hisako
H
Yang
Wei-Jun
WJ
Okuno
Atsuro
A
Tran
Thi Thanh Hien
TT
Aida
Katsumi
K
Wilder
Marcy N
MN
D000818:Animals; D033364:Decapoda / Q000235:genetics* / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006458:Hemolymph / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D010053:Ovary / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014819:Vitellogenins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*
D012333:RNA, Messenger; D014819:Vitellogenins