The Variation Of The Vitellogenin Level And Expression Of Vitellogenin MRNA In The Process Of Sexual Maturity Of The Female Fish Of Odontobutis Potamophila

The Odontobutis potamophila is subordinated to Perciformes, Odontobutidae. It isan important freshwater commercial fish in China. As far as we known, the biology,embryonic development, organ development and hanching gland,s generation、hanching enzyme,s secretion of the Odontobutis potamophila had been well-studied.By reseaching the variantion of vitellogenin level and expression of vitellogenin genemRNA in the process of sexual maturity of the female fish of Odontobutis potamophila,we could preliminary know the synthesis、transportation and deposition of earlygonadal development stage. This paper provided theoretical basis for the nurseryingand artificial breeding Odontobutis potamophila. The main results are as follows:1、The variation of the vitellogenin level in the process of sexual maturity of thefemale fish of Odontobutis potamophila.The levels of vitellogenin in the serum, liver and ovary of the process of sexualmaturity of Odontobutis potamophila were performed by an indirect method,measuring the alkali-labile phosphorus content of the lipid-free protein fraction. Thelevels of phosphorus can reflect the vitellogenin levels indirectly. In the experiment,the phosphorus levels in serum, liver and ovary of Odontobutis potamophila weremeasured by the chemical response with the aqueous trichloroacetic acid（TCA）. Thefishes in the experiment were in the gonadal development stage Ⅲ to stage Ⅴ, whichare female of Odontobutis potamophila. The results indicated that,in the process ofsexual maturity of the fish, the vitellogenin level in the liver increased at first, and thendecreased, the highest level was at stage Ⅳ,which was39.91±3.80mg·g^-1. The stageⅢ and stage Ⅳ were the active stages of the synthesis of vitellogenin. The vitellogeninlevel from15.45±1.77mg·mL^-1at the stage Ⅲ increased to33.31±5.57mg·mL^-1atthe stage Ⅴ, so the level of vitellogenin in the serum increased gradually. The level ofvitellogenin in the ovary also increased gradually, during the stage Ⅲ tostage Ⅳ, thegrowth was faster, which is the most important stage of the deposition of vitellogenin,after the stageⅢ,the weight of vitellogin was about30%of total weight of ovary, the highest level was422.25±29.98mg·g^-1at the stageⅤ. The rearsch indicated that theactive synthesis,highly-efficient transport and vast depoist of vitellogenin could assurethe nutritional requirements of embryonic development and subsequent development.2、The expression of vitellogenin gene mRNA in the process of sexual maturity ofthe female fish of Odontobutis potamophila.Fluorescent quantitation PCR method was used to examine the mRNA transcriptionlevel changes of vitellogenin gene of Odontobutis potamophila using SYBR Greenas reporter dye and standard cDNAs,gradient diluent product of PCR as standard curvetemplate.The fishes in the experiment were in the gonadal development stage Ⅲ tostage Ⅴ, which are female of Odontobutis potamophila.The results showed that theexpression value of vitellogenin gene mRNA was the highest at stage Ⅲ, which was0.544, and then decreased to0.367at stage Ⅳ, then decreased continually to thelowest value （0.123） at stage Ⅴ. So the value of vitellogenin gene mRNA decreasedgradually（P＜0.05）, and the activity of vitellogenin gene mRNA decreased graduallyalso. By analysis, we can interpret the varaiation trend of vitellogenin level in theprocess of sexual maturity of the female fish of Odontobutis potamophila throughmolecular biology, and primarily understand the mechanism of vitellogenin genemRNA expression. This paper provided a good theoretical basis to further understandthe synthesis of vitellogenin.