Genetic Sex And Phenotypic Sex Research Of Half-smooth Tongue Sole In Rearing Populations

Half-smooth tongue sole（Cynoglossus semilaevi Günthers） is a kind of largedemersal fish which has much good traits such as large individual, fast growth,moderate diet, small range of activities, low trophic levels, high market value and so on.The female tongue sole grows2-4times faster than male and2times larger than malesin the same growing period. Thus the development of all-female and high-femalepopulation would improve the economic benefits. In this study, the research was studiedto analyse the sex-determined factors from the molecular biology points using thefemale-specific mark primers designed and isolated from our laboratory. Firstly, thegenomic DNA from the mitogynogenetic embryo was detected using the SSR female-specific mark. Secondly, female:male sex ratio was detected using the SSR female-specific mark from the9normal families and the genetic sex and sex reversal ratio weredetected by comparing genetic sex with Phenotypic sex the from4of the9families.Thirdly, using the SSR female-specific mark the vary characteristic of female:male sexratio was detected in the growing process of2groups and the whole growing process ofhalf tongue sole was followed by the physiological chips. The main results were asfollows:1、The amplification genomic DNA from the mitogynogenetic embryo was madeusing the SSR female-specific mark scaffold1128₃43. Before this, the mark wasdetected using12respectively knowed female and male fish. The amplification genomicDNA from the mitogynogenetic embryos results showed that4of39mitogynogeneticembryos was super-female. This study confirmed that this female-specific mark can beused to identify the super-female half smooth tongue sole, which can provide goodmethod of selecting super-female half smooth tongue sole in practice.2、The genetic sex of9normal families of half-smooth tongue sole were detectedusing the SSR female-specific marker scaffold1128₃43, and58fishes were selected from each family in march2011.The result shows that the highest and the lowest ratioof females are55.00%and37.93%respectively. Three months later, the genetic sexand sexual reversal rate were detected in four of the nine normal family, and96fisheswere selected from each family.The two detected results of proportion of females wereconsistent. Besides the second result shows that the offspring sexual reversal ratio kepttypically genealogy features.This study provide an important information for all-femaleoffspring or a high proportion of female ratio offspring of half-smooth tongue sole.3、Using the SSR female-specific marker scaffold1128₃43, the vary characteristicof female:male sex ratio was detected in the growing process of2groups.The resultshowed that the female:male ratio of12and76days fry were49%and48%respectively, which corresponded with the female: male1:1ratio. Combining thegenetic sex identifying with the result of physiological chips the whole glandsdeveloping process of half tongue sole from25days to2years was followed. The resultshowed that the female glands differentiation was earlier than male. The female formedprimary ovarian cavity on56days while the spermary began to form lobular division on76days. On140days, the earlier primary oocytes formed nucleoli while a fewspermatid and sperm. The ovary of1-2years exists oocytes Ⅲ and Ⅱs tage in long-term.Oocytes Ⅲ stage could accumulate the yolk quickly ina right condition develops intomatured oocytes.