The Identification And Analysis For Genetic Characteristic Of Mitotic Gynogenesis Diploid In Japanese Flounder (Paralichthys Olivaceus)

The Japanese flounder Paralichthys olivaceus is a large coastal economic fish ofChina, occupies an important position in the marine finfish. Difference in growth ratebetween male and female animals is frequently observed in nature. The growth rate ofJapanese flounder is significantly faster in females than that in male. So the effectivemethods for gynogenetic inducement in this species are important for all-femalepopulation construction. Here an effective method to induce meiogynogenesis for allfemale population construction in Japanese flounder was provided. About artificialinduction of gynogenesis in Japanese flounder research began from the1970s,according to the principle of induction of gynogenesis were divided into meiosis andmitosis gynogenesis. Mitosis gynogenesis is formed by inhibiting the first cleavage, thegenome one by another template replication, the genetic composition of homozygous intheory, but in the offspring of mitosis gynogenesis in addition to the completehomozygous diploid, part of heterozygous diploid are also found. For this, this studyanalyzes the genetic characteristics of the offspring in the different diploid of the mitoticgynogenesis, and compared with the meiosis gynogenesis diploid and the normaldiploid genetic, for provide theoretical guidance to application of mitotic gynogenesisdiploid genetic breeding research work in the future.The research used280Paralichthys olivaceus were induced by mitoticgynogenesis diploid as the research object from the beidaihe center station in2009, Firstby using microsatellite marker identifiy the homozygosity among the individual, thencompared with the genetic differences among the homozygous mitosis gynogenesisdiploid, partially heterozygous diploid, meiosis gynogenesis diploid and normal diploid,the results as follows:1. Selected48microsatellite markers from the chain of the second generationspectrum group in the end region, and detected the homozygosity among the280mitotic gynogenesis diploid.104individuals in all test sites are characterized byhomozygous, the individual proportion of homozygous is37%;176individuals in alltest sites have not reached all homozygous, the individual proportion of heterozygous is63%. Among heterozygous there are17individuals heterozygous loci between2-7;159 individuals heterozygous loci between25-44;The results showed that the method ofhydrostatic pressure induce mitosis of gynogenesis can get completely homozygousParalichthys olivaceus, and partly heterozygous individuals also exist at the same time.2. Compared with heterozygote (Mitotic-B) appeared in mitosis gynogenesis andmeiotic gynogenesis diploid (MDG) from the same female parent. The results showedthat there are difference in genetic characteristics between the Mitotic-A and Mitotic-B.The features showed as follows:(1)The homozygosity is different between Mitotic-Band MDG, the homozygosity of Mitotic-B is0.3284, thus MDG is0.2521.(2)There wasdifferent homozygous at the same locus, and some even performance all for hybrid,such as the proportion of homozygous individuals in Mitotic-B are34.1%and73.9%atthe poli110TUF and poli1906TUF loci but in MGD are0and0performance forheterozygosis completely. the proportion of homozygous individuals in Mitotic-B are10.2%and9.7%at the poli1490TUF and poli1498TUF loci but in MGD are100%and100%performance for homozygous completely.(3)The genetic similarity index betweenparent and offspring of Mitotic-B is lower than the MDGS. Investigate the reason, maybe due to the meiosis gynogenesis is via restrain the second polar body eduction, itsgenome consists of female pronucleus and the second polar body; Thus mitoticgynogenesis is formed by inhibiting the first cleavage, is likely to be affected by someinfluence to form the hybrid, its composition of chromosomes is different from meiosisafter all.