The Establishment Of Parentage Identification Technique And Screening Of Growth-related Loci Based On Microsatellite Markers In Macrobrachium Nipponense

Shrimp,scientific name is Macrobrachium nipponense,commonly known as river shrimp,is one of the important freshwater species in our country.The common extracorporeal markers will be lost because that the shrimps will shell many times during the whole life.And the intracorporal markers is hard to use because the shrimps are too small and esay to dead out of water.The marking and identification become one of the main difficulty in the work of Shrimp breeding.The DNA markers can remedy this problem because that the DNA markers can not be influenced by shrimps molting and not harmful for shrimps.It is so necessary to built a method of parentage identification based on DNA markers in shrimps.Aquatic animals paternity analysis usually uses the microsatellite molecular marker,with high polymorphism and codominant inheritance.There is no application in the research of shrimp paternity tests for now.This research has studied the parentage identification of shrimp based on microsatellite molecular marker.Meanwhile,The microsatellite loci has been screened to provide some essential data for the breeding work of shrimps.12 microsatellite loci have been from selected 30 microsatellite loci with high polymorphism by analyzing the DNA of 16 wild populations from Lake Taihu.Those PIC is during 0.730 to 0.814 and average PIC is 0.773.full-sibs familys,126 individuals,have been built in this study.The 12 microsatellite primers have been used to test the DNA of the 3 full-sibs families,126 individuals.The result shows that,the average effective number of alleles of the 12 microsatellite loci is 5.583.The average polymorphism information content is 0.7245.The average expected heterozygosity is 0.7626.The average observed heterozygosity was 0.8446.By Cervus paternity test software simulation analysis,the results show that the combined exclusion probability of first parent,second parent and parent pair is 0.99596317,0.99992761 and 0.99999988,respectively.540 unknown sex parents and 890 known sex parents can be identified by those 12 microsatellite loci.The parentage identification result of 126 shrimps,including 120 offsprings and 6 parents,indicates that it needs 6 microsatellite loci at least to accomplish the parentage analysis.120 offsprings has been matched their parents and assigned to their own family.The simulation paternity test results,with high reference value for measuring the ability of 12 microsatellite loci,is reliable.The DNA of one Full-sib family including 47 shrimps have been tested by 30 microsatellite loci.The average effective number of alleles of the 30 microsatellite loci is 2.6.The average polymorphism information content is 0.431.The average expected heterozygosity is 0.5020.The average observed heterozygosity was 0.6282.The 30 microsatellite loci have been analyzed,combined with phenotypic data.The result shows that,there are 5 microsatellite loci correlative with the growth trait of shrimps.WXM02,WXM42 and Mni009 are correlated significantly with body length and body weight(P<0.05).Mni082 is correlated significantly with body weight(P<0.05).WXM07 is correlated significantly with body length(P<0.05).The method of parentage analysis of Macrobrachium nipponense is established based on microsatellites for the fist time in this study.The analysis ability of the 12 microsatellite loci has been assessed.It can be used to provide the technical support and the important reference for shrimp breeding research.Meanwhile,the microsatellite loci,correlatively with the growth trait of Macrobrachium nipponenses,have been selected.These microsatellite loci can provide some essential data for the breeding work of shrimps.