Development Of Polymorphism SSR Markers And Analysis Of Population Diversity And Genetic Structure Four Commercial Sciaenidae Species

Miichthys miiuy, Pseudosciaena polyactis, Collichthys lucidus and Pennahiaargentata, belonging to Sciaenidae, was the important extensionally commercial species inChina. In general, M. miiuy was mainly distributed in Bo hai, Yellow Sea, East Sea, Koreaand south of Japan; P. polyactis was mainly distributed in northwest Pacific, Yellow seaand East Sea; C. lucidus was mainly distributed in middle and west Pacific, while the P.argentata was mainly distributed in northwest Pacific. Though the resource of thesespecies was rich in coastal ocean of China, it has decreased attributed to over-fishing. Thisstudy aims to evaluate the population diversity and genetic structure using microsatellitesmarkers, especially for further molecular assistant breeding. This study included two parts:one is development and isolation of microsatellites markers, the other is evaluation thepopulation diversity and genetic structure using the isolated markers. The main researchwas listed as follow:1. Development and Isolation of Microsatellites Markers:（1） The microsatellites markers in M. miiuy were developed by two methods, FIASCO（fast isolation by AFLP of sequences containing repeats） and searching sequences includedmicrosatellites from public data.（AG）₁₃ and （CA）₁₃ enriched library was constructed usingFIASCO, and finally twelve polymorphism markers were isolated after cloning andsequencing.419sequences were got from the4609ESTs in public database, and thirtypolymorphismâ… type of SSR markers were developed from125pairs of primer. Thesepolymorphism markers will be candidate for further study, such as resource conversation,molecular assistant breeding.（2） The microsatellites markers in the P. polyactis were developed by cross-speciesamplification. The forty-two polymorphism markers initially isolated for M. miiuy wereused to develop in P. polyactis, and finally eleven polymorphism markers were isolated.These polymorphism markers will be candidate for further study, such as resourceconversation, molecular assistant breeding.（3） The microsatellites markers in C. lucidus were developed by two ways: one isconstructed （CA）₁₅ microsatellites enriched library using FIASCO, the other is isolated from the markers developed in M. miiuy by cross-species amplification. From the （CA）₁₅microsatellites enriched library,28pairs of primer were designed from the48clonedsequences. Finally, fourteen polymorphism microsatellites markers were isolated in C.lucidus. These polymorphism markers will be candidate and useful for further study, suchas resource conversation, molecular assistant breeding.（4） The microsatellites markers in P. argentata were developed by cross-speciesamplification. Twelve polymorphism markers in P. argentata were isolated from theforty-two markers in M. miiuy by cross-species amplification. These polymorphismmarkers will be candidate for further study, such as resource conversation, molecularassistant breeding.2. Evaluate the population diversity and genetic structure（1） Genetic diversity and structure of East Sea were examined by ten polymorphismmicrosatellites markers in M. miiuy, including six populations Zhoushan, Xiangshan,Wenling, Wenzhou, Yueqing and Ruian. The analysis showed that the average allele was4.2in the six examined populations, and the expected heterozygosity for six populationswas ranged from0.380to0.509, with an average of0.426, which suggested the genticdiversity was rich in the six populations. The genetic distance indicated the Ruian andYueqing populations were less related, while Zhoushan and Xiangshan populations werethe most related. The AMOVA indicted the main variation was within populations.（2） Genetic diversity and structure of Yellow Sea and East Sea were examined by tenpolymorphism microsatellites markers in the P. polyactis, including seven populationsQingdao, Zhoushan, Xiangshan, Ninghai, Wenling, Wenzhou, and Yueqing. The analysisshowed that the average allele was6.5in the seven examined populations, and theexpected heterozygosity for six populations was ranged from0.538to0.606, with anaverage of0.578, which suggested the gentic diversity was rich in the seven populations.The genetic distance indicated the Ning and Wenzhou populations were less related, whileNinghai and Xiangshan populations were the most related. The AMOVA indicted the mainvariation was within individuals.（3） Genetic diversity and structure of East Sea were examined by fourteen polymorphismmicrosatellites markers in C. lucidus, including four populations Zhoushan, Xiangshan,Ninghai, and Yueqing. The analysis showed that the average allele was3.385in the fourexamined populations. The genetic distance indicated the Ninghai and Zhoushanpopulations were less related, while Yueqing and Xiangshan populations were the most related. The AMOVA indicted the main variation was within populations.