Genetic Analysis Of The Inter Genus Hybridization Of Pagrosomus Major(♀) And Spraus Macrocephalus(♂)

The hybrid fish have certain growth advantage, which is important to the aquaculture industry.The hybridization often shown the Growth advantage which the parents don’t have, such as, thehigh nutritional content, the fast growth, the strong ability to adapt the environment and so on.We analysis the hybrid cichlids’(Pagrosomus major♀×Sparus macrocephalus♂)karyotype, cleared up several methods of Chromosome section. It is the first try to use the genomein situ hybridization (Genomic in situ hybridization, GISH) technology for analysis the geneticmake up of the hybrid cichlids (Pagrosomus major♀×Sparus macrocephalus♂). Also we use theAFLP technology to research the hybrid cichlids’(Pagrosomus major♀×Sparus macrocephalus♂) genetic make up.The main research results are as follows.1. The different production methods of chromosomes were compared.We adopt several waysto do the chromosome preparation. A comparison of these ways, we find a suitable way to do thechromosome preparation. We found that, young fish swimming in the water which contained colchicine would be the better method to do the chromosome preparation. For the adult f-ish, injectPHA and Colchicine will be better.2. Ana lysed the hybrid cichlids’(Pagrosomus major♀×Sparus macrocephalus♂) karyotype, The karyotype of hybrid cichlids (Pagrosomus major♀×Sparus macrocephalus♂) is:2n=2st+8t+8sm+30m=48, NF=86. The karyotype of Pagrosomus major is2n=2st+46t, NF=48;The karyotype of Sparus macrocephalus is2n=4m+4sm+38t+2st, NF=56.3. Genome in sit u hybridization technology was developed and optimized to investigate thegenomic composition of hybrid cichlids. The result showed that GISH analysis was able to distinguish the hybrid cichlids’ genetic make-up from their parents.4.Use the AFLP technology to research the hybrid cichlids’(Sparus macrocephalus♂×Pagrosomus major♀) genetic make-up. Two primer pairs were used to do the AFLP technologyfor the hybrids and their parents. The results were as follows:278selectively amplified fragments in total were detected.Among all of the fragments,the female-specific bands was108(accountingfor38.8percent of the total),the male-specific bands was93(accounting for33.5percent of thetotal). The hybrids contains37selectively amplified fragments(accounting for13.3percent of thetotal,34.3percent of the female-specific bands)which from the female-specificbands,21selectively amplified fragments (accounting for7.6percent of the total,22.6percent of themale specific bands) which from he male-specific bands. From the AFLP analysis, we found thathybrid cichlids and their parents had some of the genetic homogeneous.