Modares Journal of Biotechnology

Abstract Spermatogonial stem cells (SSCs) are unique with an important role in the transmission of genetic information to the next generation. Thus, they play an important role for the production of interspecies germ line chimeras. Therefore, the objective of this study was to produce chimera through the intraperitoneal transplantation of Caspian brown trout SSCs into newly-hatched rainbow trout. Spermatogonial cell were isolated from the testes of 8-month-old Caspian brown trout through enzymatic digestion. The spermatogonial cell suspension was enriched using differential plating technique to remove testicular somatic cells. After culturing for 48 h in L15 supplemented with 10% serum, suspended cells were collected and stained with the fluorescent membrane dye PKH26. The stained cells were intraperitoneally transplanted into triploid rainbow trout hatchlings. At 15 and 30 days after transplantation, the recipients were investigated under a fluorescent microscope. The gonads of recipients were dissected for molecular analysis at 180 days after transplantation. Transplanted spermatogonial cells migrated toward and incorporated into recipient genital ridges. The presence of the Caspian brown trout genetic material was confirmed by PCR in 41.4% of the rainbow trout testes. These results demonstrated for the first time that the interspecies spermatogonial transplantation was successful in rainbow trout and that the somatic microenvironment of the rainbow trout gonad can support the colonization and survival of intraperitoneally transplanted cells derived from a fish species belonging to a different genus. Therefore, the SSCs transplantation can be used as a tool for conservation of Caspian brown trout genetic resources.

Abstract Aims: Continuous monitoring of aquatic genetic diversity among different populations in fish hatcheries is an essential requirement to maintain the viability and sustainability of aquaculture industry. The aim of this study was cloning, sequencing, and detection of major histocompatibility complex (MHC) class II β in silver carp.
Materials and Methods: In this experimental study, the polymorphism of MHC class II β in 138 species of silver carp was studied in 4 different hatcheries of Iran (Guilan, Mazandaran, Golestan, and Khuzestan provinces) in addition to an imported group from China. By polymerase chain reaction (PCR), Hymo-DAB gene amplification was performed and the different haplotypes of the samples were analyzed by single-strand conformation polymorphism (SSCP) method and the sequences obtained with ClustalW2 were matched in Geneious 4.8.5 software and the phylogeny tree of the sequences was plotted.
Findings: The PCR reaction of the MHC-DAB II genome of the silver carp with a weight of about 350bp without side band was obtained in the samples, indicating the amplification of t Hymo-DAB1*01/DAB2*1 gene in silver carp. The highest and lowest diversity of haplotypes was observed in populations of Khuzestan and Mazandaran. The mean difference between synonymous site (dS) and nonsynonymous site (dN) of alleles was 0.25 and 0.30, respectively, with the ratio of 1.2. The highest allelic richness was observed in samples imported from China (5) and the lowest allelic richness was among Mazandaran species (3.8).
Conclusion: Haplotype diversity in silver carp belongs to Hymo-DAB1*01/DAB2*1 gene and among different groups of this species, the highest haplotype diversity is in the Khuzestan population and the highest allelic richness is related to samples imported from China.