The Mechanism Research Of Albino Trait Of Mesocricetus Auratus

The albino Mesocricetus auratus is the mutant population of the Mesocricetus auratus, whose hair mutates from dark brown to pure white and whose eyes mutate from black to red. The animal albino traits mainly performs eyes and skins. The research indicates that the alteration of color of animal hairs may attribute to deficiency of melanin. Nowadays,378 genes related to the color of animal hairs have been found. The albino traits of Mesocricetus auratus are inherited as autosomal recessive genes, but studies are rarely involved in the biological characteristics of the Mesocricetus auratus, the mechanism of albino occurrence and its application value. Thus, it shows certain academic value and application prospective to explore the occurring mechanism of the albino traits of Mesocricetus auratus and reveal its molecular mechanism, which provides theoretical basis for the development and application of albino Mesocricetus auratus as novel model of laboratory animals.This study was to observe and count the phenotypes and proportion of Fl and F2 generation with the method of hybridization and brother-sister mating in Mesocricetus auratus and albino Mesocricetus auratus. The result indicated that Fl generation did not show the traits seperation, and performed dark brown hairs; the ratio of phenotypes of Mesocricetus auratus with white hairs and dark brown hairs was approximately 1:3. As a result, the hair color of albino Mesocricetus auratus was inherited as a pair of recessive allelic genes.This study was to observe melanocytes in the tissue of skins via dopa and dopa-toluidine blue complex staining. The result showed there were both melanocytes in the tissue of skins of the Mesocricetus auratus and the albino ones, and the responding zone of the Mesocricetus auratus to dopa was obviously larger than that of albino ones, which indicated the expressing level of the gene TYR in the albino Mesocricetus auratus was lower than that in the normal ones. The dopa-toluidine blue complex staining test showed the distribution of the dopa-positive in the melanocytes in the tissue of skins, which the melanocytes in the tissue of skins of the Mesocricetus auratus and the albino ones were distributed in the hair papilla of hair follicles.The whole genome shotgun sequencing was introduced in this research to find out the mutate genes related with albino traits. The result showed that the gene TYR related to albino traits and occurring mutation was successfully found via functional annotation to 20 candidate genes obtained, which the mutate site was located in 1929544 bp, with G mutating to C. Through the analysis in NCBI, it was the missense mutation that the mutate site was located in 272 bp in Exon 1 of the gene TYR, which the corresponding cysteine mutated to serine.This study was to validate the mutant occurrence of the gene TYR and the mutant site via gene clone and sequence analysis. The result revealed that G of 272 bp in Exon 1 of the gene TYR mutated to C, whose result was consistent with the result of whole genome sequencing of albino Mesocricetus auratus.This study was to test differential expression of the mRNA level in the genes related to albino traits via RT-PCR. The result showed that the mRNA expression amount of gene TYR, OCA2 and MCIR in albino Mesocricetus auratus was lower than that in Mesocricetus auratus, but the expression amount of gene MITF in albino Mesocricetus auratus was higher than that in Mesocricetus auratus, which showed extremely significant difference in the mRNA expression amount of TYR and MCIR, significant difference in the mRNA expression amount of MITF, and no significant difference in the mRNA expression amount of gene OCA2 in albino Mesocricetus auratus compared with Mesocricetus auratus. The result above indicated that expression amount of gene TYR, MITF and MCIR would perform certain relativity to the occurrence of albino character of Mesocricetus auratus, which established the theoretical foundation for regulation of melanin generation and mechanism of the albino character occurrence of Mesocricetus auratus.The research is to systemically study the mechanism of which the albino character of Mesocricetus auratus occurs, which provides theoretical basis for the application of albino Mesocricetus auratus in the biological medicine and medical fields.