The Genetic Characteristic Research Of Golden Channa Argus

Channa argus belongs to the order Perciformes,Channidae,Channa,commonly known as snakehead.In addition to the northwest plateau area of China,there are a large number of distribution in the Yangtze River basin to the Heil-ongjiang River basin.In a normal breeding environment,the C.argus of body color is gray-black,and the eyeball is black.During the breeding process of C.argus,a body color mutant "Golden Channa Argus" was found.Its body color is light yellow or golden yellow,and its eyeballs are red.It has good ornamental value and economic value.At present,the promotion of breeding has been carried out in Shandong,Jiangsu Province and other places.In order to understand the genetic characteristics of Golden C.argus comprehensively,it is convenient for the development of genetic breeding and the protection and utilization of genetic resources.In this study,chromosome karyotype,isozyme,body color heredity and skin transcriptome were studied and analyzed.The results are as follows.1.Karyotype and lactate dehydrogenase(LDH)isoenzyme analysis of golden C.argusThrough intraperitoneal injection of PHA and colchicine in the living golden C.argus,the chromosome specimens were prepared by the conventional cold drop method,and the chromosome karyotype was analyzed and studied.It was found that the number of chromosomes of the golden C.argus was 48.The karyotype formula was 2n =4sm+22st+22t,and the number of arms NF=52.The experiment did not find the presence of satellites,secondary constrictions and heteromorphic sex chromosomes.The lactate dehydrogenase(LDH)in renal tissue of golden C.argus was detected by polyacrylamide vertical plate electrophoresis.The LDH showed 5 bands in the electrophoretic enzyme spectrum.It was found that the Golden C.argus had no significant difference in isoenzyme and chromosome levels.2.A preliminary study on inheritance of body color in golden C.argusIn order to investigate the inheritance of body color of golden C.argus,wild-type C.argus(gray-black body color and black eye color)and golden C.argus(golden or light yellow body color and red eye color)were used as parents,the self cross test of wild-type C.argus and golden C.argus,and the reciprocal cross test of wild-type C.argus and golden C.argus,F1 generation(reciprocal cross)self cross,F1 generation and golden C.argus(test cross)were designed and carried out.The number of body color of progenies in different groups were counted and analyzed.It is found that the progenies of wild-type C.argus and golden C.argus(reciprocal crosses)all showed gray-black body color,and the F1 generation of reciprocal crosses selfed,and the ratio of gray-black body color to golden body color of the offspring was to 3:1.In the test cross test,the ratio of gray-black body color to golden body color of offspring was to 1:1.The results showed that golden C.argus is a recessive mutant of the wild-type C.argus,and its body color is controlled by a pair of recessive genes on the autosomes.3.Nanopore-based full-length transcriptome sequencing analysis reveals expression signatures of golden C.argusTaking skin tissue of golden C.argus and C.argus as material,Oxford Nanopore Technologies(ONT)sequencing was performed in C.argus skin elucidate the formation mechanism of golden C.argus.About 29.0 G clean reads were generated via ONT sequencing.Overall,8,079 new transcripts were identified by comparing and analyzing redundant removed transcripts and known reference genome annotations.The results of DETs analysis showed that a total of 59 genes were differentially expressed in the two groups,including 22 up-regulated genes and 37 down-regulated genes.The expression pattern of 5 selected differentially expressed genes was validated using qRT-PCR.TYR,SOX10,S-100,NLRC3 were found to be significantly down-regulated in golden C.argus and RhoGEFs was up-regulated.Additional annotation,GO enrichment analysis and gene pathway analysis indicated that the melanogenesis pathway may be interrupted in golden C.argus.Five genes that were highly likely to be responsible for body color variation of golden C.argus were identified,including TYR,SOX10,S-100,NLRC3,RhoGEFs.These findings may provide new insights into the molecular mechanism of the occurrence of golden C.argus.At the same time,it can provide some reference for the breeding of golden C.argus.