Genetic Diversity Of MHC Class Ⅰ Gene In Amas Poeciorhyncha And Investigation Of Parasites

Wild populations of domesticated animals that survive in the wilderness need to have stronger disease resistance than domesticated populations.The existing research results show that the MHC gene is closely related to the individual’s ability to resist disease.According to the generally accepted theory of natural selection: the environment is the primary factor leading to adaptive selection,that is,under the pressure of special environmental selection,the natural selection caused by host-pathogen interaction can promote the evolution of immune-related genes.The MHC gene can form an unusual diversity through an arms race between the pathogen and the host,thereby affecting the individual’s ability to resist disease,enriching the gene pool of the population,and even mediating the adaptability of the population to the environment.Therefore,the genetic diversity of wild populations of domesticated animals plays an extremely important role in the continuation of species.In the process of evolution,the genetic diversity of wild populations is enriched by a virtuous cycle of interactions between MHC genes and environmental pairs.The wild migratory population of Amas poeciorhyncha is highly susceptible to parasites due to its special habits.This makes the wild population of spotted ducks a convenient model for studying wild populations of poultry,combined with the "dual theory" of the origin of domestic ducks,which further indicates that it is the preferred species for studying genetic differences in populations,for domestic ducks and even other poultry.Genetic research has a very important role to play.1.Neutral molecular marker researchThe mitochondrial control region gene sequence of the wild spotted duck population was analyzed by Seq Man software,and a total of 30 haplotypes were found,among which individuals with haplotype H01 were the most.The haplotype diversity and nucleotide diversity were 0.9753 and 4.3733%,respectively,indicating that the wild spotted duck population has strong individual adaptability and high potential for evolution.The network map was drawn by NETWORK and it was found that the haplotype H01 is also the ancestral gene stream in all sample genes.A total of 12 microsatellite molecular markers were used in the experiment.The results of fluorescence sequencing were analyzed by Gene Maper and Pop Gene,and a total of 161 alleles were detected.The number of alleles averaged 13.42 alleles/site;the average expected heterozygosity was 0.675.The linkage situation was calculated by the linkage disequilibrium method.The results showed that the locus AJ493289 was linked to the locus APH01 and the locus CMO11;the locus APH01 and the locus APL2,the locus AY493313,and the locus D08 were linked;the locus APL2 and the locus AY493256 Site D08 linkage;locus AY493256 and locus D08 linkage;locus AY493313 and locus D08 linkage;locus D03 and locus D09,locus D10 linkage.2.Parasite investigation and MHC gene researchThrough specific primer amplification and sequencing,the infection rate of Cryptosporidium(Cryptosporidium Tyzzer)was 89%.There were two different infection types in Coccidia(Sphaerozoum fuscum).The infection rate of Eimeria fulva was 6%,and the infection rate of Isospora was 45.%.There were no positive results for blood parasites.The MHC gene sequence was analyzed using Seq Man software.The MHC class I gene has31 haplotypes on exon 2 and 23 haplotypes on exon 3.d N/d S were 3.1029±1.7623 and3.0256±1.6575,respectively.Comparing the amino acid sequences encoded by the two genes,it was found that there was a high degree of polymorphism.The NETWORK network diagram has no obvious ancestral gene flow,but there are many evolutionary breakpoints.In this study,the genetic diversity of the wild spotted duck population was investigated,which provided an experimental basis for the adaptive evolution strategy of wild duck immune related genes.In the future,we can study the different migratory habits and wild duck immune related genes in different environments.Adaptive evolution provides a scientific reference for the conservation and sustainable development of wild duck resources.