| In order to avoid the loss of genetic diversity of limited arctic fox population in China and promote the genetic management of small captive populations in China,this study will use microsatellite molecular markers,take arctic fox as an example to judge the best matching scheme according to the prediction of genetic quality of offspring,which will provide reference for the conservation of genetic diversity of small captive populations.In addition,although microsatellite markers are universal among related species and can be used across species,the process of testing their polymorphism is very complicated.In order to obtain useful microsatellite markers for population genetic analysis,the method of mixed template amplification to evaluate the polymorphism of microsatellite loci quickly and simply will also be used in this study.The main results are as follows:1.The DNA of 10 arctic foxes were randomly selected from 2,3,5,8 and all 10 samples as templates.10 primers of four base microsatellite loci were used for amplification,and the electrophoresis typing was carried out by automatic sequencer.The electrophoresis signal peaks of all alleles were clear.Compared with single template amplification,multiple alleles at all loci could be displayed stably by mixed template amplification,and the reproducibility between different batches was 100%.The signal peak area was positively correlated with allele frequency,which can be used to infer the allele frequency distribution of the loci to be tested.The ratio of the highest signal peak area to the lowest signal peak area was positively correlated with the number of mixed samples,and negatively correlated with polymorphism information content,suggesting that there was a certain limit to the number of mixed samples,and the low-frequency alleles could not be detected at a certain limit.At the same time,through this relationship,we can also speculate polymorphism information content.2.Nine available loci were obtained,all of which were highly polymorphic(PIC>0.5).Except for REN54P11,which deviated from the H-W equilibrium significantly(P<0.01),all of them were in accordance with H-W equilibrium(P>0.05).48 alleles were detected in 59 individuals.The number range of alleles at each locus was from 4 to 7,with an average of 5.333,and the number range of effective alleles was from 2.280 to 4.290,with an average of 3.171.The average observed heterozygosity of these 9 loci in this population was 0.695,and the average expected heterozygosity was 0.682.It indicated that the population had high genetic diversity.However,the distribution of alleles in this population was not uniform,which suggested that the genetic diversity of this population was not stable.3.The offspring quality index(OQI)was constructed according to the heterozygosity,genotype diversity and the evolution relationship among alleles of the offspring at each locus produced by each pairing scheme.According to the size of OQI,good matching scheme and bad matching scheme can be judged.We found that the offspring quality index was higher when the genetic diversity of parents was rich and the genetic relationship between parents was far,which indicated that the larger the OQI was,the better the pairing scheme was.The mean level of OQI was 3.489 based on the mean level of mean multilocus heterozygosity and multilocus mean d2 of all parents in the study population.It can be used as the critical value to judge the excellent matching scheme.This method can provide guidance and suggestions in breeding period of captive arctic fox.However,the specific matching scheme should be determined according to the quality of economic characters,oestrus situation and health conditions of the individuals participating in breeding in the breeding farm. |
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