The Analysis Of Allele-specific Expression In Hybrids Of Mallards And Pekin Ducks

Massive variations,including SNPs(Single nucleotide polymorphism),Indels(Insertion/deletion),CNV(Copy number variation)and etc.,occurred on genome-wide scale during the process of domestication.Such variations further influence gene expression or protein structure.Several factors could influence gene expression,such as cis-acting elements,trans-acting factors and environment.It seemed to be difficult to confirm the reason,which led to expression difference.However,the alleles from both mallard and Pekin duck were under the same trans-acting environment in F1 hybrids,cis-acting elementsmainly resulted in the difference between the expression of two alleles.Therefore,the difference reflected the variants of regulatory sequence on genome and lay the foundation for positioning the variation of cis element quickly.We chosemallard(Anas platyrhynchos)and Pekin duck to build F2 resource population.All the blood samples and tissue samples that we need in our research were sampled from the F2 resource population.In this study,we sampled 32 tissues at three point in time from F1 hybrids to perform allelic specific expression analysis.The results were as follows:(1)The predominant predictor of gene expression is tissue type,32 samples primarily separated by tissue.Samples from distinct time points shared similar patterns,while the samples collected at one day of age clustered in a branch by itself.The male and female individuals shows no significant difference.(2)We identified 624 allelic specific genes in 16 mix-tissues consisting of abdominal adipose,liver,skin,spleen,brain,lung,heart and thymus.It approximately accounted 3.5 percentage of all genes annotated in duck genome.Some of these genes might be related to adipocyte metabolism and cell adhesion.(3)We identified 577 allelic specific genes in chest muscle tissues,it approximately accounted 3.8 percentage of all genes annotated in duck genome.The productions of OBSCN on chromosome 2,NEB on chromosome 7,MYH3 on chromosome 19 and MYBPH on chromosome 21 were the basic components of muscle.In summary,allelic specific expression of genes existed in ducks as other plants and animals.The allelic genes from mallard and Peking duck showed differential expression in F1 hybrids may play vital role in the phenotype variants,and the genes laid a solid foundation for the identification of domesticated genes and the research on duck genome.