Association Analyses On Growth And Slaughter Traits Of Meat Rabbits Based On Genome And Transcriptome Sequencing Data

Rabbit meat is much loved by people for its unique flavour and rich nutrition.Meat rabbit breeding is a guarantee for the sustainable and efficient development of the rabbit industry and has evolved from conventional breeding to molecular breeding.Genomic,transcriptomic and phenotypic data can be used to identify functional candidate genes and genetic markers that affect important economic traits in rabbits,which can provide an important foundation for molecular breeding.In this study,key genetic variants affecting growth and development and slaughter traits in rabbits were identified through association analysis of transcriptomic and phenotypic data and expression quantitative trait loci(eQTL)analysis.The main findings of the experiment are as follows:(1)The experimental material was 112 meat rabbits of the Kangda V line.Phenotypic data on growth and development and slaughter traits such as pre-slaughter live weight,skin weight,body length,abdominal girth,heart weight,liver weight,spleen weight and kidney weight were measured and counted to construct the Kangda V line test group.The statistics on the phenotypic data revealed that all traits basically conformed to a normal distribution and could be used for subsequent correlation analysis.(2)Transcriptome sequencing was performed on 112 meat rabbits to obtain 676 G of raw data,and 14412 gene expressions were obtained through the process of filtering,comparing,assembling and quantifying.A total of 7 genes were found to be significantly associated with spleen weight and body length after screening based on significance thresholds,including HCK and FOXRED for spleen weight.INSYN2 A,ZNF12,RPL13,PSD2 and CKAP2 for body length.(3)The genotype data of 19047360 loci in the genome were obtained by low-depth sequencing of 1548 rabbits combined with genotype-padding screening.Based on transcriptomic data and genomic data for eQTL analysis with Bonferroni correction,a total of191285 eQTL loci were identified,mainly on chromosomes 1,5,6,8,11,12 and 19.A total of 42,295 cis-eQTL loci(Cis-eQTL)and 148,990 trans-eQTL loci(Trans-eQTL)were obtained by classifying eQTL according to their positional relationships.The cis-eQTL were mainly distributed on chromosomes 1,5,6 and 19.The trans-eQTL were mainly distributed on chromosomes 1,5,8,11 and 12.(4)By integrating the results of transcriptome and phenotype association analysis with eQTL localization results,843 trans-eQTL loci were found to be associated with INSYN2 A,ZNF12,RPL13 and CKAP2,which affect body length traits,and 112 trans-eQTL loci were associated with HCK and FOXRED2,which affect spleen weight traits.The trans eQTL loci were found on TMCO3 and FAM198 B significantly associated with INSYN2 A,ZNF12affecting body length traits.In summary,the combined multi-omics analysis can reveal the loci-gene-trait relationship,reveal functional candidate genes and variant loci affecting important economic traits in rabbits,provide an important scientific basis for molecular breeding,and thus promote the genetic improvement of rabbits.