Whole Genome Mining And Gene Identification Of Candidate Genes For Physical Characteristics And Laying Traits Of Shitou

The Shitou goose,a unique poultry species in Guangdong Province is the only large goose species in China,and one of the largest goose species in the world.The Shitou goose has some features,such as large body size,fast growth rate,roughage-resistance,good adaptability and strong disease resistance.The breeding work of Shitou goose is relatively lagging behind for a long time.There are many problems in the goose breeding,such as low breeding rate,poor seed supply,poor uniformity of production performance,large difference in individual production performance,which seriously blocked the development of the Shitou goose industry.In this study,we used genome-wide association analysis(GWAS)to screen the candidate genes for Shitou goose body-shape,head-circumference and egg-laying traits.The results are as follows:1.Whole genome sequencing was performed on 440 Shitou goose DNA samples of,20 Magang goose DNA samples,20 Wuzong goose DNA samples,and 20 Huanzong goose DNA samples.Six candidate genes related to body-shape trait were selected.The expression of PAPPA2 gene in Shitou goose population was higher than Magang goose,Wuzong goose and Huangzong goose populations(P<0.01).The expression of DMP1 gene in Shitou goose population was higher than Magang goose population.And the LCORL,OSTN,IBSP and SPP1 gene expression levels in Wuzong goose population did not significantly express in the populations of Shitou goose,Magang goose,Wuzong goose and Huangzong goose(P>0.05).PAPPA2 gene played critical role in the body-shape differentiation of the Shitou goose,the Wuzong goose,the Huangzong goose and Magang goose populations.The PAPPA2 gene could be used as a candidate gene for genotyping of the body-shape differentiation.2.16 candidate genes related to head-circumference traits were selected bygenome-wide sequencing of 223 DNA samples of Shitou geese’ head-circumference traits.The results of q PCR showed that the expression of RAP1 A gene in the population of small-head Shitou goose was higher than that of the big-head Shitou goose population(P<0.01).There was no other genes expect RAP1 A significant expressed in the head-circumference traits of Shitou goose population.This revealed that the RAP1 A gene was closely related to the head-circumference traits of the Shitou goose.The RAP1 A gene can be used as a candidate gene for head-circumference trait of the Shitou goose.3.29 candidate genes related to egg-laying traits were selected by genome-wide sequencing of 217 DNA samples of the egg-laying trait of Shitou goose population.The results of q PCR showed that the expressions of CRTC1,GPC3,SERPINC1 and FAAH2 genes in the low-yielding egg Shitou goose population were higher than the high-yielding egg Shitou goose population(P<0.05).The expression levels of BMP4,LIF,NFYC and FRMPD3 genes in the low-yielding egg Shitou goose population were higher than the high-yield egg Shitou goose population(P<0.01).The expression levels of MAT5,CLPB and GNA12 genes in the low-yielding Shitou goose population were lower than the high-yield egg Shitou goose population(P<0.05).This revealed that the CRTC1,GPC3,SERPINC1,FAAH2,BMP4,FRMPD3,LIF,NFYC,MAT5,CLPB and GNA12 genes were closely associated with the egg-laying traits of the Shitou goose.And these gene can be used as a candidate gene for egg-laying trait of the Shitou goose.