Identification Of Potential Candidate Genes For Eyelid Deficiency In Developing Wulong Goose Embryos By Transcriptomic Analysis

The wulong goose is a source of good meat, eggs, and geese in China. The eyelid of Wulong goose serves as a distinctive emblem of this species. The mechanism underlying the eyelid deficiency trait of Wulong geese is unclear owing to the constrained related to conventional genetic techniques. Herein, Wulong goose with Huoyan (eyelid deficiency) trait at embryonic stage of 9 days (E9), 12 days (E12), and 14 days (E14) and Wulong goose with normal eyelids were selected for transcriptome sequencing. Differentially expressed gene (DEG) and functional enrichment analyses were performed, and finally eight DEGs were selected to verify the accuracy of qPCR sequencing. Overall, 466, 962, and 550 DEGs were obtained from the three control groups D9 vs N9, D12 vs N12, and D14 vs N14, respectively, by differential analysis (P<0.05). Among them, CDKN1C, CRH, CROCC, and TYSND1 were significantly expressed in the three groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed the enrichment of CROCC and TYSND1 in pathways of cell cycle process, endocytosis, microtubule-based process, microtubule organizing center organization, protein processing, and protein maturation. CDKN1C and CRH were enriched in cell cycle and cAMP signaling pathway. In addition, some collagen family genes were detected among the DEGs, including COL3A1, COL4A5, COL4A2, and COL4A1. FREM1 and FREM2 genes were detected in both Huoyan and normal eyelids. Considering the differences in sex and time, FREM1 was significantly (P<0.01) expressed in the two control groups F14D vs F9D and M14D vs M9D. These results reveal the regulatory mechanism underlying Huoyan trait in Wulong geese and provide guidance for designing experiments using DEGs and gene function pathways. This study can provide scientific references for the protection of breed characteristics, purebred breeding, and hybrid utilization.