Comparative Transcriptome Analysis Identifies Crucial Candidate Genes and Pathways in The Hypothalamic-Pituitary-Gonadal Axis During External Genitalia Development of Male Geese

Abstract

Background All birds reproduce via internal fertilization, but only ~ 3% of male birds possess the external genitalia that allows for intromission. Waterfowl (e.g., duck and goose) are representatives of them, and the external genitalia development of male geese is directly related to mating ability. Notably, some male geese show abnormal external genitalia development during ontogenesis. However, until now little is known about the molecular mechanisms of the external genitalia development in goose. In the present study, comparative transcriptomic analyses were performed on the hypothalamus, pituitary gland, testis, and external genitalia isolated from the 245-day-old male Tianfu meat geese showing normal (NEGG, n = 3) and abnormal (AEGG, n = 3) external genitals in order to provide a better understanding of the mechanisms controlling the development of the external genitalia in aquatic bird species. Results There were 107, 284, 2192, and 1005 differentially expressed genes (DEGs) identified in the hypothalamus, pituitary gland, testis and external genitalia between NEGG and AEGG. Functional enrichment analysis indicated that the DEGs identified in the hypothalamus were mainly enriched in the ECM-receptor interaction pathway. The ECM-receptor interaction, focal adhesion, and neuroactive ligand-receptor interaction pathways were significantly enriched by the DEGs in the pituitary gland. In the testis, the DEGs were involved in the neuroactive ligand-receptor interaction, cell cycle, oocyte meiosis and purine metabolism. In the external genitalia, the DEGs were mainly involved in the metabolic, neuroactive ligand-receptor interaction and WNT signaling pathways. Additionally, through protein-protein interaction (PPI) network and co-expression network integrated analysis, fifteen genes involved in the neuroactive ligand-receptor interaction and WNT signaling pathways were identified, including KNG1, LPAR2, LPAR3, NPY, PLCB1, AVPR1B, GHSR, GRM3, HTR5A, FSHB, FSHR, WNT11, WNT5A, WIF1, and WNT7B, which are potentially crucial for the development of goose external genitalia. Conclusions To our knowledge, this study is the first comparing the hypothalamus, pituitary gland, testis, and external genitalia transcriptomes of male geese exhibiting normal and abnormal external genitals. Significantly, we identified the key DEGs involved in the neuroactive ligand-receptor interaction pathway which regulates the WNT signaling pathway through PLCB1 to control the development of male goose external genitalia.

Transcriptomic study of testicular hypoxia adaptation in Tibetan sheep

“…Functional enrichment analysis yielded candidate signaling pathways which were explicitly enriched in Neuroactive ligand-receptor interaction (LPAR3), Arachidonic acid metabolism (CYP2C19), Renin-angiotensin system (AGTR2), P53 signaling pathway (IGFBP3), HIF-1 signaling pathway (EDN1), Glutathione metabolism (GGT5) and PPAR signaling pathway (APOC3, PKC1). In the KEGG analysis, most significantly enriched pathways is Neuroactive ligand-receptor interaction pathways, Relevant studies have shown that it could regulate reproductive activity and sexual maturity [18], genes related to Neuroactive ligand-receptor interaction are highly expressed in the testes of poultry [19]. In our analysis LPAR3 genes were significantly up regulated in the low altitude Tibetan sheep group, LPAR3 could interact with progesterone [20]and estrogen [21],…”

Dissociating Mechanisms That Underlie Seasonal and Developmental Programs for the Neuroendocrine Control of Physiology in Birds

“…The ECM-receptor interaction is known to play an important role in tissue and organ morphogenesis, including in adipogenesis (San et al 2021). Furthermore, a recent study on the gonadal development of male geese has implicated significant enrichment of the ECM-receptor interaction pathway by differential gene expression in the pituitary gland (Tang et al 2022). Therefore, the ECMreceptor interaction pathway is a likely area for the identification of photoperiodicallysignificant transcripts.…”