Transcriptome Analysis of Ovary Tissues From Low- and High-yielding Changshun Green-shell Laying Hens

Abstract

Background: Changshun green-shell laying hens are unique to Guizhou Province, China, with high egg quality. At this stage, improving egg production performance has become an important breeding task. In recent years, the development of high-throughput sequencing technology provides a fast and exact method for genetic selection. Therefore, this study is based on high-throughput sequencing technology to analyze the differences in the ovarian mRNA transcriptome of low-yield and high-yield Changshun green-shell layer hens, identify critical pathways and candidate genes involved in controlling the egg production rate, and provide basic data for layer breeding.Results: The egg production rates of the low egg production group (LP) and the high egg production group (HP) were 68.00 ± 5.56% and 93.67 ± 7.09%, with extremely significant differences between the groups (p <0.01). Moreover, the egg weight, shell thickness, strength and layer weight of the LP were significantly larger than those of the HP (p <0.05). More than 41 million clean reads per sample were obtained, and more than 90% of the clean reads were mapped to the Gallus gallus genome. Further analysis identified 142 differentially expressed genes (DEGs), and among them, 55 were upregulated and 87 were downregulated in the ovaries. KEGG pathway enrichment analysis identified 9 significantly enriched pathways. Among them, the neuroactive ligand-receptor interaction pathway was the most enriched. GO enrichment analysis indicated that the molecular function GO term: transmembrane receptor protein tyrosine kinase activity, as well as the DEGs identified in this GO term, including PRLR, NRP1, IL15, BANK1, NTRK1, CCK, and HGF may play crucial roles in the regulation of egg production.Conclusions: The above-mentioned differentially expressed genes should be paid attention to in molecular breeding of Changshun green-shell laying hens. Moreover, enrichment analysis suggested that the neuroactive ligand-receptor interaction pathway and receptor protein tyrosine kinases may play crucial roles in the regulation of ovarian function and egg production.

Ovary transcriptome profiling in high- and low-yielding Chinese Chahua laying chickens

“…Our results suggest that these pathways have been enriched, indicating their functions in the regulation of chicken egg production. However, our results are not consistent with those of Zhang et al (2019) and Mu et al (2021), who also conducted an RNA-seq analysis in chicken ovaries. Zhang et al (2019) identified four known pathways related to reproduction.…”

“…Among them, the focal adhesion and cytokine-cytokine receptor interaction pathways alone showed similarities with our results. Although Mu et al (2021) reported nine pathways, no pathways overlapped with our results. These conflicting results may be attributed to the differences in the chicken breed used in the respective experiments.…”

“…These conflicting results may be attributed to the differences in the chicken breed used in the respective experiments. While we used Chahua chickens, Zhang et al (2019) used Jinghai yellow chickens, and Mu et al (2021) used Changshun greenshell laying hens.…”

“…In Luhua chicken ovaries, ten candidate genes, including kynureninase (KYNU), tryptophan 2,3-dioxygenase (TDO2), and aralkylamine N-acetyltransferase (AANAT), have been identified related to the egg production (Mishra et al 2020). In another study, Mu et al (2021) identified four important candidate genes, including the prolactin receptor (PRLR), proopiomelanocortin (POMC), and galanin receptor 1 (GALR1), in the ovaries of the high and low egg-producing chickens. Hence, transcriptome sequencing can be used to provide a fast and accurate method for the genetic selection and as a complement to traditional breeding techniques.…”

Genetic Basis of Sexual Maturation Heterosis: Insights From Ovary lncRNA and mRNA Repertoire in Chicken

“…GnRH signaling is regarded as the gonadotrope and endocrine control of fertility in mice (61) and goose (62). In chicken, GnRH signaling pathway could involve in ovarian function (49,63). Here, the nonadditive genes, such as MMP2, ADCY6, EGR1, CACNA1C and GNAQ, were identified significantly enriched in GnRH signaling pathway.…”