Ovarian transcriptomic analysis and follicular development of Leizhou black duck

Abstract

This study investigated the factors that caused the differences in egg production during the development of ovarian follicles in Leizhou black ducks. Leizhou black ducks population was divided into 2 groups as high-yield group ( HG ) and low-yield group ( LG ). The number of eggs ( NE ), age at first egg ( AFE ), weight at first egg, and egg weight ( EW ) of both groups were recorded, and differences were analyzed using the t test. The logistic model was used to simulate the egg production curves to analyze the production rules. The ovarian follicles of both duck groups were collected to count the number of different grades sized follicles, weigh the ovaries, and observe follicular sections to analyze the developmental differences. Ovarian transcriptomic sequencing was performed to investigate differentially expressed genes and signal pathways in both duck groups. The results revealed a significant difference ( P < 0.01) in the NE laid, AFE, and EW between both groups. Comparatively, HG had significantly more ( P < 0.01) large yellow follicles ( LYF ) than LG. The density of medullary layer cells of the follicle section was greater in HG than LG ducks. Transcriptome sequencing revealed a total of 1,027 differentially expressed genes between the HG and LG ducks of which 495 genes were upregulated, and 532 genes were downregulated. Fifty genes were related to reproduction and reproductive processes. Kyoto Encyclopedia of Genes and Genomes–enriched signaling pathways revealed 274 signal pathways enriched in these differentially expressed genes of which the steroid biosynthesis pathway was significantly enriched. Analysis (Q < 0.05) showed that HSD3β → gonadotropin-releasing hormone ( GnRH ) and estrogen receptor ( ESR ) → LHβ/ERK1/2 were enriched in the steroid biosynthesis signal pathway. Follicle-stimulating hormone signal pathway mediated by HSD3β → GnRH and ESR → LHβ/ERK1/2 may be involved in ovarian follicle development to regulate LYF reserve process and affect its ovulation cycle, which in turn influence the egg production of Leizhou black ducks.

Hypothalamic and ovarian transcriptome profiling reveals potential candidate genes in low and high egg production of white Muscovy ducks (Cairina moschata)

“…This means that the ovary of poultry birds usually have more DEGs than the hypothalamus which might be due to the multitude effects of different genes that tightly control ovarian follicle development and hormone secretion ( Quan et. al., 2019 ; Zou et al, 2020 ). To confirm the reliability of the transcriptomic sequencing results, 9 DEGs were selected for quantitative real-time PCR ( qRT-PCR ), and the expression levels of these genes and regression coefficient proved that the 9 genes were in agreement with the RNA-seq data.…”

“…RNA sequencing ( RNA-seq ), a method based on next-generation sequencing ( NGS ), offers the opportunities to provide ample details about the transcriptional landscape of a particular organism with the usage of advanced molecular biology techniques and bioinformatics ( Wang et al, 2008 ). Recently, different studies have used this method for identification of genes or molecular pathways responsible for egg production in different species of poultry such as in chicken ( Wang and Ma, 2019 ), Jinghai Yellow chicken ( Zhang et al, 2019 ), Luhua Chicken ( Wu et al, 2017 ), Turkey ( Brady et al, 2020 ), Black and White Muscovy duck ( Bao et al, 2021 ), Leizhou Black duck ( Zou et al, 2020 ), and Goose ( Ouyang et al, 2020 ). However, no reports have used hypothalamus and ovary tissues of White Muscovy ducks to identify potential genes responsible for egg production.…”

Immunohistochemistry and Expression Profile of Estrogen Receptor 2 Gene in Different Grade Size Ovarian Follicles of Leizhou Black Ducks

“…Leizhou black duck is an egg-type duck breed known to have excellent egg production and quality traits enriched in nutrients and trace elements (1,2). As a high-quality local duck breed, much research has been done to improve its meat and egg performance and environmental adaptability (2)(3)(4)(5)(6)(7)(8)(9).…”

Enrichment and verification of differentially expressed miRNAs in the ovarian tissue of Leizhou black ducks

“…The female duck has an early birth period (of 90-120 days), a long egg production period (of 2 years), and a high egg production rate (of 200/500 days). The egg production rate can reach more than 90% in the peak period, showing a good market prospect [2], which has been studied by our research group for many years [3][4][5][6]. However, due to several factors, egg production is extremely uneven.…”