Project description:Ovarian follicle selection plays an important role in the reproduction of sexually mature hens, and this process can directly affect the growth and development of follicles until the final ovulation, thus affecting laying performance and fecundity of hens. In the laying hen ovary, one follicle from a cohort of 8-13 follicles of 6-8 mm in diameter is selected daily to enter the preovulatory hierarchy. In this study, we globally compared the proteomes of chicken ovarian follicles before and after follicle selection. A total of 5883 proteins were identified in the proteomes of chicken 6-8 mm prehierarchical follicles and 12-15 mm hierarchical follicles. 259 proteins are differentially expressed in 12-15 mm hierarchical follicle compared with prehierarchical follicle, of which 175 proteins are up-regulated and 84 proteins are down-regulated. The Gene Ontology enrichment of differentially expressed proteins revealed enriched GO terms for peptidase activity, acrosin binding for their molecular function and in the process of negative regulation of peptidase activity, and regulation of fertilization. The KEGG pathway analysis indicated that differentially expressed proteins were enriched for ribosome, lysine degradation, and endocytosis pathways. Nine differentially expressed proteins including vitellogenin-1 were validated with Parallel Reaction Monitoring (PRM) analysis, and their functions were discussed. This study provided a global proteomic view of the development of chicken ovarian follicles, which will serve as a foundation for understanding the molecular signatures and pathways of follicle selection in hens.
Project description:In mammalian females, quiescent primordial follicles serve as the ovarian reserve and sustain normal ovarian function and egg production via folliculogenesis. The loss of primordial follicles causes ovarian aging. Cellular senescence, characterized by cell cycle arrest and production of the senescence-associated secretory phenotype (SASP), is associated with tissue aging. In the present study, we report that some quiescent primary oocytes in primordial follicles become senescent in adult mouse ovaries. The senescent primary oocytes share senescence markers characterized in senescent somatic cells. The senescent primary oocytes were observed in young adult mouse ovaries, remained at approximately 15% of the total primary oocytes during ovarian aging from 6 months to 12 months, and accumulated in aged ovaries. Administration of a senolytic drug ABT263 to 3-month-old mice reduced the percentage of senescent primary oocytes and the transcription of the SASP cytokines in the ovary. In addition, led to increased numbers of primordial and total follicles and a higher rate of oocyte maturation and female fertility. Our study provides experimental evidence that primary oocytes, a germline cell type that is arrested in meiosis, become senescent in adult mouse ovaries and that senescent cell clearance reduced primordial follicle loss and mitigated ovarian aging phenotypes.
Project description:Transcriptome analysis reveals differentially expressed genes associated with high rates of egg production in chicken hypothalamic-pituitary-ovarian axis
Project description:Follicular atresia is an important factor affecting reproductive performance. In birds, less than 5% of follicles could complete their development process and mature ovulation, while the other 95% become atretic follicles and eventually degraded3. Yangzhou geese are famous for their high egg production, however, the average number of eggs per goose is 40-80 and the peak laying rate is 40%-50%12. As an important meat source of poultry, the low egg production of goose has seriously affected the production cost and industrialization development. How to avoid follicular atresia and promote its normal development could help to improve egg production. Therefore, understanding the mechanism of follicular atresia in geese is of great significance for improving egg production.Isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantitatively identify differentially expressed proteins (DEPs) between normal and atretic follicles.
Project description:Purpose: To identify the key regulatory genes and pathways involved in chicken high egg productivon in HPG axis. Methods: A total of 856 Chinese Luhua chicken was raised in poultry breeding farm of Sichuan Agricultural University, the highest two hundred and the lowest two hundred chicken egg production were considered as high egg production (HEP) and low egg production (LEP) according to the total egg number at 300 days of age, respectively, integrated with RNA-seq sequencing of samples of HPG axis (hypothalamus, pituitary gland and ovary) from three HEP and three LEP chickens at 300 days of age. Results: A total 86.7 Gb RNA-seq sequences were generated, and with each library averaged 5.1 Gb. Conclusions: These important data might improve our understanding of reproductive biology of Luhua chicken by providing comprehensive gene expression information at transcriptional level. We indicate that our approach will contribute to the isolation of effective molecular markers that can be used in genetic breeding programs in Chinese domestic Luhua chicken.
Project description:Dongxiang blue-shelled chicken, an indigenous chicken breed in China, has segregated significantly for the dermal hyperpigmentation phenotype. Two lines of the chicken have been divergently selected with respect to comb color for over 20 generations. The recent selection has also resulted in a significant difference in egg production. The red comb line (RCL) chicken produces significantly higher number of eggs than that by the dark comb line (DCL) chicken. The objective of this study was to explore potential mechanisms involved in the relationship between comb color and egg production among chickens. We performed genome-wide association study to identify candidate genes associated with chicken comb color using SNP array data, and we conducted selective sweep analysis to identify putative regions of selection harboring pleiotropic genes affecting both comb color and egg production.
Project description:Gene expression differences between the ovaries of Jingding duck with high and low egg production were assessed using the RNA-Seq technology. A total of 843 differentially expressed genes were identified. These genes have known or potential roles in regulation the egg production. Therefore, they are appealing candidates for further investigation of the gene expression and associated regulatory mechanisms related to egg production of ducks.
Project description:To evaluate the lncRNAs and mRNAs in ovaries associated with egg production performance in domestic pigeons, high-throughput RNA sequencing of ovaries between high and low egg production performance groups were performed and analyzed in this study.
Project description:Feather pecking is a major welfare problem in egg production. It may be caused by genetic, physiological and environmental factors. The main aim of this study was to uncover variability in gene expression between individuals from high (HFP) and for low feather pecking (LFP) line using Chicken Gene Expression Microarrays (Agilent Technologies).
Project description:Lack of, or abnormal, ovarian follicular development prevents establishment of pregnancy in human and is associated with reduced reproductive efficiency in farm animals. Development of new treatments is limited by our poor understanding of ovarian follicular development. The objective of this study is to identify changes in gene expression during the selection stage of bovine follicular growth. Follicles of different sizes were collected and intrafollicular concentrations of steroids were measured to identify healthy follicles. Gene expression profiles were obtained using cDNA slides containing ~18,000 bovine EST probes. Using a false discovery rate of 0.05, we identified 976 probes differentially expressed across different follicles with at least 1.4 fold changes. Genes involved in immune system, cell organization and biogenesis, and cell proliferation were significantly over represented in the list, indicating the potential involvement of these biological processes in follicular selection. Keywords: gene expression, follicle stage comparison