Global gene expression in granulosa cells of growing, plateau and atretic dominant follicles in cattle

Reproductive Biology and Endocrinology

Research

Gabriel Douville¹  Isabelle Dufort¹  Marc-André Sirard¹  Annie Girard¹ 

[1] Département des Sciences Animales, Pavillon INAF, Faculté des Sciences de l’Agriculture et de l’Alimentation, Centre de Recherche en Biologie de la Reproduction (CRBR), Université Laval, Québec, G1V 0A6, Québec, Canada;

关键词: Dominant follicle;    Gene expression;    Atresia;    Granulosa cells;   

DOI  :  10.1186/s12958-015-0010-7

 received in 2014-10-23, accepted in 2015-02-13,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe physiological state of the dominant follicle is important as it may be linked to the competence of the oocyte within. The objective of this study was to analyze, by transcriptomic analysis, the changes occurring in granulosa cells from dominant follicles at different phases of follicular growth.MethodsGranulosa cells were collected from slaughterhouse dairy cattle follicles with a diameter greater than 9 mm, and were classified at different phases of follicle growth based on flow cytometry profiles of DNA content after staining with propidium iodide. Three phases were identified based on the proportion of cells in -G1 (less than 2n DNA), G0-G1 (2n DNA) or S-M (more than 2n DNA) and follicles were thus allocated to the growing, plateau or atresia group. Between group analysis (BGA) showed clear segregation of the three groups, and the groups were contrasted against each other in a loop design to identify differently expressed genes. Ingenuity Pathway Analysis (IPA) was used to identify the functions and upstream regulators associated with the observed differently expressed genes.ResultsMajor differences were observed between the growth phases. Granulosa cells from follicles in the plateau phase had increased expression of TYRO3 and downregulation of JAM2 compared to growing follicles, supporting the idea of a shift from proliferation to differentiation. On the other hand, genes regulating the response to oxidative stress (VNN1) and angiogenesis (ANGPT2) were upregulated in granulosa cells from atretic follicles. While the predicted activated functions in cells at the plateau stage compared to cells at the growing stage included synthesis and transport of molecules, the predictions for atretic follicles relative to plateau ones included an increase in apoptosis and cell death.ConclusionConsistent with previous studies, these observations allowed us to match the presence of specific gene transcripts to a particular physiological status and consequently to classify follicles. The results also demonstrated that the plateau phase is not a simple ‘in between’ status between growth and atresia, as several characteristics are unique to this stage.

【 授权许可】

Unknown   
© Girard et al.; licensee BioMed Central. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.