Seasonal patterns of prolactin, prolactin receptor, and STAT5 expression in the ovaries of wild ground squirrels (Citellus dauricus Brandt)

Submitted: 10 July 2023
Accepted: 30 August 2023
Published: 2 October 2023
Abstract Views: 443
PDF: 216
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Prolactin (PRL) is a hormone crucial for normal reproduction, functioning as an autocrine, paracrine, and endocrine factor. This study aimed to examine the immunolocalization and expression patterns of PRL, prolactin receptor (PRLR), and signal transducer and activator of transcription 5 (STAT5) in the ovaries of wild ground squirrels during both breeding and non-breeding periods. Significant seasonal variations were observed in ovarian weights, with higher values during the breeding season and relatively lower values during the nonbreeding season. PRL, PRLR, STAT5, and p-STAT5 were immunolocalized in granulosa cells and luteal cells during the breeding season, whereas they were exclusively found in granulosa cells during the non-breeding season. The mRNA expression levels of Prl, Prlr, and Stat5 were increased in ovarian tissues during the breeding season compared to the non-breeding season. Moreover, the mean mRNA levels of Prl, Prlr, and Stat5 exhibited a positive correlation with ovarian weights. Both circulating PRL and ovarian PRL concentrations were significantly elevated during the breeding season. Additionally, transcriptomic analysis of ovarian tissues revealed differentially expressed genes possibly associated with ovarian function and mammary gland development, including ovarian follicle development, steroid synthesis, and regulation of reproductive process. These findings suggest that PRL might play an essential endocrine, autocrine, or paracrine role in the regulation of seasonal changes in the ovarian functions in wild ground squirrels.



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Ethics Approval

All animal testing procedures were approved by the Animal Protection and Utilization Policy of the Beijing Forestry University Ethics Committee and approved by the Hebei Provincial Department of Agriculture

Supporting Agencies

Beijing Natural Science Foundation, National Natural Science Foundation of China

How to Cite

Gao, Q., Xie, W., Lu, W., Liu, Y., Zhang, H., Han, Y., & Weng, Q. (2023). Seasonal patterns of prolactin, prolactin receptor, and STAT5 expression in the ovaries of wild ground squirrels (<em>Citellus dauricus</em> Brandt). European Journal of Histochemistry, 67(4).