Exploring the expression and preliminary function of chicken regulator of G protein signalling 3 ( RGS3) gene in follicular development

1. The following study explored the expression and preliminary function of the RGS3 gene. The spatial and temporal expression patterns of the RGS3 gene were analysed in the ovarian stroma of Shendan No. 6 Green shell hens and Hy-line Brown hens at four time points (6, 28, 40, and 52 weeks old), as well as in various organs and follicles of Hy-line Brown hens.2. Based on the genomic and protein sequences of RGS3 in NCBI database, phylogenetic trees were constructed using MEGA-X. The protein interaction network was analysed using STRING. According to the results of protein-protein interaction network and pathways, the mRNA expression levels of RGS3 and three interaction proteins were explored by qRT-PCR in vitro.3. Spatio-temporal expression data revealed that RGS3 mRNA was expressed in all the organs tested, being highest in the hypothalamus. In different follicles, RGS3 mRNA was highly expressed in post-ovulatory follicles, followed by ovarian stroma and large white follicles. The expression levels of RGS3 mRNA in the ovarian stroma were significantly higher in Shendan No. 6 Green shell hens than that in the Hy-line Brown hens at all egg-laying stages.4. The phylogenetic tree results showed that ducks, geese and chickens had higher homology based on the genomic and protein sequence of RGS3. Moreover, chicken RGS3 interacted with GSK3B, RAF1 and BRaf based on STRING prediction. In vitro follicle stimulating hormone (FSH) treatment showed that mRNA expression levels of RGS3 and those of its predicted interacting proteins BRaf and GSK3B decreased with increasing FSH concentration. The results suggested that RGS3 responds to FSH and may play an important role in the regulation of follicular development in chicken.