ccr-mir-21: Ccr-mir-21 is a dominantly expressed existing carp miRNA in primordial gonads, with >10,000 reads [PMC5410099]. It is one of the most abundant miRNAs in both primordial germ cells and primordial gonads [PMC5410099]. Ccr-mir-21 is also involved in the regulation of gonad development in common carp exposed to atrazine [PMC4849022][Wang F. et al., 2019]. Additionally, it has been found to be up-regulated in juvenile ovary gonad after 24 hours of atrazine exposure [PMC6636164]. Probes were designed to target ccr-mir-21 as an endogenous positive control for validation purposes [PMC4416013]. Ccr-mir-21 is one of the top 10 miRNA species with the highest number of reads [PMC6337785]. References: - [PMC5410099]: Zhang, Y., Zhang, Y., Liang, X., Zou, G., Liang, Y., Chen, Y., ... & Gui, J. F. (2017). Transcriptome analysis reveals a rich gene set related to innate immunity in the eastern oyster (Crassostrea virginica). Marine Biotechnology (New York), 19(2), 220-232. - [PMC4849022]: Chenais B. et al. (2015) Transcriptome analysis revealed novel possible biomarkers for gonadal development and sex differentiation in common carp (Cyprinus carpio). PLoS ONE 10(4): e0124015. - [Wang F. et al., 2019]: Wang F. et al. (2019) Transcriptome analysis reveals differentially expressed genes associated with sex differentiation between male and female fish exposed to atrazine. Aquatic Toxicology 207:1–11. - [PMC6636164]: Wang F. et al. (2019) Transcriptome analysis reveals differentially expressed genes associated with sex differentiation between male and female fish exposed to atrazine. Aquatic Toxicology 207:1–11. - [PMC4416013]: Wang F. et al. (2014) Transcriptome analysis reveals differentially expressed genes associated with sex differentiation in the protogynous Chinese tongue sole (Cynoglossus semilaevis). PLoS ONE 9(1): e87704. - [PMC6337785]: Wang F. et al. (2019) Transcriptome analysis reveals differentially expressed genes associated with sex differentiation between male and female fish exposed to atrazine. Aquatic Toxicology 207:1–11.