Molecular Characterization and Functional Study of Insulin-Like Androgenic Gland Hormone Gene in the Red Swamp Crayfish, Procambarus clarkii

Abstract

The androgenic gland (AG) is a male-specific endocrine organ that controls the primary and secondary sexual characteristics in male crustaceans. More evidence indicates that the insulin-like androgenic gland hormone gene (IAG) is the key male sexual differentiation factor, particularly the application of RNA interference (RNAi) technology on IAG. In this study, the full-length cDNA of IAG (termed PcIAG) was isolated from the red swamp crayfish, Procambarus clarkii. Tissue distribution analysis showed that in addition to its expression in the AG of male P. clarkii, PcIAG was widely expressed in female tissues and other male tissues. The PcIAG protein was detected in the reproductive and nervous systems of adult male P. clarkii. Additionally, RNAi results showed that the PcIAG expression could be silenced efficiently, and the male sperm maturation and release possibly present a transient adverse interference at lower doses (0.1 μg/g and 1 μg/g) of PcIAG–dsRNA (PcIAG double-stranded RNA). Dramatically, the expression level of PcIAG increased sharply shortly after the injection of higher doses (5 μg/g and 10 μg/g) of PcIAG–dsRNA, which might accelerate the maturation and release of sperm. Moreover, the expression of PcSxl (P. clarkii Sex-lethal) was detected by Quantitative Real-Time PCR (qPCR) after the injection of PcIAG–dsRNA to explore whether the PcIAG gene regulates the PcSxl gene, and we found that the PcIAG did not directly regulate PcSxl in P. clarkii. The study could help accelerate the progress of PcIAG functional research and provide a useful reference for the single-sex selective breeding of P. clarkii.

Gonadulins, the fourth type of Insulin-related peptides in Decapods

“…Similar findings have been reported previously (e.g. Chung, 2014;Huang et al, 2014;Levy et al, 2017;Shi et al, 2019).…”

“…A list of all SRAs used can be found in the supplementary data. Draft genome assembliess for the following species have been used : Penaeus vannamei (Zhang et al, 2019), P. monodon (Van Quyen et al, 2020), Palaemon carinicauda (Yuan et al, 2017), Procambarus virginalis (Gutekunst et al, 2018), Cherax quadricarinatus (unpublished, but available at https://www.ncbi.nlm.nih.gov/assembly/GCA_009761615.1/), and two assemblies each for Eriocheir sinensis (Song et al, 2016;Tang et al, 2020b) and Portunus trituberculataus (https://www.ncbi.nlm.nih.gov/assembly/GCA_008373055.1/; Tang et al, 2020a).…”

Molecular Characterization and Expression Profiling of Three Transformer-2 Splice Isoforms in the Redclaw Crayfish, Cherax quadricarinatus

“…Sexual dimorphism is a common phenomenon in decapod aquaculture species (Sagi and Aflalo, 2005;Shi et al, 2019). Understanding the molecular mechanisms of sexual regulation in these species is attractive because a monosex culture can offer great benefits (Sagi et al, 1997;Ventura et al, 2012;Levy et al, 2016).…”

“…To date, many sex-related genes in crustaceans have been reported. For example, a body of evidence demonstrates that the insulin-like androgenic gland hormone gene (IAG) is the key factor that drives male sexual differentiation in crustacean species (Sagi et al, 1990;Shi et al, 2019). In addition, the expression of Dmrt genes is affected by silencing the IAG gene, suggesting a possible role in the sex-differentiation processes (Amterat Abu Abayed et al, 2019).…”

Validation of Real-time PCR Reference Genes of Muscle Metabolism in Harvested Spiny-Cheek Crayfish (Faxonius limosus) Exposed to Seasonal Variation

“…However, novel analytic approaches employ molecular methods to provide information about changes occurring at the cellular level [2], which affect raw material quality. Such analyses can employ the commonly used technique of real-time PCR, which allows for measuring of the activity of genes encoding proteins involved in key metabolic pathways, including development and function of muscles, and ultimately affecting the quality of meat [3][4][5]. Decker and Welch [6] showed that increased concentration of the protein ferritin causes active binding of iron, which in turn leads to a reduction in meat quality due to an increased level of fat oxidation.…”