The Regulatory Mechanism of Sexual Development in Decapod Crustaceans

Abstract

Crustacean culture has been developing rapidly in various parts of the world. Therefore, it is important to understand their reproductive biology. Insulin-like androgenic gland hormone (IAG) secreted from the androgenic gland (AG) is widely accepted as a key regulator of sexual differentiation in male crustaceans. However, recently several sex-related genes (i.e., CFSH, DEAD-box family, Tra-2, Sxl, Dsx, Fem-1, Sox gene family, Foxl2, and Dmrt gene family) have been identified via transcriptomic analysis in crustaceans, indicating that sexual differentiation in crustaceans is more complicated than previously expected. It has been found that several non-coding RNAs (i.e., miRNAs, lncRNAs, and piRNAs) and IAG receptors may be involved in the sexual development of decapods. Identification and study of the regulation mechanism of sex-related genes, non-coding RNAs, and IAG receptors will provide valuable information regarding sexual development in decapods. In this review, the roles of hormonal and genetic factors in both males and females are discussed. In males, crustacean female sex hormone (CFSH), Sxl, Dmrt gene family, Dsx, Sox gene family, GEM, Fem-1, l-GnRH-III, and corazonin play important roles in IAG regulation in the “eyestalk-IAG-testis” endocrine axis. Unlike males, the regulation mechanism and interaction of sexual genes are relatively unknown in females. However, CFSH, IAG, Fem-1, FAMeT, Slo, UCHLs, Erk2, Cdc2, EGFR, Vg, VgR, and VIH seem to play crucial roles during ovarian development. This study summarizes the available information in the field, highlights gaps, and lays the foundations for further studies and a better understanding of the regulatory mechanism of sexual development in decapods.

Full Functional Sex Reversal Achieved Through Silencing of MroDmrt11E Gene in Macrobrachium rosenbergii: Production of All-Male Monosex Freshwater Prawn

“…Firstly, the important highlight of this study has given remarkable evidence that MroDmrt11E played a crucial role in male sexual differentiation in M. rosenbergii and provided a novel sexual regulation illustration of the conserved Dmrt gene family in crustaceans. Although the crucial role of IAG in orchestrating male sexual differentiation has been characterized and the production of all monosex progenies on IAG or IAG’s receptor manipulation has been achieved, limited information on conserved genes involved in sexual differentiation has been published to date ( 13 ). In the present study, a gene silencing strategy was implemented to expound whether MroDmrt11E participated in male sexual differentiation of M. rosenbergii .…”

“…Until now, in crustaceans, the central role of IAG in orchestrating male sexual differentiation has been well characterized ( 10 , 12 ), but the understanding of other conserved genes involved in sex determination and sexual differentiation is still fragmentary. On the other hand, identifying and studying the regulation mechanism of sex-related genes and noncoding RNAs also provide valuable sexual development information of decapods ( 13 ). Thus, the first question is whether the crustacean develops a novel sexual differentiation pathway, which connects the AG-specific genes and other sex-related regulatory factors.…”

Evidence of Sex Differentiation Based on Morphological Traits During the Early Development Stage of Mud Crab Scylla paramamosain

“…Sexual dimorphism deriving from sex differentiation of animals is always one of the critical propositions in life science, which makes life more complex and wonderful (1). The significant sexual differences in morphology and physiology are known as secondary sexual traits, which encompass a suite of traits from the external genitalia, to courtship behaviors, to any other sexspecific morphological, behavioral, or physiological traits (2,3). These different traits allow each sex to better adapt to the environment and occupy a favorable ecological niche (4,5).…”

“…Contrary to the females, there is only one pair of uniramous gonopods in the narrow and straight male abdomen. Additionally, one pair of gonopores is in the third thoracic segment of the female, and no gonopore was found at the same position in the males (2) The females keep a faster growth rate and a bigger body size than the males except for the cheliped size (14). Apart from that, several studies have been implemented about morphological differences between the sexes of crabs.…”

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“…While in other crustaceans including shrimps, crayfish, and crabs (Mareddy et al, 2011;Li et al, 2012;Zhang et al, 2014;Shi L. et al, 2019;Jiang et al, 2020c) the IAG is specifically expressed in the AG, it also expressed in other tissues. Therefore, IAG may is not the only key regulator of sexual differentiation (Farhadi et al, 2021a).…”