Insulin-like androgenic gland hormone 1 (IAG1) regulates sexual differentiation in a hermaphrodite shrimp through feedback to neuroendocrine factors

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.

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RNAi Reveals Role of Insulin-Like Androgenic Gland Hormone 2 (IAG2) in Sexual Differentiation and Growth in Hermaphrodite Shrimp

Frontiers in Marine Science ◽

10.3389/fmars.2021.666763 ◽

2021 ◽

Vol 8 ◽

Author(s):

Fang Liu ◽

Wenyuan Shi ◽

Haihui Ye ◽

An Liu ◽

Zhihuang Zhu

Keyword(s):

Sexual Differentiation ◽

Ovarian Development ◽

Individual Growth ◽

Androgenic Gland ◽

Vitellogenin Receptor ◽

Functional Differences ◽

Peppermint Shrimp ◽

Gonad Inhibiting Hormone ◽

Lower Expression

Insulin-like androgenic gland hormone (IAG) is the most widely known hormone that regulates sexual differentiation in crustaceans. Previously, a transcriptome study described two transcripts of IAGs (Lvit-IAG1 and Lvit-IAG2) in the peppermint shrimp Lysmata vittata, a species characterized by a rare reproductive system of protandric simultaneous hermaphroditism (PSH). Herein, we explored the function of Lvit-IAG2 via RNA interference (RNAi) experiments, and then compared the functional differences between the two IAGs. We demonstrated that Lvit-IAG2 positively regulated the expression of crustacean hyperglycemic hormone (Lvit-CHH) in eyestalk ganglion but exhibited no significant effect on the expression of gonad-inhibiting hormone (Lvit-GIHs) and crustacean female sex hormone (Lvit-CFSHs). Besides, Lvit-IAG2 gene knockdown caused degeneration in appendices masculinae (AM) and suppressed germ cells at the secondary spermatocyte stage. Moreover, silencing the Lvit-IAG2 gene impeded ovarian development, including smaller previtellogenic oocytes, and lower expression of vitellogenin (Lvit-Vg) gene in hepatopancreas and vitellogenin receptor (Lvit-VgR) gene in the ovarian region. Notably, silencing the Lvit-IAG2 gene impeded individual growth of the species. Collectively, findings from this study demonstrate that Lvit-IAG2 and Lvit-IAG1 coordinatively function to modulate sexual differentiation in L. vittata; meanwhile, Lvit-IAG2 stimulates the growth of the PSH species.

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Sexual differentiation in decapod crustaceans: role of the androgenic gland

Invertebrate Reproduction & Development ◽

10.1080/07924259.1997.9672563 ◽

1997 ◽

Vol 31 (1-3) ◽

pp. 55-61 ◽

Cited By ~ 89

Author(s):

AMIR SAGI ◽

EVIATAR SNIR ◽

ISAM KHALAILA

Keyword(s):

Sexual Differentiation ◽

Androgenic Gland ◽

Decapod Crustaceans

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Expression of an Androgenic Gland-Specific Insulin-Like Peptide during the Course of Prawn Sexual and Morphotypic Differentiation

ISRN Endocrinology ◽

10.5402/2011/476283 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 35

Author(s):

Tomer Ventura ◽

Rivka Manor ◽

Eliahu D. Aflalo ◽

Simy Weil ◽

Isam Khalaila ◽

...

Keyword(s):

Sexual Differentiation ◽

Reproductive Strategies ◽

Sex Differentiation ◽

Macrobrachium Rosenbergii ◽

Androgenic Gland ◽

Temporal Expression ◽

Androgenic Hormone ◽

Temporal Expression Pattern ◽

Male Specific ◽

Specific Insulin

The crustacean male-specific androgenic gland (AG) regulates sexual differentiation. In the prawn Macrobrachium rosenbergii, silencing an AG-specific insulin-like encoding transcript (Mr-IAG) inhibited the development of male sexual characters, suggesting that Mr-IAG is a key androgenic hormone. We used recombinant pro-Mr-IAG peptide to generate antibodies that recognized the peptide in AG cells and extracts, as verified by mass spectrometry. We revealed the temporal expression pattern of Mr-IAG and studied its relevance to the timetable of sex differentiation processes in juveniles and after puberty. Mr-IAG was expressed from as early as 20 days after metamorphosis, prior to the appearance of external male sexual characters. Mr-IAG expression was lower in the less reproductively active orange-clawed males than in both the dominant blue-clawed males and the actively sneak mating small males. These results suggest a role for Mr-IAG both in the timing of male sexual differentiation and in regulating reproductive strategies.

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Morphological studies on sexual differentiation in Armadillidium vulgare (Isopoda: Armadillidae) : androgenic gland and male sexual characters

Crustacean Research ◽

10.18353/crustacea.24.0_93 ◽

1995 ◽

Vol 24 (0) ◽

pp. 93-103 ◽

Cited By ~ 8

Author(s):

Sachiko Suzuki ◽

Kenji Yamasaki

Keyword(s):

Sexual Differentiation ◽

Androgenic Gland ◽

Armadillidium Vulgare ◽

Morphological Studies

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Androgen-induced plasticity at a “vocal” neuromuscular synapse

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167895 ◽

1994 ◽

Vol 52 ◽

pp. 32-33

Author(s):

Darcy B. Kelley ◽

Martha L. Tobias ◽

Mark Ellisman

Keyword(s):

Xenopus Laevis ◽

Motor Neurons ◽

Sexual Differentiation ◽

Molecular Basis ◽

Neuromuscular Synapse ◽

Sexually Dimorphic ◽

Intracellular Protein ◽

Developmental Program ◽

Androgen Action ◽

Clawed Frog

Brain and muscle are sexually differentiated tissues in which masculinization is controlled by the secretion of androgens from the testes. Sensitivity to androgen is conferred by the expression of an intracellular protein, the androgen receptor. A central problem of sexual differentiation is thus to understand the cellular and molecular basis of androgen action. We do not understand how hormone occupancy of a receptor translates into an alteration in the developmental program of the target cell. Our studies on sexual differentiation of brain and muscle in Xenopus laevis are designed to explore the molecular basis of androgen induced sexual differentiation by examining how this hormone controls the masculinization of brain and muscle targets.Our approach to this problem has focused on a highly androgen sensitive, sexually dimorphic neuromuscular system: laryngeal muscles and motor neurons of the clawed frog, Xenopus laevis. We have been studying sex differences at a synapse, the laryngeal neuromuscular junction, which mediates sexually dimorphic vocal behavior in Xenopus laevis frogs.

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