Analysis of mRNA and MicroRNA Expression Profiles of Nervous Tissues and Reproductive Tissues in Male Procambarus clarkii After Silencing IAG

Gonadal transcriptome analysis reveals MAG participates in ovarian suppression of intersex red claw crayfish (Cherax quadricarinatus)

BACKGROUND

The red claw crayfish (Cherax quadricarinatus) is a commercially and ecologically significant species that displays a unique intersex model with an ovotestis gonad and was identified to have functional testes and a vestigial ovary, which was inhibited by insulin-like androgenic gland hormone (IAG), but the underlying molecular mechanisms are still unclear.

RESULTS

In this study, the structure and transcriptomic profiles of ovotestis and female and male gonad was analysis and compared, 406 differentially expressed genes were identified, among which membrane-anchored AG-specific factor (MAG) exhibited significantly greater expression in ovotestis gonads than in male or female gonads. The localization of MAG in type I or II cells of androgenic gland revealed its potential function of IAG hormone synthesis. Furthermore, the analyses of gene regulation relationship revealed that IAG positively regulates MAG expression, while MAG negatively regulates vitellogenin gene (VTG) expression.

CONCLUSIONS

Our research suggesting MAG participates in the IAG regulated ovarian suppression in the intersex red claw crayfish, which provides important information on the regulatory mechanism of the ovarian dysplasia in the ovotestis of intersex red claw crayfish. These results will enhance the knowledge of IAG-related pathways in the female reproductive axis, as well as the mechanisms of sexual differentiation in crustaceans.

A study on the functional role of the DHCR24 gene in gonadal differentiation and development of Macrobrachium nipponense

Sex differentiation in crustaceans is a complex process influenced by various factors, including the androgenic gland and sex-related genes. This study characterized the role of the Mn-DHCR24 gene in the oriental river prawn (Macrobrachium nipponense). We used bioinformatics to analyze sequence features and phylogenetic relationships of a single Mn-DHCR24 gene. The expression patterns of Mn-DHCR24 across different tissues and developmental stages were determined by real-time PCR, and its localization in testis was determined by in situ hybridization. RNA interference was used to knock down Mn-DHCR24 expression, followed by examining changes in sex ratio and gonadal development at the PL10 stage. Additionally, an enzyme-linked immunosorbent assay measured 17α-methyltestosterone levels, and tissue sections were used to characterize gonadal development. The results indicated that Mn-DHCR24 was high expression in testis, which was critical for sperm maturation and gonadal differentiation. RNAi experiments showed the role of Mn-DHCR24 during reproductive regulation rather than as a master gene for sex differentiation. This study further showed that Mn-DHCR24 regulated sex and hormone-related genes, influencing steroid biosynthesis pathways. Together, these findings provided valuable insights into the genetic and hormonal mechanisms of gonadal differentiation in M. nipponense, and supported the development of monosex culture technology.

Monosex Populations of the Giant Freshwater Prawn Macrobrachium rosenbergii-From a Pre-Molecular Start to the Next Generation Era

Sexual manipulation in the giant freshwater prawn Macrobrachium rosenbergii has proven successful in generating monosex (both all-male and all-female) populations for aquaculture using a crustacean-specific endocrine gland, the androgenic gland (AG), which serves as a key masculinizing factor by producing and secreting an insulin-like AG hormone (IAG). Here, we provide a summary of the advancements from the discovery of the AG and IAG in decapods through to the development of monosex populations in M. rosenbergii. We discuss the broader sexual development pathway, which is highly divergent across decapods, and provide our future perspective on the utility of novel genetic and genomic tools in promoting refined approaches towards monosex biotechnology. Finally, the future potential benefits of deploying monosex prawn populations for environmental management are discussed.