Transcriptomic Changes Following Induced De-Masculinisation of Australian Red Claw Crayfish Cherax quadricarinatus

Transcriptomic Analysis across Crayfish (Cherax quadricarinatus) Claw Regeneration Reveals Potential Stem Cell Sources for Cultivated Crustacean Meat

In the face of rising global demand and unsustainable production methods, cultivated crustacean meat (CCM) is proposed as an alternative means to produce delicious lobster, shrimp, and crab products. Cultivated meat requires starting stem cells that may vary in terms of potency and the propensity to proliferate or differentiate into myogenic (muscle-related) tissues. Recognizing that regenerating limbs are a non-lethal source of tissue and may harbor relevant stem cells, we selected those of the crayfish Cherax quadricarinatus as our model. To investigate stem cell activity, we conducted RNA-Seq analysis across six stages of claw regeneration (four pre-molt and two post-molt stages), along with histology and real-time quantitative PCR (qPCR). Our results showed that while genes related to energy production, muscle hypertrophy, and exoskeletal cuticle synthesis dominated the post-molt stages, growth factor receptors (FGFR, EGFR, TGFR, and BMPR) and those related to stem cell proliferation and potency (Cyclins, CDKs, Wnts, C-Myc, Klf4, Sox2, PCNA, and p53) were upregulated before the molt. Pre-molt upregulation in several genes occurred in two growth peaks; Stages 2 and 4. We therefore propose that pre-molt limb regeneration tissues, particularly those in the larger Stage 4, present a prolific and non-lethal source of stem cells for CCM development.

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.

Identifying sex-differential gene expression in the antennal gland of the swimming crab by transcriptomic analysis

The antennal glands (AnGs) are recognized as an important organ that functions in ion regulation and excretion in decapods. Previously, many studies had explored this organ at the biochemical, physiological, and ultrastructural levels but had few molecular resources. In this study, the transcriptomes of the male and female AnGs of Portunus trituberculatus were sequenced using RNA sequencing (RNA-Seq) technology. Genes involved in osmoregulation and organic/inorganic solute transport were identified. This suggests that AnGs might be involved in these physiological functions as versatile organs. A total of 469 differentially expressed genes (DEGs) were further identified between male and female transcriptomes and found to be male-biased. Enrichment analysis showed that females were enriched in amino acid metabolism and males were enriched in nucleic acid metabolism. These results suggested differences in possible metabolic patterns between males and females. Furthermore, two transcription factors related to reproduction, namely AF4/FMR2 family members Lilli (Lilli) and Virilizer (Vir), were identified in DEGs. Lilli was found to be specifically expressed in the male AnGs, whereas Vir showed high expression levels in the female AnGs. The expression of up-regulated metabolism and sexual development-related genes in three males and six females was verified by qRT-PCR and the pattern was found to be consistent with the transcriptome expression pattern. Our results suggest that although the AnG is a unified somatic tissue composed of individual cells, it still demonstrates distinct sex-specific expression patterns. These results provide foundational knowledge of the function and differences between male and female AnGs in P. trituberculatus.