Changes in bud morphology, growth-related genes and nutritional status during cheliped regeneration in the Chinese mitten crab, Eriocheir sinensis

Abstract

During pond culture of Eriocheir sinensis, a high limb-impairment rate restricts the industry development and quality. Therefore, research on limb autotomy and regeneration has important practical significance for the industrial development and basic biology of E. sinensis. This study evaluated the changes in bud morphology, growth-related gene expression and nutritional status during cheliped regeneration in E. sinensis. The study found that the new cheliped was pre-formed in the bud and then regenerated with the completion of molting of E. sinensis. The new cheliped was similar in morphology to the normal cheliped after the first molting but smaller in size. The qRT-PCR results of growth-related genes showed that the expression levels of EcR-mRNA (ecdysteroid receptor) and Chi-mRNA (chitinase) were significantly up-regulated, whereas the expression of MIH-mRNA (molt-inhibiting hormone) was significantly down-regulated (P < 0.05). The nutritional status during the regeneration process showed that the hepatopancreas total lipid content decreased significantly within 28 days and was significantly lower in the autotomy group than in the control group at 14 d and 21 d (P < 0.05). The hepatopancreas fatty acid composition results showed that saturated fatty acids (SFA), highly unsaturated fatty acids (HUFA) and n-3/n-6 were significantly higher in the autotomy group than in the control group at 21 d (P < 0.05), whereas the ∑ n-6 PUFA and ∑ n-3 PUFA at 1 d and 7 d, and the monounsaturated fatty acid (MUFA) at 28 d in the autotomy group were significantly lower than in the control group (P < 0.05). Moreover, the levels of eicosatetraenoic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) showed that DHA was significantly lower at 7 d and significantly higher at 21 d in the autotomy group than in the control group (P < 0.05), whereas ARA and EPA were not significantly different between the two groups. Muscle L-tryptophan content was significantly lower at 1 d and significantly higher at 7 d in the autotomy group than in the control group (P < 0.05). These results indicate that during the cheliped regeneration process, crabs could accelerate molting and regeneration by regulating growth-related gene expression (e.g., EcR-mRNA and MIH-mRNA) and nutrient metabolism (e.g., lipid metabolism).

Comparative Study on Growth Index and Nutritional Quality of Female Chinese Mitten Crab Eriocheir sinensis Selected at Different Growth Periods in Rice-Crab Culture Systems

“…Chitinase ( CHI ) can hydrolyze chitin in old bones. Therefore, CHI plays an important role in the molting process of E. sinensis [ 34 ]. In this experiment, female E. sinensis 20-E content and mRNA expression levels of RXR and CHI reached their maximum values on August 15, and the mRNA expression level of RXR was higher from August 15 to August 30, which was similar to the change trend of weight gain, weight gain rate, and specific growth rate of female E. sinensis in our previous research results, confirming that the 20-E content was closely related to the growth and development.…”

Recent development in ecdysone receptor of crustaceans: current knowledge and future applications in crustacean aquaculture

“…According to a study by Wang et al (2017), the CPGs are regulated by HR3 and HR4 , and it has been shown that CPG10 may regulate cuticle pressure by activating the ecdysone biosynthesis process. Looking specifically at crustaceans, Zhang et al (2018) showed that the gene expressions of CHT and EcR were significantly upregulated during E. sinensis limb bud regeneration. Although available in all moult stages of juvenile shrimps Fenneropenaeus chinensis , two CHT genes ( FcChi and FcChi‐1 ) showed increased expressions during premoult stage and peaked at late premoult stage (Priya et al 2009).…”

“…The involvement of EcR and RXR in protein synthesis of crabs during the regeneration phase is evident based on their high expressions during this phase (Durica et al 2002). For example, limb autotomy resulted in the upregulation of EcR mRNA expression in various tissues of E. sinensis and subsequently promoted limb regeneration and moulting (Zhang et al 2018). It was noted that the concentration of EcR mRNA shows slight reduction at the end of proecdysis and right before the next moult in fiddler crab Uca pugilator (Chung et al 1998).…”

Impact of salinity changes on growth, oxygen consumption and expression pattern of selected candidate genes in the orange mud crab ( Scylla olivacea )

“…Specialized biological traits (ability to rapidly regulate: body fluid osmolality, cellular volume in the gill lamellae and gene expression) present in crabs (also broadly across the crustaceans that exhibit spawning migrations) are believed to be the main driving force for their ability to tolerate wide-ranging salinities (Lv et al, 2019;Rahi, Mather, Ezaz, & Hurwood, 2019;Zhang et al, 2018).…”

“…Ionic balance is the major problem for any aquatic organisms if environmental salinity levels changes (Freire, Onken, & McNamara, 2008; Lv et al., 2013; Moshtaghi, Rahi, Mather, & Hurwood, 2018; Rahi, Amin, Mather, & Hurwood, 2017). Specialized biological traits (ability to rapidly regulate: body fluid osmolality, cellular volume in the gill lamellae and gene expression) present in crabs (also broadly across the crustaceans that exhibit spawning migrations) are believed to be the main driving force for their ability to tolerate wide‐ranging salinities (Lv et al., 2019; Rahi, Mather, Ezaz, & Hurwood, 2019; Zhang et al., 2018).…”