Nemo-like kinase (NLK) gene regulates apoptosis via the p53 signaling pathway in Litopenaeus vannamei under low-temperature stress

The hippo pathway: a molecular bridge between environmental cues and pace of life

The pace of life (POL) is shaped by a complex interplay between genetic and environmental factors, influencing growth, maturation, and lifespan across species. The Hippo signaling pathway, a key regulator of organ size and cellular homeostasis, has emerged as a central integrator of environmental cues that modulate POL traits. In this review, we explore how the Hippo pathway links environmental factors-such as temperature fluctuations and dietary energy availability-to molecular mechanisms governing metabolic balance, hormonal signaling, and reproductive timing. Specifically, we highlight the regulatory interactions between the Hippo pathway and metabolic sensors (AMPK, mTOR, SIRT1 and DLK1-Notch), as well as hormonal signals (IGF-1, kisspeptin, leptin, cortisol, thyroid and sex steroids), which together orchestrate key life-history traits, including growth rates, lifespan and sexual maturation, with a particular emphasis on their role in reproductive timing. Furthermore, we consider its role as a potential coordinator of POL-related molecular processes, such as telomere dynamics and epigenetic mechanisms, within a broader regulatory network. By integrating insights from molecular biology and eco-evolutionary perspectives, we propose future directions to dissect the Hippo pathway's role in POL regulation across taxa. Understanding these interactions will provide new perspectives on how organisms adaptively adjust life-history strategies in response to environmental variability.

Litopenaeus vannamei heat shock protein 90 (LvHSP90) interacts with white spot syndrome virus protein, WSSV322, to modulate hemocyte apoptosis during viral infection

As cellular chaperones, heat shock protein can facilitate viral infection in different steps of infection process. Previously, we have shown that the suppression of Litopenaeus vannamei (Lv)HSP90 not only results in a decline of white spot syndrome virus (WSSV) infection but also induces apoptosis in shrimp hemocyte cells. However, the mechanism underlying how LvHSP90 involved in WSSV infection remains largely unknown. In this study, a yeast two-hybrid assay and co-immunoprecipitation revealed that LvHSP90 interacts with the viral protein WSSV322 which function as an anti-apoptosis protein. Recombinant protein (r) LvHSP90 and rWSSV322 inhibited cycloheximide-induced hemocyte cell apoptosis in vitro. Co-silencing of LvHSP90 and WSSV322 in WSSV-infected shrimp led to a decrease in expression level of viral replication marker genes (VP28, ie-1) and WSSV copy number, while caspase 3/7 activity was noticeably induced. The number of apoptotic cells, confirmed by Hoechst 33342 staining assay and annexin V/PI staining, was significantly higher in LvHSP90 and WSSV322 co-silenced-shrimp than the control groups. Moreover, the co-silencing of LvHSP90 and WSSV322 triggered apoptosis by the mitochondrial pathway, resulting in the upregulation of pro-apoptotic protein expression (bax) and the downregulation of anti-apoptotic protein expression (bcl, Akt). This process also involved the release of cytochrome c (CytC) from the mitochondria and a decrease in mitochondrial membrane potential (MMP). These findings suggest that LvHSP90 interacts with WSSV322 to facilitate viral replication by inhibiting host apoptosis during WSSV infection.

Using a metabolomics approach to investigate the sensitivity of a potential Arctic-invader and its Arctic sister-species to marine heatwaves and traditional harvesting disturbances

Coastal species are threatened by fishing practices and changing environmental conditions, such as marine heatwaves (MHW). The mechanisms that confer tolerance to such stressors in marine invertebrates are poorly understood. However, differences in tolerance among different species may be attributed to their geographical distribution. To test the tolerance of species occupying different thermal ranges, we used two closely related bivalves the softshell clam Mya arenaria (Linnaeus, 1758), a cold-temperate invader with demonstrated potential for establishment in the Arctic, and the blunt gaper Mya truncata (Linnaeus, 1758), a native polar species. Clams were subjected to a thermal stress, mimicking a MHW, and harvesting stress in a controlled environment. Seven acute temperature changes (2, 7, 12, 17, 22, 27, and 32 °C) were tested at two harvesting disturbance intensities (with, without). Survival was measured after 12 days and three tissues (gills, mantle, and posterior adductor muscle) collected from surviving individuals for targeted metabolomic profiling. MHW tolerance differed significantly between species: 26.9 °C for M. arenaria and 17.8 °C for M. truncata, with a negligeable effect of harvesting. At the upper thermal limit, M. arenaria displayed a more profound metabolomic remodelling when compared to M. truncata, and this varied greatly between tissue types. Network analysis revealed differences in pathway utilization at the upper MHW limit, with M. arenaria displaying a greater reliance on multiple DNA repair and expression and cell signalling pathways, while M. truncata was limited to fewer pathways. This suggests that M. truncata is ill equipped to cope with warming environments. MHW patterning in the Northwest Atlantic may be a strong predictor of population survival and future range shifts in these two clam species. As polar environments undergo faster rates of warming compared to the global average, M. truncata may be outcompeted by M. arenaria expanding into its native range.

Regulation Mechanism of Dopamine Receptor 1 in Low Temperature Response of Marsupenaeus japonicus

Dopamine receptors (DARs) are important transmembrane receptors responsible for receiving extracellular signals in the DAR-mediated signaling pathway, and are involved in a variety of physiological functions. Herein, the D1 DAR gene from Marsupenaeus japonicus (MjDAD1) was identified and characterized. The protein encoded by MjDAD1 has the typical structure and functional domains of the G-protein coupled receptor family. MjDAD1 expression was significantly upregulated in the gills and hepatopancreas after low temperature stress. Moreover, double-stranded RNA-mediated silencing of MjDAD1 significantly changed the levels of protein kinases (PKA and PKC), second messengers (cyclic AMP (cAMP), cyclic cGMP, calmodulin, and diacyl glycerol), and G-protein effectors (adenylate cyclase and phospholipase C). Furthermore, MjDAD1 silencing increased the apoptosis rate of gill and hepatopancreas cells. Thus, following binding to their specific receptors, G-protein effectors are activated by MjDAD1, leading to DAD1-cAMP/PKA pathway-mediated regulation of caspase-dependent mitochondrial apoptosis. We suggest that MjDAD1 is indispensable for the environmental adaptation of M. japonicus.

Andrographis paniculata improves growth and non-specific immunity of shrimp Litopenaeus vannamei, and protects it from Vibrio alginolyticus by reducing oxidative stress and apoptosis

Andrographis paniculata (AP) is a traditional medicinal plant with many pharmacological activities, including anti-inflammatory, antimicrobial, immunity stimulation and so on. Several studies have reported that AP plays a strong role in promoting the immune system of aquatic animals to resist several pathogens. In the present study, we investigate the effects of a diet containing AP on the immune responses, growth, and the resistance to Vibrio alginolyticus (V. alginolyticus) in Litopenaeus vannamei (L. vannamei). Four diets were formulated by adding AP at the dosage of 0% (Control), 0.25%, 0.5%, and 1% in the basal diet, respectively. Each diet was randomly fed to one group with three replicates of shrimps in a 28-day feeding trial. The results showed that dietary AP improved the growth performance and non-specific immune function of shrimps. To investigate the effect of AP on disease resistance of L. vannamei, shrimps fed with diet containing AP were challenged with V. alginolyticus. Compared with the control group, the shrimps fed diet containing AP showed significantly higher survival. Furthermore, the hepatopancreas injury in the shrimp fed with AP was less than control group at 6 h after V. alginolyticus infection. However, no difference was observed in the degree of hepatopancreas injury between AP groups and control group at 12 h and 24 h after V. alginolyticus infection. Based on this result, the samples at 6 h after V. alginolyticus infection was selected for subsequent detection. Reactive oxygen species (ROS) accumulation in hemocytes and O₂^- production in hepatopancreas caused by V. alginolyticus infection was significantly reduced after feeding a diet containing 0.25% and 0.5% AP (p < 0.05). In addition, we found that feeding AP significantly up-regulated the expression of pro-apoptotic genes (Bax, Caspase 3, p53) and down-regulated the expression of anti-apoptotic genes (Bcl-2) in hepatopancreas after V. alginolyticus infection. In conclusion, AP promote the growth and immunity of L. vannamei, and protects shrimps against V. alginolyticus by regulating the oxidative damage and apoptosis. These results provide useful information regarding the effects of AP extracts as a shrimp feed additive for sustainable shrimp culture.

RNA-seq analysis of the differential response to low-temperature stress in two morphs of mud crabs (Scylla paramamosain)

The mud crab (Scylla paramamosain) is an economically important crab species that is distributed along the southern coast of China. Previously we reported that various morphological types of mud crabs differentially adapt to temperature changes. This study investigates the effects of temperature on morphs with one or two spines (Sp1 and Sp2, respectively) on the outer margin of the carpus of cheliped at a low temperature (8 °C) and a control temperature (20 °C). The hepatopancreas were the transcriptome source, and a total of 81,853 unigenes were obtained by sequencing, with an average length of 420 bp, and an N50 of 1460 bp. Of these, 22.33 % were known genes. Under low-temperature stress, there were 361 differentially expressed genes (DEGs) between the two morphs; 96 and 265 were up- and down-regulated genes, respectively. There were no DEGs between the morphs at 20 °C. Functional enrichment analysis revealed that the DEGs encoded abundant metallocarboxypeptidase activity, extracellular space, proteolysis, and sequence-specific DNA binding, and were further enriched in signal pathway components, including ubiquinone and other terpenoid-quinone biosynthesis, phenylalanine metabolism, MAPK signaling pathway, apoptosis, and other signaling pathways. The gene expressions of acid phosphatase (ACP), chymotrypsin (CHY), serine carboxypeptidase (SCP), and trypsin (TRY) under low-temperature stress were detected. The expressions of ACP, CHY, and SCP gradually decreased with time. The ACP, CHY, SCP, and TRY gene expression of the Sp1 morph was lower than that of the Sp2 morph; however, the ACP gene expression of the Sp1 morph was higher than that of the Sp2 morph at several time points. In conclusion, adaptability differences between the morphs to low-temperature stress were confirmed, which will enable the selection of cold-tolerant, high-quality varieties of mud crabs for breeding.