Isolation and characterization of three skeletal troponin genes and association with growth-related traits in Exopalaemon carinicauda

Advancing Cardiomyocyte Maturation: Current Strategies and Promising Conductive Polymer-Based Approaches

Cardiovascular diseases are a leading cause of mortality and pose a significant burden on healthcare systems worldwide. Despite remarkable progress in medical research, the development of effective cardiovascular drugs has been hindered by high failure rates and escalating costs. One contributing factor is the limited availability of mature cardiomyocytes (CMs) for accurate disease modeling and drug screening. Human induced pluripotent stem cell-derived CMs offer a promising source of CMs; however, their immature phenotype presents challenges in translational applications. This review focuses on the road to achieving mature CMs by summarizing the major differences between immature and mature CMs, discussing the importance of adult-like CMs for drug discovery, highlighting the limitations of current strategies, and exploring potential solutions using electro-mechano active polymer-based scaffolds based on conductive polymers. However, critical considerations such as the trade-off between 3D systems and nutrient exchange, biocompatibility, degradation, cell adhesion, longevity, and integration into wider systems must be carefully evaluated. Continued advancements in these areas will contribute to a better understanding of cardiac diseases, improved drug discovery, and the development of personalized treatment strategies for patients with cardiovascular disorders.

Growth trait gene analysis of kuruma shrimp (Marsupenaeus japonicus) by transcriptome study

Growth traits are a vital standard for the animal culture industry. The molecular mechanism of growth traits remains poorly understood, especially in aquaculture, which hinders the development of the selective breeding industry. Genomic resources discovered by next-generation sequencing (NGS) have been widely applied in certain species. However, accurate assembly and downstream analysis by NGS are still major challenges for species without reference genomes. In this study, a comparative transcriptome analysis of an economic crustacean species (Marsupenaeus japonicus) between a fast growth group and slow growth group at different stages was performed by SMRT (single molecule real time) and NGS. A high-quality full-length transcriptome (e.g., mean length of unigenes was longer than those unigenes assembled by Illumina clean reads from previous reports, and annotation rate was higher than Illumina sequencing in the same studies) was generated and analyzed. Several differentially expressed genes (DEGs) related to growth were identified and validated by quantitative real-time PCR (qPCR). The results showed that compared with the late stage, more DEGs were identified at the early stage, indicating that the growth-related physiological activity differences between different individuals at the early stage were higher than at the late stage. Moreover, 215 DEGs were shared between the early stage and late stage, and 109 had divergent functions during development. These 109 genes may play an important role in regulating the specific growth rate (SGR) of kuruma shrimp. In addition, twelve growth-related pathways were shared between the two comparative groups. Among these pathways, the fly Hippo signaling pathway and its key gene Mj14-3-3-like were identified for the first time to be involved in growth traits in crustaceans. Further analysis showed that Mj14-3-3-like was significantly downregulated in the fast growth group at the early stage and late stage; its expression level was reduced to its lowest level at the intermolt stage (C), the most important growth stage in shrimp, suggesting that Mj14-3-3-like may inhibit the growth of kuruma shrimp. Our study helps to elucidate the genes involved in the molecular mechanisms governing growth traits in kuruma shrimp, which is valuable for future shrimp developmental research.

Proteomic analysis of individual giant freshwater prawn, Macrobrachium rosenbergii, growth retardants

"Iron prawn" is a condition of severe growth retardation that fishers call. The giant river prawn (Macrobrachium rosenbergii) is a commercially important species contains high protein content and functional nutrients. However, no proteomic information is available for this species. We performed the shotgun 2DLC-MS/MS proteomic analysis of the total protein from "iron prawn". Total 19,758 peptides corresponding to 2613 high-confidence proteins were identified. These proteins range in size from 40 to 70 kDa. KEGG analysis revealed that the largest group consisting total 102 KEGG pathway proteins comparing the "iron prawn" with the normal prawn. Additionally, 7, 11, 1, 6, and 5 commercially important enzymes were found in the eyestalk, liver, muscle, ovary, and testis, respectively. The functions of these differently expressed enzymes include immune system action against pathogens, muscle contraction, digestive system metabolism, cell differentiation, migration, and apoptosis in the severe growth retardation of "iron prawn". Our work provides insight into the understanding of the formation mechanism of "iron prawn".

Molecular characterization of troponin T in Scylla paramamosain and its role in Vibrio alginolyticus and white spot syndrome virus (WSSV) infection

This study investigated the function of Troponin T (TnT) in the mud crab, Scylla paramamosain. The 1952 bp cDNA sequence of TnT was cloned from S. paramamosain using rapid amplification of cDNA ends (RACE) PCR. The quantitative real-time PCR analysis showed that TnT was highly expressed in the muscle and heart of S. paramamosain. Challenging with white spot syndrome virus (WSSV) or Vibrio alginolyticus (VA), two common pathogens that infect mud crabs, enhanced the expression of TnT in S. paramamosain. Knockdown of TnT using TnT-dsRNA led to up-regulating the expression of immune-related genes, such as c-type-lectin, toll-like-receptor, crustin antimicrobial peptide and prophenoloxidase. The cumulative mortality of WSSV- and VA-infected crabs was significantly increased following TnT knockdown. After WSSV or VA infection, TnT knockdown caused a significant reduction in phenoloxidase (PO) activity, superoxide dismutase (SOD) activity and total hemocyte count (THC), indicating a regulatory role of TnT in the innate immune response of S. paramamosain to pathogens. Apoptosis of hemocytes was higher in crabs treated with TnT-dsRNA compared with control crabs treated with phosphate-buffered saline. Knockdown of TnT increased apoptosis of hemocytes following VA infection, but reduced hemocyte apoptosis following WSSV infection. In summary, TnT may enhance the immune response of S. paramamosain to WSSV infection by regulating apoptosis, THC, PO activity and SOD activity. And TnT may play a positive role in the immune response against VA infection by regulating apoptosis, THC, SOD activity and PO activity.

Transcriptional profiling of skeletal muscle reveals starvation response and compensatory growth in Spinibarbus hollandi

BACKGROUND

Spinibarbus hollandi is an economically important fish species in southern China. This fish is known to have nutritional and medicinal properties; however, its farming is limited by its slow growth rate. In the present study, we observed that a compensatory growth phenomenon could be induced by adequate refeeding following 7 days of fasting in S. hollandi. To understand the starvation response and compensatory growth mechanisms in this fish, the muscle transcriptomes of S. hollandi under control, fasting, and refeeding conditions were profiled using next-generation sequencing (NGS) techniques.

RESULTS

More than 4.45 × 108 quality-filtered 150-base-pair Illumina reads were obtained from all nine muscle samples. De novo assemblies yielded a total of 156,735 unigenes, among which 142,918 (91.18%) could be annotated in at least one available database. After 7 days of fasting, 2422 differentially expressed genes were detected, including 1510 up-regulated genes and 912 down-regulated genes. Genes involved in fat, protein, and carbohydrate metabolism were significantly up-regulated, and genes associated with the cell cycle, DNA replication, and immune and cellular structures were inhibited during fasting. After refeeding, 84 up-regulated genes and 16 down-regulated genes were identified. Many genes encoding the components of myofibers were significantly up-regulated. Histological analysis of muscle verified the important role of muscle hypertrophy in compensatory growth.

CONCLUSION

In the present work, we reported the transcriptome profiles of S. hollandi muscle under different conditions. During fasting, the genes involved in the mobilization of stored energy were up-regulated, while the genes associated with growth were down-regulated. After refeeding, muscle hypertrophy contributed to the recovery of growth. The results of this study may help to elucidate the mechanisms underlying the starvation response and compensatory growth.