Transcriptomic analysis of male three-spot swimming crab (Portunus sanguinolentus) infected with the parasitic barnacle Diplothylacus sinensis

Diplothylacus sinensis is reported as an intriguing parasitic barnacle that can negatively affect the growth, molting, reproduction in several commercially important portunid crabs. To better understand the molecular mechanisms of host-parasite interactions, we characterized the gene expression profiles from the healthy and D. sinensis infected Portunus sanguinolentus by high-through sequence method. Totally, the transcriptomic analysis generated 52, 266, 600 and 51, 629, 604 high quality reads from the infected and control groups, respectively. The clean reads were assembled to 90,740 and 69,314 unigenes, with the average length of 760 bp and 709 bp, respectively. The expression analysis showed that 18,959 genes were significantly changed by the parasitism of D. sinensis, including 4769 activated genes and 14,190 suppressed genes. The differentially expressed genes were categorized into 258 KEGG pathways and 647 GO terms. The GO analysis mapped 13 DEGs related to immune system process and 32 DEGs related to immune response, respectively, suggesting a potential alteration of transcriptional expression patterns in complement cascades of P. sanguinolentus. Additionally, 4 representative molting-related genes were down-regulated in parasitized group, indicating D. sinensis infection appeared to suppress the producing of ecdysteroid hormones. In conclusion, the present study improves our understanding on parasite-host interaction mechanisms, which focuses the function of Ecdysone receptor, Toll-like receptor and cytokine receptor of crustacean crabs infestation with rhizocephalan parasites.

Elemental composition of three-spot swimming crab Portunus sanguinolentus (Herbst, 1783) shell from the coasts of Sindh and Balochistan, Pakistan

The present study aimed to investigate the elemental composition of the hard shell of the three-spot swimming crab, Portunus sanguinolentus, collected from the coasts of Pakistan. Thirty crab shells were collected and divided into three groups considering their size. The element detection was performed by energy-dispersive X-ray spectroscopy with scanning electron microscope (SIM/EDAX). The mean concentration of carbon, oxygen, calcium, copper, magnesium, and phosphorus observed in the shell of P. sanguinolentus was 13.63 ± 6.21%, 46.25 ± 12.62%, 34.39 ± 18.33%, 3.19 ± 1.25%, 1.15 ± 0.99%, and 1.39 ± 0.51%, respectively. The concentration pattern of these observed elements in P. sanguinolentus shells was found in the following order: O > Ca > C > Cu > P > Mg. To compare among the three groups of shells, the highest concentration of calcium (54.60%) was obtained in large-sized shell groups, which was significantly different from the other groups (p < 0.05). A high concentration of copper was found to be accumulated in the large-sized (3.55%) and medium-sized (4.21%) shell groups, which was significantly higher than in small-sized shell groups (p < 0.05). In the case of the large-sized shell group, the mean concentrations of magnesium and phosphorus were significantly lower than the medium-sized shell group (p < 0.05). The results indicate that crab shells could act as a good bio-sorbent for several minerals in its ecosystem. P. sanguinolentus shell is very rich in calcium, magnesium, and phosphorus. Extraction of calcium, magnesium, and phosphorus from P. sanguinolentus shells could be profitable for biofertilizer and pharmaceutical industries.

Identification of Sex-Related Genes from the Three-Spot Swimming Crab Portunus sanguinolentus and Comparative Analysis with the Crucifix Crab Charybdis feriatus

Simple Summary

Crabs within the family Portunidae are important marine species in both aquaculture and fishery sectors. The current aquaculture status of most portunids still relies on wild-caught fisheries due to the lack of essential knowledge regarding their reproductive biology and underlying governing mechanism. In the present study, we compared the differentially expressed genes (DEGs) between the different sexes of Portunus sanguinolentus based on their gonadal transcriptome profiles and subsequently contrasted them with the gonadal DEGs of Charybdis feriatus, the other member of the family Portunidae. In total, 40,964 DEGs between the ovaries and testes of P. sanguinolentus were uncovered, with 27,578 up-regulated and 13,386 down-regulated in females. After comparison, C. feriatus has approximately 63.5% of genes in common with P. sanguinolentus, with 62.6% showing similar expression patterns. Interestingly, the DMRT gene was specifically expressed in male P. sanguinolentus, while its homologous gene—doublesex (DSX)—was specifically expressed in male C. feriatus. The DEGs obtained from the gonadal transcriptome of P. sanguinolentus are a beneficial resource for future genetic and genomic research in P. sanguinolentus and its close species. The transcriptomic comparison analysis might provide references for better understanding the sex determination and differentiation mechanisms among portunids.

Abstract

Crabs within the family Portunidae are important marine species in both aquaculture and fishery sectors. The current aquaculture status of most portunids, however, still relies on wild-caught fisheries due to the lack of essential knowledge regarding their reproductive biology and underlying governing mechanism. With the advancement of sequencing technology, transcriptome sequencing has been progressively used to understand various physiological processes, especially on non-model organisms. In the present study, we compared the differentially expressed genes (DEGs) between sexes of Portunus sanguinolentus based on their gonadal transcriptome profiles and subsequently contrasted them with the gonadal DEGs of Charybdis feriatus, the other member of Family Portunidae. In total, 40,964 DEGs between ovaries and testes were uncovered, with 27,578 up- and 13,386 down-regulated in females. Among those, some sex-related DEGs were identified, including a dmrt-like (DMRT) gene which was specifically expressed in males. C. feriatus has approximately 63.5% of genes common with P. sanguinolentus, with 62.6% showing similar expression patterns. Interestingly, the DMRT gene was specifically expressed in male P. sanguinolentus while its homologous gene—doublesex (DSX)—was specifically expressed in male C. feriatus. The DEGs obtained from the gonadal transcriptome of P. sanguinolentus are a beneficial resource for future genetic and genomic research in P. sanguinolentus and its close species. The transcriptomic comparison analysis might provide references for better understanding the sex determination and differentiation mechanisms among portunids.

pH-sensitive chitosan nanoparticles loaded with dolutegravir as milk and food admixture for paediatric anti-HIV therapy

The present study aims to develop Chitosan-based polymeric nanoparticles of anti-HIV drug Dolutegravir, to aid appropriate dose adjustment and ease of oral administration as milk and food admixture for children. The isolated Chitosan from the crab shell species Portunus Sanguinolentus has been characterized for their physicochemical properties. Nanoparticles were developed with varying ratio of drug: Chitosan and assessed for particle size (140-548 nm), zeta potential (+26.1 mV) with a maximum of 75 % drug content. Nanoparticles exhibited improved stability and drug release in the 0.1 N HCl medium compared to pure drug. The MTT assay and the Syncytia inhibition assay in C8166 (T-lymphatic cell line) infected with HIV_IIIB viral strain, which showed better therapeutic efficiency and lesser cytotoxicity compared to the pure drug. In consonance with the data obtained, the use of chitosan from a novel source for drug delivery carrier has opened exceptional prospects for delivering drugs efficiently to paediatrics.

Complete sequence and characterization of mitochondrial genome in the swimming crab Portunus sanguinolentus (Herbst, 1783) (Decapoda, Brachyura, Portunidae)

The three-spot swimming crab Portunus sanguinolentus (Herbst, 1783) is a commercially important fishery species, widely distributed in the Indo-Pacific region. In this study, we present the complete mitochondrial genome of P. sanguinolentus. The genome is 16 027 bp in length with circular organization, encoding the standard set of 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. The overall A + T content is 65.60%, which is lower than that of its congeneric species Portunus pelagicus and Portunus trituberculatus. The mitogenome carries 1254 bp of intergenic region constituting 7.82% of the genome, and six pairs of overlapping genes with the overlap size from 1 to 7 bp. The complete mitogenome sequence information of P. sanguinolentus would provide useful data for further studies on population genetics and molecular systematics.