Invertebrate Survival Journal

Cloning and subcellular localization of silkworm suppressor of cytokine signaling 6 and its expressional changes in response to the infection of Bombyx mori nucleopolyhedrovirus

M Cui — 2024-04-08

The role of suppressor of cytokine signaling (SOCS) 6 in the silkworm growth and development and in the immune response to Bombyx mori nucleopolyhedrovirus (BmNPV) infection remains largely unclear. In this study, we cloned the ORF of silkworm SOCS6, named as BmSOCS6. We found that BmSOCS6 locates mainly in cytoplasmic space, and expresses at the highest level in embryogenesis. BmSOCS6 expresses relatively highly in the fat body of BmNPV-susceptible silkworm 306 but lowly in BmNPV-resistant silkworm NB and BC8, and BmNPV inoculation further reduces its expression with more pronounced effect in NB and BC8 than 306. However, BmSOCS6 expression in the midgut and hemolymph decreases without BmNPV inoculation but recovers with BmNPV inoculation, both of which are more pronounced in NB and BC8 than 306. BmNPV inoculation also induces a general down-regulation of BmSOCS6 expression in BmN cells. SOCS6 has previously been shown to positively regulate apoptosis and negatively regulate the production of antimicrobial peptides (AMPs). Therefore, compared to susceptible silkworms, BmSOCS6 may promote apoptosis in the midgut and hemolymph with increased expression and enhance the production of AMPs in the fat body with decreased expression, contributing to the resistance to BmNPV infection in resistant silkworms.

Identification and expression analysis of Na+/K+-ATPase and NKA-interacting protein in oyster

K Zhang — 2024-09-19

Oysters hold a key ecological position in intertidal ecosystems worldwide, and their distribution across various sea areas is largely influenced by the range of salinity. Sodium-potassium ATPase (NKA), a central ion pump involved in maintaining cellular osmotic balance, plays a pivotal role in oyster adaptation to salinity fluctuations. This study identified one NKA-α subunit and two distinct NKA-β subunits by utilizing genome assemblies and transcriptomics data from multiple oyster species. Furthermore, we discovered a conserved NKA-interacting protein (NKAIN) in oysters. Through transcriptome assembly, we identified five different splice variants of NKAIN in oysters. Sequence alignment and phylogenetic analysis confirmed the high conservation of NKA-α and -β subunits in oysters, albeit with significant distinction between the two -β subunits. Multi-population comparative transcriptomic analysis illuminated the regulatory roles of NKA and NKAIN in the adaptive responses to salinity stress. The findings shed light on the compositional details and osmotic regulation mechanisms of the oyster's NKA-NKAIN system, thereby enhancing our understanding of the comprehensive osmotic adaptation mechanisms in oysters. This knowledge is instrumental for future studies aiming to improve oyster resilience to environmental salinity changes.

Toxicological effects of caffeine on the antioxidant defense system and some biochemical responses in earthworm, Allolobophora caliginosa

HM El-Danasoury — 2024-08-05

Allolobophora caliginosa, an earthworm, was exposed to caffeine (CAF) via artificial soil to evaluate the effects on antioxidant enzymes in animals treated to 0, 10, 20, 40, and 80 mg CAF/kg soil after 7, 14, 28, and 56 d of exposure. There is evidence that antioxidant enzymes protect cells from free radical damage. A high CAF concentration generated changes in the activities of superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxide (POD), but had slight effects on malondialdehyde (MDA) levels after 56 d of exposure. Earthworms¢ MDA levels elevated somewhat after 7, 14, and 28 d. Earthworms treated with CAF were unable to induce the cytotoxic action over a very long period of time (56 d), as three enzymes [polyphenol oxidase (PPO), acetyl cholinesterase (AChE), and cellulose] were significantly inhibited. These data support the notion that oxidative stress plays a role in the response of earthworms to CAF poisoning.

Sequence features and expression profiles of a novel α-amylase gene from Chinese mitten crab Eriocheir sinensis

S-R Shao — 2024-04-08

Amylase is the main digestive enzyme in crustaceans, and plays extremely important roles in metabolism, growth and development. Some studies have also shown that amylase may play a role in the immune defense system of aquatic organisms. In this study, a novel α-amylase gene (designated as EsAMY) was cloned and identified from Chinese mitten crab Eriocheir sinensis. The complete cDNA sequence of EsAMY contained a 5' untranslated region (UTR) of 39 bp, a 3' UTR of 70 bp with a polyA tail, and an open reading frame (ORF) of 1554 bp encoding a polypeptide of 517 amino acids with the predicted molecular weight of 56.9 kDa. The deduced amino acids sequence of EsAMY contained conserved cysteine site, active catalytic site, calcium binding site and chloride binding site, which was similar with previously identified α-amylase genes in other species. Quantitative real-time PCR (qPCR) analysis showed that EsAMY transcripts were detectable in all the tested tissues, with the highest mRNA expression levels in hemocytes. Both Aeromonas hydrophila and polybrominated diphenyl ether-47 (BDE-47) stimulation could significantly induce the mRNA expression of EsAMY gene in hemocytes, and its responses to A. hydrophila was more intense than those of BDE-47. These results indicate that EsAMY is a new member of the amylase family and may be involved in the immune response of Chinese mitten crab to both invasive microorganisms and external pollutant stimulation.

Sequence characterization and expression analysis of a PDGF/VEGF related factor gene in swimming crab Portunus trituberculatus

Y Gu — 2024-02-23

PDGF/VEGF factors are closely associated with immune defense systems. In this study, a PDGF/VEGF related factor gene (designated as PtPVF) from swimming crab Portunus trituberculatus was identified and analyzed. Its full-length cDNA is 1320 bp, containing an open reading frame (ORF) of 582 bp, 5’ untranslated regions (UTR) of 105 bp and 3’ UTR of 633 bp, which encoded a polypeptide of 193 amino acid residues. The deduced amino acid sequence of PtPVF contained a signal peptide, a typical PDGF/VEGF domain, and a cysteine knot motif (CXCXC). Quantitative real-time PCR analysis demonstrated that the mRNA of PtPVF was detectable in gills, gonads, heart, hemocytes, hepatopancreas, intestines, muscles, optic stalk, stomach, and the highest level was found in hemocytes, followed by gill and hepatopancreas. After stimulation by Vibrio alginolyticus, pentachlorophenol (PCP) or cadmium chloride (CdCl2), the relative mRNA expression levels of PtPVF in hemocytes reached their respective peaks at 3 h, 6 h and 6 h, and 36.61-fold, 3.06-fold and 21.26-fold compared with the original level, respectively, and the respond to V. alginolyticus and CdCl2 is earlier than to PCP, while under the challenge of V. alginolyticus and CdCl2, the mRNA expression level of PtPVF was significantly higher than that of PCP stimulation. Furthermore, the mRNA expression level of PtPVF first decreased at 3 h and then increased rapidly to a peak at 6 h after PCP challenge. All these results demonstrated that PtPVF might be involved in the response to invading pathogens and environmental pollution stimulants of P. trituberculatus.

Combined effects of some insecticides and different isolates of Beauveria bassiana and Metarhizium anisopliae on mortality and immune responses of Chilo suppressalis Walker (Lepidoptera: Crambidae)

H Firouzbakht — 2024-07-23

The combined use of microbial agents and chemical insecticides is an effective strategy against insect pests in agroecosystems. This study evaluates the effects of four insecticides-permethrin, fenitrothion, trichlorfon, and tebufenozide-together with four isolates of the entomopathogenic fungus Beauveria bassiana and two isolates of Metarhizium anisopliae on the fourth instar larvae of Chilo suppressalis. In the first experiment, treatment with fungal isolates induced the activities of general esterases and glutathione S-transferases (GST) in the larvae. Field concentrations of insecticides increased larval mortality in both control and fungus-treated groups, except for BBLN2, which showed no significant difference. In the second experiment, conidia cultured in control and insecticide-treated media were exposed to field concentrations of insecticides on C. suppressalis larvae. This resulted in a significant decrease in larval mortality when treated with conidia cultured with insecticides. In the third experiment, larvae treated with permethrin exhibited the highest total hemocyte counts among those injected with BBLN1 and BBLN2, whereas larvae treated with fenitrothion and trichlorfon showed similar results after injection with BBAL1. All insecticide and fungal isolate treatments increased phenoloxidase activity compared to control larvae. These results underscore the importance of screening for optimal combinations of insecticides and entomopathogenic fungi to enhance control measures, which depend on the specific fungal isolate and type of insecticide.

XXIV scientific meeting of the Italian Association of Developmental and Comparative Immunology (IADCI), February 14-16, 2024, Department of Life Sciences - DSV, University of Modena and Reggio Emilia, National Academy of Sciences, Letters and Arts, Modena

D Malagoli — 2024-04-29

Detection and control of pébrine disease in the silkworm (Bombyx mori)

H Gu — 2024-09-19

Pébrine disease in silkworms, caused by Nosema bombycis, significantly impacts silkworm reproduction and cocoon quality. Recognized as a legal quarantine concern in silkworm egg production, the damage from pébrine disease is on the rise. Currently, sericulture production relies on a combination of chemical and physical methods for pébrine control. Rapid and precise detection of N. bombycis is essential for effective disease management. Detection methods for microsporidia in silkworms include optical microscopy, electron microscopy, immunological methods, and molecular biology techniques such as PCR, qPCR, and LAMP technologies, along with biosensor-based methods. Despite their respective advantages, these methods face challenges in large-scale application. To effectively combat pébrine disease, future research must focus on developing innovative detection methods that are highly efficient, rapid, accurate, portable, and suitable for on-site instant detection of N. bombycis, thereby ensuring better control and swift detection of pébrine disease in silkworms.

Regeneration puzzle: correlations of immunity and DNA methylation in regenerative annelid models

C Brotzki da Costa — 2024-04-29

Distinct gene expression patterns are important to various biological functions, spanning developmental processes, wound healing, and the restoration of body parts. Moreover, immunity intertwines with these processes, as researchers propose links between immune system evolution and the variable regenerative capacities seen across different organisms. Concomitantly, elements that influence gene expression can also affect regeneration, since DNA methylation is a key epigenetic mechanism that emerges as a critical regulator of cellular fate and behavior. While various studies propose methodologies for detecting and quantifying DNA methylation under diverse experimental settings, its interaction with regeneration remains relatively unexplored, particularly in annelids. This review aims to address this gap through exploring the connections between immunity, regeneration, and epigenetics by compiling information from studies conducted in different organisms and focusing on annelids as regenerative models. Additionally, it also provides an overview of protocols applying monoclonal antibodies to target specific DNA methylation forms.