scholarly journals Chemosensitivity and role of swimming legs of mud crab, Scylla paramamosain, in feeding activity as determined by electrocardiographic and behavioural observations

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11248
Author(s):  
Gunzo Kawamura ◽  
Chi Keong Loke ◽  
Leong Seng Lim ◽  
Annita Seok Kian Yong ◽  
Saleem Mustafa
Keyword(s):  
Scientific Evidence ◽  
Feeding Activity ◽  
Structural Features ◽  
Scylla Paramamosain ◽  
Mud Crab ◽  
Food Items ◽  
Feeding Activities ◽  
Underlying Mechanisms ◽  
Touch Stimulus

Swimming crabs have a characteristic fifth pair of legs that are flattened into paddles for swimming purposes. The dactyl of these legs bears a thick seta along its edge. The chemoreceptive and feeding properties of the seta are supported with scientific evidence; however, there is no available data on the sensitivity of the setae in portunid crabs. The underlying mechanisms of the chemo- and mechano-sensitivity of appendages and their involvement in feeding activities of the mud crab (Scylla paramamosain) were investigated using electrocardiography and behavioural assay, which focused on the responses of the mud crab to chemical and touch stimulus. Electrocardiography revealed the sensory properties of the appendages. The dactyls of swimming legs and the antennules were chemosensitive, but not mechanosensitive and vice versa for the antennae. However, the mouthparts, claws, and walking legs were chemo- and mechanosensitive. Only the chemosensitive appendages, including the swimming legs, were directly involved in feeding. The flattened dactyls of the swimming legs were more efficient than the pointed dactyls of the walking legs in detecting the food organism crawling on the substrate. The structural features enhanced the capacity of the crab in coming into contact with scattered food items. This study revealed that the swimming legs are important appendages for feeding in the mud crab.

scholarly journals A Possible Role of Allatostatin C in Inhibiting Ecdysone Biosynthesis Revealed in the Mud Crab Scylla paramamosain

2021 ◽  
Vol 8 ◽  
Author(s):  
An Liu ◽  
Wenyuan Shi ◽  
Dongdong Lin ◽  
Haihui Ye
Keyword(s):  
Scylla Paramamosain ◽  
Dependent Manner ◽  
Mud Crab ◽  
Methyl Farnesoate ◽  
Independent Manner ◽  
Wide Range ◽  
Negative Effect

C-type allatostatins (C-type ASTs) are a family of structurally related neuropeptides found in a wide range of insects and crustaceans. To date, the C-type allatostatin receptor in crustaceans has not been deorphaned, and little is known about its physiological functions. In this study, we aimed to functionally define a C-type ASTs receptor in the mud crab, Scylla paramamosian. We showed that C-type ASTs receptor can be activated by ScypaAST-C peptide in a dose-independent manner and by ScypaAST-CCC peptide in a dose-dependent manner with an IC50 value of 6.683 nM. Subsequently, in vivo and in vitro experiments were performed to investigate the potential roles of ScypaAST-C and ScypaAST-CCC peptides in the regulation of ecdysone (20E) and methyl farnesoate (MF) biosynthesis. The results indicated that ScypaAST-C inhibited biosynthesis of 20E in the Y-organ, whereas ScypaAST-CCC had no effect on the production of 20E. In addition, qRT-PCR showed that both ScypaAST-C and ScypaAST-CCC significantly decreased the level of expression of the MF biosynthetic enzyme gene in the mandibular organ, suggesting that the two neuropeptides have a negative effect on the MF biosynthesis in mandibular organs. In conclusion, this study provided new insight into the physiological roles of AST-C in inhibiting ecdysone biosynthesis. Furthermore, it was revealed that AST-C family peptides might inhibit MF biosynthesis in crustaceans.

scholarly journals Role of Oxytocin/Vasopressin-Like Peptide and Its Receptor in Vitellogenesis of Mud Crab

2020 ◽  
Vol 21 (7) ◽  
pp. 2297
Author(s):  
Dongdong Lin ◽  
Yujie Wei ◽  
Haihui Ye
Keyword(s):  
In Situ Hybridisation ◽  
Cerebral Ganglion ◽  
Scylla Paramamosain ◽  
Mud Crab ◽  
Signaling System ◽  
Regulation Of Metabolism ◽  
F Cells ◽  
17Β Estradiol

Oxytocin (OT)/vasopressin (VP) signaling system is important to the regulation of metabolism, osmoregulation, social behaviours, learning, and memory, while the regulatory mechanism on ovarian development is still unclear in invertebrates. In this study, Spot/vp-like and its receptor (Spot/vpr-like) were identified in the mud crab Scylla paramamosain. Spot/vp-like transcripts were mainly expressed in the nervous tissues, midgut, gill, hepatopancreas, and ovary, while Spot/vpr-like were widespread in various tissues including the hepatopancreas, ovary, and hemocytes. In situ hybridisation revealed that Spot/vp-like mRNA was mainly detected in 6–9th clusters in the cerebral ganglion, and oocytes and follicular cells in the ovary, while Spot/vpr-like was found to localise in F-cells in the hepatopancreas and oocytes in the ovary. In vitro experiment showed that the mRNA expression level of Spvg in the hepatopancreas, Spvgr in the ovary, and 17β-estradiol (E2) content in culture medium were significantly declined with the administration of synthetic SpOT/VP-like peptide. Besides, after the injection of SpOT/VP-like peptide, it led to the significantly reduced expression of Spvg in the hepatopancreas and subduced E2 content in the haemolymph in the crabs. In brief, SpOT/VP signaling system might inhibit vitellogenesis through neuroendocrine and autocrine/paracrine modes, which may be realised by inhibiting the release of E2.

The role of Mu-type glutathione S-transferase in the mud crab (Scylla paramamosain) during ammonia stress

2020 ◽  
Vol 227 ◽  
pp. 108642 ◽  
Author(s):  
Chang-Hong Cheng ◽  
Hong-Ling Ma ◽  
Yi-Qin Deng ◽  
Juan Feng ◽  
Xiao-Long Chen ◽  
...  
Keyword(s):  
Scylla Paramamosain ◽  
Mud Crab ◽  
Glutathione S Transferase ◽  
Ammonia Stress

scholarly journals Cryo-electron Microscopy Structures of Novel Viruses from Mud Crab Scylla paramamosain with Multiple Infections

2019 ◽  
Vol 93 (7) ◽  
Author(s):  
Yuanzhu Gao ◽  
Shanshan Liu ◽  
Jiamiao Huang ◽  
Qianqian Wang ◽  
Kunpeng Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
3D Structure ◽  
Structural Features ◽  
Economic Losses ◽  
Scylla Paramamosain ◽  
Multiple Infections ◽  
Mud Crab ◽  
Cryo Electron Microscopy ◽  
Novel Virus ◽  
Icosahedral Capsid

ABSTRACT Viruses associated with sleeping disease (SD) in crabs cause great economic losses to aquaculture, and no effective measures are available for their prevention. In this study, to help develop novel antiviral strategies, single-particle cryo-electron microscopy was applied to investigate viruses associated with SD. The results not only revealed the structure of mud crab dicistrovirus (MCDV) but also identified a novel mud crab tombus-like virus (MCTV) not previously detected using molecular biology methods. The structure of MCDV at a 3.5-Å resolution reveals three major capsid proteins (VP1 to VP3) organized into a pseudo-T=3 icosahedral capsid, and affirms the existence of VP4. Unusually, MCDV VP3 contains a long C-terminal region and forms a novel protrusion that has not been observed in other dicistrovirus. Our results also reveal that MCDV can release its genome via conformation changes of the protrusions when viral mixtures are heated. The structure of MCTV at a 3.3-Å resolution reveals a T= 3 icosahedral capsid with common features of both tombusviruses and nodaviruses. Furthermore, MCTV has a novel hydrophobic tunnel beneath the 5-fold vertex and 30 dimeric protrusions composed of the P-domains of the capsid protein at the 2-fold axes that are exposed on the virion surface. The structural features of MCTV are consistent with a novel type of virus. IMPORTANCE Pathogen identification is vital for unknown infectious outbreaks, especially for dual or multiple infections. Sleeping disease (SD) in crabs causes great economic losses to aquaculture worldwide. Here we report the discovery and identification of a novel virus in mud crabs with multiple infections that was not previously detected by molecular, immune, or traditional electron microscopy (EM) methods. High-resolution structures of pathogenic viruses are essential for a molecular understanding and developing new disease prevention methods. The three-dimensional (3D) structure of the mud crab tombus-like virus (MCTV) and mud crab dicistrovirus (MCDV) determined in this study could assist the development of antiviral inhibitors. The identification of a novel virus in multiple infections previously missed using other methods demonstrates the usefulness of this strategy for investigating multiple infectious outbreaks, even in humans and other animals.

Immunomodulatory role of crustacean cardioactive peptide in the mud crab Scylla paramamosain

2022 ◽  
Author(s):  
Yujie Wei ◽  
Zhanning Xu ◽  
Shuang Hao ◽  
Songlin Guo ◽  
Huiyang Huang ◽  
...  
Keyword(s):  
Scylla Paramamosain ◽  
Mud Crab ◽  
Crustacean Cardioactive Peptide

Role of neuroparsin 1 in vitellogenesis in the mud crab, Scylla paramamosain

2020 ◽  
Vol 285 ◽  
pp. 113248 ◽  
Author(s):  
Jing Liu ◽  
An Liu ◽  
Fang Liu ◽  
Huiyang Huang ◽  
Haihui Ye
Keyword(s):  
Scylla Paramamosain ◽  
Mud Crab

scholarly journals Reacciones adversas a los alimentos: ¿Cuál es el papel de los microorganismos?

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Alberto Caminero
Keyword(s):  
Adverse Reactions ◽  
Scientific Evidence ◽  
Fecal Microbiota ◽  
Point Of View ◽  
Food Allergies ◽  
Vast Number ◽  
New Therapeutic Approaches ◽  
Underlying Mechanisms ◽  
And Function

It is estimated that around 25% of the population worldwide experience adverse reactions to food, which are very diverse based on both etiology and clinical presentation. According to the pathophysiological processes involved, adverse reactions to foods can be broadly classified as sensitivities or intolerances, depending on whether they are immune-mediated, or not. Specifically, food sensitivities have become a growing clinical, economic, and social problem nowadays. Although the reason for the increased prevalence of well-determined food sensitives such as celiac disease and food allergies is not well understood, the role of microbes in both inducing and protecting from these conditions has been proposed. First, several studies suggest that the gut microbiota, the vast number of microbes that live in our digestive tract, influence the appearance of different adverse reactions to food. These studies are based on observational changes in the composition and function of the fecal microbiota of celiac, allergic and food intolerant patients when compared to controls or healthy participants. Second, infectious microbial agents have been related to the loss of oral tolerance towards dietary components and the occurrence of different adverse reactions to foods. However, how could microbes participate in food sensitivities and intolerances from a mechanistic point of view? Preclinical studies with animal models not only support observations in humans, they also show a causal role of microbes in the occurrence and course of these diseases, while informing the specific underlying mechanisms. The aim of this review is to summarize the scientific evidence that supports the role of microbes in the main adverse reactions to food described, with an emphasis on the underlying mechanisms. The discovery of the main molecular pathways involved in pathogenic reactions to diet foods will accelerate the development of new therapeutic approaches with the aim of preventing and treating food sensitivities and intolerances.

scholarly journals miR-2 contributes to WSSV infection by targeting Caspase 2 in mud crab (Scylla paramamosain)

2021 ◽  
Author(s):  
Yi Gong ◽  
Jiao Chen ◽  
Yalei Cui ◽  
Sheng-Kang Li
Keyword(s):  
Immune Response ◽  
White Spot Syndrome Virus ◽  
Marine Invertebrates ◽  
Regulatory Function ◽  
Scylla Paramamosain ◽  
Apoptosis Induction ◽  
Mud Crab ◽  
Caspase 2 ◽  
The Relationship

As we known, Caspase 2 is widely studied for its apoptosis regulatory function in mammals. However, despite the fundamental role of apoptosis during the anti-viral immune response, the relationship between Caspase 2 and virus infection has not been extensively explored in invertebrates, whether miRNAs are involved in this process also remains unclear. To address this issue, the miRNA-mediated regulation of Caspase 2 in mud crab Scylla paramamosain was characterized in this study. The results suggested that Sp-Caspase 2 could suppress white spot syndrome virus (WSSV) infection via apoptosis induction. The further data showed that Caspase 2 was directly targeted by miR-2 in mud crab. Silencing or overexpression of miR-2 could affect apoptosis and WSSV replication through regulating the expression level of Caspase 2. Taken together, all these results demonstrated the crucial role of miR-2-Caspase 2 pathway in the innate immunity of mud crab and revealed a novel mechanism during anti-viral immune response in marine invertebrates.

Immunomodulatory role of short neuropeptide F in the mud crab Scylla paramamosain

2021 ◽  
pp. 104260
Author(s):  
Zhanning Xu ◽  
Yujie Wei ◽  
Huiyang Huang ◽  
Songlin Guo ◽  
Haihui Ye
Keyword(s):  
Scylla Paramamosain ◽  
Mud Crab ◽  
Neuropeptide F
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