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The complement component 9 (C9) plays a significant role in the formation of membrane attack complex (MAC) on the targeted cell surface. The current study is dealt with molecular characterization of C9 gene from rohu, Labeo rohita, an important cultured carp species in India. An open reading frame (ORF) of 1998 bp was amplified by polymerase chain reaction (PCR) that encodes a polypeptide of 666 amino acids having a signal peptide of 19 amino acids and a mature peptide of 647 amino acids. The SMART domain architecture analysis revealed two thrombospondin type‐1 domains (TSP1), a low‐density lipoprotein receptor domain class A (LDLa), a membrane attack complex and perforin (MACPF) domain, and an epidermal growth factor (EGF)‐like domain. Multiple sequence alignment and evolutionary analysis revealed a primitive C9 sequence of rohu with maximum similarity and clustering with common carp, grass carp and zebrafish. C9 was highly expressed in liver and constitutively expressed in wide array of tissues except in eye of rohu juveniles. It was expressed during early developmental days of rohu including in milt. A variable level of up‐regulation in C9 expression was noticed upon poly I:C induction, Aeromonas hydrophila and Argulus siamensis infections in liver, spleen and gill tissues of rohu at different time points. A constitutive expression of C9 in different stages of rohu during the ontogeny and in response to pathogen exposures along with high degree of sequence homology with other fish species proved it as an important primitive immune molecule of the complement system lytic pathway. [ABSTRACT FROM AUTHOR]

Abstract: Parasite species often show a heterogeneous, highly dispersed pattern of infestation within hosts. Varieties of factors including morphological, physiological, immunological and nutritional characteristics affect the infestation level of a specific parasite in homogenous pray. Limited attempts, however, have been made to explore such underlying drivers of infestation pattern. Here, three stages of Labeo rohita (fingerling, juvenile and pre‐adult) were challenged with ectoparasite, Argulus siamensis in same aquaria. The parasite load on individuals was determined at 5‐day interval for 1 month. The load was found to be highest in pre‐adult stage followed by juveniles and fingerlings. On day 20 post infection, the load of parasite on pre‐adult fish was high along with detectable skin damages. Skin tissues were collected for immune gene expression analysis and histopathology. Histological studies showed increased melanization in the dermis and mild inflammatory cellular reactions in pre‐adult fish whereas, massive subcutaneous myositis with engorged blood vessels were observed in fingerlings. The expression levels of various inflammation and innate immune‐related genes viz., interleukin (IL)‐8, IL‐10, IL‐11, IL‐15, natural killer enhancing factor, toll‐like receptor 4, apolipoprotein A–I and immunoglobulin Z were significantly high in skin samples of infected fingerlings as compared to other two growth stages or controls of each stage. On the other hand, the expression of immunoglobulin M was down‐regulated in all infected samples as compared to their respective controls. The results thus depict that local immuno‐inflammatory response plays a significant role in determining susceptibility of host in intra‐specific group, and has important implications for ecology and aquaculture. [ABSTRACT FROM AUTHOR]

Copyright of Veterinary Archives/Veterinarski Arhiv is the property of University of Zagreb, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Veterinary Archives/Veterinarski Arhiv is the property of University of Zagreb, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Interleukin-10, an important regulator of both the innate and adaptive immune systems, is a multifunctional major cytokine. Though it is one of the major cytokines, IL-10 from the Indian major carp, Labeo rohita, has not yet been characterized. In the present study, we report large scale production and purification of biologically active recombinant IL-10 of L. rohita (rLrIL-10) using a heterologous expression system and its biophysical and functional characterization. High yield (~70 mg/L) of soluble rLrIL-10 was obtained at shake flask level. The rLrIL-10 was found to exist as a dimer. Far-UV CD spectroscopy showed presence of predominantly alpha helices. The tertiary structure of the purified rLrIL-10 was verified by fluorescence spectroscopy. Two-dimensional gel analysis revealed the presence of six isoforms of the rLrIL-10. The rLrIL-10 was biologically active and its administration significantly reduced serum proinflammatory cytokines, namely, interleukin 1β, TNFα, and IL-8, and augmented the NKEF transcript levels in spleen of L. rohita. Anti-inflammatory role of the rLrIL-10 was further established by inhibition of phagocytosis using NBT reduction assay in vitro. The data indicate that the dimeric alpha helical structure and function of IL-10 of L. rohita as a key regulator of anti-inflammatory response have remained conserved during evolution. [ABSTRACT FROM AUTHOR]

Lectins play important role in innate immunity of animals. The affinity of the natural haemagglutinin of the giant freshwater prawn Macrobrachium rosenbergii towards vertebrate erythrocytes and its level with relation to sex, size and moult stages were studied. The strongest agglutinating titres in haemolymph of prawns were marked against guinea pig, chicken, Clarias batrachus, and rabbit erythrocytes, and the weakest towards cattle, dog, horse and goat erythrocytes. A moderately agglutinating titre was evident in duck and human erythrocytes. The haemolymph of adult, male or intermoult stage prawns weighing more than 100 g had the highest haemagglutinating activity as compared to their respective counterparts with varied responses observed towards various erythrocytes.