Vol. 10, Special Issue 4 (2021)

Author(s):
Rahul Singh, Manipati Narasimhudu, Anju MV, Dr. Swapna P Antony and Dr. Roshma Phlip

Abstract:
A Cyprinids family species including Catla catla, Labeo rohita, Cirrhinus mrigala, Ctenopharyngodon idella, Hypopthalmichthys molitrix, H. nobilis, Cyprinus carpio and Carassius auratus are being investigated as future aquaculture species in countries around the world. However they face a number of issues and limitations which will need to be overcome to ensure future stability and growth, one of which is disease outbreak. However, very little has been done to understand the immune system of fishes and very few immune genes have been characterized. Antimicrobial peptides (AMP) are naturally occurring low molecular weight polypeptides that play a major role in an organism’s immune system and act effectively as a first line of defence. In the present study, gene based approach was employed for identifying AMP genes in freshwater fishe C. carpio carpio were taken for identification and characterization of antimicrobial peptide genes present in this organisms. A novel Histone H2A derived AMP genes could be identified and characterized from C. carpio carpio from the current study. The AMP genes were the first report of this gene from this fish specie. The AMP genes were named HIS-K1. An mRNA fragment 166 bp encoding 55 amino acid corresponding to histone H2A genes could be amplified from the koi carp, C. carpio (HIS-K1), multiple alignment of this gene showed the presence of conserved regions in both nucleotide and amino acid sequences. Phylogenetic tree was constructed using histone H2A sequences and this also showed the basal placement of this AMP along with other histone identified from other fishes belonging to Family Cyprinidae. Examination of AMPs in significant fish families such as Cyprinidae, possessing aquaculture importance as food fish or ornamental fishcan help understand the role of these peptides in innate host defense of the fish. Furthermore, they can provide important information for the better design of novel therapeutic agents, both for microbial infections as well as other conditions. Unique for the field of fish AMPs is the potential application to aquaculture.