Analysis of Growth Gene Expression and DNA Barcoding of Indian Major Carps

Abstract

Pakistan is bestowed with very diverse fauna of fish naturally. The proper identification and conservation of this fish fauna is on prime importance of many fish biologist. DNA barcoding tool has gained much popularity worldwide due to its precise and effective ability of species identification and discrimination. Moreover the sound knowledge about growth and development of fishes is also vital for better production and to uplift country‘s economy. Present study was conducted to identify Indian major carps and four other freshwater fishes as well as to assess the differential growth gene expression in Indian major carps under uniform culture conditions. Blood samples (n=210) fishes were taken carefully from caudal veins of each captured fish species. Genomic DNA was extracted from blood and short segment COI gene (680bp) was amplified by PCR. Mean conspecific, congeneric and confamilial K2P genetic distance was 0.25%, 5.75% and 16.45% respectively. The mean congeneric K2P genetic distance was 23 fold greater than the mean conspecific K2P genetic distance which declared that COI region of mtDNA is very effective for species discrimination. For differential growth gene expression, tissue samples (n=360) were collected and further subjected to RNA isolation, cDNA development and Real-time PCR. Growth hormone gene expression was checked against the reference gene beta- actin. Expression analysis revealed a partial dependency of body weight with growth gene expression in Indian major carps. It was a first documented report from freshwater reservoirs of Punjab Province of Pakistan granted with diverse fish fauna which needs to be focused for sustainable management and proper breeding and conservation plan in future. Keywords: Labeo rohita, Cirrhinus mrigala, Catla catla, COI gene, DNA barcoding, GH gene, Beta-actin gene, Real-time PCR.