PCR-based molecular characterization, phylogenetic analysis and secondary structure of the 28S rDNA of Thaparocleidus wallagonius (Monogenea: Dactylogyridae) – the most primitive species of this genus from India

Abstract

Species of the monogenean genus Thaparocleidus are specific to freshwater siluriform fish. The infection caused by these gill parasites are a major health problem to fish. But, to focus the control strategies of these parasites, first it is important to establish an accurate discrimination by molecular methods. In the present study, phylogenetic and structural analysis of 28S region of ribosomal DNA of T. wallagonius species collected from fish Wallago attu from Meerut (U.P.), India, was carried out. In the first step, we amplified, sequenced 28S region of ribosomal DNA of T. wallagonius to establish the phylogenetic relationship with other species of this genus. T. wallagonius found on gill filaments of fish W. attu, is the most primitive parasite of this genus from India, was unequivocally discriminate from other species of the same genus in this study. A secondary-structure model of the large subunit rDNA was also predicted using a combined comparative and thermodynamic approach. Molecular morphometric and phylogenetic relationship of T. wallagonius are discussed in detailed that based on molecular analysis using bioinformatic tools.

A review of Monogenean diversity in India: Pathogens of fish diseases

“…Additional molecular sampling might uncover the diversity of these species rich group of parasites but this trend has not much popular in case of monogeneans. In India, only a few species of freshwater monogeneans has been sequenced through studies of some workers [27][28][29][30][31][32][33][34][35][36] . But with this data, it is difficult to establish the phylogeny and discuss the validity of freshwater monogenean having very minute differences in their body parts.…”

“…The present study takes a broad look at monogenean diversity in the fishes of five major river systems of India in order to determine the status of monogenean diversity. The study reveals that approximately 35.45% fishes have so far been investigated for monogenean infection in general and still 74% are remaining that are not screened. As far as investigations related to five different major river systems are concerned, the data is presented in the form of table and figure ( Table 2).…”

Ribosomal DNA as molecular markers and their applications in the identification of fish parasites (Platyhelminthes: Monogenea) from India

“…By exploring the possibility of using DNA based methodology to overcome these taxonomic problems, the utility of DNA sequences for taxonomic purposes is well established. DNA sequencing provides a valuable approach for the genetic characterization of a parasite species [12,13] . Hence, systematic workers are extremely interested in new technologies that could make this procedure more efficient.…”

Study on species composition of parasite in striped catfish (Pangasianodon hypophthamus Sauvage, 1878) based on morphological and genetic characters

“…Tuy nhiên, tình hình dịch bệnh ở cá tra phức tạp do sự bùng phát bệnh ký sinh trùng (KST), một tác nhân gây bệnh phổ biến. Trên thế giới đã có nhiều nghiên cứu về thành phần loài KST cá tra dựa trên đặc điểm hình thái [10,11,12,13] và di truyền [14,15,16,17], còn ở Việt Nam chủ yếu chỉ dừng lại ở nghiên cứu hình thái [4,5,7]. Nghiên cứu này kết hợp nghiên cứu đặc điểm hình thái và di truyền để xác định thành phần loài ký sinh trùng và xác định vị trí phân loại một số loài ký sinh trùng ký sinh trên cá tra…”

“…DNA được tách từ từng cá thể bằng Chelex 10% (BioRad) theo hướng dẫn của nhà sản xuất. Sử dụng dung dịch DNA đã tách chiết cho phản ứng PCR để khuếch đại đoạn gen 28S DNA ribosome (28S rDNA) của sán lá đơn chủ với cặp mồi 28SF 5'-TCAGTAAGCGGAGGAAAAGAA-3'và 28SR 5'-CAAAACCACAGTTCTCACAGC-3' [16]; sán lá song chủ sử dụng đoạn gen ITS1 của DNA ribosome (ITS1 rDNA) với cặp mồi ITS1F 5'-GGTAAG TGCAAGTCATAAGC-3' và ITS1R 5'-GCTGC GCTCTTCATCGACA-3' [1]. Phản ứng PCR được thực hiện với tổng thể tích 50 µl bao gồm: 5 µl 10x DreamTaq Buffer, 1,0 µl dNTP (10mM), 1 µl từng mồi (10 mM), 0,25 µl DreamTaq polymerase ( …”