Transferrin in the mosquito, Culex quinquefasciatus Say (Diptera: Culicidae), up-regulated upon infection and development of the filarial parasite, Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae)

• Published in: Parasitology research (1987) 2007-07, Vol.101 (2), p.325-330
• Main Authors: Paily, K. P, Kumar, B. Agiesh, Balaraman, K
• Format: Article
• Language: English
• Subjects: Aedes aegypti; Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Blotting, Western; Cloning, Molecular; Culex - genetics; Culex - immunology; Culex - parasitology; Culex quinquefasciatus; Culicidae; Diptera; Female; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Hemolymph - chemistry; Insecta; Invertebrates; Molecular Sequence Data; Reverse Transcriptase Polymerase Chain Reaction; RNA - genetics; RNA - isolation & purification; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Spirurida; Transferrin - biosynthesis; Transferrin - genetics; Up-Regulation; Wuchereria bancrofti; Wuchereria bancrofti - growth & development
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-007-0474-2

Transferrin is a defence protein known to be up-regulated upon infection of parasites/pathogens in Aedes aegypti mosquito. However, no information is available on its up-regulation in Culex quinquefasciatus, the vector of bancroftian filarial parasite. In the present study, enhancement of transferrin in C. quinquefasciatus infected with Wuchereria bancrofti is demonstrated through amplification of the specific mosquito transcript, its sequencing, cloning, and expression. By using two oligonucleotide primers, a 950-bp polymerase chain reaction product was obtained from the first strand cDNA made from RNA of C. quinquefasciatus infected with W. bancrofti. A 707-bp sequence encoding the mature portion of transferrin was confirmed by sequencing the product. This is the first report of transferrin expression in C. quinquefasciatus. The deduced amino acid sequence shared 85% homology with A. aegypti transferrin precursor molecule. Western blot analysis of haemolymph proteins of infected C. quinquefasciatus with antibodies raised against recombinant transferrin protein showed binding to a 66-kDa protein, confirming its identity as transferrin. Hence, this molecule also could be added to the list of immune molecules of C. pipiens group, such as the defensin, gambicin, and cecropin, which are already known.