Tissue distribution and functional analysis of vitellogenin-6 of Toxocara canis

•Quantitative assays indicated high transcription level of Tc-vit-6 in both intestine of male and female adult Toxocara canis.•Anti-TcVg6 polyclonal antiserum was produced from the recombinant TcvWD domain protein.•Localisation showed extensive distribution of TcVg6 in the intestine, reproductive tract and musculature of adult T. canis.

Toxocara canis is an common intestinal nematode of canids and the principal causative agent of human toxocariasis. Vitellogenin (Vg), a source of amino acids and lipids in the eggs, are considered to play an important role in embryo development of a wide range of organisms. In the present study, the transcriptional levels of Tc-vit-6 gene in male and female adult T. canis were determined by quantitative real-time PCR, which indicated high transcription of Tc-vit-6 in the intestine, reproductive tract and body wall of male and female adult T. canis. The fragment of Tc-vit-6 encoding a vWD domain, was cloned and expressed to produce a rabbit anti-TcvWD polyclonal antibody. Tissue distribution of TcVg6 was detected by immunohistochemical assays, which showed predominant distribution of TcVg6 in the tissues of intestine, as well as reproductive tract (including some of the germ cells) and musculature of male and female adult worms. Collectively, these results indicated multiple biological roles of TcVg6 apart from that in the reproduction of T. canis.

Graphical abstractThis figures represent the Immunolocalization of TcVg6 in the tissues of Toxocara canis. H&E: Hematoxylin and Eosin stained sections (×40); Control: Negative controls hybridized with pre-immune IgG (×40); DAB: sections hybridized with anti-TcvWD polyclonal antibodies and visualised using diaminobenzidine (×40). (Abbreviation U for uterus, I for intestine, S for spermaduct, BW for body wall).Download high-res image (369KB)Download full-size image