Molecular characterization and transcriptional analysis of the female-enriched chondroitin proteoglycan 2 of Toxocara canis

• Published in: Journal of helminthology 2018-03, Vol.92 (2), p.154-160
• Main Authors: Ma, G.X., Zhou, R.Q., Hu, L., Luo, Y.L., Luo, Y.F., Zhu, H.H.
• Format: Article
• Language: English
• Subjects: adults; Amino acid sequence; Amino acid sequences; Amino acids; Animals; Ascaris suum; Biodiversity; Caenorhabditis elegans; Cell division; Chitin; chondroitin; Chondroitin Sulfate Proteoglycans - genetics; Cloning; DNA; Domains; Eggs; Embryogenesis; Embryonic Development; Embryonic growth stage; etiological agents; Extracellular; Extracellular matrix; Female; Females; Genes; Genomes; germ cells; humans; Macromolecules; males; Morphogenesis; Nematodes; Nervous system; Nucleotide sequence; Oogenesis; open reading frames; Oviduct; Oviducts; Parasites; PCR; Peptides; Peritrophin; Phylogenetics; Phylogeny; Polymerase chain reaction; Polypeptides; Proteins; Proteoglycans; quantitative polymerase chain reaction; Real-Time Polymerase Chain Reaction; Reproduction; Research Papers; reverse transcriptase polymerase chain reaction; Sequence Alignment; Sequencing; signal peptide; Tissue; tissues; Toxocara canis; Toxocara canis - chemistry; Toxocara canis - genetics; Toxocara canis - physiology; Toxocariasis; Toxocariasis - parasitology; Transcription; transcription (genetics); Transcription, Genetic; Worms
• ISSN: 0022-149X; 1475-2697; 1475-2697
• DOI: 10.1017/S0022149X17000359

Toxocara canis is an important but neglected zoonotic parasite, and is the causative agent of human toxocariasis. Chondroitin proteoglycans are biological macromolecules, widely distributed in extracellular matrices, with a great diversity of functions in mammals. However, there is limited information regarding chondroitin proteoglycans in nematode parasites. In the present study, a female-enriched chondroitin proteoglycan 2 gene of T. canis (Tc-cpg-2) was cloned and characterized. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to measure the transcription levels of Tc-cpg-2 among tissues of male and female adult worms. A 485-amino-acid (aa) polypeptide was predicted from a continuous 1458-nuleotide open reading frame and designated as TcCPG2, which contains a 21-aa signal peptide. Conserved domain searching indicated three chitin-binding peritrophin-A (CBM_14) domains in the amino acid sequence of TcCPG2. Multiple alignment with the inferred amino acid sequences of Caenorhabditis elegans and Ascaris suum showed that CBM_14 domains were well conserved among these species. Phylogenetic analysis suggested that TcCPG2 was closely related to the sequence of chondroitin proteoglycan 2 of A. suum. Interestingly, a high level of Tc-cpg-2 was detected in female germline tissues, particularly in the oviduct, suggesting potential roles of this gene in reproduction (e.g. oogenesis and embryogenesis) of adult T. canis. The functional roles of Tc-cpg-2 in reproduction and development in this parasite and related parasitic nematodes warrant further functional studies.