Iranian Journal of Parasitology 2014. 9(2):209-217.

Identification and Characterization of a Differentially Expressed Gene (07E12) in the Infective Larvae of the Parasitic Nematode Ascaris suum.
Cuiqin Huang, Jingzhou You, Fangfang Nai


Background: Parasitic nematodes cause animal and human diseases of major socio-economic importance worldwide. The suppression of parasite development at particular developmental stages could provide an alternative approach for nema-tode control. In this study, Ascaris suum was used as a model system in the study of the differentially expressed genes in the infective L3 stage.

Methods: The gene (07E12) was screened and identified from the subtractive cDNA library for the infective larvae of Ascaris suum using real-time quantitative PCR. Then, the full-length cDNA of 07E12 was characterized by 3′ and 5′ rapid amplification of cDNA ends (RACE). The characteristics of the gene were further analyzed using bioinformatic analyses.

Results: The results showed that the gene 07E12 was differentially expressed in the third-stage larvae of A. suum and its expression level in the infective larvae was much higher than in other stages. It was shown that the gene 07E12 had 99% iden-tity with the corresponding sequences of the A. suum whole genome shotgun se-quence containing the homologous sequences with conserved sequences of Neu-ropeptide-Like Protein family member. Likewise, by performing BLASTN and BLASTP searches in the GenBank™, it was shown that this gene had 99 % identity with A. suum cre-nlp-2 protein.

Conclusion: This gene 07E12 which is differentially expressed in the third-stage larvae of A. suum may encode a neuropeptide-like protein family member, a very important molecule in the process of infecting a host.


Ascaris suum; Gene; Identification; RT-PCR; Real-time quantitative PCR

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