Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 9 2 2014 06 15 209 217 EN Cuiqin Huang College of Life Sciences, Longyan University, Longyan, China AND Engineering Research Center for the Prevention and Control of Zoonosis, Longyan, China. Jingzhou You College of Life Sciences, Longyan University, Longyan, China AND Longyan Entry-Exit Inspection and Quarantine Burean of the People's Republic of China, Longyan, China. Fangfang Nai College of Life Sciences, Longyan University, Longyan, China. 2015 10 14 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. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/411 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/411/333