Absence of population genetic structure in Heterakis gallinarum of chicken from Sichuan, inferred from mitochondrial cytochrome c oxidase subunit I gene

Abstract

Population genetics information provides a foundation for understanding the transmission and epidemiology of parasite and, therefore, may be used to assist in the control of parasitosis. However, limited available sequence information in Heterakis gallinarum has greatly impeded the study in this area. In this study, we first investigated the genetic variability and genetic structure of H. gallinarum. The 1325 bp fragments of the mitochondrial COX1 gene were amplified in 56 isolates of H. gallinarum from seven different geographical regions in Sichuan province, China. The 56 sequences were classified into 22 haplotypes (H1–H22). The values of haplotype diversity (0.712) and nucleotide diversity (0.00158) in Sichuan population indicate a rapid expansion occurred from a relatively small, short-term effective population in the past. The haplotype network formed a distribution around H1 in a star-like topology, and the haplotypes did not cluster according to their geographical location. Similar conclusions could be made from MP phylogenetic tree. The F_st value (F_st<0.16965) and AMOVA analysis revealed that no significant genetic differentiation was observed among the seven different geographical populations. Neutrality tests (Tajima's D and Fu’s Fs) and mismatch analysis indicated that H. gallinarum experienced a population expansion in the past. Our results indicated that H. gallinarum experienced a rapid population expansion in the past, and there was a low genetic diversity and an absence of population structure across the population.

• COX1 gene
• genetic variability
• Heterakis gallinarum
• Sichuan

Acknowledgements

The authors wish to thank Yue Xie, Ning Wang, Xuan Zhou, and Xiuqin Zhong for their technical assistance.

Declaration of interest

This work was supported by the National Natural Science Foundation of China (Grant no. 31402188) and the “211” Project Double Plan in Sichuan Agricultural University (Grant no. SC-03570422). The authors declare that they have no competing interests. The authors alone are responsible for the content and writing of this report.

Supplementary material available online

Supplementary File S1 and S2