Genetic diversity and differentiation of Dermatophagoides farinae (Astigmata: Pyroglyphidae) populations in different habitats

ABSTRACT Dermatophagoides farinae (Astigmata: Pyroglyphidae) occurs in both homes and storage environments. The species produces biochemically diverse allergens that cause allergic reactions and seriously endanger human health. Habitat diversity can lead to divergent adaptive selection and reduced gene flow, thereby increasing genetic drift; both factors contribute to genetic differentiation. However, there is a lack of research concerning the genetic diversity and differentiation of D. farinae in different habitats. In this study, the genetic diversity and differentiation of D. farinae populations in different habitats were studied using the mitochondrial cytochrome b (Cytb) gene, the cytochrome c oxidase subunit I (COI) gene, and the ribosomal internal transcribed spacer (ITS) region. Both pillow cores (ZX) and dormitory (SS) habitats had higher haplotype diversity than the flour mill (MF) habitat. The reasons for this phenomenon are likely to be food availability as well as differences in temperature and humidity among habitats. There was significant genetic differentiation (Fst > 0.05, P < 0.05) between the ZX and MF and between the MF and SS habitats, but there was no significant genetic differentiation between the ZX and SS habitats (Fst < 0.05, P > 0.05) based on both Cytb and COI genes, reflecting the difference between mitochondrial and nuclear genes. The low level of gene flow observed for ZX-MF and MF-SS and the gene flow between the ZX and SS habitats supported the above results. A haplotype network and a neighbour-joining phylogenetic tree showed that individuals from the ZX and SS habitats occurred in two clades without a clear distribution boundary, indicating that the genetic structure was not correlated with the habitat distribution. This research is the first genetic analysis of D. farinae in different habitats. The study can improve our understanding of the population genetics of D. farinae in different habitats and aid in the development of more effective management strategies.