Molecular identification of goat lice (Anoplura: Linognathidae) based on conserved motif analysis

Goat lice (Anoplura: Linognathidae) are important ectoparasites in pediculosis. However, their molecular classification and identification remain challenging owing to a lack of molecular data in GenBank. This study aimed to establish a molecular method for identifying Anoplura spp. Goat lice were captured in Yulin, China, and morphologically identified as Linognathus africanus (L. africanus). Sequences from across Anoplura were downloaded from GenBank and conserved motif analysis showed that ribosomal DNA (rDNA) 18S V4, mitochondrial DNA (mtDNA) 12S, and 16S were candidate gene fragments suitable for universal primer design because of abundant sequences and long conserved motifs with few mutations. These three gene fragments of the lice specimens were successfully amplified and sequenced, and their divergences were 0.1–1.7%, 0–0.6%, and 0.3–1.3%, respectively, indicating that the lice specimens belonged to the same species. BLAST analysis showed that the 18S sequences were only aligned with Linognathus, while the 12S and 16S sequences showed 98.8–99.4% and 98.7–99.3% similarities, respectively, with those of L. africanus from Pakistan. Therefore, the lice specimens were molecularly identified as L. africanus without geographical isolation. In conclusion, the goat lice specimens were identified to L. africanus. 12S and 16S are potential DNA barcodes of Anoplura spp.