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ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » LAPRU » Research » Publications at this Location » Publication #364621
Research Project: Cattle Fever Tick Control and Eradication

Location: Livestock Arthropod Pests Research

Title: Sequence and transcript expression of the super-kdr locus of the horn fly, Haematobia irritans

Author
item DOMINGUES, LUISA - Department Of Energy
item SOLIS, GABRIELA - US Department Of Agriculture (USDA)
item Bendele, Kylie
item Perez De Leon, Adalberto - Beto
item Guerrero, Felicito

Submitted to: Medical and Veterinary Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2020
Publication Date: 3/31/2020
Citation: Domingues, L.N., Solis, G.D., Bendele, K.G., Perez De Leon, A.A., Guerrero, F. 2020. Sequence and transcript expression of the super-kdr locus of the horn fly, Haematobia irritans. Medical and Veterinary Entomology. https://doi.org/10.1111/mve.12442.
DOI: https://doi.org/10.1111/mve.12442

Interpretive Summary: In horn flies, target site resistance to pyrethroids can be diagnosed by a DNA-based PCR diagnostic assay that genotypes individual flies at two pyrethroid resistance-associated mutation sites, the super-kdr (skdr) and kdr loci. When this assay uses genomic DNA as template, some molecular rearrangements such as alternative RNA splicing and RNA editing are not detected. Since alternative splicing at the super-kdr locus has been reported in several species of flies, if this occured in horn flies, the PCR diagnostic assay may not accurately reflect the frequency of the skdr mutation. We designed a study to detect the reliability of the PCR diagnostic assay and did not detect any sequence indicative of alternative splicing at the super-kdr locus. Therefore, if alternative splicing is occurring at the super-kdr locus of H. irritans, then it must be rare as it is in Musca domestica.

Technical Abstract: In horn flies (Diptera: Muscidae), target site resistance to pyrethroids can be diagnosed by an allele-specific PCR that genotypes individual flies at both the super-kdr (skdr) and the kdr pyrethroid resistance-associated loci. When this technique uses genomic DNA as template, modifications, such as alternative RNA splicing and RNA editing are not detected. Alternative splicing at the super-kdr locus has been reported in Dipterans. Therefore, the allele-specific PCR may not accurately reflect the frequency of the skdr mutation in field populations. To study if alternative splicing occurs at the skdr locus of horn flies, we sequenced compared the sequences of genomic DNA and cDNA isolated from individual flies and pool of flies collected from two wild populations and two laboratory-reared colonies, a susceptible colony and a highly pyrethroid resistant colony, and compared their sequences with varying degrees of pyrethroid resistance. We did not detect any sequence indicative of alternative splicing at the super-kdr locus. Therefore, if alternative splicing is occurring at the super-kdr locus of H. irritans, then it must be rare as it is in Musca domestica.