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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 #358361

Research Project: Cattle Fever Tick Control and Eradication

Location: Livestock Arthropod Pests Research

Title: Genetic structure analysis of Amblyomma mixtum populations in Veracruz State, Mexico

item AGUILAR-DOMINQUEZ, MARIEL - University Of Veracruz
item SANCHEZ-MONTES, SOKANI - Universidad Nacional Autonoma De Mexico
item ESTEVE-GASSENT, MARIA - Texas A&M University
item BARRIENTOS-SALCEDO, CAROLINA - University Of Veracruz
item Perez De Leon, Adalberto - Beto
item ROMERO-SALAS, DORA - University Of Veracruz

Submitted to: Ticks and Tick Borne Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: Amblyomma mixtum ticks transmit microbes that cause diseases and are a major problem for livestock, humans, and wildlife in Mexico. However, little is known of their genetic diversity in the country. Fifty A. mixtum were collected across the state of Veracruz. A common modern molecular technique was used to characterize variability of specific genes in these ticks. Variations in the DNA of these specific genes are indicative of genetic differences between populations of the same species. This study did not find significant differences between A. mixtum ticks across the state of Veracruz. A plausible explanation for this observation is the frequent movement of livestock and minimal geographic boundaries. This is the first report on the genetic structure of A. mixtum populations in Mexico.

Technical Abstract: Amblyomma mixtum Koch, 1844 parasitizes livestock, humans, and wildlife in Mexico. However, information on population genetics for this tick species in the country is missing. Tick samples were collected from livestock in ten regions across the state of Veracruz (22º28'N, 17º09S, 93º36'E, 98º39'W) to analyze the genetic structure of A. mixtum populations. Ticks were morphologically identified using taxonomic keys. In order to test the intra-specific variability of A. mixtum fragments of the mitochondrial gene 16S-rRNA and cytochrome oxidase subunit 1 (COI) were amplified. Ninety-six sequences were amplified from the 50 specimens analyzed (96% amplification success). Eleven haplotypes were detected in 16S-rRNA gene and 10 more for COI. Neutrality tests showed negative results in most of the locations anlayzed, which is indicative of an excess of recently derived haplotypes. However, these results were not statistically significant. Minimal union network analysis revealed that there is no separation of populations by geography, and that there is an overlap of several haplotypes among diverse populations. Significant genetic differentiation was not detected in the A. mixtum populations sampled in the state of Veracruz, Mexico; this may be due to the frequent movement of livestock hosts. This is the first report on the genetic structure of A. mixtum populations in Mexico.