Multiple paternity in Rhipicephalus (Boophilus) microplus confirmed by microsatellite analysis

Area of Science:

• Veterinary Entomology
• Molecular Ecology
• Reproductive Biology

Background:

• Rhipicephalus (Boophilus) microplus is a significant cattle ectoparasite.
• Understanding tick reproductive strategies is crucial for effective pest management.
• Previous studies have not conclusively determined the extent of multiple mating in R. microplus.

Purpose of the Study:

• To ascertain whether progeny from a single Rhipicephalus (Boophilus) microplus female result from mating with one or multiple males.
• To investigate the occurrence of multiple paternity in natural tick populations.

Main Methods:

• Simulations were performed using existing microsatellite genotype data to optimize experimental design.
• Genotyping of 15 engorged female ticks and their progeny (14-22 individuals each) was conducted.
• Microsatellite genotyping focused on the BmM1 locus to determine the minimum number of unique male parents per progeny group.

Main Results:

• Analysis of progeny genotypes at the BmM1 locus revealed evidence of multiple sires in 10 out of 15 tick progeny groups.
• The presence of unique alleles in progeny, not attributable to the maternal parent, indicated contributions from multiple males.
• This genetic evidence strongly supports multiple paternity in Rhipicephalus (Boophilus) microplus.

Conclusions:

• The study provides definitive evidence for multiple paternity in Rhipicephalus (Boophilus) microplus.
• This finding has implications for understanding tick population genetics and developing novel control strategies.
• Further research may explore the ecological and evolutionary drivers of multiple mating in this important tick species.