Differential staining of tick chromosomes: techniques for C-banding and silver-staining and karyology of Rhipicephalus sanguineus (Latreille).

A new karyotypic procedure is described for tick chromosomes along with modifications of accepted techniques for C-banding and silver-staining. The staining procedures produce patterns with staining limited to the centromeric regions and the nucleolar organizer regions (NORs). The possible reasons for the concordant patterns are discussed based on the staining characteristics of the 2 techniques. The karyotype of Rhipicephalus sanguineus possesses 20 acrocentric autosomes with a single pair of NORs located proximal to the centromere on the largest autosomal pair. The sex-determining system is XX:XO with the X chromosome being the largest chromosome in the complement and subtelocentric.