Diurnal Activity of Ixodes Ricinus in Denmark: Aspects of Physiological Age and Genotypic Variation

Abstract

Four different alleles in the nymphal Ixodes ricinus were found for the Malate Dehydrogenase enzyme (MDH). The allele frequency of the MDH genotypes in nymphal I. ricinus was observed to change during the day. Some genotypes were present in the morning, but not in the afternoon and evening. The physiological age of the nymphs was also determined. No significant correlation could be found between physiological age and genotypes. Based on the results it must be anticipated that the comparability of tick samples not only differs in quantity but also in quality for various hours, but not necessarily for various months. Therefore isoenzyme analysis of nymphs at least as regards the MDH alleles appears to be a convenient biological tool to analyse differences in host seeking behaviour.

Allozyme polymorphism of Mdh and α-Gpdh in Ixodes ricinus populations: comparison of borreliae-infected and uninfected ticks

“…The whole adult ticks, or body parts in the case of ticks from Bovan Lake sample, were separately frozen in Eppendorf tubes (1.5 ml) at -70°C about 24 h before electrophoretic assay. Frozen ticks were homogenized in tubes by Eppendorf micropestles and suspended with 20 ll of enzyme extraction buffer prepared according to Jensen et al (1999). The homogenates were centrifuged for 2 · 20 min (14,000 rpm) at 4°C and 10 ll of the supernatant was applied to the gel.…”

“…A low level of allozymic polymorphism was detected in the species I. ricinus (Delaye et al 1997;Jensen et al 1999), and only three genetic loci appeared as polymorphic: Pgm (encoding phosphoglucomutase--PGM; EC 2.7.5.1), a-Gpdh (encoding a-glycerophosphate dehydrogenase--a-Gpdh; EC 1.1.1.8) and Mdh (encoding malate dehydrogenase--MDH; EC 1.1.1.37) (Healy 1979a, b;Delaye et al 1997;Jensen et al 1999;Jensen and Kaufmann 2003;Healy et al 2004). Gene flow between I. ricinus populations, mediated by transport of ticks on mobile vertebrates, leads to creation of panmictic areas diameter of which is 60-70 km (Healy 1979a, b;Delaye et al 1997).…”

“…According to Jensen et al (1999), isozyme analysis of I. ricinus ticks, at least as regards the Mdh alleles, appears to be a reliable research tool in analysing differences in host seeking behaviour.…”

Isozyme structure of the Ixodes persulcatus Schulze (Acari: Ixodidae) tick populations in the Baikal Region

“…Preparation of samples (Jensen et al, 1999) and electrophoresis analysis (Davis, 1964;Peacock et al, 1965) were carried out by standard methods. To separate proteins, two running buffers were used: Trisglycine buffer and Tris-borate-EDTA buffer.…”