Genetic differences betweenTropilaelaps clareaeandTropilaelaps koenigerumin Thailand based on ITS and RAPD analyses

Abstract

-Tropilaelaps koenigerum was first reported in Thailand. Species-diagnostic markers of bee mites, T. clareae and T. koenigerum were examined by sequencing of ITS and RAPD analysis. A lack of intraspecific polymorphism within T. clareae and T. koenigerum ITS was observed. At an interspecific level, 19 substitutions were found. Sequence divergence between ITS of these bee mites was 3.82%. A 5 bp (TTCTC) insertion was found in T. koenigerum. Based on ITS sequences, identification of these mites was simplified to restriction analysis of the amplified ITS with Mse I and/or Sau3A I. RAPD analysis using primers OPA07, OPA11 and OPA12 revealed 16 and 20 species-specific markers of T. clareae and T. koenigerum, respectively. A UPGMA phenogram based on genetic distance between pairs of geographic samples indicated clear differentiation between T. clareae and T. koenigerum genetically. Partial differentiation of T. clareae from different host species was observed.Tropilaelaps / bee parasite / RAPD / ITS / species-diagnostic marker / genetic diversity

Genetic and morphological variation of bee-parasitic Tropilaelaps mites (Acari: Laelapidae): new and re-defined species

“…Its primary host was subsequently recognized as the 'giant' Asian honeybee, A. dorsata Fabricius (Laigo and Morse 1968) and it has now been reported throughout the entire distribution range of A. dorsata (Matheson 1996), except Sri Lanka, where A. dorsata hosts the only other recognized species of the genus, T. koenigerum DelWnado-Baker and Baker. This enigmatic mite has also been found sympatric with T. clareae on A. dorsata in India, Nepal, Thailand and Borneo, (DelWnado-Baker and Baker 1982;DelWnado-Baker et al 1985;Koeniger et al 2002;Tangjingjai et al 2003).…”

“…However, they are morphologically distinct (DelWnado and Baker 1961;DelWnado-Baker and Baker 1982), their internal transcribed spacer (ITS) genes diVer by almost 4% and their RAPD proWles are quite diVerent (Tangjingjai et al 2003).…”

“…Isolates of Tropilaelaps were collected from honeybee hosts throughout Asia and neighbouring regions. Genetic variation among the isolates was determined using mtDNA (CO-I) and nuclear DNA (ITS1-5.8S-ITS2) gene sequences which, in other studies on Acari, have proved useful in diVerentiating mites at the intra/interspecies and interspecies level respectively (Navajas et al 1994;1998;Anderson and Trueman 2000;Navajas and Fenton 2000;Tangjingjai et al 2003;Walter and Campbell 2003). Morphological studies and observations on mite reproduction helped with the interpretation of molecular data and with determining the associations between mites and their honeybee hosts.…”

Standard methods forTropilaelapsmites research

“…Molecular studies have confirmed that T. clareae is native to A. breviligula in the Philippines (except on Palawan Island), T. mercedesae and T. koenigerum to A. dorsata and A. laboriosa in other parts of Asia (including Palawan Island) and T. thaii to A. laboriosa, in mountainous region of Mainland Asia (Laigo and Morse, 1969;Delfinado-Baker and Baker, 1982;Tangjingjai et al, 2003;Anderson and Morgan, 2007 (Walter and Proctor, 1999). Evidence suggests that T. koenigerum and T. thaii are restricted to their Asian bee hosts and are harmless to A. mellifera (Anderson and Morgan, 2007).…”

“…Molecular technology was first used in Tropilaelaps research in the 1990s to examine genetic variation between so-called T. clareae and T. koenigerum (Tangjingjai et al, 2003). It has since proved very useful to examine genetic variation within the genus and to help re-define known species and describe new species and new types within species (Anderson and Morgan, 2007).…”