title: Molecular markers for analyses of intraspecific genetic diversity in the Asian Tiger mosquito, Aedes albopictus.
abstract: BACKGROUND
  The dramatic worldwide expansion of Aedes albopictus (the Asian tiger mosquito) and its vector competence for numerous arboviruses represent a growing threat to public health security. Molecular markers are crucially needed for tracking the rapid spread of this mosquito and to obtain a deeper knowledge of population structure. This is a fundamental requirement for the development of strict monitoring protocols and for the improvement of sustainable control measures.
  
  
  METHODS
  Wild population samples from putative source areas and from newly colonised regions were analysed for variability at the ribosomal DNA internal transcribed spacer 2 (ITS2). Moreover, a new set of 23 microsatellite markers (SSR) was developed. Sixteen of these SSRs were tested in an ancestral (Thailand) and two adventive Italian populations.
  
  
  RESULTS
  Seventy-six ITS2 sequences representing 52 unique haplotypes were identified, and AMOVA indicated that most of their variation occurred within individuals (74.36%), while only about 8% was detected among populations. Spatial analyses of molecular variance revealed that haplotype genetic similarity was not related to the geographic proximity of populations and the haplotype phylogeny clearly indicated that highly related sequences were distributed across populations from different geographical regions. The SSR markers displayed a high level of polymorphism both in the ancestral and in adventive populations, and F ST estimates suggested the absence of great differentiation. The ancestral nature of the Thai population was corroborated by its higher level of variability.
  
  
  CONCLUSIONS
  The two types of genetic markers here implemented revealed the distribution of genetic diversity within and between populations and provide clues on the dispersion dynamics of this species. It appears that the diffusion of this mosquito does not conform to a progressive expansion from the native Asian source area, but to a relatively recent and chaotic propagule distribution mediated by human activities. Under this scenario, multiple introductions and admixture events probably play an important role in maintaining the genetic diversity and in avoiding bottleneck effects. The polymorphic SSR markers here implemented will provide an important tool for reconstructing the routes of invasion followed by this mosquito.
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. mose.manni01@universitadipavia.it.
authors.forename: Mosè
authors.initials: M
authors.lastname: Manni
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. gomulski@unipv.it.
authors.forename: Ludvik M
authors.initials: LM
authors.lastname: Gomulski
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. na_beau@hotmail.com.|Department of Biotechnology, Mahidol University, Bangkok, Thailand. na_beau@hotmail.com.
authors.forename: Nidchaya
authors.initials: N
authors.lastname: Aketarawong
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. gabriella.tait01@universitadipavia.it.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Tait
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. francesca.scolari@unipv.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Scolari
authors.affiliation: Department of Parasitology, Chiang Mai University, Chiang Mai, Thailand. psomboon@med.cmu.ac.th.
authors.forename: Pradya
authors.initials: P
authors.lastname: Somboon
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. c.r.guglielmino@gmail.com.
authors.forename: Carmela R
authors.initials: CR
authors.lastname: Guglielmino
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. malacrid@unipv.it.
authors.forename: Anna R
authors.initials: AR
authors.lastname: Malacrida
authors.affiliation: Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy. gasperi@unipv.it.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Gasperi
mesh_terms: D000330:Aedes / Q000235:genetics*; D063147:Animal Distribution; D000818:Animals; D003001:Cloning, Molecular; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005819:Genetic Markers; D014644:Genetic Variation; D007558:Italy; D017508:Reunion; D013785:Thailand
chemical_list: D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers