Genetic diversity and structure of urban populations ofPierisbutterflies assessed using amplified fragment length polymorphism

Abstract

Conservation programs in urban ecosystems need to determine the genetic background in populations of urban dwellers. We examined the genetic diversity and structure of Pieris rapae and P. melete using AFLP markers, and compared them between species and between urban and rural environments. As a result: (i). in both species, there was no reduction in genetic diversity within urban populations by direct comparison of diversity measurements, although the analysis of molecular variance suggested significant reductions in the variance within seasonal subpopulations in urban populations; (ii). P. rapae retained greater genetic diversity within species and populations; (iii). populations of both species showed significant genetic differentiation, and P. melete was more strongly subdivided; (iv). in both species, geographically close populations did not cluster with one another in the upgma analysis; (v). there was no genetic isolation due to geographical distance in either species; (vi). the genetic composition of seasonal subpopulations differed in urban populations of both species, and the genetic distances among subpopulations were correlated with seasonal differences in P. rapae and with temporal differences in P. melete. These results indicate that the genetic diversity in urban populations of both species was reduced at times, but was maintained by dispersal from genetically differentiated populations. Differences in the ability and mode of dispersal in the two species may be reflected in the degree of population subdivision and patterns of seasonal change in the genetic composition.

Parnassius apollo nevadensis: identification of recent population structure and source–sink dynamics

“…This would support the hypothesis that there has been a population size reduction in the sink populations. It has already been demonstrated for other butterflies species that anthropic disturbance can lead to a reduction in genetic diversity that is, however, maintained by dispersal from other populations (Takami et al 2004). …”

How to increase the value of urban areas for butterfly conservation? A lesson from Prague nature reserves and parks

“…Responses of butterflies to urbanisation have been investigated in various regions of the world and using a variety of methods, such as analysing distribution maps (Hardy & Dennis, 1999), walking transects from city centres to periphery (Kitahara & Fujii, 1994;Blair, 1999;Hogsden & Hutchinson, 2004), comparing assemblages differently affected by urbanisation (Koh & Sodhi, 2004;Collier et al, 2006;Ockinger et al, 2009) and working with molecular markers (Takami et al, 2004;Snep et al, 2006). The studies agree that densities of specialised species decrease from peripheries towards city centres.…”

Diversidade genética de Tibraca limbativentris Stål (Hemiptera: Pentatomidae) de Santa Catarina e do Rio Grande do Sul, usando marcadores RAPD

“…Esse fato foi demonstrado para S. frugiperda, que teve a maior similaridade genética entre os indivíduos provenientes de uma mesma planta hospedeira (Drès & Mallet 2002, Busato et al 2004. Assim, a baixa variabilidade genética entre diferentes populações estaria relacionada ao alto fl uxo gênico, às mudanças de comportamento e, também, à pressão de seleção exercida sobre a população, que selecionariam indivíduos mais resistentes às variações de clima, fonte alimentar, ação de parasitóides, patógenos e inseticidas químicos, isolando um grupo de indivíduos geneticamente similar e mais adaptado ao ambiente (Takami et al 2004) Os marcadores RAPD utilizados foram eficientes na diferenciação genética preliminar das populações de T. limbativentris, no entanto, estudos adicionais com marcadores moleculares mais específi cos são necessários para compreender melhor como se dá a distribuição dessa espécie. A identifi cação de regiões de importância dentro do genoma através de microssatélites, AFLP (Amplifi ed Fragment Length Polymorphism) e seqüenciamento, permitiriam avaliar diferenças de indivíduos dentro e entre as populações, subsidiando estudos para detecção da origem e quais os padrões de migração e dispersão que a espécie obedece em relação ao ambiente em que está inserida.…”