Molecular characterization ofTunga trimamillataandT. penetrans(Insecta, Siphonaptera, Tungidae): taxonomy and genetic variability

Abstract

Summary :A new species of the genus Tunga, T. trimamillata has recently been described on the basis of several morphological traits. To explore the taxonomic status of this flea with respect to T. penetrans, we undertook a molecular analysis of cytochrome oxydase II and 16S rDNA mitochondrial genes and of the internal transcribed spacer 2 nuclear marker on samples of both species. Maximum Parsimony evaluations of the three data set indicate a differentiation compatible with a specific rank between the two fleas with very high levels of divergence. Both mitochondrial and nuclear data are in line with a recent bottleneck in the Malagasy population of T. penetrans, possibly due to the recent colonisation of Africa via human transportation. Further, significantly lower mitochondrial variability in the Ecuadorian populations of T. penetrans with respect to the T. trimamillata ones is also evidenced. Résumé

Genetic variability of Tunga penetrans (Siphonaptera, Tungidae) sand fleas across South America and Africa

“…Seven haplotypes were scored (H1-H7; Table 1), three of which were previously observed in PEL (H3), ISA (H3, H4) and FDU (H1) populations (Luchetti et al 2005). A further haplotype obtained in the ISA sample (H8; Luchetti et al 2005), but absent in presently analysed populations, was also considered.…”

“…Recombinant clones were identified using the β-galactosidase gene blue-white colour system and directly sequenced. Five recombinant colonies were sequenced only in one individual per population, as it is not expected differentiation within the population (Luchetti et al 2005).…”

“…Test for deviation from the neutrality of COII sequences were performed following Tajima's D (Tajima 1989) and McDonald and Kreitman (McDonald and Kreitman 1991) tests included in the DnaSP software (Rozas and Rozas 1999). Table 1; capital letters between parentheses indicate ITS2 genotypes (A Atlantic; P Pacific) To make a more extensive analysis, sequences previously obtained from populations of S.ta Isabel (ISA), Pelileo (PEL) and Fort Dauphin (FDU) were also included (Luchetti et al 2005; ANs: AY425821, AF551752-4-COII; AY425818-9-ITS2). Sequences of T. trimamillata (ANs: AF551751-COII; AY425820-ITS2) were utilised as outgroup.…”

“…A previous survey based on both mitochondrial and nuclear markers of three T. penetrans populations evidenced a very low genetic variability, with two very closely related Ecuadorian samples and a more differentiated Malagasy population (Luchetti et al 2005).…”

Repetitive sequences in the ITS1 region of the ribosomal DNA of Tunga penetrans and other flea species (Insecta, Siphonaptera)

“…Additional markers frequently used are the cytochrome oxydase I, II and 16S rDNA mitochondrial genes. Some investigations of various flea species using molecular markers have been made and showed significant species specific sequence variations (Luchetti et al 2005(Luchetti et al , 2007Vobis et al 2005).…”