TY - JOUR
T1 - Mapping the presence of Wolbachia pipientis on the phylogeny of filarial nematodes
T2 - Evidence for symbiont loss during evolution
AU - Casiraghi, Maurizio
AU - Bain, Odile
AU - Guerrero, Ricardo
AU - Martin, Coralie
AU - Pocacqua, Vanessa
AU - Gardner, Scott L.
AU - Franceschi, Alberto
AU - Bandi, Claudio
N1 - Funding Information:
The authors would like to thank Nathan Lo and Dietrich Büttner for their criticisms and helpful reading of the manuscript. Claudio Genchi played a pivotal role in stimulating and encouraging this work. O. Bain, R. Guerrero and C. Martin collected most of the new material screened for the first time in this work ( L. brasiliensis , L. galizai , L. hamletti , L. yutajensis , Ochoterenella sp., D. gracile ); S.L. Gardner collected the samples of L. westi ; A. Franceschi collected the specimens of S. equina and S. labiatopapillosa . We would also like to thank for providing parasite material: J.W. McCall ( B. malayi , B. pahangi , L. sigmodontis and A. viteae ), L. Venco ( D. immitis and D. repens ), T. Bianco ( O. ochengi, O. gutturosa and O. gibsoni ), S. Novati ( O. volvulus and L. loa ), E. H. Karunanayake ( W. bancrofti ), D. Otranto ( T. lacrimalis and T. gulosa ), W. Bertazzolo ( T. callipaeda ), L. Rossi ( S. tundra ), S. Giannetto ( A. reconditum ), R. Lia ( F. martis ). We are grateful to M. Coluzzi for providing samples of Wolbachia -infected Culex pipiens . Special thanks go to Robin Gasser, for logistic assistance related with the shipment of L. galizai material. The work was supported by MIUR-COFIN and CNRS-CONICIT grant nos. 10055 and 99000230. The authors wish to thank the excellent and thorough review of the manuscript.
PY - 2004/2
Y1 - 2004/2
N2 - Wolbachia pipientis is a bacterial endosymbiont associated with arthropods and filarial nematodes. In filarial nematodes, W. pipientis has been shown to play an important role in the biology of the host and in the immuno-pathology of filariasis. Several species of filariae, including the most important parasites of humans and animals (e.g. Onchocerca volvulus, Wuchereria bancrofti and Dirofilaria immitis) have been shown to harbour these bacteria. Other filarial species, including an important rodent species (Acanthocheilonema viteae), which has been used as a model for the study of filariasis, do not appear to harbour these symbionts. There are still several open questions about the distribution of W. pipientis in filarial nematodes. Firstly the number of species examined is still limited. Secondly, it is not clear whether the absence of W. pipientis in negative species could represent an ancestral characteristic or the result of a secondary loss. Thirdly, several aspects of the phylogeny of filarial nematodes are still unclear and it is thus difficult to overlay the presence/absence of W. pipientis on a tree representing filarial evolution. Here we present the results of a PCR screening for W. pipientis in 16 species of filariae and related nematodes, representing different families/subfamilies. Evidence for the presence of W. pipientis is reported for five species examined for the first time (representing the genera Litomosoides, Litomosa and Dipetalonema); original results on the absence of this bacterium are reported for nine species; for the remaining two species, we have confirmed the absence of W. pipientis recently reported by other authors. In the positive species, the infecting W. pipientis bacteria have been identified through 16S rDNA gene sequence analysis. In addition to the screening for W. pipientis in 16 species, we have generated phylogenetic reconstructions based on mitochondrial gene sequences (12S rDNA; COI), including a total of 28 filarial species and related spirurid nematodes. The mapping of the presence/absence of W. pipientis on the trees generated indicates that these bacteria have possibly been lost during evolution along some lineages of filarial nematodes.
AB - Wolbachia pipientis is a bacterial endosymbiont associated with arthropods and filarial nematodes. In filarial nematodes, W. pipientis has been shown to play an important role in the biology of the host and in the immuno-pathology of filariasis. Several species of filariae, including the most important parasites of humans and animals (e.g. Onchocerca volvulus, Wuchereria bancrofti and Dirofilaria immitis) have been shown to harbour these bacteria. Other filarial species, including an important rodent species (Acanthocheilonema viteae), which has been used as a model for the study of filariasis, do not appear to harbour these symbionts. There are still several open questions about the distribution of W. pipientis in filarial nematodes. Firstly the number of species examined is still limited. Secondly, it is not clear whether the absence of W. pipientis in negative species could represent an ancestral characteristic or the result of a secondary loss. Thirdly, several aspects of the phylogeny of filarial nematodes are still unclear and it is thus difficult to overlay the presence/absence of W. pipientis on a tree representing filarial evolution. Here we present the results of a PCR screening for W. pipientis in 16 species of filariae and related nematodes, representing different families/subfamilies. Evidence for the presence of W. pipientis is reported for five species examined for the first time (representing the genera Litomosoides, Litomosa and Dipetalonema); original results on the absence of this bacterium are reported for nine species; for the remaining two species, we have confirmed the absence of W. pipientis recently reported by other authors. In the positive species, the infecting W. pipientis bacteria have been identified through 16S rDNA gene sequence analysis. In addition to the screening for W. pipientis in 16 species, we have generated phylogenetic reconstructions based on mitochondrial gene sequences (12S rDNA; COI), including a total of 28 filarial species and related spirurid nematodes. The mapping of the presence/absence of W. pipientis on the trees generated indicates that these bacteria have possibly been lost during evolution along some lineages of filarial nematodes.
KW - Filarial nematodes
KW - Phylogeny
KW - Symbiosis
KW - Thelazia
KW - Wolbachia pipientis
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U2 - 10.1016/j.ijpara.2003.10.004
DO - 10.1016/j.ijpara.2003.10.004
M3 - Article
C2 - 15037105
AN - SCOPUS:1242316942
VL - 34
SP - 191
EP - 203
JO - International Journal for Parasitology
JF - International Journal for Parasitology
SN - 0020-7519
IS - 2
ER -