TY - JOUR
T1 - An endosymbiotic bacterium in a plant-parasitic nematode member of a new Wolbachia supergroup
AU - Haegeman, Annelies
AU - Vanholme, Bartel
AU - Jacob, Joachim
AU - Vandekerckhove, Tom T M
AU - Claeys, Myriam
AU - Borgonie, Gaetan
AU - Gheysen, Godelieve
PY - 2009
Y1 - 2009
N2 - Wolbachia is an endosymbiotic bacterium widely present in arthropods and animal-parasitic nematodes. Despite previous efforts, it has never been identified in plant-parasitic nematodes. Random sequencing of genes expressed by the burrowing nematode Radopholus similis resulted in several sequences with similarity to Wolbachia genes. The presence of a Wolbachia-like endosymbiont in this plant-parasitic nematode was investigated using both morphological and molecular approaches. Transmission electronmicroscopy, fluorescent immunolocalisation and staining with DAPI confirmed the presence of the endosymbiont within the reproductive tract of female adults. 16S rDNA, ftsZ and groEL gene sequences showed that the endosymbiont of R. similis is distantly related to the known Wolbachia supergroups. Finally, based on our initial success in finding sequences of this endosymbiont by screening an expressed sequence tag (EST) dataset, all nematode ESTs were mined for Wolbachia-like sequences. Although the retained sequences belonged to six different nematode species, R. similis was the only plant-parasitic nematode with traces of Wolbachia. Based on our phylogenetic study and the current literature we designate the endosymbiont of R. similis to a new supergroup (supergroup I) rather than considering it as a new species. Although its role remains unknown, the endosymbiont was found in all individuals tested, pointing towards an essential function of the bacteria.
AB - Wolbachia is an endosymbiotic bacterium widely present in arthropods and animal-parasitic nematodes. Despite previous efforts, it has never been identified in plant-parasitic nematodes. Random sequencing of genes expressed by the burrowing nematode Radopholus similis resulted in several sequences with similarity to Wolbachia genes. The presence of a Wolbachia-like endosymbiont in this plant-parasitic nematode was investigated using both morphological and molecular approaches. Transmission electronmicroscopy, fluorescent immunolocalisation and staining with DAPI confirmed the presence of the endosymbiont within the reproductive tract of female adults. 16S rDNA, ftsZ and groEL gene sequences showed that the endosymbiont of R. similis is distantly related to the known Wolbachia supergroups. Finally, based on our initial success in finding sequences of this endosymbiont by screening an expressed sequence tag (EST) dataset, all nematode ESTs were mined for Wolbachia-like sequences. Although the retained sequences belonged to six different nematode species, R. similis was the only plant-parasitic nematode with traces of Wolbachia. Based on our phylogenetic study and the current literature we designate the endosymbiont of R. similis to a new supergroup (supergroup I) rather than considering it as a new species. Although its role remains unknown, the endosymbiont was found in all individuals tested, pointing towards an essential function of the bacteria.
KW - Animals
KW - Arthropods
KW - Gene Expression Profiling
KW - Genes, Helminth
KW - Host-Parasite Interactions
KW - Molecular Sequence Data
KW - Nematoda
KW - Phylogeny
KW - Sequence Analysis, DNA
KW - Symbiosis
KW - Wolbachia
U2 - 10.1016/j.ijpara.2009.01.006
DO - 10.1016/j.ijpara.2009.01.006
M3 - A1: Web of Science-article
C2 - 19504759
SN - 0020-7519
VL - 39
SP - 1045
EP - 1054
JO - International Journal for Parasitology
JF - International Journal for Parasitology
IS - 9
ER -