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Heterorhabditis gerrardi n. sp. (Nematoda: Heterorhabditidae): the hidden host of Photorhabdus asymbiotica (Enterobacteriaceae: γ-Proteobacteria)

  • K.L. Plichta (a1), S.A. Joyce (a2), D. Clarke (a2), N. Waterfield (a3) and S.P. Stock (a1)...

A new entomopathogenic nematode species from Australia, Heterorhabditis gerrardi n. sp. (Nematoda: Heterorhabditidae) is described. Morphological and molecular studies together with cross-hybridization tests indicated that this nematode represents a new undescribed species, closely related to members in the ‘indica-group’. However, the new species can be distinguished from other species in this genus by a combination of several qualitative and quantitative morphological traits. Key diagnostic features include: body size and excretory pore position of the third-stage infective juveniles; male bursa with a reduction of bursal rays, usually affecting the terminal set of papillae, with symmetrical or asymmetrical loss of one or two pairs; vulva of hermaphrodites more anteriorly located than in other species in the indica-group (V% average: 43), with non-protruding or slightly protruding lips, and longer tail length (average: 106 μm). The new species can be further characterized by molecular traits of sequence data from the internal transcribed spacer (ITS) region of ribosomal DNA. Additionally, the bacterial symbiont of this new species, Photorhabdus asymbiotica Kingscliff strain, was phenotypically characterized and compared with other P. asymbiotica strains. The Kingscliff strain revealed many characters not present in other strains of this species. We hypothesize that the newly found traits may contribute to the maintenance of this mutualistic association of the bacterium with its nematode host.

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B.J. Adams , A. Fodor , M.G. Klein , H.L. Smith , E. Stackenbrandt & S.P. Stock (2006) Biodiversity and systematics of nematode–bacterium entomopathogens. Biological Control 37, 3249.

R.J. Akhurst & K. Smith (2002) Regulation and safety. pp. 311332in R. Gaugler (Ed.) Entomopathogenic nematology. Wallingford (UK), CAB International.

V. Andaló , K.B. Nguyen & A. Moino (2007) Heterorhabditis amazonensis n. sp. (Rhabditida: Heterorhabditidae) from Amazonas, Brazil. Nematology 8, 853867.

J.G. Gerrard , S.A. Joyce , D.J. Clarke , R.H. ffrench-Constant , G.R. Nimmo , D.F.M. Looke , E.J. Feil , L. Pearce & N.R. Waterfield (2006) Nematode symbiont for Photorhabdus asymbiotica. Emerging Infectious Diseases 12, 15621564.

S.A. Joyce & D.J. Clarke (2003) A hexA homologue from Photorhabdus regulates pathogenicity, symbiosis and phenotypic variation. Molecular Microbiology 47, 14451457.

S.A. Joyce , A.O. Brachmann , I. Glazer , L. Lango , G. Schwär , D.J. Clarke & H. Bode (2008) Bacterial biosynthesis of a multipotent stilbene. Angewandte Chemie International Edition in English 47, 19421945.

H.K. Kaya & S.P. Stock (1997) Techniques in insect nematology. pp. 281324in L. Lacey (Ed.) Manual of techniques in insect pathology. San Diego, California, Academic Press.

J. Liu & R.E. Berry (1996) Heterorhabditis marelatus n. sp. (Rhabditida: Heterorhabditidae) from Oregon. Journal of Invertebrate Pathology 67, 4854.

A.P. Malan , K.B. Nguyen , J.Y. De Waal & L. Tiedt (2008) Heterorhabditis safricana n. sp. (Rhabditida: Heterorhabditidae), a new entomopathogenic nematode from South Africa. Nematology 10, 381396.

K.B. Nguyen , D.I. Shapiro-Ilan , R.J. Stuart , C.W. McCoy , R.R. James & B.J. Adams (2004) Heterorhabditis mexicana n. sp. (Rhabditida: Heterorhabditidae) from Tamaulipas, Mexico, and morphological studies of the bursa of Heterorhabditis spp. Nematology 6, 231244.

K.B. Nguyen , D.I. Shapiro-Ilan & G.B. Mbata (2008) Heterorhabditis georgiana n. sp. (Rhabditida: Heterorhabditidae) from Georgia, USA. Nematology 10, 433448.

K.L. Phan , S.A. Subbotin , N.C. Nguyen & M. Moens (2003) Heterorhabditis baujardi sp. n. (Rhabditida: Heterorhabditidae) from Vietnam and morphometric data for H. indica populations. Nematology 5, 367382.

G.O. Poinar Jr (1976) Description and biology of a new insect parasitic rhabditoid, Heterorhabditis bacteriophora n. gen. n. sp. (Rhabditida, Heterorhabditidae n. fam.). Nematologica 21, 463470.

J.W. Seinhorst (1959) A rapid method for the transfer of nematodes from fixative to anhydrous glycerin. Nematologica 4, 6769.

D.I. Shapiro-Ilan , D.H. Gouge & A.M. Koppenhöfer (2002) Factors affecting commercial success: case studies in cotton, turf and citrus. pp. 333356in R. Gaugler (Ed.) Entomopathogenic nematology. New York, CABI.

S.P. Stock & H.K. Kaya (1996) A multivariate analysis of morphometric characters of Heterorhabditis species (Nemata: Heterorhabditidae) and the role of morphometrics in the taxonomy of species of the genus. Journal of Parasitology 82, 806813.

S.P. Stock , J.F. Campbell & S.A. Nadler (2001) Phylogeny of Steinernema Travassos, 1927 (Cephalobina, Steinernematidae) inferred from ribosomal DNA sequences and morphological characters. Journal of Parasitology 87, 877889.

S.P. Stock , C.T. Griffin & A.M. Burnell (2002) Morphological characterization of three isolates of Heterorhabditis Poinar, 1976 from the ‘Irish group’ (Nematoda: Rhabditida: Heterorhabditidae) and additional evidence supporting their recognition as a distinct species, H. downesi n. sp. Systematic Parasitology 51, 95106.

J.D. Thompson , T.J. Gibson , F. Plewniak , F. Jeanmougin & D.G. Higgins (1997) The CLUSTAL_X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Research 25, 48764882.

R.J. Watson , S.A. Joyce , G.V. Spencer & D.J. Clarke (2005) The exbD gene of Photorhabdus temperata is required for full virulence in insects and symbiosis with the nematode Heterorhabditis. Molecular Microbiology 56, 763773.

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