title: Characterisation of guanylyl cyclase genes in the soybean cyst nematode, Heterodera glycines.
abstract: Parasitism by the soybean cyst nematode, Heterodera glycines, has become one of the major limiting factors in soybean production world-wide. A partial HG-gcy-1 cDNA clone was obtained by screening a H. glycines cDNA library with a probe derived from the HG-gcy1 genomic sequence, and HG-gcy-1 full-length cDNA was obtained by nested PCR and 5' rapid amplification of cDNA ends (5' RACE). Two additional, full-length guanylyl cyclase cDNA clones from H. glycines, named HG-gcy-2 and HG-gcy-3, were recovered directly by screening the H. glycines cDNA library with a probe derived from sequence of the HG-gcy-1 catalytic domain. The encoded proteins of all three HG-gcy genes had an extracellular ligand-binding domain, a single membrane-spanning domain, an intracellular protein kinase-like domain, and a guanylyl cyclase catalytic domain. The three HG-GCY proteins had conserved cysteine residues to form disulfide bridges within the extracellular domain similar to the predicted ligand-binding domains of other known membrane-bound guanylyl cyclases. mRNA in situ hybridisation detected the expression of HG-gcy-1 and HG-gcy-2 transcripts in specific and different sensory neurons within H. glycines specimens. HG-gcy-3 transcripts were not localised in H. glycines specimens by in situ hybridisation. The discovery of the three guanylyl cyclase genes in H. glycines is the first of its kind in a plant-parasitic nematode and may be representative of a conserved gene family used for chemosensory recognition in parasitic nematodes.
authors.affiliation: Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Yitang
authors.initials: Y
authors.lastname: Yan
authors.forename: Eric L
authors.initials: EL
authors.lastname: Davis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D006162:Guanylate Cyclase / Q000737:chemistry / Q000235:genetics*; D017403:In Situ Hybridization; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009348:Nematoda / Q000201:enzymology* / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013025:Glycine max / Q000469:parasitology*
chemical_list: D018509:DNA, Helminth; D007527:Isoenzymes; D012333:RNA, Messenger; D006162:Guanylate Cyclase