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The World of

The World of. NEMATODES. Image: Courtesy of Thomas O. Powers, Ph.D. and Rebecca Higgins. What are nematodes?. Unsegmented roundworms Aquatic (Live in water) Small.

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The World of

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  1. The World of NEMATODES Image: Courtesy of Thomas O. Powers, Ph.D. and Rebecca Higgins

  2. What are nematodes? • Unsegmented roundworms • Aquatic (Live in water) • Small Nematode Management for Nursery Crops (Ornamentals and Planting Stock of Fruits and Nuts), 2005 UF/IFAS. On the web a http://edis.ifas.ufl.edu/NG011

  3. Where do nematodes live? Image: Redrawn by Becky Westerdahl from Ayoub, S.M. 1977. Plant nematology an agricultural training aid. Sacramento California Department of Food and Agriculture, Division of Plant Industry. On the world wide web at http://ucdnema.ucdavis.edu/imagemap/nemmap/Ent156html/intro/WHERE.GIF

  4. “Good”-vs-“Bad” nematodes • Bacterial feeders • Fungal feeders • Predators • Animal-parasites • Plant-parasites “Good guys” “Bad guys”

  5. Predatory nematodes Mmmm Tastes like chicken!! Image: Courtesy of John Chitambar. On the world wide web at http://ucdnema.ucdavis.edu/imagemap/nemmap/ENT156HTML/slides/fromCD/0847/025B.GIF

  6. Intestinal roundworms Ascaris lumbricoides Image: Courtesy of Richard Cyr. On the world wide web at http://courses.bio.psu.edu/fall2005/biol110/tutorials/tutorial39.htm

  7. Hookworm Image: Courtesy of Richard Cyr. On the world wide web at http://courses.bio.psu.edu/fall2005/biol110/tutorials/tutorial39.htm

  8. Plant Parasitic Nematodes Sting nematodes on soybean Image: Sting Nematode, Belonolaimus longicaudatus Rau (Nematoda: Secernentea: Tylenchida: Tylenchina: Belonolaimidae: Belonolaiminae), 2005 UF/IFAS. On the web a http://edis.ifas.ufl.edu/IN395

  9. Entomopathogenic Nematodes and their Bacterial Associates • The Nematode: • Soil dwelling, aquatic organism • The Bacterium: • Motile, lives in the nematode gut • Nematode + Bacterium • Obligate, mutualistic symbionts • Lethal parasites of insects • Can infect many different insects • Found everywhere on earth Steinernema image: Courtesy of Thomas O. Powers, Ph.D. and Rebecca Higgins. May be copied for educational purposes. Bacterial image: Courtesy of TJ Bliss. May be copied for educational purposes.

  10. Xenorhabdus (bacterium) lives in Steinernema (nematode) Photorhabdus (bacterium) lives in Heterorhabditis (nematode) Steinernema image: Courtesy of Thomas O. Powers, Ph.D. and Rebecca Higgins. May be copied for educational purposes. All other images: Courtesy of TJ Bliss. May be copied for educational purposes.

  11. Steinernema and Heterorhabditis • Nematodes enter insect through natural openings • Once in the insect, the nematode releases the bacteria that are carried in the intestine • Bacterial cells reproduce rapidly and kill the insect within 24-48 hours using many different toxins. • The nematodes eat the bacteria and reproduce for 3 or 4 generations • Over 100,000 nematodes exit the insect

  12. Xenorhabdus and Photorhabdus • Produce enzymes and highly potent insect toxins • Produce antibacterial and antifungal antibiotics • Photorhabdus produces enzymes that cause it to glow in the dark Image: Courtesy of TJ Bliss. May be copied for educational purposes.

  13. Model Organisms • Primates • Rats and Mice • Nematodes!!! Primate: Courtesy of David Bygott. On the world wide web at http://www.tolweb.org/treehouses/?treehouse_id=3029l Lab Mouse: Courtesy of Ellis Jensen, Ph.D. Nematode: Courtesy of TJ Bliss. May be copied for educational purposes.

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