Embryology and Cytology of Bursaphelenchus xylophilus

Abstract

Because of their small size, availability, simple and transparent body, and reproducible development nematodes have been popular organisms for studying animal development since the nineteenth century. The many important events in embryogenesis, such as fertilization, meiosis, pronuclear meeting, and chromosome-based sex-determination were discovered as the result of observations of the horse roundworm Parascaris equorum (Ascaris megalocephala) embryo, and the concepts of individuality and physical continuity of the chromosomes were established and generalized as biological phenomena by nineteenth century nematologists (Triantaphyllou 1971). A variety of chromosome numbers, reproduction modes, and early developmental patterns have been discovered and studied in both parasitic and free-living nematodes. © 2008 Springer.