Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Changes Associated with Parasitism in Nematodes. III. Ultrastructure of the Egg Shell, Larval Cuticle, and Contents of the Subventral Esophageal Glands in Meloidogyne javanica, with Some Observations on Hatching

Alan F. Bird
The Journal of Parasitology
Vol. 54, No. 3 (Jun., 1968), pp. 475-489
DOI: 10.2307/3277069
Stable URL: http://www.jstor.org/stable/3277069
Page Count: 15
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Changes Associated with Parasitism in Nematodes. III. Ultrastructure of the Egg Shell, Larval Cuticle, and Contents of the Subventral Esophageal Glands in Meloidogyne javanica, with Some Observations on Hatching
Preview not available

Abstract

Egg development proceeds normally under the influence of a number of environmental stimuli. Hatching is associated with an increase in larval activity and plasticity of the egg shell resulting from the breakdown of a lipid layer. During this period protein granules are formed in the subventral esophageal glands. The fine structure of the egg shell during different stages of larval development is described together with structural changes which take place both in the cuticle and in the subventral esophageal glands of the larva during its transition from the preparasitic to the parasitic mode of life. The egg shell consists of two basic layers; an outer chitinous layer, and an inner lipid layer. The former is about 0.5 µ thick and has a dense outer layer which is about 30 mµ thick. The lipid layer varies in thickness and appears to break down just before hatching. The cuticle of the preparasitic larva is just over 0.3 µ thick. It is characterized by a pronounced striped layer which disappears within a week of the nematode becoming a parasite. The granules in the subventral esophageal glands of preparasitic larvae are about 0.6 to 0.8 µ in diameter, irregular in shape, and have a distinct outer membrane, in contrast to granules in the subventral esophageal glands of parasitic larvae which lack a distinct outer membrane, are smaller, and have contents which stain differently. These observations support those made earlier with the light microscope and the U.V. microspectrograph.

Page Thumbnails

  • Thumbnail: Page 
475
    475
  • Thumbnail: Page 
476
    476
  • Thumbnail: Page 
477
    477
  • Thumbnail: Page 
478
    478
  • Thumbnail: Page 
479
    479
  • Thumbnail: Page 
480
    480
  • Thumbnail: Page 
481
    481
  • Thumbnail: Page 
482
    482
  • Thumbnail: Page 
483
    483
  • Thumbnail: Page 
484
    484
  • Thumbnail: Page 
485
    485
  • Thumbnail: Page 
486
    486
  • Thumbnail: Page 
487
    487
  • Thumbnail: Page 
488
    488
  • Thumbnail: Page 
489
    489