ISSN:
1432-1955
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Clamp formation inGastrocotyle trachuri occurs around an infolding of the body wall epidermis. Associated with the region around the epidermal infoldings, and subsequently, with each developing clamp is a number of differentiating cells. These cells produce cytoplasmic extensions towards the region of clamp formation. The extensions form a syncytical region around the epidermal infolding and it is within this area that clamp formation occurs. The cells also produce groups of electron-lucent membrane-bound vesicles and these pass along the extensions towards the region of clamp formation. The sclerites appear first as a collection of short, hollow, tubules. The number of tubules increases and areas of denser material appear within the developing sclerites. The sclerites become uniformly electron-dense and then change in appearance to eventually resemble the sclerites of the fully formed clamps. The clamp wall myofibres are formed within the areas enclosed by the clamp wall internal basement lamina, which arises de novo, and the external basement lamina, which is formed from the basement lamina of the infolded epidermis. The cytoplasmic extensions within this area become re-orientated and it is within these extensions that the myofibres are formed. Associated with the forming myofibres are many of the electron-lucent vesicles formed within the differentiating cells. In any developing clamp the developing myofibres exhibit a highly varied pattern of stages in differentiation with late and early stages often being found in close proximity to each other.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00927522
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