ISSN:
1432-0878
Keywords:
Leucocytes
;
Invertebrates
;
Oyster
;
Ultrastructure
;
Cytochemistry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The fine structure of oyster leucocytes resembles to a great extent, that of typical eucaryotic cells. Organelles which have been described for the first time in this report are light granules, dense granules, protocentriole and X structure. Light microscopy reveals two morphological types of oyster leucocytes: agranular and granular. Based upon nuclear morphology and cytoplasmic compositions revealed in electron microscopy, at least three types of agranular and one type of granular cells are recognized. In the Giemsa-stained preparations, granular leucocytes exhibit three distinct types of cytoplasmic granules: refractile, dark blue, and pink, which presumably correspond to light granules Type A, B, and C seen in the electron micrographs. A granular leucocyte may contain one or more types of granules. Cytochemical investigations show that oyster leucocytes contain at least three hydrolytic enzymes: non-specific esterases, acid, and alkaline phosphatase. The latter two enzymes constitute 63% of the enzyme activity detected. These intracellular enzymes may be associated with the light granules and/or lysosome-like bodies. It is also demonstrated that the granular leucocyte population is significantly higher (P〈0.001) in the oysters experimentally infected with Bacillus mycoides (72.19±4.71%) as contrasted with that of the controls (37.18±4.48%). Leucocytes in progressive stages of degeneration are also described.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00335537
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