|
KMID : 0616619960020010021
|
|
Journal of Soonchunhyang Medical College
1996 Volume.2 No. 1 p.21 ~ p.42
|
|
|
An Ultrastructural Study on Larval Hemocytes of Lepidoptera
|
|
|
|
|
Abstract
|
|
|
Morphological studies on larval hemocytes of various insects were performed in two ways of research.
I. Finestructures.
An electron microscopical study on hemocytes of last instar larvae of 12 species of Lepidoptera was performed to observe cell types, structures, ratios, relationships and their origins.
The results are as follows;
1) Prohemocytes are the smallest round cells with large nucleus, poorly developed cytoplasmic organelles and lower composition ratio, accounting for less than 5% of all cell types. Little remarked differences were revealed among prohemocytes of various insects and they are thought to be the origins of other cell types.
2) Plasmatocytes are relatively large cells with higher composition ratio, accounting for about 40%. They could be subdivided into two forms, oval and spindle. Oval cells are rich in cytoplasmic projections and organelles. But the spindle cells include few of them, while nearly all of the spindle cells possess some microtubules as their cytoskeletons. Some marked difference were revealed among different insects. The most exceptional structure was the fibrous bundles located in both nucleus and cytoplasm in Sericinus telamon Donovan.
3) Granular cells are characterized by various granules in cytoplasm, and by higher composition ratio, accounting for about 50% of all cell numbers. They could be subdivided into,three forms, oval, round and spindle with fully developed cytoplasmic organelles, and Projections. Cellular fractions were often noticed to be enclosed by granular cells, indicating some activities of phagocytosis. Granular cells are the most pleomo rphous; of all, cell types, and the most exceptional structures are the bundles of microfibrils~ in Phalerodonta manleyi Leech.
4) Adipohemocyte were found only in Plodia interpunctella Hu(¨)bner. They are somewhat oval forms with few cytoplasmic projections and less developed organelles. Some granular cells were found to accumulate lipid droplets into the cytoplasm by trapping floating lipid droplets, and the adipohemocytes are believed to be originated from formers.
5) Sperule cells were found nearly in all specimens and characterized by sperules composed of flocculent materials. They are round or oval with few cytoplasmic organelles. The most conspicuous spherules of all sperule cells were radial arrangement of sperules in Adristyrannus amurensis Staudinger and presence of the specific granules in Mamestra illoba Butler. Young sperule cells resembled the granular cells, and it is possible that they originate from granular cells.
6) Oenocytoids are large cells and were found nearly in all specimens. They could be subdivided into 3 types according to their inclusions, such as microfibrils, microtubules and none of them. Young Oenocytoids resemble the giant plasmatocytes, perhaps in dica.ting to be originated from the latters.
Ⅱ. Composition ratios of cell types from mid 5-instar to late prepupa. Composition ratios of cell types were investigated in phalerodonta manley: Leech and could be summarized as follows;
1) Prohemocytes disappeared from the stage of early prepupa.
2) Plasmatocytes increased in number at mid stages of each inster and decreased nearing to pupal stage.
3) Granular cells reached peak at early prepupal stage.
4) Adipohemocytes heavily increased at late prepupal stage.
5) Sperule cells increased at late stage of each instar and reached peak at late prepupal stage.
6) Oenocytoids increased at late stage of each instar and reached peak at early prepupal stage.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|