PROGRAMMED CELL-DEATH IN THE HONEYBEE (APIS-MELLIFERA L) LARVAE MIDGUT

The histochemical and cytochemical localization of acid phosphatase ha s been used in an attempt to map the sites of cellular lysis and death . Reaction product was found both in the brush border of the midgut ep ithelium and in the basal membrane. Vacuolar acid phosphatase activity was found in the regenerative epithelial cells. Extra-cisternal react ion product was associated with the endoplasmic reticulum which was di lated in lysed areas of the cytoplasm. Free acid and alkaline phosphat ase activity was found in the basal area of the midgut epithelial cell s and the former also occurred in the haemocoel. In the tracheoblastic cells only vacuolar acid phosphatase activity was seen. Chromatin agg regates were distributed throughout the nucleus and the nuclear envelo pe showed some infolding. Certain mature epithelial cells proved posit ive for anti-histone associated DNA fragmentation indicative of progra mmed cell death. (C) 1997 Academic Press Limited.