ISSN:
1432-0878
Keywords:
Cell death
;
Central nervous system
;
Embryogenesis of Calliphora (Insecta)
;
Vital staining
;
Light microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary During the late embryonic period, cell death occurs in the central nervous system of Calliphora erythrocephala. The degenerating cells are small and rounded, contain a pyknotic nucleus, and selectively accumulate basic vital dyes such as nile blue sulphate and acridine orange. The number of degenerating cells is highest 13–15 hours after oviposition and decreases during the shortening of the ventral nerve cord. Nevertheless, these degenerating cells do not represent a morphogenetic phenomenon, since their number is too small to account for the 55% decrease in the length of the ventral nerve cord. In all probability the pyknoses seen in the central nervous system of this holometabolic insect are to be interpreted as phylogenetic degenerations of clearly vestigial neuroblasts that have lost functions they might have retained in the larvae of insects in lower orders, for instance the innervation of legs, wings, a larger number of abdominal segments, etc. About half of the pyknoses occur in pairs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00222224
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