Ether-induced segmentation disturbances in Drosophila melanogaster

Abstract

Drosophila embryos, exposed to ether between 1 and 4 h after oviposition, develop defects ranging from the complete lack of segmentation to isolated gaps in single segments. Between these extremes are varying extents of incomplete and abnormal segmentation. On the basis of both their temporal and spatial characteristics, five major phenotype classes may be distinguished: headless - unsegmented or incompletely segmented anteriorly; gap - interruptions of segmentation not obviously periodic; alternating segment gaps - interruptions with double segment periodicities; fused segments; and short segments - truncations with single segment periodicities. Many defects resemble known mutant phenotypes. The disturbances in segmentation are predominantly global and frequently accompanied by alterations in segment specification, such that the segments obtained show no resemblance to the normal homologues. These features, together with the distinctive spatiotemporal characteristics of the defects, all point to segmentation as a dynamic process. The regular spacing of the segments and the fact that the entire range of defects is inducible by ether are further consistent with the hypothesis that at least part of the segmentation process may consist of physicochemical reactions coordinated over the whole body. The relationship between our data and data from genetic and other analyses are briefly discussed.

Developmental changes in Drosophila melanogaster following exposure to alternating electromagnetic fields

“…Pattern determination processes are known to occur within the first 3 h of development, during which the body structure (following larval stage) is sensitive to a wide variety of environmental agents [Ho et al, 1987]. After the larval stage and during metamorphosis, adult (imago) structures are formed by groups of undifferentiated cells called imaginal discs [Elseth and Baumgardner, 1995].…”

Development and Evolution Revisited

“…The segmentation pattern of the first instar Drosophila larva is determined during early embryogenesis, when brief exposures to ether vapor produced characteristic defects in the segmental pattern reflecting a dynamic process arrested at different stages (Ho, Matheson, Saunders, Goodwin, & Smallcombe, 1987). We showed that a model of successive bifurcation was capable of producing all the observed defects as well as predict the existence of ones not yet observed (Ho, 1990).…”

The Role of Action in Evolution: Evolution By Process and the Ecological Approach To Perception

“…of morphological disturbances can be produced by exposure to an organic solvent such as ether (Ho et al 1987). In other words, there is an underlying dynamic structure -an invariant which limits the possible forms so that, regardless of the nature or extent or perturbation, the same variations turn up again and again.…”