Oocyte maturation without follicular epithelium alters egg shape in a dipteran insect

Abstract

Oocytes of the parthenogenetic gall midge Heteropeza pygmaea assume an elongate shape when they mature inside the follicular epithelium. However, when the oocyte-nurse chamber complexes grow without the regular follicular layer, they form spherical eggs. Such eggs may develop as far as the blastoderm stage. These findings indicate that the follicular epithelium is responsible for the shape of the egg but is not required for oocyte maturation and for initial steps in embryonic development.In early oogenesis, the insect oocyte is enveloped by a layer of follicle cells, the follicular epithelium. The oocyte grows within the follicular epithelium and accumulates yolk. There products participate in the formation of

Sex Pheromone Gland of the Female European Corn Borer Moth, Ostrinia nubilalis (Lepidoptera, Pyralidae): Ultrastructural and Biochemical Evidences

“…Microtubules have been reported to be important in providing mechanical support for midge follicles (Tucker and Meats 1976;Went 1978). In the hemipteran bug, Rhodnius prolixus Stal, (Reduviidae), microtubules are an important cytological element that is involved in the change of the follicular epithelium during vitellogenesis (Huebner 1976;Abu-Hakima and Davey 1977).…”

Expanding the Morphogenetic Repertoire: Perspectives from the Drosophila Egg

“…Pioneering investigations were made on the Dipteran gall midge Heteropeza , whose eggs also elongate from spherical to ellipsoid during development. Removal of the follicle epithelium through irradiation, chemical, or mechanical manipulation caused spherical eggs to develop, suggesting a critical role for the epithelium in elongation (Went, 1978; Went and Junquera, 1981). Strikingly, nearly spherical eggs are also produced by Drosophila homozygous for a female sterile mutation isolated by Nusslein-Volhard called kugelei (kug) ( Fig.…”

Paedogenesis in the dipteran insectHeteropeza pygmaea:an interpretation

“…For this purpose, the ovaries or follicles were explanted from larvae, taken in culture, and drawn with the aid of an inverted microscope equipped with Nomarski optics. Oocyte-nurse chamber complexes developing without the follicular epithelium were obtained by X-ray irradiation of ovaries developing in situ [12]. The methods used for cinemicrographic analysis have been described elsewhere [ 10].…”

“…This is shown by the mode of development of 'follicles' devoid of the regular follicular epithelium. Such 'naked' oocyte-nurse chamber complexes can be obtained in different ways [12]. Cultured in vitro, these oocyte-nurse chamber complexes may develop through maturation and early embryonic development up to the blastoderm stage.…”