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Interactions between social factors and ovarian development in the European house cricket Acheta domesticus (1985)

Bradley, James T.

Springer

Entomologia experimentalis et applicata 38 (1985), S. 249-254

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ISSN: 1570-7458

Keywords: Group effect ; crowding ; oogenesis ; vitellogenesis ; Acheta domesticus

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Description / Table of Contents: Résumé L'étude a examiné les effets de groupement sur la production d'oeufs et sur la vitesse de la vitellogenèse chez les femelles vierges d'Acheta domesticus. Des femelles à la moitié de leur dernier stade larvaire, isolées d'une population adulte de base, et des nymphes des deux sexes ont été conservées en groupes ou isolées dans des récipients en plastique de 150 mm de diamètre et de 25 mm de hauteur à 26–27°C, 70% d'humidité relative et avec une photopériode de 12/12. La production totale des oeufs mûrs formés pendant les 18 premiers jours de vie imaginale était plus faible pour les animaux en groupes de 10 ou 15 que pour ceux qui étaient isolés, mais l'antennotectomie a éliminé cet effet de groupe. Au contraire, la longueur des derniers et avant-derniers ovocytes et le poids sec des ovaires étaient supérieurs pour les paires de 2 femelles de 5 jours que chez les individus isolés. La présence de mâles mûrs pendant les 21 premiers jours de vie imaginale n'a pas eu d'effet sur la production totale d'oeufs. L'hypothèse avancée est que ces effets de groupe (négatifs et positifs) sur le développement des ovaires d'Acheta domesticus ont reflété respectivement des accélérations et ralentissements de la vitellogenèse. La dépendance de l'induction de la vitellogenèse chez Acheta domesticus par les hormones juvéniles est connue (Benford, 1983) ainsi que les changements dans la quantité de produits neurosécréteurs, susceptibles d'être colorés dans la pars intercerebralis au cours du cycle reproductif (Bradley et Simpson, 1981). Nous ne savons pas si ces effets de groupement sur le développement des ovaires de grillon sont médiatisés par le système endocrine.

Notes: Abstract Several endocrine-mediated processes in insects are influenced by environmental factors including the density and sex ratio of populations. Effects of grouping on total egg production and rate of vitellogenic ovary development were assessed in virgin Acheta domesticus (L.). Females midway through their last nymphal instar were isolated from a stock population of adults and nymphs of both sexes and maintained in groups or as isolates at 26–27°C, 70% relative humidity, on a 12L-12D photoperiod. The number of fully grown oocytes produced during the first 18 days of adult life was lower for animals in groups of 10 or 15 than for isolates, but antennectomy abolished this group effect. By contrast, terminal and penultimate oocyte length and ovary dry weight were greater in 5-day-old ♀-♀ pairs than in isolates. The presence of mature males during the first 21 days of adult life did not affect total egg production. Whether these group effects on cricket ovary development are mediated by the endocrine system is not yet known.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00295258

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Ovarian follicle development during vitellogenesis in the house cricket Acheta domesticus (1989)

Dennis, John C. ; Bradley, James T.

New York, NY : Wiley-Blackwell

Journal of Morphology 200 (1989), S. 185-198

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ISSN: 0362-2525

Keywords: Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology , Medicine

Notes: To determine the morphological correlates of vitellogenin uptake and distribution, vitellogenic ovarian follicles of Acheta domesticus were examined by light and transmission electron microscopy. Yolk deposition was usually restricted to the terminal follicle of each panoistic ovariole, but if the terminal follicle had completed vitellogenesis and had not yet been ovulated, the penultimate follicle was often vitellogenic. Vitellogenesis occurred only in the ovaries of adults, with follicles representing all stages of vitellogenic development occurring simultaneously within a single ovary. Vitellogenic follicles were 0.75 to 〉2.0 mm long. The single irregularly shaped nucleus of each follicle cell contained two to three nucleoli. During vitellogenesis the epithelium of individual follicles progressed from columnar to cuboidal to squamous. The distribution of cytoplasmic organelles within individual follicle cells was polarized during early and middle stages of vitellogenesis. Near the end of vitellogenesis, polarity disappeared, the follicular epithelium became squamous, and the frequency of vesicular and multivesicular bodies in the follicle cell cytoplasm increased. A well-developed capability for follicle cell protein synthesis and secretion throughout vitellogenesis was indicated by abundant rough endoplasmic reticulum and Golgi bodies. Receptor-mediated endocytotic activity by the follicle cells during all stages of vitellogenesis was suggested by omnipresent coated pits on all surfaces. Septate junctions, gap-like junctions, and desmosomes all occurred in the lateral membranes, while gap-like junctions predominated at the oocyte-follicle cell interface. In follicles longer than 1 mm, adjacent follicle cells were separated by intercellular channels that widened to as much as 10 m̈m by the completion of vitellogenesis. The channels contained a flocculent material, and a similar-appearing material filled the space between the oolemma and follicle cell apical membranes. The oolemma contained a profusion of coated pits throughout vitellogenesis.

Additional Material: 24 Ill.