摘要:

In the corn earwormHelicoverpa zeayolk deposition in oocytes begins 8–10 h after adult eclosion and is controlled by juvenile hormone (JH). Hemolymph from females at the time of yolk formation, analyzed by SDS-PAGE, contains polypeptides apparently identical to polypeptides from eggs; and these have been tentatively designated as apovitello-genins (apoVgs). ApoVgs were not found in male hemolymph. The hormonal control of production of the apoVg with an apparent molecular weight of 165 kDa (apoVg-I) was studied by SDS-PAGE. Decapitation of females immediately after eclosion did not prevent the appearance of apoVg-I whereas the same operation done 5–7 h prior to eclosion abolished its production. Treatment of the latter group of females with methoprene, a JH analogue, restored production of apoVg-I whereas injection of 20-hydroxyecdysone (20-HE) did not. When pharate adults were kept at 10°C from 10–12 h before the time of their anticipated eclosion, eclosion was delayed for 4–7 d. In such females, maintained at the same temperature, apoVg-I appeared only on day 3, and its appearance could be accelerated by two days with methoprene treatment immediately after eclosion. Decapitation of chilled females just after eclosion prevented the appearance of apoVg-I even after 16 d at 10°C. Likewise, Vg was absent in chilled females decapitated after eclosión and then maintained at room temperature. Methoprene induced apoVg-I production one day after treatment in chilled decapitated females maintained after eclosion either chilled or at room temperature. 20-HE had no effect on these females. Methoprene did not induce Vg in adult males. ApoVg-I ofH. zeadid not cross-react withManduca sextaandPlodia interpunctellaVg antibodies. These results demonstrate that Vg synthesis inH. zeais regulated by JH.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672235

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Alterations in the integument of masculinized females ofArmadillidium vulgarecaused by the implantation of androgenic glands from normal males involve both pigment cells and epidermal cells with respect to the intracellular structure and the ommochrome content. Epidermal cells beneath the cuticle of masculinized females are thicker than those of normal females, having a number of small secretory granules and well developed rough endoplasmic reticulum in the cytoplasm. As a result of epidermal cell thickening, pigment cells are more widely separated from the cuticle in masculinized females than in normal females. The ommochrome content in the integument of masculinized females, which was initially the same as that of normal females, increased with each postoperative stage and coincided with that of male integument by the fourth postoperative stage. The observations suggest that the slate grey color characteristic of the male body, shown during masculinization of females after the implantation of androgenic glands, is possible caused by both the structural changes in epidermal cells and alterations in the ommochrome content in pigment cells.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672236

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The titre of insulin-like-peptides (ILP) in the haemolymph, developing oocytes and developing eggs was examined by a radioimmunoassay for human anti-insulin. ILP in the haemolymph increased in a two-stage pattern during oogenesis, but fell at ovulation. ILP accumulated in the oocyte during the same period but was not detectable in the ovulated oocyte. During embryogenesis three peaks of ILP concentration could be detected in extracts of embryonated eggs. The timing of these peaks was closely correlated with the timing of peaks of ecdysone titre previously reported by Lagueux et al. (1979). It is postulated that the ILP stimulate the previously observed synthesis and release of ecdysteroids during oogenesis and embryogenesis (Lagueux et al., 1979; Porcheron et al., 1982).

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672237

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The ingestion of an animal's own faeces (coprophagy) is a common phenomenon in terrestrial isopods. In the present investigation the influence of withholding faeces on growth and on the hemolymph protein composition of different life stages of the wood-louseOniscus aselluswas assessed. JuvenileOniscus asellusreared without access to their faeces suffered severely under this treatment. Their gain in body mass was significantly lower than that in the control group. In contrast, the effect of non-coprophagous rearing was moderate or not detectable in subadult and adult individuals, respectively. No correlation occurred between coprophagy and survival rates in all test groups.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672238

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An experiment was conducted to examine whether extended courtship display (a major component of mating behaviour) or repeated copulation in the course of a reproductive season stimulates egg production in the simultaneously hermaphroditic land snailArianta arbustorum.Repeated copulation was found to increase the number of eggs produced while courtship display did not appear to affect egg production. However, repeated copulation neither accelerated the onset of egg laying nor increased the hatching success of eggs. These results suggest that reciprocal intromission and/or receipt of a spermato-phore, but not the long-lasting courtship behaviour, stimulates egg production inA. arbustorum.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672239

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Five structural types of the adult ovary were distinguished in a parthenogenetic viviparous scorpionLiocheles australasiaebased on the presence or absence of swollen ovarian diverticula (SD) containing embryos and/or empty ones (ED) as remnants of past pregnancies. These structural types seem to correspond to the following ovarian functional phases: the ovary (1) with SD and without ED corresponds to the first pregnancy; (2) without SD and with ED to after the first parturition; (3) with SD and ED to the second pregnancy; (4) without SD and with old and new ED to after the second parturition; and (5) with SD and old and new ED to the third pregnancy. Such correspondence indicates that a female can repeat pregnancies at least three times. Some possible cases in which the present structural types correspond to other functional phases were also discussed.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672240

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The morphology of larval development and some aspects of oogenesis are described inMicromaldanespp. from eastern Australia. All four species breed throughout the year, and in all the oocytes are released into the coelom prior to vitellogenesis.Micromaldane androgyne, M. pamelaeandM. rubrospermathecaall have solitary oogenesis, whileMicromaldane nutriculahas “nurse” cells attached to the oocytes throughout vitellogenesis. Mature females ofMicromaldane nutriculabrood up to two groups of 1–4 directly developing larvae at a time. Newly fertilized eggs are ellipsoidal, 150x350 μm. No ciliation is visible during development. Larvae leave the tube after developing 12 chaetigers. AllMicromaldane androgyneadults brood a single batch of two or three directly developing larvae at a time. Newly deposited eggs are 1 mm long and 150 μm in diameter. No ciliation is visible on the larvae during development. Larvae develop 19 chaetigers before leaving the tube.Mature females of Micromaldane pamelaebrood single batches of up to 31 larvae at a time. Mature oocytes are ellipsoidal 300 X 150 μm. Larvae show a distinct neurotroch in early stages of development, but this is resorbed as chaetigers are formed. Larvae probably leave the tube at the 16-chaetiger stage.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672241

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The possibility that biogenic amines affect ovarian development in the red swamp crayfish,Procambarus clarkii, was investigated. Females were administered 15 μg/g body weight (bw) of norepinephrine, dopamine, 5-hydroxytryptamine (5-HT) or octopamine on days 1, 5 and 10 and were sacrificed on day 15. Crayfish given 5-HT showed significant increases in ovarian index (30.5%) and oocyte size (34.0%) over the concurrent controls, while norepinephrine, dopamine and octopamine did not significantly affect either the ovarian index or oocyte size. Significantly more labeling by14C-leucine of ovarian proteins was found in ovaries of crayfish that were injected with 5-HTin vivo, but when ovarian lobes from crayfish that had not been injected with 5-HT were incubatedin vitrowith 5-HT added to the incubation medium, no significant change in the level of incorporation of14C-leucine into ovarian proteins occurred.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672242

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

During the tail-bud stage ofAscidiella aspersaembryogenesis, the test cells or innermost cells of the egg envelope manifest locomotive activities. Light microscopy further reveals that the adhesive behaviour of test cells changes in the course of embryogenesis. Mechanical dechorionation experiments performed on 846 embryos demonstrate that up to the tail-bud stage all test cells are attached to the inner surface of the chorion. The embryo is completely devoid of test cells. At the onset of larval tunic secretion, increasing numbers of test cells settle on the embryo until all test cells adhere to it. This switch in adhesive properties is completed within 65 min. The hatched larva carries the entire complement of test cells until the onset of metamorphosis. SEM and observations show that test cells do not establish direct cell-to-cell contacts to ectodermal cells but attach to the larval tunic.

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672243

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0792-4259    

DOI:10.1080/07924259.1992.9672244

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor