摘要:

AbstractAllograft rejection processes of two taxonomically related sponge species,Polymastia robustaandPolymastia mamillaris, have been studied at the cellular level. Grafts in parabiosis have been made by pairing papillae. They were investigated using histology and scanning and transmission electron microscopy.InPolymatia robusta, allografts undergo progressive rejection with adhesion. A few days after grafting, archaeocytes and collencytes migrate toward the zone of contact and fall into line on either side of this zone. The narrow space which separates the grafted papillae is progressively filled up with collagen fibers thanks to which the parabionts are firmly held together. Allografts ofPolymastia mamillarisnever fuse to each other; the specimens are completely and directly rejected. In this species, the cell migration to the zone of contact is not followed by their alignment nor by deposition of a collagen layer. Autografts made in similar conditions succeed in all cases in both species.These experiments demonstrate for the first time that sponges, even taxonomically closely related, may develop different but defined processes of rejection.

ISSN:0022-104X    

DOI:10.1002/jez.1402270102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe responses of melanophores of a cyprinid fishZacco temminckito changes in illumination were examined in isolated scale preparations of the adult fishes. Melanosomes in the melanophores aggregated in darkness and dispersed in light. These responses were invariably induced, even in denervated melanophores. These light responses, the dark‐induced aggregation and the light‐induced dispersion, were not affected by a number of alpha and beta adrenergic blocking agents. It was concluded that the melanophores ofZacco temminckiwere themselves light sensitive and responded directly to light by melanosome translocations. The light responses were quantitatively assessed in relation to the intensity of illuminat

ISSN:0022-104X    

DOI:10.1002/jez.1402270103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractIn various species of animals the level of body hydration is known to affect feeding responsiveness. In order to understand the mechanisms that underlie this form of behavioral modulation, hydration‐induced changes in feeding have been examined in the terrestrial slugsLimax pseudoflavusandLehmannia valentiana.Air‐dehydration of slugs to 70–60% of initial body weight (%IBW) abolishes feeding. Feeding responsiveness is rapidly restored in these slugs after they are allowed to rehydrate in contact with a moist surface. Injections of hyperosmotic mannitol or sucrose solution also result in abolition of feeding, thus suggesting that hemolymph osmotic pressure is involved in modulation of the feeding response. Correspondingly, if mannitol‐injected or air‐dehydrated slugs are injected with 0.1 × saline, feeding is restored in a manner similar to that observed following contact‐rehydration. Feeding was restored, however, only in those slugs whose hemolymph was diluted to at least 180–190 mOsm/kg H2O, which is the hemolymph osmolality of slugs at 75–70% IBW. The present results are consistent with the hypothesis that hydration modulation of feeding in slugs is mediated by hemolymph

ISSN:0022-104X    

DOI:10.1002/jez.1402270104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe gas bladder of leiognathid fishes functions not only in buoyancy but also in reflection of bioluminescent light from the circumesophageal light organ. Purine distribution, quality (guanine/hypoxanthine ratio), and concentration, as the basis for reflectivity, were assayed enzymatically for different portions of the gas bladder lining of the common leiognathid,Leiognathus equulus(Forskal). For highly reflective areas, the percentage of tissue wet mass and dry mass represented by purine was also determined. The results indicate that total purine content in the reflective areas of the leiognathid bladder was significantly higher than values determined for other similar, shallow water fishes; instead, purine content in these reflective areas was similar to that known for very deep‐dwelling fishes, in which heavy purine deposition is correlated with high pressures and high oxygen concentrations in the bladder. In addition, the results show that differential purine distribution within the bladder correlates strikingly with the path of bioluminescent light. The dorsal bladder lining, the primary site of incident luminescence, had extremely high purine concentrations (averaging 2.80 mg/cm2), whereas the secondary reflective surfaces, the lateral (1.81 mg/cm2) and ventral (1.22 mg/ cm2) portions, although high in purine content, had concentrations significantly lower than the dorsum. Areas through which light is transmitted, the light organ‐bladder interface (0.09 mg/cm2) and the posterior region (0.19 mg/ cm2), were greatly reduced in purine content. The enhancement of purine in the reflective portions of the bladder and the correlation of the differential distribution of purines with the path of light indicate that theL. equulusgas bladder is exquisitely adapted to function as a reflector of bioluminescent li

ISSN:0022-104X    

DOI:10.1002/jez.1402270105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe thermal acclimatization of hepatic cytochrome P‐450‐dependent polysubstrate monooxygenase (PSMO) and UDP‐glucuronosyltransferase of mature rainbow trout (Salmo gairdneri) was studied.The results indicate that the PSMO system, 7‐ethoxycoumarin and benzo(a)pyrene as substrates, shows almost ideal acclimatization pattern in autumn during water cooling. The enzyme activities were identical if measurements were carried out at acclimatization (=environmental) temperatures which were 20°C in August and 5°C in November. If a constant incubation temperature (18°C) was used, the PSMO activities were significantly higher in cold (5°C)‐acclimatized fish. The acclimatization process could be seen both in specific and total activities. The content of cytochrome P‐450 remains at constant level from August to November.In early summer during water warming the PSMO activities increased considerably in both sexes in all incubation conditions.The specific and total UDP‐glucuronosyltransferase activities were significantly higher in warm‐acclimatized fish both in the autumn and in the spring if the activities were measured at environmental temperature. No differences could be detected if the measurements were carried out at constant experimental

ISSN:0022-104X    

DOI:10.1002/jez.1402270106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractBlepharida sacra(Weise) is one of many species of flea beetles that have remarkable jumping abilities. The energy for its prodigious leaps is evidently stored in a central scroll‐shaped organ inside the hind femur of this insect—the metafemoral spring. X‐ray diffraction, scanning electron microscope, and analytical studies have established that this structure consists primarily of well‐oriented fibers of the polysaccharide α‐chitin, together with protein. The composition and orientation of these fibers appear to explain the role of this organ in the flea beetle jumping

ISSN:0022-104X    

DOI:10.1002/jez.1402270107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractVincristine was given to pregnant mice on day 7½ of pregnancy and the teratogenic effects of this treatment were assessed 2 and 3 days thereafter. Most of the embryos in litters removed on day 9½ of pregnancy (2 days after treatment) were morphologically normal, whereas on day 10½ most embryos were either developmentally retarded by the treatment or malformed. The morphologically “normal” embryos removed on day 9½ of pregnancy were cultured in vitro for 24 h. During this procedure more than 50% of them showed growth retardation or abnormal development. These data indicate that exposure of early postimplantation embryos to vincristine has an immediate teratogenic and embryocidal action, and also a delayed effect which becomes apparent only several days after exposure and following an ostensibly “normal” period of embryonic

ISSN:0022-104X    

DOI:10.1002/jez.1402270108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractAnalysis of C57BL/6J ↔ A/J allophenic mice for their lymphocyte composition, usingH‐2 antigens as external markers, and glucose phosphate isomerase (GPI) isozymes as internal markers, has led to the discovery of two unusual mice. Both mice showed heterodimers of GPI isozymes upon electrophoresis of the lymphocyte lysate. Specific anti‐H‐2 antisera confirmed that the cells of the mice were of C57BL/6J and A/J origin, as expected, but that the “A/J” cells seemed to behave as F1hybrids containing theGpi‐1aandGpi‐1balleles. Possible origins of theGpi‐1ballele in the “A/J

ISSN:0022-104X    

DOI:10.1002/jez.1402270109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe effect of symbiotic zoochlorellae on tentacle number and budding in Swiss and Israeli strains ofHydra viridisin the light and in the dark, in normally grown and in regenerating specimens has been studied. The mean tentacle number in symbiotic and aposymbiotic hydra was 8.65 ± 1.05 and 7.48 ± 0.86 in the Swiss strain, and 8.62 ± 1.29 and 6.66 ± 0.72 in the Israeli strain. In aposymbiotic hydra reinfected with zoochlorellae isolated from either strain, the number of tentacles increased to that of symbiotic hydra. Decapitated symbiotic hydra regenerated more tentacles than aposymbionts, and regenerating Swiss symbionts also formed more buds than their respective aposymbiotic hydra. The algal enhancing effect was found in the light and in the dark. Regeneration rate was initially higher in the symbiotic hydra, and the ratio between the number of tentacles formed by the regenerating symbiotic and aposymbiotic hydra varied daily during the experimental period of 7 days. We conclude that inH. viridisthe endosymbiotic zoochlorellae exert a significant stimulatory and morphogenic effect in the light and in the dark. We do not know yet how the algal effect is mediated to their host. We suggest that a distinction should be made between the stimulatory effect on regeneration rate and the morphogenic effect on the final number of tentacles or b

ISSN:0022-104X    

DOI:10.1002/jez.1402270110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe storage of large quantities of juvenile hormone (JH) in adult male Cecropia silkmoths is dependent upon the combined activities of two organs: secretion by the corpora allata (CA) and accumulation by the accessory sex gland (ASG). We describe here some aspects of CA‐ASG development and physiology which lead to JH storage.The ASG were found to have completed development and had secreted the luminal materials before eclosion. After day 16 of adult development, the ASG were able to convert JH‐I acid to JH‐I and store the JH‐I. When incubated in vitro, the ASG showed a specificity for the uptake and storage of the three JH acids in the following order : JH‐I>JH‐II ≫ JH‐III. The CA of male and female larvae secreted JH‐I and JH‐II when incubated in vitro, whereas adult male CA secreted JH‐I acid and JH‐II acid. The total equivalent synthetic productivity of adult male CA was found to be considerably greater than that of adult female CA. When cultured in vivo during metamorphosis to the adult in hosts of the opposite sex, the male and female CA maintained their respective pattern of secretory activity. Thus, the CA appear to be programmed to express the sexually dimorphic activity prior to the initiati

ISSN:0022-104X    

DOI:10.1002/jez.1402270111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY