摘要:

AbstractGenetic similarity between species of rodents of theAkodongenus (A. dolores, A. molinae, andA. azarae) has been estimated by analysis of electrophoretic zymograms corresponding to 23 loci. Nei's coefficient betweenA. doloresandA. molinaewas within the range usually found in conspecific populations. This evidence plus the successful production of “hybrids” (Merani et al., J. Exp. Zool.,206:343–346, '78) suggests thatA. doloresandA. molinaemay represent geographic races of the same sp

ISSN:0022-104X    

DOI:10.1002/jez.1402290102

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

年代:1984

数据来源: WILEY

摘要:

AbstractAllograft rejection in sponges has been repeatedly reported to be associated with cytotoxicity and tissue necrosis. The present work was undertaken in order to investigate the cellular aspects of antagonistic allograft rejection inAxinella polypoides, as part of an extended analysis of sponge immune reactions. Allografts were made by parabiosis of sponge branches, and their reaction was followed using light, transmission, and scanning electron microscopy. Rejection began paradoxically with the strong adherence of the parabionts. After three days, the zone of contact was characterized by extensive archaeocyte invasion, intensive phagocytosis, and cell lysis. Phagocytosis, achieved by the accumulated archaeocytes, involved healthy spherulous cells, and a substantial accumulation of cellular debris resulting from lysis of randomly dispersed single cells, mainly archaeocytes. The reaction lasted seven to nine days, after which cleavage of the reaction zone occurred, resulting in the separation of the parabionts. The reaction appeared to be limited to the former zone of contact, leaving a scar of denuded skeleton network. Our results clearly point out the role of archaeocytes in the rejection processes ofAxinella polypoides; they suggest that cell lysis in antagonistic rejection of sponges depends on cytotoxic interactions between archaeocytes, since these cells appear to achieve both cytotoxicity, or killing activity, and phagocytosis. Some aspects of histoincompatibility in sponges and their analogies with those found in vertebrates are discussed.

ISSN:0022-104X    

DOI:10.1002/jez.1402290103

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe analysis and understanding of immune reactions in sponges are presently impaired by numerous discrepancies and inconsistencies between the results obtained for different species that make critical judgment difficult. In order to determine the possible influence of experimental procedures, parabiotic allografts were performed onAxinella verrucosaandAxinella damicornis. Three reactions were observed in allogrfts ofAxinella verrucosa: acceptance, nonfusion, and chronic rejection. The acceptance reaction differed from the fusion of control autografts by a transient phase of dense cell accumulation between the parabionts. Nonfusion resulted in the virtual absence of reaction between the incompatible sponges. Chronic rejection was characterized by: 1) intensive cell migration and accumulation of collencytes in the zone of contact; 2) regular alignment of these cells on each side of that zone; 3) deposition of a collagen barrier that progressively joined but demarcated the parabionts. Some sponges presented nonfusion or chronic rejection depending on their graft partner. All allografts inAxinella damicornisdisplayed a chronic rejection reaction, which was essentially similar, but more intense and faster, than inAxinella verrucosa. However, inAxinella damicornis, the parabionts which were separated by the barrier became independent instead of joined. Reasons for and the implications of such a diversity of immune reactions in sponges are discussed.

ISSN:0022-104X    

DOI:10.1002/jez.1402290104

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe variations of the glycoconjugate concentrations (PAS‐positive material), with special reference to the membrane sialic component have been studied during the annual cycle in erythrocytes of three mammalian species (Erinaceus europaeus, Glis glis, Talpa europaea) and of one amphibian species (Rana esculenta). InR. esculentathe structural modifications of nuclear chromatin (different degree of compactness) have also been examined through the propidium iodide intercalation at different concentrations.The membrane sialic components during hibernation increase inRana(457%),Glis(304%), andErinaceus(244%), and decrease inTalpa(59%), not really a hibernating species. These data can be related with a slowing down of erythropoiesis and with the increase of the average length of erythrocyte life in the winter. Residual glycoconjugate components are also modified with a similar, but less evident, pattern. The changes in the fluorescence fading during the annual cycle show a substantial independence from the concentration index of the PAS‐positive material; this fact might be related to molecular modifications or heterogeneity of the substrate.The DNA‐propidium iodide intercalation in frog erythrocyte chromatin decreases during the hibernation, possibly related to a reduced functional activity of

ISSN:0022-104X    

DOI:10.1002/jez.1402290105

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

年代:1984

数据来源: WILEY

摘要:

AbstractPineal concentrations of N‐acetylserotonin and melatonin and serum levels of melatonin were studied in 3‐wk‐old (prepubertal), 8‐wk‐old (adult), and 17‐mo‐old (senile) male rats. They were adapted to a photoperiod of 12 h light/12 h darkness for a minimum of 1 wk and killed at mild‐light and mid‐dark. Melatonin and N‐acetylserotonin were determined by radioimmunoassay. The concentrations of pineal N‐acetylserotonin and melatonin were high in the dark period and low in the light period. Statistical analysis indicated that pineal N‐acetylserotonin and melatonin levels per 100 gm body weight declined with age. Similarly, serum melatonin demonstrated diurnal changes in all the age groups studied. In addition, there was a significant reduction in the levels of serum melatonin with age. The parallel patterns of decrease in pineal and serum melatonin levels with age suggest a decline in pineal secretion of melaton

ISSN:0022-104X    

DOI:10.1002/jez.1402290106

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe potential abilities of adult femaleE. laticepsto detect conspecific odors and to discriminate between male and female conspecific odors were investigated by comparisons of tongue extrusion rates emitted in response to chemical stimuli presented on moist cotton applicators. Postreproductive females treated with estradiol‐17β to stimulate possible increases in sensitivity to odors associated with the breeding season showed significantly higher tongue‐flick rates to the cloacal odors of both sexes than to distilled water. There was no evidence that the females discerned any difference between male and female odors. Estrogen‐injected females had somewhat higher tongue‐flick rates than did untreated postreproductive females, but the differences were not significant. Tongue extrusion rates of estrogen‐injected females were substantially lower than those of testosterone‐implanted males for all odor stimuli. It is argued, but not demonstrated, that femaleE. laticepsrespond to the cloacal odors as stimuli arising from conspecific or at least closely re

ISSN:0022-104X    

DOI:10.1002/jez.1402290107

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

年代:1984

数据来源: WILEY

摘要:

AbstractPreliminary experiments with 2,4‐dinitrophenol (DNP), 2,4,6‐trinitrophenol (TNP), and sodium azide (NaN3) indicated that most of the oxygen consumption by ribbed mussel gill tissue is the result of mitochondrial respiration. A procedure utilizing isoosmotic sucrose, EGTA, defatted serum albumin, and HEPES as the isolation medium was devised for the preparation of fully coupled ribbed mussel gill mitochondria. Optimal rates of respiration and respiratory coupling required substrate, ADP, inorganic phosphate, and a fairly high KCl concentration (90 mM) in the assay medium. Glutamate, proline, malate, and succinate stimulated oxygen consumption with high respiratory control indices and P/O of 3, 3, 3 and 2, respectively. Pyruvate was a weak stimulator of mitochondrial respiration and showed a low respiratory control index with a low P/O. Preparation of gill mitochondria in isoosmotic solutions containing high KCl concentrations (150 mM) yielded mitochondria showing state 2 respiration, slow partially uncoupled ATP synthesis during state 3 respiration and no state 4 respiration. D‐mannitol was not used in the mitochondrial isolation or assay medium because of the probable presence of a D‐mannitol oxidase in these gill mitoc

ISSN:0022-104X    

DOI:10.1002/jez.1402290108

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe presence of chitinase was checked in three species ofHydrozoaby incubating γ‐chitin‐red (Hackmann and Goldberg, '64) with crude extracts of entire polyps or parts of them. When the substrate is lytically degraded it releases its soluble red dye the quantities of which were spectrophotometrically (λ = 510 nm) determined. Crude extracts of entire polyps ofHydra attenuataPall.,H. circumcinctaM. Sch., andPodocoryne carneaM. Sars all contained active chitinase. A more detailed localization which was studied inH. attenuatarevealed that the enzyme is confined to the endoderm of the body column and that it is absent in the ectoderm and in the tentacles which contain the stenotele nematocysts. Therefore, it is very unlikely that enzymatic action of chitinase aids the nematocyst in boring holes in the cuticule of the

ISSN:0022-104X    

DOI:10.1002/jez.1402290109

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe possibility of adrenergic innervation to melanophores in scales ofOryzias latipeswas investigated using3H‐norepinephrine (3H‐NE) by light microscopic autoradiography. When isolated scales were incubated in3H‐NE, there was observed plexus of varicose fibers labeled with3H‐NE which intimately enclosed the stellate processes and cell bodies of melanophores. These labeled fibers could not be detected in cocaine‐treated or denervated scales. Potassium ions caused a considerable reduction in the labeling of varicose fibers, which was accompanied with aggregation of melanosomes within melanophores. These findings suggest that the labeled fibers observed are compatible with adrenergic nerve fibers that control the melanosome movements within mel

ISSN:0022-104X    

DOI:10.1002/jez.1402290110

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

年代:1984

数据来源: WILEY

摘要:

AbstractChlorotetracycline (CTC), a calcium‐chelating fluorescent probe identifies and localizes calcium when applied to cultured neural crest cells. The fluorescence occurs at specific membrane regions involved in cell attachment and spreading as well as with the formation of cytoskeletal stress fibers (actin microfilament bundles). The observed CTC reaction indicates that calcium sequestration and the development of these membrane‐cytoskeletal features share a temporal and spatial pattern. Thus, the selective availability of calcium may be an important determinant of cell morphogene

ISSN:0022-104X    

DOI:10.1002/jez.1402290111

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

年代:1984

数据来源: WILEY