摘要:

AbstractCells from sponges of six different species when injected into rabbits induced the formation of specific agglutinating antibodies. Cells of each species were shown by cross‐agglutination and cross‐absorption tests to possess species‐specific antigenic determinants on their surfaces, and the observed cross reactions between species were in general accord with taxonomic relationships ascribed on more conventional criteria. Preparations containing complex heteropolysaccharides together with peptide were obtained by extraction of sponges with trichloroacetic acid and were shown to possess the serological specificities of the sponge cell surfaces. These preparations, from each of the six species, sensitized fowl erythrocytes to agglutination by homologous sponge cell antisera. The titers of cross hemagglutination obtained with an individual antiserum and variously sensitized erythrocytes were paralleled by the titers obtained in direct agglutination of sponge cells, indicating that the antigenic groups responsible for hemagglutination were similar to those present on the sponge cell surface and dominating its serological reactions. The isolated polysaccharide‐containing substances precipitated agglutinating antibodies and were themselves antigenic in rabbits. Chemical and serological analysis of a purified polysaccharide obtained from crude material by ion‐exchange chromatography, together with other lines of evidence, suggested that carbohydrate rather than peptide antigenic specificities underlay the serological behaviour of the sponge cell surface.The cell surface specificities detected serologically appeared not to be due to sensitization of sponge cells by intracellular substances liberated during the preparation of cell suspensions from intact sponge. Certain pairs of the sponges examined showed specific cellular reaggregation but the species specificity exhibited did not correlate in any simple manner with the demonstrated antigenic relationships of the species. The serological results are discussed in relation to the various postulated mechanisms of specific reag

ISSN:0022-104X    

DOI:10.1002/jez.1401720302

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

年代:1969

数据来源: WILEY

摘要:

AbstractIn the uterine secretions of certain mammals, gross qualitative and quantitative differences in their protein content were observed depending on whether or not the animals exhibited delayed implantation. Diapause blastocysts of the animals representative of those with obligate delayed implantation were stimulated to grow (as measured by total expansion and increased mitotic index) when maintainedin vitroin medium containing rabbit “blastokinin” but not in serum‐containing medium. Diapause rat blastocysts taken from animals where a facultative delayed implantation has been produced by heavy lactation, expanded in F10 medium alone or containing serum or the macromolecular components of uterine secretions taken from a 5‐day pregnant animal, but not in rabbit “blastokinin.” The mitotic index, however, was the same under all three conditions and higher than in uncultured controls. Growth of active 5‐day rat blastocysts was stimulated by medium containing the proper concentration of uterine macromolecular components; mitotic activity increased three to four‐fold.We conclude that delayed implantation results from the failure of the mother to provide sufficient protein and/or certain specific proteins as needed for active growth of the blastocysts. In facultative delayed implantation, as exemplified by the lactating rat, there is evidence that, in addition to the protein deficiency, some substance or condition exists in the uterus which inhibits growth of

ISSN:0022-104X    

DOI:10.1002/jez.1401720303

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

年代:1969

数据来源: WILEY

摘要:

AbstractPhysiochemical properties (serum osmolality and blood pH), serum inorganic ions (sodium, potassium, calcium, magnesium, chloride, phosphate and bicarbonate) and tissue water were studied in parallel groups of adult maleFundulus heteroclitusacclimated to various temperatures (30°C, 20°C, 10°C, 4°C, 2°C, −1°C and −1.5°C) in salt water under otherwise constant laboratory conditions. When the acclimation temperature was lowered from 20°C to −1.5°C, serum osmolality increased by 20%. This increase was not indicative of osmoregulatory failure, however, since the proportion of total serum osmolality accounted for by inorganic electrolytes dropped from 98% at 20°C to 93% at −1.5°C. Serum electrolytes such as sodium, chloride, calcium, magnesium and bicarbonate increased in the subzero cold by 12%, 17%, 30%, 33% and 11% respectively whereas serum potassium and inorganic phosphate levels were unchanged. Blood pH was significantly higher at 10°C than at any other temperature. The water content of liver, testes and muscle decreased by 8% in the subzero cold. These changes in serum electrolytes and tissue water did not indicate osmoregulatory failure, however, since the new levels, once established, were maintained as long as the fish were alive. Although osmotic and ionic regulation were not as effective in the cold, they were by no means so poor as to cause death b

ISSN:0022-104X    

DOI:10.1002/jez.1401720304

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe ability of rabbit embryos to incorporate tritiated uridine and thymidine into acid‐insoluble materialin vitrohas been quantitated by liquid scintillation counting at daily intervals throughout the preimplantation period. The ribonucleic acid content of the embryos has been determined by the orcinol reaction. It is shown that, in spite of a low level of Actinomycin D‐sensitive uridine incorporation during cleavage, there is no net synthesis of ribonucleic acid until immediately prior to blastocyst formation. The acceleration of ribonucleic acid synthesis which occurs at that time precedes, by some 36 hours, the acceleration of protein synthesis. This finding is discussed from the standpoint of genetic expression in the preimplantation rabbit embryo, and with reference to the possibilities for post‐transcriptional control of protein synt

ISSN:0022-104X    

DOI:10.1002/jez.1401720305

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

年代:1969

数据来源: WILEY

摘要:

AbstractPhoto‐sexual responses inAnolis carolinensisduring the fall are highly temperature dependent and show distinct thermal thresholds. If body temperatures are maintained at 32°C (the species' preferred temperature), day lengths of 13 hours or more stimulate testicular growth, whereas day lengths of 12 hours or less inhibit recrudescence. The testis develops slowly and independently of day length at 25°C or below. With fluctuating body temperatures, photoperiodism depends on both the duration of daily heating to 32°C (the thermoperiod) and the level of nocturnal cooling. Photo‐sexual responses occur with thermoperiods of eight hours or more when the nocturnal temperature is 20°C, but longer thermoperiods are required if nocturnal temperatures are reduced. There may be some equivalence between heat and light with regard to photo‐sexual responses; the critical day length for photostimulation varies with temperature.Field observations of behavioral thermoregulation and climatic data for the lizards' habitat (around New Orleans, Louisiana) indicate that body temperatures are high enough to allow photoperiodism in September. Since the effective day length is 12 hours or less, testicular growth may be photoperiodically inhibited in September and early October. The natural onset of testicular growth in mid‐October may be due to a reduction of thermoperiod and nocturnal temperatures which abolishes the photo‐periodic responsiveness and to an inherent reduction in photosensitivity.Studies begun in January confirm that the completion of testicular recrudescence in the spring is determined largely by the elevation of body temperatures and is independent of day length. Testicular development is rapidly completed with only a few hours of daily heating to preferred levels (32°C) even if nights are col

ISSN:0022-104X    

DOI:10.1002/jez.1401720306

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

年代:1969

数据来源: WILEY

摘要:

AbstractLiver esterase zymograms of representatives of 21 species of rodents and of three inbred strains ofMus musculusare sufficiently variable to reflect species differences yet conservative enough for at least one group of esterases (the major liver carboxylesterases) to indicate phylogenetic relationships. The carboxylesterases of theMyomorphspecies exhibit a distinct multiple banding pattern. The species ofCaviidaeandHystricidaealso have characteristic patterns of esterase activity. Utilizing characteristics of the zymogram patterns such as degree of multiplicity, electrophoretic mobility, inhibitor specificity and heat lability of the major liver carboxylesterases, it is possible to arrange the rodent species into groups which are in accord with classical phylogeny. Studies of polymorphism of liver esterases from inbred strains of mice indicate that the multiple band phenotype of the major liver carboxylesterases is fixed or in high frequency in the population. Other carboxylesterases and the cholinesterases are variable within a species and would serve little use in phylogenetic comparisons.

ISSN:0022-104X    

DOI:10.1002/jez.1401720307

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe fishing tentacle of the sea nettle (Chrysaora quinquecirrha) has four basic layers: an outermost epithelial layer, a muscle cell layer, a core of mesoglea and an innermost epithelial layer. The outermost epithelium contains three different cell types: (1) supporting cells, (2) nematocytes and (3) mucous cells. Apical cellular processes of smooth muscle fibers extend into the outermost epithelial layer whereas basal processes penetrate the mesoglea. The mesoglea contains randomly oriented fibrils (60–70 Å in diameter). Inner epithelial cells vary in morphology. Some cells contain mostly phagocytotic vacuoles while other cells have an abundance of rough surfaced endoplasmic reticul

ISSN:0022-104X    

DOI:10.1002/jez.1401720308

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

年代:1969

数据来源: WILEY

摘要:

AbstractDifferences in regeneration of isolated postpharyngeal body sections were observed in two laboratory groups ofDugesia tigrina.One group regenerated 14.8% of bipharyngeal specimens, which in some cases, also showed abnormal polarity. The other group regenerated only 1.19% of bipharyngeal forms under similar conditions, with no indications of seriously deviant polarity.In the first strain, the application of actinomycin D at early stages of regeneration of the body sections increased greatly the incidence of multipharyngeal regenerates (with 2–5 pharynges); it also slightly enhanced the occurrence of abnormal polarity in the reconstituted worms. In the second strain, the increase in percentage of bipharyngeal forms regenerated from similar body fragments was insignificant (up to 5%). It was without effect on either strain if introduced to the regenerating sections at later stages of regeneraton. A test for incorporation of32P into RNA showed that actinomycin, as used in the present study, suppressed over 90% of synthesis of total RNA in the regenerating body fragments.From these findings a hypothetical model is developed to explain reorganization in the isolated postpharyngeal section as a sequence of certain local inductions and inhibitions of differentiation. The significance of synthesis of RNA in relation to these developmental events is discusse

ISSN:0022-104X    

DOI:10.1002/jez.1401720309

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

年代:1969

数据来源: WILEY

ISSN:0022-104X    

DOI:10.1002/jez.1401720301

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

年代:1969

数据来源: WILEY