摘要:

AbstractThe sera of Atlantic sea herring, collected from 13 contiguous oceanic locations, were analyzed by immunoelectrophoresis for precipitinogen differences. An immune serum (rabbit) against the sera from each location was required. Electro‐phoretic characteristics suitable for identifying the geographic origins of herring sera were not detected. Immune serum aliquots were therefore individually neutralized with undiluted or one of a series of dilutions of herring serum from each geographic location prior to analysis. The use of undiluted serum resulted in complete precipitin neutralization regardless of its origin. Equivalent dilutions of each serum resulted in varying degrees of precipitin neutralization. This capacity of origin‐separate precipitinogens appears to be related to the geographical distance separating the origins of immunizing and neutralizing sera, i.e., the greater the distance the higher the concentration necessary for equivalent neutralization. Sera of unknown origins can be related to sera from specific origins by comparison at equivalent dilutions for equivalent precipitin neutralization, providing they originate from the overall area sampled. Immunoelectrophoretic results are consistent regardless of sex, number of individuals contributing to the sample or the collection date. Herring precipitinogens are identified by comparison with the well‐established mobilities of human precipitinogens and are discussed based on the frequency with which they are associated with geographic group differ

ISSN:0022-104X    

DOI:10.1002/jez.1401620102

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

年代:1966

数据来源: WILEY

摘要:

AbstractAdultRana sylvaticadoes not regrow an amputated forelimb whereasXenopus laevisdoes. This difference in regenerative behavior has been analyzed in terms of the number of nerve fibers available at the amputation surface because previous studies have shown that nerve fibers must satisfy a quantitative threshold in order that regeneration occur. Our results show thatXenopushas more fibers per unit area thanRana.However, the value for both is far below that ofTriturusand, indeed, even lower than that of the mouse. The relative scarcity of fibers in the anuran limb thus brings into question the direct relation previously drawn between nerve number and regenerative capacity in vertebrates. However, anuran nerve fibers are much larger fibers than those of other vertebrates; and, indeed, those ofXenopussurpass in size the fibers of the vertebrates we have investigated. Initial studies show that if the size of fibers is taken into account and the inneryation is expressed as amount of neuroplasm available at the amputation surface rather than as the number of fibers, the limb ofXenopusis then as richly innervated as the limb ofTrituruswhereas that ofRanacontains much less nervous substance.

ISSN:0022-104X    

DOI:10.1002/jez.1401620103

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe pre‐fertilization behavior of the sperm of the thecate hydroidsCampanularia flexuosaandCampanularia calceoliferahas been observed and recorded by means of dark‐field cinephotomicrography. The sperm of both species activate and aggregate homotypically around the aperture of the female gonangium. Plots of the paths of sperm approaching the aperture show that the aggregations are the result of directed turning movements and not of so‐called trap‐actions or an increased random turning of the spermatozoa. An aperture‐associated tissue of ectoderm origin has been found to produce the attractive substances.Active sea water and alcohol extracts of female gonangia ofC. calceoliferahave been prepared. The substance affects sperm in the same ways as the material released by the female gonangium. The active material is heat stable, non‐volatile, dialyzable, polar, and appears to be a single molecular species of less than 5,000 mw. Injection of these extracts into sperm suspensions by means of a micropipette produces activation and aggregation of only the sperm of C.calceoliferaabout the pipette tip. If agar impregnated with the chemotactant is used as a source, the sperm are seen to orient with considerable accuracy. Extraction ofC. flexuosafemale gonangia has not yielded active extracts.These results demonstrate that chemotaxis does occur during fertilization in an animal. The mechanism of the reaction remains to be

ISSN:0022-104X    

DOI:10.1002/jez.1401620104

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

年代:1966

数据来源: WILEY

摘要:

AbstractThree genetic loci (a, b, and c) control lactate dehydrogenase synthesis in many mammalian and avian species. A survey of the lactate dehydrogenase isozyme composition of somatic tissues from approximately 1,000 wild pigeons revealed three phenotypic classes. The frequency distribution of the three classes in wild pigeons and the results of appropriate breeding experiments demonstrated that the phenotypic differences were due to alleles at theb‐locus. One of the alleles produces a B' polypeptide with an electrophoretic mobility identical to that of the A polypeptide, but with substrate affinity and heat inactivation properties similar to those of the B polypeptid

ISSN:0022-104X    

DOI:10.1002/jez.1401620105

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

年代:1966

数据来源: WILEY

摘要:

AbstractIn an investigation of six stocks of platyfish (Xiphophorus maculatus) in the Genetics Laboratory of the New York Zoological Society, only one exhibited pituitary cysts. Cysts were discovered in 58 of 76 (76%) of the fish of the Gp (Grijalva) strain that were one month or older. This strain originated from the Rio Grijalva, Mexico, and has been inbred for many generations in this laboratory.Cysts were first seen shortly after birth and they increased in size with age. This enlargement results from an increase in the number of typical goblet cells that form the wall of the cyst and by an accumulation of their PAS — positive secretion. More than one cyst rarely occurs in a gland. Cysts may be found in all portions of the adenohypophysis, most frequently in the meso‐adenohypophysis, but they never occur in the neurohypophysis. Hypophysial cysts were not found in Gp embryos, in offspring of crosses between Gp females and males from other platyfish stocks and in wild‐caught fish from the Rio Grijalva. Fish of the Gp strain that showed abnormal gonadal development always possessed a pituitary cyst, but not all fish with pituitary cysts were hypogonadal.The information presented points to the fact that the origin of cysts has a genetic basis and perhaps arose as a result of inbreeding. It is suggested that cysts result when cells of the adenohypophysial anlage fail to differentiate into pituitary cells but become goblet cells in

ISSN:0022-104X    

DOI:10.1002/jez.1401620106

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

年代:1966

数据来源: WILEY

摘要:

AbstractLarvae of the leopard frog,Rana pipiens, regularly reject skin homo‐grafts. Grafts from sibling larvae show initial signs of necrosis later than grafts from non‐siblings; grafts between very young feeding larvae also show initial necrosis later than those between older larvae. Homograft rejection pattern is essentially the same in larvae of stage IV and older, in hypophysectomized larvae, and in larvae immersed in thyroxine for two weeks after grafting. Second grafts from the same donor are necrotic 4 to 5 days before first grafts are. The conclusion is drawn that destruction of skin homografts in frog larvae is independent of metamorphic phenomena, and is an immunologic reaction, possibly involving the thymus gland. The weakened response of very young larvae may reflect an immunologic mechanism that is not yet mat

ISSN:0022-104X    

DOI:10.1002/jez.1401620107

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe increase in length, wet weight, dry weight, DNA content and chondroitin sulfate content of the tibiotarsus of the embryonic chick has been compared in vivo andin vitroon a chemically defined medium. Both the rate and magnitude of increase were lower in tibiotarsi in organ culture than those in the whole animal.Comparison of ratios of various growth responses gave some indication of the mode of growth in the two situations. The dry weight/wet weight ratio of tibiotarsiin vivoremained virtually unchanged during the growth period in this study, while the ratio of tibiotarsiin vitrodeclined continually during the cultivation period. The hydration of skeletal elements growing in culture is probably due to degenerative phenomena. The ratio of dry weight to DNA showed that the cells of tibiotarsi in culture did not synthesize dry matter as rapidly as those in the whole chick. On the other hand, the ratio of chondroitin sulfate to DNA indicated that the cells of tibiotarsi in culture were producing chondroitin sulfate at a rate similar to thatin vivo.Furthermore, the proportion of chondroitin sulfatein vitrotended to be greater than in the chick embryo. These findings suggest that the matrix of skeletal elements growing in culture, although chondroitin sulfate rich, may be deficient in one or more matrix components.

ISSN:0022-104X    

DOI:10.1002/jez.1401620108

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

年代:1966

数据来源: WILEY

摘要:

AbstractAttempts were made to study the effects onSwedishinbredDrosophila melanogasterfemales of replacing equivalent volumes of hemolymph from younger and older donors of the same strain. The physiological effects on hosts were studied by examining the fecundity and the adult life span.Nine to ten‐day‐old hosts, receiving 0.25 μl of hemolymph from 3‐4‐day‐old donors, do not differ appreciably either in fecundity or longevity from the controls. Similarly, 12–13‐day‐old hosts, undergoing replacements of 0.25 μl and 0.50 μl of hemolymph from freshly emerged donors, fail to show an improvement in the egg production or in the life span. It is suggested that the hemolymph donated by younger females lacks the properties that are associated with a higher fecundity or a higher expectation of life.Freshly emerged hosts, in which 0.25 μl of hemolymph from 12–13, 16–17 and 23–24‐day‐old hosts was replaced, undergo a remarkable life‐shortening without a decrease in the egg production. In individuals, deprived of 0.25 μl of hemolymph, similar results are obtained; that is, only reduction in the life span is realized, the fecundity being unaffected.The reduction in the life span of hosts injected with the hemolymph from older females is explained as due to the presence of deleterious factors in the hemolymph of older individuals. Such factors are considered in terms of “accumulation and depletion phenomena” commonly observed in insects. The absence of reduced egg production in females under stress is interpreted as due to homeostatic mechanisms which tend to insure the period of active reproduction. The bearing of these results on the evolution of

ISSN:0022-104X    

DOI:10.1002/jez.1401620109

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

年代:1966

数据来源: WILEY

摘要:

AbstractEmbryonic lens vesicles from both species of salamander self‐differentiated into a small lens with fibers when implanted into either the dorsal fin or anterior chamber of the larval eye. Growth of these lenses was very slow inAmblystomaand somewhat faster inTriturus.When implanted into the pupil in place of the extirpated host lens, the embryonic lens vesicles differentiated normally and had a normal rate of growth. Lens regeneration from the host iris inTrituruswas frequently inhibited by the implanted lens. A statistical analysis by the method of covariance showed that, in both species, lenses from the implants were largest in the lentectomized eyes, smaller in the vitreous chamber of eyes with intact host lens and smallest in the anterior chamber, host lens present. InAmblystoma, the growth rates, as indicated by the coefficients for linear regression, were significantly different between lenses developing in the absence of the host lens and those growing from implants into either the anterior or vitreous chambers of eyes containing the host lens. In Triturus, a significant difference was observed only between growth rates of lenses in the lentectomized eyes and in the anterior chambers, host lens present or in the dorsal fin. These results show that the neural retina stimulates growth and differentiation of embryonic lens vesicles and that the host lens retards their growt

ISSN:0022-104X    

DOI:10.1002/jez.1401620110

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

年代:1966

数据来源: WILEY

ISSN:0022-104X    

DOI:10.1002/jez.1401620101

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

年代:1966

数据来源: WILEY