摘要:

AbstractAmputated hyperinnervatedAnolis carolinensislimbs were studied histologically at various times from early stages of post‐amputational wound healing to formation of mature mounds. Comparable stages of normally innervated amputated limbs were also studied. The sequence of events involved in tissue repair was found to be similar in both groups. The mounded adigital outgrowths which were produced on the hyperinnervated limbs were composed, in 80% of the cases, of large amounts of connective tissue or bone, whereas the other 20% contained primarily nerve fascicles and adipose tissue. The mounds were formed as the result of extensive regeneration of individual tissues without the interposition of a mesenchymatous cell blastema. It was concluded that the regenerative response shown by the hyperinnervatedAnolislimb differs from thede novoregeneration seen in urodele amphibians. Whether this hyperinnervation procedure accurately tests the influence of nerve tissue on reptilian limb regeneration is discusse

ISSN:0022-104X    

DOI:10.1002/jez.1401720102

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe sera of Atlantic sea herring, collected from 13 contiguous oceanic locations, were assayed by gel (double) diffusion for precipitinogen differences. An immune serum (rabbit) against the sera of each location was required. Gel diffusion patterns characteristic of specific geographic origins of herring sera were not detected. Immune serum aliquots were therefore individually neutralized with one of a series of dilutions of herring serum from the various geographic locations prior to diffusion (the use of undiluted serum results in complete precipitin neutralization regardless of its origin). The neutralization capacity of origin‐separate precipitinogens appears to be related to the geographical distance separating the origins of immunizing and neutralizing sera. Sera of unknown origins, providing they originate from the overall area sampled, can be related to sera of specific origins by comparison of their neutralization capacities. The gel diffusion results are in agreement with previously reported immunoelectrophoretic data (DiCapua, 1966) and are consistent regardless of sex, pool size constituting the sample or collection date. The serological relationship of the five dominant clupeoid species is examine

ISSN:0022-104X    

DOI:10.1002/jez.1401720103

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

年代:1969

数据来源: WILEY

摘要:

AbstractAn investigation of several tropical frogs was undertaken in order to find species in which synchronous oogenesis takes place, so that the RNA synthesized at the lampbrush stage could be labelled and followed through early development. The reproductive cycle ofEngystomops pustulosuswas found to include both synchronous and asynchronous phases. Laboratory maintenance and induction of synchronous oogenesis in this organism are described. By using toads carrying out synchronous oogenesis, RNA synthesized during the lampbrush stage was shown to be retained through gastrulation. The pattern of new RNA synthesis in the embryo resembles that in other anurans. Radioautographs suggest that the distribution in the embryo of maternal RNA synthesized at the lampbrush stage is distinct from that of RNA newly synthesized by the embryo; the possible implications of these observations are discussed.

ISSN:0022-104X    

DOI:10.1002/jez.1401720104

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe acetylcholinesterases and non‐specific esterases of embryo and chick muscle, brain, heart and other tissues were investigated using acrylamide disc gel electrophoresis and spectrophotometric enzyme assays. Migration of the proteins as a function of acrylamide gel concentration was used to determine their molecular weights and relative charges. Acetylcholinesterase isozymes in embryonic skeletal muscle and brain differed in size but not appreciably in charge. Their molecular weights were approximately 420,000, 300,000 and 220,000. The non‐specific esterases of all the tissues studied differed only by charge from each other; their molecular weight averaged 160,000.Previous experiments indicated that white‐fibered muscles from birds selected for muscular dystrophy exhibited acetylcholinesterase isozymes similar to those in embryonic muscle while normal muscles did not. The studies reported here show that the acetylcholinesterases of normal embryo muscle and dystrophic chick muscle migrated similarly on acrylamide gels and responded similarly to anticholinesterase agents. The acetylcholinesterase activity of muscles from chicks of normal females X dystrophic males resembled that of normal chicks. The results are consistent with the hypothesis that white‐fibered muscles of birds inbred for muscular dystrophy are unable to repress the synthesis of isozymes of acetylcholinesterase characteristic of normal embryo skeletal

ISSN:0022-104X    

DOI:10.1002/jez.1401720105

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe lactate dehydrogenase isozymes of Pacific hake (Merluccius productus) are described. Evidence from molecular weight estimations and subunit recombination tests indicate that these isozymes have physicochemical properties similar to those of higher vertebrates. The predominant isozymes in most tissues appear to be composed of subunits coded at two loci. These subunits and loci were designated as A and B because of phenotypic similarities to isozymes coded by the LDH A and B loci of higher vertebrates; no attempts were made, however, to establish homologies between isozymes of Pacific hake and those of higher vertebrates. The predominant isozyme in extracts of skeletal muscle appears to be independent of those composed of A and B subunits and may reflect a third LDH locus in Pacific hake. In contrast to many species of teleost fish, no unique LDH isozymes were found in the eye.Isozyme phenotypes reflecting two alleles, A and A′, were observed at the A locus. The frequency of the A′ allele was 0.01 in fish taken from the Pacific Ocean off the coasts of California, Oregon, and Washington and 0.25 in those from Puget Sound, Wash., it appears that the two populations are noninterbreeding. Gene‐frequency analyses of samples taken in various areas of Puget Sound indicate that the Puget Sound hake consist of a single breeding popul

ISSN:0022-104X    

DOI:10.1002/jez.1401720106

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

年代:1969

数据来源: WILEY

摘要:

AbstractAspects of fertilization encompassing the meiotic events of the maternal chromatin, the formation of the polar bodies, and the development of the female pronucleus have been investigated in the lamellibranch,Mytilus edulis.The cromosomes of the mature egg ofMytilus edulisat the time of fertilization are organized on the first metaphase plate of meiosis. The first meiotic metaphase figure, oriented normal to the egg's cortex, consists of two asters, each of which contains paired centrioles, microtubules, and some smooth endoplasmic reticulum. Subsequent to sperm incorporation, the first polar body is produced by a process akin to cytokinesis following the movement of the chromosomes at anaphase. Later, the metaphase plate of the second meiotic apparatus is formed. Morphologically, the second metaphase figure is similar to the first; however, each aster appears to contain only one centriole. The second polar body, produced in the same manner as the first, remains associated with the zygote via a cytoplasmic bridge which persists up to the time of the first cleavage. Both polar bodies contain the same cellular inclusions as the zygote; however, only the second polar body has its chromatin delimited by a perforated nuclear envelope. After the formation of the second polar body, the maternal chromatin is organized into chromosomal vesicles. The chromosomal vesicles later fuse to form the female pronucleus.

ISSN:0022-104X    

DOI:10.1002/jez.1401720107

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe events of fertilization involving the modifications of the incorporated spermatozoon and the association of the paternally and maternally derived pronuclei have been studied by techniques of light and electron microscopy in the lamellibranch,Mytilus edulis.At the site of gamete plasma membrane fusion a small fertilization cone is produced. As the spermatozoon moves through the fertilization cone, its nuclear envelope degenerates. The degeneration of the nuclear envelope is followed by the dispersion of the sperm chromatin and the formation of the pronuclear envelope. The sperm aster, produced during the formation of the male pronucleus, consists of fasicles of microtubules and endoplasmic reticulum which radiate from a centrosphere region containing two centrioles.When the pronuclei complete their migration toward each other they are structurally similar and contain a fibro‐granular nucleoplasm. Eventually, the pronuclei become closely apposed, their proximal surfaces flatten, and produce an array of interdigitating nucleoplasmic projections. Concomitantly, the chromatin condenses and forms large reticular aggregations. Association of the parentally derived chromosomes is effected when the two pronuclear envelopes are dismantled. Microtubules that comprise a portion of the mitotic spindle become associated with the chromosomes as they move together in preparation for the first cleavage division. Hence, like many vertebrates, but unlike sea urchins, no zygotic nucleus is produce

ISSN:0022-104X    

DOI:10.1002/jez.1401720108

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.1401720101

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

年代:1969

数据来源: WILEY