Abstract:
:The role of dying cells in the optic stalk in relation to retinal fiber migration was investigated in the chick embryo. Cell death was analysed at various stages of development by counting pycnotic nuclei and also by the Gomori acid phosphatase reaction, while nerve fibers were visualised by the Bodian method. A wave of cell death, beginning in the neural retina at stage 18 and advancing with time through the stalk towards the diencephalon, occurred simultaneously or slightly prior to differentiation and migration of ganglion cell axons. Cell death stopped and gliogenesis occurred in the stalk after penetration by retinal fibers. Cell death occurred in the stalk even when fiber penetration was prevented by optic cup ablation. In this case, necrosis ensued until almost complete degeneration of the stalk, usually within three days after the operation, and gliogenesis did not occur. As the stalk degenerated, its cells became heavily pigmented. These observations suggest that the onset of cell death in the optic stalk is determined prior to and independently of retinal fiber penetration. On the other hand, cessation of cell death and subsequent gliogenesis occur only in the presence of ingrowing optic fibers.
journal_name
J Morpholjournal_title
Journal of morphologyauthors
Ulshafer RJ,Clavert Adoi
10.1002/jmor.1051620105subject
Has Abstractpub_date
1979-10-01 00:00:00pages
67-76issue
1eissn
0362-2525issn
1097-4687journal_volume
162pub_type
杂志文章abstract::Patterns of ectocranial suture fusion among Primates are subject to species-specific variation. In this study, we used Guttman Scaling to compare modal progression of ectocranial suture fusion among Hominidae (Homo, Pan, Gorilla, and Pongo), Hylobates, and Cercopithecidae (Macaca and Papio) groups. Our hypothesis is t...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20218
更新日期:2014-03-01 00:00:00
abstract::Anseriform birds were surveyed to examine how the degree of postcranial pneumaticity varies in a behaviorally and size-diverse clade of living birds. This study attempts to extricate the relative effects of phylogeny, body size, and behavioral specializations (e.g., diving, soaring) that have been postulated to influe...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10190
更新日期:2004-08-01 00:00:00
abstract::Basket stars, that is, Ophiuroidea in Echinodermata, exhibit distinctive morphological characteristics with their complicatedly branched arms that can regenerate immediately after mutilation. Although, in brittle stars, that is, ophiuroids with nonbranched arms, the arm regeneration process following accidental trauma...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.21296
更新日期:2021-02-01 00:00:00
abstract::Many studies in the genus Poecilia have focused on reproductive and genetic characteristics of Poecilia formosa, the Amazon molly, and its sympatric species P. latipinna and P. mexicana. The research literature of Poecilia dentition has been limited to general tooth morphology. Essentially absent are comparative analy...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/(SICI)1097-4687(199903)239:3<271::AID-JMOR
更新日期:1999-03-01 00:00:00
abstract::The overall anatomy of Neodasys as well as data for hemoglobin-containing cells are described. Hemoglobin-containing cells are shown to be mesodermal specializations constituting approximately 14% of the animal's total body volume (4.87 ± 104 μl). These globular cells (10-14 μm) are situated in two longitudinal rows, ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051750106
更新日期:1983-01-01 00:00:00
abstract::The spleen of sea bass (Dicentrarchus labrax) is composed mainly of red pulp, whereas the white pulp is poorly developed. The red pulp consists of clear reticular cells intermingled with blood cells, sinusoids, and melanomacrophage centers (MMCs). The MMCs are enclosed by an interrupted connective tissue capsule and s...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052060304
更新日期:1990-12-01 00:00:00
abstract::To date, the phylum Cycliophora comprises only one described extant species of acoelomate marine invertebrates, Symbion pandora. Adult specimens live commensally on the mouthparts of the Norwegian lobster, Nephrops norvegicus. Its complicated life cycle includes an asexually produced Pandora larva and a sexually produ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10354
更新日期:2005-08-01 00:00:00
abstract::The cat hindlimb contains several long, biarticular strap muscles composed of parallel muscle fascicles that attach to short tendons. Three of these muscles--sartorius, tenuissimus, and semitendinosus--were studied by dissecting individual gold-stained fibers and determining the surface distribution of acetylcholinest...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051910102
更新日期:1987-01-01 00:00:00
abstract::Sabellid and sabellariid polychaetes are regarded as sister groups in a number of recent phylogenetic analyses. This is based mainly on a shared specific arrangement of chaetae referred to as chaetal inversion. Remarkably, the uncini have a notopodial position in the abdomen, whereas capillary chaetae occur in the neu...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10537
更新日期:2008-01-01 00:00:00
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journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051720208
更新日期:1982-05-01 00:00:00
abstract::Timed-sequence studies have shown that reticulate scales on the ventral footpads of birds do not undergo "epidermal placode" formation during their morphogenesis, but arise as symmetrical evaluations similar to the scales of snakes and lizards. Unlike the scutellate scales on the dorsal surface of the foot, in which t...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051540106
更新日期:1977-10-01 00:00:00
abstract::The lungs of the New Caldeonian gecko Rhacodactylus leachianus were examined by means of gross dissection and light and electron microscopy. This tropical species, which is the largest living gecko, possesses two simple, single-chambered lungs. Right and left lungs are of similar size and shape. The lung volume (27.2 ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051990104
更新日期:1989-01-01 00:00:00
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journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20135
更新日期:2013-06-01 00:00:00
abstract::Remarkably preserved specimens of Cowralepis mclachlani Ritchie, 2005 (Proc Linn Soc NSW 126:215-259) (Phyllolepida, Placodermi) represent a unique ontogenetic sequence adding to our understanding of anatomy, function, and phylogeny among basal jawed vertebrates (gnathostomes). A systematic review demonstrates that th...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10719
更新日期:2009-07-01 00:00:00
abstract::In this study, we compare and contrast armoring strategies during early ontogeny among three related species of marine turtles: the hawksbill, a species that diverged about 29 mya from the loggerhead and Kemp's ridley, which diverged from one another about 16 mya. Our purpose was to determine whether there was a corre...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20844
更新日期:2018-09-01 00:00:00
abstract::The antennal circulatory organ of Periplaneta americana and Blaberus craniifer was investigated by light and electron microscopy. This organ consists of two pulsatile ampullae located near the antennal base which are interconnected by a large transverse muscle and associated blood vessels which run into the antennae. ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051850210
更新日期:1985-08-01 00:00:00
abstract::To illustrate vascular modification accompanying transition from aquatic to amphibious life in gobies, we investigated the respiratory vasculatures of the gills and the bucco-opercular cavities in one of the most terrestrially-adapted mudskippers, Periophthalmodon schlosseri, using the corrosion casting technique. The...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10944
更新日期:2011-05-01 00:00:00
abstract::As part of an effort to characterize reproductive modifications in internally inseminating catfishes, ovaries and male reproductive systems were examined histologically in two species of auchenipterid catfishes, Trachelyopterus lucenai and T. galeatus, from southeastern Brazil. Internal insemination was documented in ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/1097-4687(200011)246:2<131::AID-JMOR7>3.0.
更新日期:2000-11-01 00:00:00
abstract::Non-innervated macrotrichia and microtrichia, thick-walled chemoreceptors and three kinds of thin-walled chemoreceptors are present on the antennal flagellum of Frenesia missa. One of the thin-walled receptors, the plate organ, is of a type not previously recorded for any insect. About four times as many plate organs ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051350309
更新日期:1971-11-01 00:00:00
abstract::During epidermal differentiation in mammals, keratins and keratin-associated matrix proteins rich in histidine are synthesized to produce a corneous layer. Little is known about interkeratin proteins in nonmammalian vertebrates, especially in reptiles. Using ultrastructural autoradiography after injection of tritiated...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10181
更新日期:2004-02-01 00:00:00
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journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20309
更新日期:2014-12-01 00:00:00
abstract::Previous studies of squamate epidermal structure have focused on either histology and ultrastructure or oberhautchen surface texture as revealed by scanning electron microscopy (SEM). Using SEM data drawn from a variety of lizard taxa (primarily iguanids, but also agamids, chamaeleonids, and scincids), as well as amph...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051970108
更新日期:1988-07-01 00:00:00
abstract::From the elongated neck of the giraffe to the elaborate train of the peacock, extreme traits can result from natural or sexual selection (or both). The extreme chelicerae of the long-jawed spiders (Tetragnatha) present a puzzle: do these exaggerated chelicerae function as weapons or genitalia? Bristowe first proposed ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.21282
更新日期:2020-10-19 00:00:00
abstract::The plainfin midshipman fish, Porichthys notatus, is a nocturnal marine teleost that uses social acoustic signals for communication during the breeding season. Nesting type I males produce multiharmonic advertisement calls by contracting their swim bladder sonic muscles to attract females for courtship and spawning wh...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20724
更新日期:2017-11-01 00:00:00
abstract::Two free-living marine euplotid ciliates, Pseudodiophrys nigricans and Diophrys japonica, collected from the coastal waters off Qingdao, northern China, were investigated using live observations and protargol impregnation methods. The cortical development of P. nigricans was observed during binary division. Although i...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20097
更新日期:2013-04-01 00:00:00
abstract::Two different patterns of wing venation are currently supposed to be present in each of the three orders of Paraneoptera. This is unlikely compared with the situation in other insects where only one pattern exists per order. We propose for all Paraneoptera a new and unique interpretation of wing venation pattern, assu...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.11036
更新日期:2012-05-01 00:00:00
abstract::Odontophoral cartilages are located in the molluscan buccal mass and support the movement of the radula during feeding. The structural diversity of odontophoral cartilages is currently known only from limited taxa, but this information is important for interpreting phylogeny and for understanding the biomechanical ope...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10699
更新日期:2009-05-01 00:00:00
abstract::The form of amniote claws has been extensively investigated, often with inferences about ecological association being drawn from studies of their geometry. Various methods have been used to quantify differences in the geometry of claws, but rarely have the underlying assumptions of such methods been addressed. Here, w...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20625
更新日期:2017-02-01 00:00:00
abstract::Data describing segmental masses and moments of inertia (MOI) of limb segments are required for inverse dynamic calculations. In horses, these values are usually calculated using regression equations that have been developed from a limited number of horses representing a small number of breeds. The objective of the pr...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20829
更新日期:2018-07-01 00:00:00
abstract::The SEM was used to study the development of respiratory structures in successive stages in relation to the overall changes occurring in the scorpions. Book lung development is a slow process, starting with spiracles and a sac-like atrium in the early embryo and continuing lamellar formation to 150 or more in the adul...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10653
更新日期:2008-09-01 00:00:00