Abstract:
:Zambian common mole-rats are subterranean rodents that live in families with only one female breeding. Her offspring remain in the parental nest and do not reproduce. Behavioral experiments (Burda, '95) demonstrated that their apparent "sterility" is based on incest avoidance and individual recognition of family members. To elucidate whether some kind of morphologically apparent ovarian suppression still takes place in daughters, ovaries of females of known age, weight, and reproductive histories were examined histologically and morphometrically. The body mass of old females (more than 3 years of age) begins to decrease, and the ovaries seem to begin to atrophy at the age of about 3-6 years. Ovaries in neonates exhibited primordial and primary follicles, sometimes clustered in nests. Ovaries of adult nonbreeding females expressed all stages of the follicular development up to tertiary follicles. Many unruptured luteinized follicles were present, but true corpora lutea as a morphological sign of ovulation were missing. Unruptured luteinized follicles also could be found (additionally to true corpora lutea) in ovaries of breeding females. The number of primordial follicles dropped rapidly during the first 2 years of age; the number of primary, secondary, and tertiary follicles was subject to individual variation; and there was no clear correlation with age or reproductive status. While a tendency to form accessory unruptured luteinized follicles may just reflect taxonomic affinities of bathyergids to hystricomorphs, the otherwise complete folliculogenesis in "sterile" daughters and the presence of unruptured luteinized follicles even in breeding females are further evidence that there is no hormonal suppression of the ovarial cycle. We suggest that ovulation in nonbreeding females is not actively suppressed by the breeding female, but instead that it is not released because the triggering mechanisms, most probably repeated copulation, are missing.
journal_name
J Morpholjournal_title
Journal of morphologyauthors
Willingstorfer WJ,Burda H,Winckler Jdoi
10.1002/(SICI)1097-4687(199807)237:1<33::AID-JMOR3subject
Has Abstractpub_date
1998-07-01 00:00:00pages
33-41issue
1eissn
0362-2525issn
1097-4687pii
10.1002/(SICI)1097-4687(199807)237:1<33::AID-JMOR3journal_volume
237pub_type
杂志文章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::Adult female white-footed mice, Peromyscus leucopus, were exposed to long (LP) or short (SP) photoperiods for 6 weeks (experiment I). Another group of animals was kept for 6 weeks in SP, then injected SC with 30 micrograms prolactin twice daily for 2, 3, 4, or 6 days (experiment II). Ovaries from the mice in both expe...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051760211
更新日期:1983-05-01 00:00:00
abstract::The ovary of the seahorse, Hippocampus erectus, is a cylindrical tube bounded by an outer layer consisting of a mesothelium and muscular wall and by an inner luminal epithelium, with a single row of developing follicles sandwiched between the two layers. Follicles are produced by a germinal ridge, which contains oogon...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052090305
更新日期:1991-09-01 00:00:00
abstract::The structure and crystallography of the internal shell of the pulmonate gastropod slug Limax maximus were studied at the levels of light and scanning electron microscopy, revealing patterns of shell ontogeny and morphogenesis. The calcified portion of the slightly convex ovoid shell is composed of a single palisade l...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051800304
更新日期:1984-06-01 00:00:00
abstract::During ontogeny, the apical and basal components of dicamptodontid teeth exhibit three major developmental stages: nonpedicellate, subpedicellate, and pedicellate. Premetamorphic larvae tend to have nonpedicellate teeth, incompletely or recently metamorphosed individuals tend to have subpedicellate teeth, and fully tr...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051990204
更新日期:1989-02-01 00:00:00
abstract::Cubozoans have a complex lifecycle in many ways similar to the scyphozoan lifecycle. The sexual reproduction within cubozoans varies between species with one clade having copulation and internal fertilization and the release of planula larvae. This cubozoan clade, the family Tripedaliidae, includes three species, Copu...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.21046
更新日期:2019-10-01 00:00:00
abstract::Spermatogenesis discontinues during both adult reproductive diapause and quiescence in the flightless males of Omorgus freyi. During both types of dormancy, spermatogenesis discontinuity is a dynamic process involving an uninterrupted supply of primary spermatocytes that undergoes partial development and lyses before ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052180309
更新日期:1993-12-01 00:00:00
abstract::Many cases of predator-induced morphological plasticity in daphnids are well studied examples of inducible defenses. However, little is known about the early development of these sometimes conspicuous traits. We compared for the first time in five different Daphnia species the embryonic development of predator-induced...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10270
更新日期:2004-12-01 00:00:00
abstract::The enteric nervous system consists of a number of interconnected networks of neuronal cell bodies and fibers as well as satellite cells, the enteric glia. Basic fibroblast growth factor (bFGF) is a mitogen for a variety of mesodermal and neuroectodermal-derived cells and its presence has been described in many tissue...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10252
更新日期:2004-09-01 00:00:00
abstract::Branchial food traps are regions of specialized secretory tissue in the tadpole pharynx, where suspended food particles are trapped in mucus. Light and scanning electron microscopy were used to study branchial food traps from larvae of ten anuran families (36 species). Most anuran larvae from "advanced" (suborder Neob...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051590307
更新日期:1979-03-01 00:00:00
abstract::The fate and possible roles of the cytoskeleton in the process of conjugation in the hyptrich ciliate Euplotes aediculatus were investigated. Following the coalescence of the plasma membranes of the conjugant cells, a fusion zone or bridge of cytoplasm contributed by both partners is constructed. The sub-alveolar micr...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051920104
更新日期:1987-04-01 00:00:00
abstract::Sea urchin adoral tube feet are highly specialized organs that have evolved to provide efficient attachment to the substratum. They consist of a disk and a stem that together form a functional unit. Tube foot disk tenacity (adhesive force per unit area) and stem mechanical properties (e.g., stiffness) vary between spe...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.11004
更新日期:2012-01-01 00:00:00
abstract::This work is concerned with the ultrastructural organization and some histochemical features of the vacuolar cells of the demosponge Oscarella lobularis. Vacuolar cells are characterized by large clear vacuoles containing an aqueous fluid. They are commonly found in the mesohyl of this sponge and tend to constitute a ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051880104
更新日期:1986-04-01 00:00:00
abstract::The paired tubular accessory glands in Haemaphysalis longicornis open at the junction of the cervical and the vestibular parts of vagina via short and narrow ducts. The pseudostratified columnar glandular epithelium covered by the muscle layer consists of both secretory and supporting cells. As feeding proceeds, the s...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052210105
更新日期:1994-07-01 00:00:00
abstract::The Antarctic snailfish Paraliparis devriesi (Liparididae) occupies an epibenthic habitat at a depth of 500-650 m in the subzero waters of McMurdo Sound, Antarctica. Although lacking a swim bladder, this species is neutrally buoyant through the combined effects of reduced skeletal ossification and expansion of a water...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052200108
更新日期:1994-04-01 00:00:00
abstract::The octavolateralis area of actinopterygian fishes can be subdivided into a dorsal lateralis area composed of first-order lateral line nuclei, and a ventral octavus area composed of nuclei receiving first-order input from the eighth nerve. Three patterns of organization of the lateralis area are recognized in the pres...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051710205
更新日期:1982-02-01 00:00:00
abstract::The feline anterior sartorius is a long strap-like muscle composed of short muscle fibers. Nerve branches that enter this muscle contain the axons of motor units whose constituent muscle fibers are distributed asymmetrically within the muscle. In the present study, twitch and tetanic isometric contractions were evoked...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052130204
更新日期:1992-08-01 00:00:00
abstract::Ultrastructural studies of spermiogenesis and sperm morphology have found many characters that are likely to provide clues to the phylogeny of the Platyhelminthes. However, the lack of information on many free-living groups has been a limiting factor. There is a single description of the spermatogenesis and spermatozo...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20800
更新日期:2018-05-01 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::Topological and histological analyses of Mabuya mabouya embryos at different developmental stages showed an extraembryonic membrane sequence as follows: a bilaminar omphalopleure and progressive mesodermal expansion around the whole yolk sac at gastrula stages; mesodermal split and formation of an exocoelom in the ent...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10138
更新日期:2003-11-01 00:00:00
abstract::Light and electron microscopic techniques show that the eye of the marine prosobranch gastropod, Ilyanassa obsoleta, is composed of an optic cavity, lens, cornea, retina, and neuropile, and is surrounded by a connective tissue capsule. The adult retina is a columnar epithelium containing three morphologically distinct...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051810207
更新日期:1984-08-01 00:00:00
abstract::The cytoarchitecture and neuronal morphology of the torus semicircularis in the red-eared turtle, Chrysemys scripta elegans, were examined in Nissl-stained and Golgi-impregnated material. The torus semicircularis begins in the caudodorsal mesencephalon and extends rostrally and laterally to end ventrally to the tectal...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051690207
更新日期:1981-08-01 00:00:00
abstract::The plainfin midshipman fish Porichthys notatus has both inter- and intra-sexual dimorphism in the sound-producing (vocal or sonic) muscles attached to the swimbladder wall. The "Type I" and "Type II" male morphs differ in that dramatic structural changes related to sexual maturity occur in the mass, the area of mitoc...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052160306
更新日期:1993-06-01 00:00:00
abstract::The amphibian tongue contains two types of papilla which are believed to function in gustation and in the secretion of salivary fluid. Scanning electron microscopy reveals that columnar, filiform papillae are compactly distributed over nearly the entire dorsal surface of the tongue of the frog, Rana cancrivora, and fu...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052150106
更新日期:1993-01-01 00:00:00
abstract::Bone is a dynamic tissue adapting to loading according to "Wolff's law of bone adaptation." During very early life, however, such a mechanism may not be adequate enough to adapt to the dramatic change in environmental challenges in precocial species. Their neonates are required to stand and walk within hours after bir...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20548
更新日期:2016-07-01 00:00:00
abstract::The chimaeroid holocephalian fishes are distinguished among extant chondrichthyans by the possession of three pairs of tooth plates, evergrowing and partially hypermineralized, that are not shed and replaced like the teeth of living elasmobranchs. Although derivation of the chimaeroid tooth plate from the fusion of me...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052220108
更新日期:1994-10-01 00:00:00
abstract::The dorsal vessel (DV) in the abdomen of the blood-feeding insect Rhodnius prolixus was divided functionally into two regions, the heart, into which haemolymph entered the DV through four pairs of ostia located in abdominal segment VII, and the aorta, along which the haemolymph was propelled from abdominal segment VI ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052040103
更新日期:1990-04-01 00:00:00
abstract::Nematocytes containing microbasic mastigophores are intimately associated with accessory cells in the epidermis of Chironex fleckeri. Large microbasic mastigophores may be surrounded by seven to nine such cells. Each accessory cell possesses an apical portion containing secretory droplets and a basal portion which car...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051950110
更新日期:1988-01-01 00:00:00
abstract::As part of a study of ulcer formation and healing, regeneration of colonic mucosa in rats was studied following placement of a surgical lesion. Alterations in mucosubstances and connective tissue were examined and their possible significance discussed. The sequence of events in healing was: 1) The mucosa adjacent to t...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051630208
更新日期:1980-02-01 00:00:00
abstract::The muscles, fin ray joints, and supporting structures underlying the dorsal fin are described for two seahorse species: Hippocampus zosterae and Hippocampus erectus. A fan-shaped array of cartilaginous bones, the pterigiophores, form the internal supporting structure of the dorsal fin. Each pterigiophore is composed ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1022
更新日期:2001-04-01 00:00:00