Development of the innervation of long bones: expression of the growth-associated protein 43

It has been known from clinical and experimental observations that the peripheral nervous system is involved in the development of long bones. Expression of growth-associated protein 43 (GAP-43/B-50) was found in axonal growth cones during embryonic and postnatal ontogeny as well as in regenerating axons after nerve injury. The aim of the present study was to examine the occurrence of growing nerve fibers in rat tibia from gestational day 16 (GD 16) to postnatal day 28 (PD28). An indirect immunoenzymatic reaction using antibodies raised against GAP-43 was applied to detect outgrowing nerve fibers penetrating into the developing bone. On GD 16 and GD 17 no GAP-43-immunoreactive (IR) fibers were observed in the close vicinity of bone rudiments. On GD19 GAP-43-IR fibers were scarcely present within the periosteum of the central portion of the diaphysis. In the perichondrium surrounding the proximal epiphysis, nerve fibers were first detected around birth. From PD1 onward, numerous fibers were seen in the fibrous buds of the perichondrium at the epi-metaphyseal junction (Ranvier's grooves), some of them being adjacent to the blood vessels. Nerve fibers penetrating into the bone and located in the bone marrow, predominantly associated with blood vessels, were first observed on GD21 and their number increased with further development. They were initially located in the central portion of the diaphysis and later extended towards the metaphyses. On PD4 an increased number of GAP-43-IR fibers appeared in the perichondrium of proximal and distal epiphyses. In the fibrous strands penetrating into the epiphyses and in the secondary ossification centers, nerve fibers were first observed on PD10. From PD14 onward the pattern of tibial innervation remained unchanged but the intensity of GAP-43 immunostaining visibly decreased. The present study demonstrates that developing long bones of rat hindlimbs are supplied by growing nerve fibers immunoreactive for GAP-43 from GD 19 onward. Time and location of their appearance were at least partially correlated with known events taking place during long bone development, e.g. formation of primary and secondary ossification centers. Decreased expression of GAP-43 immunoreactivity in later developmental stages is believed to reflect nerve fiber maturation.     

Three-dimensional arrangement of muscle bundles in the outer layers of rodentia vasa deferentia

Three-dimensional arrangement of the smooth muscle bundles of the outer layer of the vas deferens musculature in mammals (guinea-pigs, rats and mice) was examined under the scanning electron microscope (SEM) after removal of fibrous connective tissue elements. Muscle fibers of all examined animals formed bundles. In the guinea-pig, similar sized bundles extended longitudinally along the tubular vas deferens and branched to anastomose with branches of neighboring bundles to create a net which was regular in form. In the rat, longitudinal muscle bundles constituted an outer layer in the form of a net, which was roughly enmeshed with variously-sized, transverse or oblique bundles in anastomosis with underlying longitudinal bundles. In the mouse, longitudinal bundles of irregular thickness branched into many small bundles and anastomosed not only with neighboring bundles to create an irregular net. In both the rat and the mouse there were bundles extending over many other bundles to anastomose with them at a far point. Junctional structures were well developed between neighboring fibers. Myofibrils were represented as thin streaks on muscle fiber surfaces. Varicosed nerve fibers existed between muscle fibers and in narrow cytoplasmic grooves in all the examined animal species. The findings are discussed in correlation with electrophysiological data.     

Blood flow to long bones indicates activity metabolism in mammals, reptiles and dinosaurs

The cross-sectional area of a nutrient foramen of a long bone is related to blood flow requirements of the internal bone cells that are essential for dynamic bone remodelling. Foramen area increases with body size in parallel among living mammals and non-varanid reptiles, but is significantly larger in mammals. An index of blood flow rate through the foramina is about 10 times higher in mammals than in reptiles, and even higher if differences in blood pressure are considered. The scaling of foramen size correlates well with maximum whole-body metabolic rate during exercise in mammals and reptiles, but less well with resting metabolic rate. This relates to the role of blood flow associated with bone remodelling during and following activity. Mammals and varanid lizards have much higher aerobic metabolic rates and exercise-induced bone remodelling than non-varanid reptiles. Foramen areas of 10 species of dinosaur from five taxonomic groups are generally larger than from mammals, indicating a routinely highly active and aerobic lifestyle. The simple measurement holds possibilities offers the possibility of assessing other groups of extinct and living vertebrates in relation to body size, behaviour and habitat.     

THE FINE STRUCTURE OF THE MID-BODY OF THE RAT ERYTHROBLAST

The development of the mid-body has been studied in mitotic erythroblasts of the rat bone marrow by means of thin sections examined with the electron microscope. A differentiated region on the continuous spindle fibers, consisting of a localized increase in density, is observed at the equatorial plane. The mid-body seems to develop by the aggregation of such denser lengths of spindle fiber. Its appearance precedes that of the cleavage furrow. A plate-like arrangement of fibrillary material lies transversely across the telophase intercellular bridge. Later, this material becomes amorphous and assumes the form of a dense ring closely applied to a ridge in the plasma membrane encircling the middle of the bridge. Although the mid-body forms in association with the spindle fibers, it is a structurally distinct part, and the changes which it undergoes are not shared by the rest of the bundle of continuous fibers.     

Body cavities in fishes

Four types of body cavity arrangement were found in 20 species of fish (see Materials and Methods). The body cavities of fishes were also compared with those of mammals and birds. It was concluded that higher vertebrates utilized only the Tinca type for their evolution, while the other types were dead-end evolutionary forms which terminated at fish level, or possibly with amphibians and reptiles. The necessary research in these groups still remains to be done.     

Comparative study of the lamina cribrosa and the pial septa in the vertebrate optic nerve and their relationship to the myelinated axons

The optic nerve contains the connective tissues, i.e. the lamina cribrosa and pial septa. This report presents a histological comparison of the lamina cribrosa and pial septa in the five classes (mammals, birds, reptiles, amphibians and teleosts) of vertebrates. Furthermore, the distribution of myelinated fibers was observed from the optic nerve through the retina in the same animals. The lamina cribrosa is found in mammals except for mice, and in birds. Structural complexity of the lamina was different in animals but generally dependent of the optic nerve thickness. The pial septa were present in the optic nerve proper of the mammals except for the mice, in birds and in a part of teleosts. Fasciculation of the optic nerve by the pial septa tended to be more prominent as the optic nerve become thicker. The optic nerve consisted of largely myelinated fibers in vertebrates. The retina contained some myelinated fibers in submammals but was thoroughly devoid of myelinated fibers in mammals. The borderline between myelinated and unmyelinated portions in the optic nerve of different species did not related to the lamina cribrosa. Amphibians had exceptionally only a few myelinated fibers in the optic nerve and no myelinated fibers in the retina.     

Fiber type composition of the plantarflexors of giraffes (Giraffa camelopardalis) at different postnatal stages of development

1. A sample of fibers from deep (close to the bone) and superficial (away from the bone) regions of the plantaris (PLT) and medial (MG) and lateral (LG) gastrocnemius muscles of a neonatal, a 17-day-old and an adult giraffe were typed qualitatively as dark or light based on alkaline preincubation myosin ATPase staining properties and then sized. 2. Each muscle at all ages showed a higher percentage and a larger cross-sectional area (CSA) or light ATPase fibers in the deep than the superficial region. This relationship was qualitatively, although not quantitatively, similar to that reported in hindlimb muscles of other mammals. 3. At all ages, the PLT, the deepest muscle in the synergistic group, had the highest relative total CSA of light ATPase fibers among the muscles sampled. 4. At birth, the PLT had an unusually high percentage of light ATPase fibers in comparison to that found in the same muscle of other mammals. With age, the total CSA of light ATPase fibers increased dramatically in the PLT and decreased slightly in the MG and LG. 5. These data suggest that the PLT, especially the deep portion, may functionally replace the soleus muscle which is absent in the giraffe. In addition, the fiber type results demonstrate that the changes in the fiber type composition of individual muscles observed at different postnatal ages in the giraffe are relatively similar to that reported in smaller mammals, suggesting the existence of similar regulatory mechanisms.     

Specificity of the interrelations of Leishmania and host cells in vitro

Experiments on cross infection of peritoneal macrophages of mice with Leishmania of reptiles L. gymnodactyli and free cells of abdominal cavity of caucasian Agama (some part of which is composed by fibroblasts) with Leishmania of mammals L. major and L. donovani have shown the possibility of reproduction of the above species both in reptiles and mammals. The persistence of L. gymnodactyli and L. major in macrophages of mice was traced up to 10 days, the abundance of L. gymnodactyli during the whole period of observations being lower than that of L. major. The abundance of the above Leishmania in these cells happened to be higher than in the cells of reptiles. In the cells of reptiles the infection with these three species of Leishmania was eliminated by 5-6 days. More activity internalization of Leishmania of reptiles into cells of reptiles as compared to Leishmania of mammals was revealed that, apparently, reflects a definite degree of their adaptation to existence in reptiles in vivo.     

两栖和爬行类生长及生长激素分泌活动的调节

根据生长内分泌学,综述了近年来两栖和爬行类生长激素（ＧＨ）分泌活动的调节及生长激素在两栖爬行类生长中作用这一研究领域所取得的主要成就和研究进展,研究结果表明：在脊椎动物的进化过程中,ＧＨ的化学结构和功能是相当保守的;ＧＨ对两栖爬行类的生长起促进作用;类胰岛素生长因子（ＩＧＦｓ）也能冰分传递ＧＨ促进两栖类的生长;在两栖爬行类,下丘脑对ＧＨ分泌的调控较哺乳类缺乏特异性,利用外源ＧＨ促进两栖爬行类的生长     

Comparative anatomical study of the synovial membrane in representatives of 4 classes of terrestrial vertebrate

The synovial membrane (SM) of some representatives of four terrestrial vertebrate classes was studied by means of scanning electron microscope (SEM). The figures of SM of the mammals (man, mini-pig), birds (fowl, Gallus domesticus L.), reptiles (lizard, Lacerta viridis Laur. and turtle, Testudo graeca L.) and amphibians (frog, Rana esculanta L.) are documented. The SM of all animal species investigated presents a great locally variable appearance in form and surface arrangement of the living cells. The surface of synoviocytes is mostly very rough, forked, the cells having a plenty of wart-like, spiny-like or leaf-like microvilli, with cytoplasmic projections protruding from cell bodies. The largest possible functional surface of SM in mammals is formed by multiple villi and folds, whereas in other animal classes--by a specific arrangement of the lining cells. Locally variable appearance of synoviocytes from human and rabbit joints was described by Date (1979); we have documented the same in birds, reptiles and amphibians, as well. Three characteristic types of locally variable appearance of the surface lining cells were picked out in representatives of the every animal class cited. These cells correspond to the histological types, classified by Key. Beside these basic types, a number of transitory cells appear, that increase the diversity of the appearance of the lining cells in different regions of the SM. We may conclude that all the synoviocytes present the largest possible functional surface, although their external form differs. Their cytoplasm contains all sorts of organelles necessary for synthesis and secretion of mucopolysaccharides of the synovial liquid, as well as for the resorption and phagocytosis.     

The diet of feral cats on islands: a review and a call for more studies

Cats are among the most successful and damaging invaders on islands and a significant driver of extinction and endangerment. Better understanding of their ecology can improve effective management actions such as eradication. We reviewed 72 studies of insular feral cat diet from 40 islands worldwide. Cats fed on a wide range of species from large birds and medium sized mammals to small insects with at least 248 species consumed (27 mammals, 113 birds, 34 reptiles, 3 amphibians, 2 fish and 69 invertebrates). Three mammals, 29 birds and 3 reptiles recorded in the diet of cats are listed as threatened by the IUCN. However, a few species of introduced mammals were the most frequent prey, and on almost all islands mammals and birds contributed most of the daily food intake. Latitude was positively correlated with the predation of rabbits and negatively with the predation of reptiles and invertebrates. Distance from landmass was positively correlated with predation on birds and negatively correlated with the predation of reptiles. The broad range of taxa consumed by feral cats on islands suggests that they have the potential to impact almost any native species, even the smallest ones under several grams, that lack behavioral, morphological or life history adaptations to mammalian predators. Insular feral cat??s reliance on introduced mammals, which evolved with cat predation, suggests that on many islands, populations of native species have already been reduced.     

The evolution of the mechanical properties of amniote bone

162 specimens from 19 species of amniote were tested for various mechanical and physical properties to ascertain whether there were characteristic differences between different groups. All mechanical properties showed very great variation. In general the reptiles were not inferior to the mammals and birds. The histology of living forms was compared to that of fossil forms, to see whether 'weak' histology was more characteristic of primitive amniotes. The earliest reptiles probably had rather complaint bone, but it was probably tough. Modern types of bone appeared over two hundred million years ago. Very specialised bone, like that of the bullae of whales and antlers, may have evolved only in the mammals, but the fossil record is not complete enough to assert this confidently.     

Development and growth of long bones in European water frogs (Amphibia: Anura: Ranidae), with remarks on age determination

Differentiation and development of long bones were studied in European water frogs: Rana lessonae, R. ridibunda, and R. esculenta. The study included premetamorphic larvae (Gosner Stage 40) to frogs that were 5 years old. Femora, metatarsal bones, and proximal phalanges of the hindlimb exhibit the same pattern of periosteal bone differentiation and the same pattern of growth. Longitudinal and radial growth of these bones was studied by examination of the diaphyses and epiphyses, particularly where the edge of periosteal bone is inserted into the epiphysis. The periosteum seems to be responsible for both longitudinal and radial growth. Investigation of the formation, length, and arrangement of lines of arrested growth reveals that the first line is present only in the middle 25-35% of the length of the diaphysis of an adult bone; therefore, only the central portion of the diaphysis should be used for age estimation in skeletochronological studies. Comparison of the shapes and histological structures of epiphyses in the femur, metatarsal bones, and phalanges revealed that epiphyseal cartilages are composed of an inner and outer part. The inner metaphyseal cartilage has distinct zones and plugs the end of the periosteal bone cylinder; its role in longitudinal growth is questioned. The outer epiphyseal cartilage is composed of articular cartilages proper, in addition to lateral articular cartilages. Differences in the symmetry of the lateral articular cartilages of distal epiphyses of the femur and toes may reflect adaptations to different kinds of movements at the knee and in the foot.     

Comparative development of fiber in wild and cultivated cotton

SUMMARY One of the most striking examples of plant hairs is the single-celled epidermal seed trichome of cultivated cotton. The developmental morphology of these commercial "fibers" has been well-characterized in Gossypium hirsutum , but little is known about the pattern and tempo of fiber development in wild Gossypium species, all of which have short, agronomically inferior fiber. To identify developmental differences that account for variation in fiber length, and to place these differences in a phylogenetic context, we conducted SEM studies of ovules at and near the time of flowering, and generated growth curves for cultivated and wild diploid and tetraploid species. Trichome initiation was found to be similar in all taxa, with few notable differences in trichome density or early growth. Developmental profiles of the fibers of most wild species are similar, with fiber elongation terminating at about two weeks post-anthesis. In contrast, growth is extended to three weeks in the A- and F-genome diploids. This prolonged elongation period is diagnosed as a key evolutionary event in the origin of long fiber. A second evolutionary innovation is that absolute growth rate is higher in species with long fibers. Domestication of species is associated with a further prolongation of elongation at both the diploid and allopolyploid levels, suggesting the effects of parallel artificial selection. Comparative analysis of fiber growth curves lends developmental support to previous quantitative genetic suggestions that genes for fiber "improvement" in tetraploid cotton were contributed by the agronomically inferior D-genome diploid parent.     

Diversity of cortical bone morphology in anuran amphibians

The cortical bones of mammals, birds, and reptiles are composed of a complex of woven bone and lamellar bone (fibrolamellar bone) organized into a variety of different patterns; however, it remains unclear whether amphibians possess similar structures. Importantly, to understand the evolutionary process of limb bones in tetrapods, it is necessary to compare the bone structure of amphibians (aquatic to terrestrial) with that of amniotes (mostly terrestrial). Therefore, this study compared the cortical bones in the long bones of several frog species before and after metamorphosis. Using micro-computed tomography (CT), we found that the cortical bones in the fibrolamellar bone of Xenopus tropicalis (Pipoidea superfamily) and Lithobates catesbeianus (Ranoidea superfamily) froglets are dense, whereas those of Ceratophrys cranwelli (Hyloidea superfamily) are porous. To clarify whether these features are common to their superfamily or sister group, four other frog species were examined. Histochemical analyses revealed porous cortical bones in C. ornata and Lepidobatrachus laevis (belonging to the same family, Ceratophryidae, as C. cranwelli). However, the cortical bones of Dryophytes japonicus (Hylidae, a sister group of Ceratophryidae in the Hyloidea superfamily), Microhyla okinavensis (Microhylidae, independent of the Hyloidea superfamily), and Pleurodeles waltl, a newt as an outgroup of anurans, are dense with no observed cavities. Our findings demonstrate that at least three members of the Ceratophryidae family have porous cortical bones similar to those of reptiles, birds, and mammals, suggesting that the process of fibrolamellar bone formation arose evolutionarily in amphibians and is conserved in the common ancestor of amniotes.     

大鼠肠系膜淋巴结内高内皮微静脉周围网状支架的研究

目的：研究高内皮微静脉周围网状细胞和网状纤维网的形态、密度、排列方式及其空间联系,探讨高内皮微静脉周围网状的组织构筑与功能。方法：用镀银染色光镜观察法和冻裂割断扫描电镜观察法观察健康、成熟Wistar大鼠肠系膜淋巴结内高内皮微静脉的基质网状结构。结果：高内皮微静脉周围基质结构主要由密集、交织的网状细胞和网状纤维组成,并在高内皮微静脉周围形成轮样结构。结论：高内皮微静脉周围网状纤维形成网状纤维网,并与淋巴迷路周围的淋巴迷路周围的网状纤维网相连,可能是淋巴细胞归巢的重要通路。     

Polypeptide YY- and neuropeptide Y-immunoreactive cells and nerves in the endocrine and exocrine pancreas of some vertebrates: An onto- and phylogenetic study

Summary The occurrence of polypeptide YY- and neuropeptide Y-immunoreactive cells and nerves in the pancreas of some species from all the eight main vertebrate groups (cyclostomes, cartilaginous fish, bony fish, amphibia, reptiles, birds, and mammals) was investigated. In addition, an ontogenetic study of these neurohormonal peptides was performed, using the rat pancreas. The distribution of these two peptides was compared with that of the structurally closely related pancreatic polypeptide.Polypeptide YY-immunoreactive cells were found to occur in the endocrine pancreas and neuropeptide Y-immunoreactivity was observed both in neurons and nerve fibres. The polypeptide YY-immunoreactive cells were limited to mammals and reptiles only. Neuropeptide Y-immunoreactive neurons and nerves were observed in reptiles, birds, and mammals only. One reptilian species (out of three) and one mammalian (out of six) failed to show any kind of immunoreactivity for the polypeptide or neuropeptide. Pancreatic polypeptide-immunoreactive cells were found in all the species examined except in the hagfish islet.In rat foetuses, polypeptide YY-immunoreactive cells and neuropeptide Y-immunoreactive nerve elements were first demonstrated at the seventeenth day of gestation, whereas pancreactic peptide-immunoreactive cells did not appear until postnatally, namely in two day-old rats. The polypeptide-containing cells, a new cell type in the endocrine pancreas, are rare. In contrast to the pancreatic peptide cells, they do not seem to have any kind of regional distribution.     

A quantitative collagen fibers orientation assessment using birefringence measurements: calibration and application to human osteons

Even though mechanical properties depend strongly on the arrangement of collagen fibers in mineralized tissues, it is not yet well resolved. Only a few semi-quantitative evaluations of the fiber arrangement in bone, like spectroscopic techniques or circularly polarized light microscopy methods are available. In this study the out-of-plane collagen arrangement angle was calibrated to the linear birefringence of a longitudinally fibered mineralized turkey leg tendon cut at variety of angles to the main axis. The calibration curve was applied to human cortical bone osteons to quantify the out-of-plane collagen fibers arrangement. The proposed calibration curve is normalized to sample thickness and wavelength of the probing light to enable a universally applicable quantitative assessment. This approach may improve our understanding of the fibrillar structure of bone and its implications on mechanical properties.     

Metabolic profile of the perivertebral muscles in small therian mammals: implications for the evolution of the mammalian trunk musculature

In order to gain a better understanding of the ancestral properties of the perivertebral muscles of mammals, this study investigated the fiber type composition of these muscles in six small, extant therians (two metatherians and four eutherians) similar in body shape to early mammals. Despite a few species-specific differences, the investigated species were very similar in their overall distribution of fiber types indicating similar functional demands on the back muscles in mammals of this body size and shape. Deep and short, mono- or multisegmental muscles (i.e., mm. interspinales, intermammillares, rotatores et intertransversarii) consistently showed the highest percentage of slow, oxidative fibers implying a function as local stabilizers of the vertebral column. Superficial and large, polysegmental muscles (i.e., mm. multifidus, sacrospinalis, iliopsoas et psoas minor) were predominantly composed of fast, glycolytic fibers suggesting they function to both globally stabilize and mobilize the spine during rapid non-locomotor and locomotor activities. Some muscles contained striking accumulations of oxidative fibers in specific regions (mm. longissimus et quadratus lumborum). These regions are hypothesized to function independently from the rest of the muscle belly and may be comparable in their functionality to regionalized limb muscles. The deep, central oxidative region in the m. longissimus lumborum appears to be a general feature of mammals and likely serves a proprioceptive function to control the postural equilibrium of the pelvic girdle and lumbar spine. The potential functions of the m. quadratus lumborum during ventilation and ventral stabilization of the vertebral column are discussed. Because representatives of the stem lineage of mammals were comparable in their body proportions and probably also locomotor parameters to the species investigated here, I suggest that the described fiber type distribution is representative of the ancestral condition in mammals. The origin of mammals was associated with a substantial enlargement of the epaxial muscles and the addition of subvertebral muscle mass. Because this novel muscle mass is mainly composed of fast, glycolytic fibers in extant species, it is plausible that these changes were associated with the evolution of increased sagittal mobility in the posterior trunk region in the therapsid ancestors of mammals. The caudally increasing role of sagittal bending in body propulsion is consistent with the overall increase in the percentage of glycolytic fibers in the cranio-caudal direction. The evolution of mammals was also associated with a loss of ribs in the posterior region of the trunk. This loss of ribs is thought to have decreased the stability of the posterior trunk, which may explain the observed greater oxidative capacity of the caudal local stabilizers. The increased need for postural feedback in the more mobile lumbar region may also explain the evolution of the proprioceptive system in the m. longissimus lumborum. Furthermore, the anatomical subdivision of the transversospinal muscle into several smaller muscle entities is suggested to facilitate their functional specialization.