共查询到20条相似文献,搜索用时 15 毫秒
1.
本研究通过形态解剖、免疫组织化学等技术,对中华蜜蜂Apis cerana cerana工蜂蕈形体胚后发育中神经胶质的形成过程进行了比较研究。结果表明:蕈形体中神经胶质增殖的高峰期集中在幼虫发育末期到蛹发育早期;在工蜂蕈形体的蕈体冠、蕈体柄以及小叶的发育过程中,神经胶质细胞往往先于神经纤维网出现在特定的区域,引导神经纤维网的形成。它们一方面规定了神经纤维网的边界和区域,为神经纤维网提供内部的分隔;另一方面也为神经纤维的移动提供特定的“路标"和靶向。与神经纤维网相关联的神经胶质的数量的持续增加,除了神经胶质的分裂增殖外,还有一部分来自于外部细胞体层的神经胶质的迁入。 相似文献
2.
Using electron microscopy we demonstrate that degenerating neurons and cellular debris resulting from neuronal reorganization
are phagocytosed by glial cells in the brain and nerve cord of the fruitfly Drosophila melanogaster during the first few hours following pupariation. At this stage several classes of glial cells appear to be engaged in intense
phagocytosis. In the cell body rind, neuronal cell bodies are engulfed and phagocytosed by the same glial cells that enwrap
healthy neurons in this region. In the neuropil, cellular debris in tracts and synaptic centres resulting from metamorphic
re-differentiation of larval neurons is phagocytosed by neuropil-associated glial cells. Phagocytic glial cells are hypertrophied,
produce large amounts of lysosome-like bodies and contain a large number of mitochondria, condensed chromatin bodies, membranes
and other remains from neuronal degeneration in phagosomes.
Received: 23 January 1996 / Accepted in revised form: 21 May 1996 相似文献
3.
Susanne C. Hoyer Jürgen Liebig Wolfgang Rssler 《Arthropod Structure & Development》2005,34(4):429-440
Many studies suggest a role for biogenic amines in a variety of insect behaviors including intraspecific aggression. In ants, despite a rich behavioral repertoire and prominent aggressive interactions, little is known about the potential impact of biogenic amines. This may partly be due to the general lack of information about aminergic systems in the ant brain. The present study investigates serotonergic and dopaminergic neuronal systems in the brain of the ponerine ant Harpegnathos saltator. In H. saltator, intraspecific aggression is important for the regulation of reproduction. This species, therefore, is amenable to comparative studies of aminergic neuronal effects on long-term changes in aggression. Using immunocytochemistry and confocal microscopy, we found that in the brains of sterile workers, the distributions of serotonergic and dopaminergic neuronal processes differed substantially. In addition, branching patterns of serotonergic neurons showed marked differences between males and females. Brains of workers after 3 days and 3 weeks of aggressive interactions revealed no marked differences in serotonergic and dopaminergic neurons compared to those of reproductive and non-aggressive individuals. We conclude that different levels of intraspecific aggression do not involve profound anatomical changes in serotonergic and dopaminergic neurons. Subtle changes may be masked by inter-individual variances. 相似文献
4.
《Arthropod Structure & Development》2017,46(6):805-814
During ontogenesis, the size of a spider body, tissues and organs increases dramatically. The aim of the study was to estimate changes in the central nervous system of postembryonic stages of Eratigena atrica and compare them with the literature data on species differing in behavioural traits. Allometric analysis involved evaluation of histological slides embedded in paraffin and stained with hematoxylin and eosin. The reduced major axis regression (RMA) was applied to find allometric relationships between the volumes of the particular parts of the body. All the measured parts of the central nervous system (CNS) were negatively allometrically related to the volume of the prosoma, showing that the increment of the CNS was lower than that of the entire body. The growth of the brain was negatively allometrically related to the growth of the CNS but the increment of the subesophageal ganglion was greater than that of the CNS, exhibiting a positive allometry. Within both these structures, the increase in neuropil volume was greater than the growth of the cortex (cell body rind). Thus, in postembryonic development, the share of the subesophageal ganglion and neuropil in the total volume of the CNS increased, whereas that of the brain and cortex decreased. The mode of the CNS development in E. atrica is similar to that observed in other arthropods, including Argiope aurantia, a spider of different ecology and behaviour. 相似文献
5.
The biogenic amine serotonin is a neurotransmitter and modulator in both vertebrates and invertebrates. In the CNS of insects, serotonin is expressed by identifiable subsets of neurons. In this paper, we characterize the onset of expression in the brain and suboesophageal ganglion of the honeybee during pupal development. Several identified serotonin-immunoreactive neurons are present in the three neuromeres of the suboesophageal ganglion the dorsal protocerebrum, and the deutocerebrum at pupal ecdysis. Further immunoreactive neurons are incorporated into the developing pupal brain in two characteristic developmental phases. During the first phase, 5 days after pupal ecdysis, serotonin immunoreactivity is formed in the protocerebral central body, the lamina and lobula, and the deutocerebral antennal lobe. During the second phase, 2 days later, immunoreactivity appears in neurons of the protocerebral noduli of the central complex, the medulla, and the pedunculi and lobes of the mushroom bodies. Three novel serotonin-immunoreactive neurons that innervate the central complex and the mushroom bodies can be individually identified. 相似文献
6.
Serotonin-immunoreactive neurons in the antennal lobes and suboesophageal ganglion of the honeybee 总被引:2,自引:0,他引:2
Summary We have used immunohistochemical methods to investigate the morphology of identified, presumptive serotonergic neurons in the antennal lobes and suboesophageal ganglion of the worker honeybee. A large interneuron (deutocerebral giant, DCG) is described that interconnects the deutocerebral antennal and dorsal lobes with the suboesophageal ganglion and descends into the ventral nerve chord. This neuron is accompanied by a second serotonin-immunoreactive interneuron with projections into the protocerebrum. Two pairs of bilateral immunoreactive serial homologues were identified in each of the three suboesophageal neuromeres and were also found in the thoracic ganglia. With the exception of the frontal commissure, no immunoreactive processes could be found in the peripheral nerves of the brain and the suboesophageal ganglion. The morphological studies on the serial homologues were extended by intracellular injections of Lucifer Yellow combined with immunofluorescence. 相似文献
7.
Eusocial insects are characterized by division of labor among a sterile worker caste and a reproductive queen. In the honeybee both female castes are determined postembryonically by environmental factors, and queens develop substantially faster than workers. Since olfaction plays a crucial role in organizing honeybee behavior and social interactions, we compared the development of primary and secondary olfactory centers in the brain. Age-synchronized queen and worker pupae were raised in incubators at 34.5 degrees C, and their external morphology was characterized for all pupal stages. The development of olfactory synaptic neuropil was analyzed using anti-synapsin immunocytochemistry, f-actin-phalloidin labeling and confocal microscopy. In the antennal lobes of queens olfactory glomeruli formed approximately 4 days earlier than in workers. The adult number of olfactory glomeruli was in a similar range, but the total glomerular volume was slightly smaller in queens. Olfactory and visual subdivisions (lip, collar) of the mushroom-body calyx formed early, whereas the basal ring separated late. Synaptic microglomeruli in the olfactory lip were established approximately 3-4 days earlier in queens compared to workers. We propose that developmental heterochrony results in fewer synapses in olfactory centers (smaller glomeruli, fewer microglomeruli) in queens, which may result in poorer performance on olfactory learning tasks compared to workers. 相似文献
8.
We have studied the binding pattern of antibody mAB 2B8 directed against even-skipped orthologous proteins (EVE) in honeybee embryos. Primary and secondary EVE stripes form in roughly anterior-to-posterior succession;
there are 8 primary and 16 secondary stripes. The most posterior primary stripes appear only after the onset of gastrulation.
The secondary stripes form by a splitting of primary stripes; they demarcate the parasegmental pattern. While these findings
resemble EVE expression in long-germ beetles, the honeybee differs from both beetles and dipterans by two transient pair-rule
traits in the parasegmental EVE pattern: the secondary stripes in head and thorax alternate in strength, yet out of register
with the Drosophila pattern, and over the whole pattern the odd-numbered stripes vanish earlier than their even-numbered counterparts. As in Drosophila, however, the strong EVE stripes coincide with the weak engrailed (EN) stripes. These findings are taken to indicate that (1) honeybee and beetles share a conserved mode of EVE stripe formation
whilst Drosophila has diverged in this respect, (2) honeybee and Drosophila have diverged from the beetles in specific pair-rule traits during the parasegmental expression of both EVE and EN, and (3)
some of these traits differ in the register of segment pairing and thus may reflect regulatory divergences at the pair-rule
level between dipterans and the honeybee. 相似文献
9.
The antennal lobe (AL) is the first center for processing odors in the insect brain, as is the olfactory bulb (OB) in vertebrates. Both the AL and the OB have a characteristic glomerular structure; odors sensed by olfactory receptor neurons are represented by patterns of glomerular activity. Little is known about when and how an odor begins to be perceived in a developing brain. We address this question by using calcium imaging to monitor odor-evoked neural activity in the ALs of bees of different ages. We find that odor-evoked neural activity already occurs in the ALs of bees as young as 1 or 2 days. In young bees, the responses to odors are relatively weak and restricted to a small number of glomeruli. However, different odors already evoke responses in different combinations of glomeruli. In mature bees, the responses are stronger and are evident in more glomeruli, but continue to have distinct odor-dependent signatures. Our findings indicate that the specific glomerular patterns for odors are conserved during the development, and that odor representations are fully developed in the AL during the first 2 weeks following emergence. 相似文献
10.
A forest fire event is influenced by climatic conditions and is supported by accumulation of fuel on forest floor. After
forest fire, photosynthetically active solar radiation was reduced due to accumulation of ash and dust particles in atmosphere.
Post-fire impacts on Quercus leucotrichophora, Rhododendron arboreum and Lyonia ovalifolia in a broadleaf forest were analysed after a wild fire. Bark depth damage was greatest for L. ovalifolia and least for Q. leucotrichophora. Regeneration of saplings was observed for all the tree species through sprouting. Epicormic recovery was observed for the
trees of all the species. Young trees of Q. leucotrichophora (<40 cm circumference at breast height) were susceptible to fire as evident by the lack of sprouting. Under-canopy tree species
have a high potential for recovery as evident by greater length and diameter of shoots and numbers of buds and leaves per
shoot than canopy species. Leaf area, leaf moisture and specific leaf area were greater in the deciduous species, with few
exceptions, than in evergreen species.
Received: 26 July 1995 / Revised: 1 March 1996 / Accepted: 9 September 1996 相似文献
11.
T. A. Williams 《Development genes and evolution》1998,207(7):427-434
In Drosophila, Distalless (Dll) is critical in establishing the proximal/distal axis of the leg. Lack of proper Dll expression causes distal limb structures to be truncated or lost. Dll expression was examined through the course of development in the limbs of two crustaceans, Triops and Nebalia. Because the limbs of these two species are branched, they provide a comparison to the uniramous (unbranched) leg of Drosophila. In Triops and Nebalia, development of limb branches is not tightly coupled with Dll expression: in some cases, branches can arise prior to Dll expression and in others, certain branches never express Dll. These data suggest that, while Dll may indeed initiate overall limb outgrowth, limb branches are unlikely to be patterned by a simple iteration of the mechanism
patterning the unbranched leg of Drosophila.
Received: 14 May 1997 / Accepted: 25 September 1997 相似文献
12.
H. W. J. Stroband Marcus P. S. Dekens Geertruy te Kronnie Henk Schipper Johannis Samallo 《Development genes and evolution》1998,208(1):56-59
The homeobox gene Carp-Ovx1 shows similarity to vertebrate and invertebrate Ovx genes and to Drosophila unplugged. Its expression pattern was studied by in situ hybridization in carp embryos and juveniles. During segmentation, expression
becomes gradually limited to the neural tube. In juveniles up to 9 weeks old, cells in the ventral telencephalon, the facial
lobe and the vagal lobe show Ovx1 expression, confining expression to parts with chemosensory projections.
Received: 29 October 1997 / Accepted: 12 November 1997 相似文献
13.
Mauro Vallarino Maura Mathieu Claudia Pinelli R. K. Rastogi 《Cell and tissue research》1998,293(1):47-55
Immunocytochemical distribution of the atrial natriuretic factor (ANF) has been studied in the brain and pituitary of the
anuran Rana esculenta during development and in juvenile animals. Using human ANF and rat α-ANF antisera, immunoreactive cell bodies and nerve
fibers were revealed in stage II–III tadpoles and in successive larval stages. Soon after hatching, stages II–III, the ANF-like-immunoreactive
elements were confined to the preoptic area-median eminence complex. During successive stages of development, new groups of
ANF-immunoreactive cell bodies appeared. In larval stage VI, immunoreactive perikarya were found in the rostral part of the
anteroventral area of the thalamus and numerous ANF-like-immunoreactive cells appeared in the pars distalis of the pituitary.
In larval stages XIV and XVIII, the distribution of ANF immunoreactivity was virtually similar. The ANF-immunoreactive cells
in the preoptic nucleus and in the pituitary pars distalis were comparatively more abundant than in stage VI. During the metamorphic
climax (stages XXI–XXII), a new group of ANF-immunoreactive cell bodies appeared in the rostral part of the ventrolateral
area of the thalamus. During this stage, ANF-immunoreactive fiber projections were found in the pars intermedia for the first
time. However, the pars distalis cells were very weakly immunofluorescent. The pattern of ANF immunoreactivity in the brain
of juvenile animals was very similar to that described for stages XXI and XXII, whereas the pars distalis cells showed no
immunoreactivity. It is conceivable that, early during development, ANF-related peptides may be involved in the regulation
of pituitary secretion by means of autocrine mechanisms or may act as a classic pituitary hormone.
Received: 28 July 1997 / Accepted: 8 December 1997 相似文献
14.
15.
Identification of proteins whose expression is up- or down-regulated in the mushroom bodies in the honeybee brain using proteomics 总被引:1,自引:0,他引:1
To identify protein(s) with different expression patterns in the mushroom bodies (MBs) in the honeybee brain, we compared the protein profiles of MBs and optic lobes (OLs) using proteomics. Two-dimensional gel electrophoresis revealed that five and three spots were selectively expressed in the MBs or OLs, respectively. Liquid chromatography tandem mass spectrometry analysis identified juvenile hormone diol kinase and glyceraldehyde-3-phosphate dehydrogenase as MB- and OL-selective proteins, respectively. In situ hybridization revealed that jhdk expression was upregulated in MB neuron subsets, whereas gapdh expression was downregulated, indicating that MBs have a distinct gene and protein expression profile in the honeybee brain. 相似文献
16.
We have studied the embryonic development of the pars intercerebralis/central complex in the brain of the grasshopper using
immunocytochemical and histochemical techniques. Expression of the cell-surface antigen lachesin reveals that the neuroblasts
of the pars intercerebralis first differentiate from the neuroectoderm at around 26% of embryogenesis. Differentiation of
medial and lateral neuroblasts occurs first. By the 28% stage a more or less uniform sheet of 20 neuroblasts has formed. As
a result of both cell proliferation and cell translocation, the pars intercerebralis proliferative cluster in each hemisphere
expands so that at 30% the most medial neuroblasts lie apposed at the midline. We followed the further development of the
pars intercerebralis of each brain hemisphere using bromo-deoxy-uridine incorporation and osmium-ethyl-gallate staining. Within
the pars intercerebralis itself, the neuroblasts redistribute into discrete subsets. The neuroblasts of each subset generate
clusters of progeny which extend in a stereotypic, subset-specific direction in the brain. We have used this feature to identify
one subset of four neuroblasts as being the likely progenitor cells for four clusters of embryonic neurons (W, X, Y, Z) which
develop at around 55% of embryogenesis. We show that these progeny project axons via four discrete fascicles (w, x, y, z)
into the embryonic central complex. At the single cell level, Golgi impregnation reveals that the axons from these neighbouring
cell clusters remain discrete, and those from the same cluster tightly fasciculated, as they project into the central complex,
consistent with a modular organization for this brain region.
Received: 16 June 1997 / Accepted: 25 June 1997 相似文献
17.
The mammalian Dlx homeobox gene family has been shown to play multiple roles in tooth development, but a detailed comparison
of the expression pattern of all members throughout tooth development has been lacking. We provide such an analysis for the
six known murine Dlx genes. The expression patterns for these genes allow a refinement of previously proposed models for the
role of Dlx genes in tooth type specification and raise the possibility of roles for subsets of these genes in tooth initiation,
morphogenesis (enamel navel formation, enamel knot induction, cervical loop growth), and enamel formation. The relationship
of Dlx gene expression to their genomic organization suggests coordinate regulation of linked genes at early stages but regulatory
differences at later stages.
Received: 19 July 1999 / Accepted: 3 December 1999 相似文献
18.
K. R. Straatman J. Nijsse H. Kieft A. C. van Aelst J. H. N. Schel 《Sexual plant reproduction》2000,13(1):43-51
Changes in nuclear pore complex (NPC) densities, NPCs/nucleus and NPCs/μm3, are described using freeze-fractured Brassica napus microspores and pollen in vivo and in vitro. Early stages of microspore- and pollen-derived embryogenic cells were also analysed.
The results of in vivo and in vitro pollen development indicate an increase in activity of the vegetative nucleus during maturation
of the pollen. At the onset of microspore and pollen culture, NPC density decreased from 15 NPCs/μm2 at the stage of isolation to 9 NPCs/μm2, under both embryogenic and non-embryogenic conditions. This implies that the drop in NPC density might be a result of culturing
the microspores and pollen rather than an indication for microspore and pollen embryogenesis in Brassica napus. However, after 1 day in culture under embryogenic conditions, the NPC density increased again and stabilised around 13 NPCs/μm2, whereas under non-embryogenic conditions the NPC density remained about 9 NPCs/μm2. This low density of 9 NPCs/μm2 was also found in the nuclei of sperm cells, in contrast to the 19 NPCs/μm2 found in the vegetative nucleus. It means that, although both the vegetative and sperm nuclei are believed to be metabolically
rather inactive in mature pollen, the NPC density of vegetative nucleus is twice as high as the NPC density of the sperm nuclei.
In a few cases, embryos formed suspensor-like structures with a NPC density of 9 NPCs/μm2, indicating a lower nucleocytoplasmic exchange of the nuclei of the suspensor cells than with the nuclei in the embryo proper.
In addition, observations on NPCs and other organelles, obtained by high resolution cryo-scanning microscopy, are presented.
Received: 29 December 1999 / Revision accepted: 3 March 2000 相似文献
19.
《Arthropod Structure & Development》2017,46(2):287-296
The antennae of Insecta consist of two basal segments and the distal annulated flagellum lacking intrinsic muscles. Non-muscular joints are important to preserve the flexibility and structure of the long heteropteran antennae which bear an intersegmental nodule on each non-muscular joint. Little is known about their properties or function. Here we characterize the structure and postembryonic development of the non-muscular joints of Rhodnius prolixus antennae. Using Scanning Electron Microscopy, we tracked the changes in shape and size of both intersegmental nodules during the course of the hemimetabolous insect life cycle. Using Atomic Force Microscopy, we established a qualitative correlation between the topography of the surface and the rigidity of the joint between pedicel and flagellum. Our results confirmed the presence of two sub-articulations on each non-muscular joint. Also, the two intersegmental nodules have different origins: the one between the two flagellar segments (intraflagelloid) is a sclerite already present from the early nymph, while the nodule between pedicel and flagellum (prebasiflagellite) originates by gradual separation of the proximal end of the basiflagellum during postembryonic development. Various changes occur in the non-muscular joints and segments of the antenna during the life cycle of R. prolixus. 相似文献
20.
Coronato F 《International journal of biometeorology》1999,42(3):113-118
Weather conditions are the main factors affecting the survival rate of newborn lambs. In the windy climate of Patagonia, the
influence of weather conditions is exacerbated as the wind speed increases noticeably in spring. If the wind increases faster
than the temperature rises, wind chill conditions worsen temporarily. This departure from the predictable improvement in bioclimatic
conditions as the season moves towards summer may coincide with lambing, if this is not adequately regulated. This paper explores
bioclimatic conditions during the 2-month period in which lambing may take place (i.e. mid-September to mid-November), and
identifies the unfavourable period that occurs in the second fortnight of October. Starting from the Mount and Brown (Agric
Meteorol 27:241–255, 1982) model to assess thermal stress in sheep by means of common meteorological records, a simpler model
was developed employing in long-term records. For 2-week averages of temperature (T
f), wind speed (V
f) and total precipitation (P
f), the average heat loss in sheep (HLf) was 40.40–2.07T
f+5.64V
f+0.04P
f. (r2=0.95). A 24-year series of T
f, V
f and P
f data was employed in the calculation of HLf, and results showed this parameter was significantly higher in the second fortnight in October. HLf values were classified into four groups (from ”very good” to ”very bad” conditions); once again, significant differences
appeared in the second fortnight in October. Finally, HLf during the lambing period was correlated to the percentage of lambs surviving 2 months later. Significant differences between
the survival of lambs born under ”very bad” and ”very good” conditions were found, but intermediate HLf conditions did not show a clear pattern. The survival rate was best correlated to HLf in the fortnight preceding lambing (P<0.05). This suggests that bioclimatic conditions during late pregnancy are at least as important as conditions during lambing
in determining the survival lambs.
Received: 14 December 1998 / Revised: 26 July 1999 / Accepted: 26 July 1999 相似文献