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1.
Beate Sopott-Ehlers 《Zoomorphology》1990,109(5):245-249
Summary The intercentriolar body in the biciliary spermatids of Nematoplana coelogynoporoides and its changes during spermiogenesis are described. Different functional aspects of the body, for example its presumed role as microtubule-organising centre and its influence on cell elongation, are discussed.Abbreviations
bb
basal body
-
ce
cell elongation
-
ci
cilium
-
icb
intercentriolar body
-
mt
microtubules
-
n
nucleus
-
r
ciliary rootlet 相似文献
2.
Summary The calcified body wall of an ophiuroid was investigated by a new method and compared with that of other echinoderms. The previous opinion that the epidermis of ophiuroid arm shields consists of a reduced syncytium continuous with the underlying dermis is incorrect. The epidermis is distinctly separated from the dermis by a basal layer and consists of (1) supporting cells which bear the cuticle, (2) ciliated cells (hitherto unknown and probably sensory), (3) gland cells, and (4) nerve cells with the basal nerve plexus. The overall structure of the epidermis is a three-dimensional tube system (marked by the basal lamina) which penetrates the dermal tissue of the scale's pore space and continues with nerve cords situated below the scale. This arrangement is unique in echinoderms.The dermal sclerocytes largely conform with those of the echinoid Eucidaris. The mineral skeleton is produced intracellularly or intrasyncytially. Moreover, dermal sclerocytes were found to release extracellular microfibrils which have nothing to do with calcite deposition. The attachment of the cuticle to the dermis is achieved by means of epidermal coupling areas. Collagen fibers fasten the scale to the underlying connective tissue sheath. The supposed fibrocytes within this sheath resemble sclerocytes. Each collagen bundle is provided with a strand of nerve fibers which, in contrast to the basal nerve plexus, are naked. They are said to infuence the mechanical properties of the connective tissue.Structures associated with cilia occur in cell types which normally lack a cilium. This finding suggests that most echinoderm cells are potentially monociliate.Abbreviations
A
apical shield
-
asp
secretory products
-
B
bacteria
-
bb
basal body
-
bl
basal lamina
-
C
ciliated cell
-
ca
coupling area
-
ci
cilium,
-
cf
collagen fibrils
-
cs
cell surface
-
CTS
connective tissue sheath
-
cu
i
inner cuticular layer
-
cu
m
middle cuticular layer
-
dp
distal processes (Sc)
-
EC
epineural canal
-
G
Golgi complex
-
gv
granular vesicle
-
H
haemal vessel
-
hb
homogeneous body
-
hl
horizontal lamina (Su)
-
j
cell junction
-
L
lateral shield
-
le
boundary layer (Sc)
-
lo
distal lobe (Su)
-
M
intervertebral muscle or its attachment
-
m
mitochondrium
-
mf
microfibrils
-
mu
mucus
-
mv
microvilli
-
mvb
multivesicular body
-
N
nerve cell
-
n
nucleus
-
nf
neurofibrils
-
ng
neurogranules
-
nn
naked neurofibrils
-
O
oral shield
-
P
tube foot
-
Pc
phagocyte
-
pg
pigment granules
-
rl
rootlet
-
RN
radial nerve
-
RV
radial vessel
-
Sc
sclerocyte
-
sh
cytoplasmic sheath (Sc)
-
sj
septate junction
-
Su
supporting cell
-
sv
secretory vesicle
-
T
calcite trabeculum
-
V
vertebral ossicle
-
v
vesicle (Su) 相似文献
3.
W. E. R. Xylander 《Zoomorphology》1984,104(1):21-25
Summary The fine structure of a paired lamellate body in the anterior region of the lycophora larva of Gyrocotyle urna is described. Each structure is built up by one specialized cell. Lamellae derive from membranes of about 15 cilia that protrude into an intracellular cavity. The lamellae divide into several flattened branches and are rolled up forming a whorl.The lamellate body is presumed to have photoreceptory function. Comparative deliberations are made for similar structures within several platyhelminths.Abbreviations used in figures
bb
basal body
-
ci
cilium
-
cm
circular muscles
-
cp
ciliary photoreceptor
-
cs
cytoplasmatic sheath
-
dg
dark granules
-
em
intercellular electron-dense material
-
ep
ciliated epidermis
-
go
gland opening of striped granules-gland
-
ic
intracellular cavity
-
lb
lamellate body
-
lg
light-coloured granules
-
lh
larval hooks
-
lm
lamellae
-
lo
longitudinal muscles
-
mi
irregularly shaped mitochondria of the ciliophore cell
-
mw
membranous structure of the adjacent cell
-
nc
nerve cell
-
nu
nucleus of ciliophore cell
-
rs
rib-like structure
-
sg
striped granules
-
ta
tegument anlage 相似文献
4.
Limestones of the Upper Oligocene Antigua Formation of Antigua contain unusual burrows filled with the densely packed debris of shelly benthos. Unlined burrows (Planolites?) in deep-water biofacies at Half Moon Bay, parish of Saint Philip, are packed with a monospecific assemblage of large benthic foraminiferans (Lepidocyclina canelli Lemoine &; Douvillé) and a single brachiopod valve, Tichosina sp. A similar burrow in shallower-water biofacies at Hughes Point, parish of Saint Philip, is packed with echinoderm debris and, particularly, test fragments of the spatangoid echinoid Lovenia n. sp. Fragments of the same echinoid fill a conical burrow, Bergaueria isp. The latter is probably a physical accumulation, the common fragments of echinoid being washed into an empty burrow. In contrast, the infill of Planolites? isp. is more likely to be an accumulation mediated by the burrower. 相似文献
5.
Summary The statocyst of otoplanids is enveloped by a bipartite capsule which consists of two different extracellular matrices. This capsule encircles three different types of aciliary cells: several peripherally located flattened parietal cells, one central statolith forming cell (lithocyte) and two clusters of accessory cells. Intracapsular lumina exist which are different from extracapsular intercellular spaces. The accessory cells most probably represent those structures that are mainly involved in nervous conduction. These cells extend cytoplasmatic processes towards different peripheral regions of the statocyst where processes of outer nerve cells penetrate the capsule. The statocyst does not seem to represent a more evolved equilibrium receptor system but may function as a relatively simple aciliary sense organ suitable for positive geotactic behaviour. The otoplanid statocyst corresponds to statocysts in other lithophorous proseriates but not to statocysts in other taxa of the free-living Plathelminthes. The monophyly of a taxon Lithophora within the Proseriata is corroborated by this autapomorphic characteristic.Abbreviations
ac
accessory cell(s)
-
c
capsule of the statocyst
-
ce
cerebrum
-
ci
cephalic intestine
-
co
capsule opening
-
cp
cell process(es) of accessory cell(s) and cell(s) containing filaments
-
ecm
extracellular matrix
-
fc
cell(s) containing filaments
-
ic
intercellular spaces within the capsule
-
mc
muscle cell(s)
-
n
lobed nucleus of the lithocyte
-
nac
nucleus (nuclei) of accessory cell(s)
-
nc
nerve cell(s)
-
npc
nucleus (nuclei) of parietal cell(s)
-
pc
parietal cell(s)
-
s
statolith
-
sc
statolith cell (lithocyte) 相似文献
6.
Fine structure of the epidermis in Gnathostomulida 总被引:1,自引:1,他引:0
V. Lammert 《Zoomorphology》1989,109(3):131-144
Summary The fine structure of the epidermis in Haplognathia simplex, Haplognathia rosea, Pterognathia meixneri (Filospermoidea) and Gnathostomula paradoxa (Bursovaginoidea) has been investigated. The epidermis in the filospermoidean species is uniform, consisting of epidermal cells with a single locomotory cilium. The structure and development, including ciliogenesis, of these epidermal cells are described. In G. paradoxa additional epidermal elements have been found: mucous cells with a presumably apocrine secretion modus are scattered in a strip-like arrangement within the epidermis. Their deverlopment is separate from epidermal cells with locomotory function. Two further types of glandular cells with either a single cilium or a diplosome are located ventrally. It is assumed that they represent an adhesive system.Abbreviations (used in figures)
ac
accessory centriole
-
ap
appendix of accessory centriole
-
ax
axoneme
-
bb
basal body
-
bf
basal foot
-
bl
basal lamina
-
c
cilium
-
cA
ciliary adhesive cell
-
ce
centriole
-
cp
ciliary pit
-
d
diplosome
-
dy
dictyosome
-
dA
diplosomal adhesive cell
-
E
epidermal cell with locomotory cilium, epidermis
-
ev
epidermal vesicle (epitheliosome)
-
gv
gland vesicle
-
m
mitochondrion
-
ma
microvillus of apical cell membrane
-
mp
microvillus of ciliary pit
-
mv
microvillus
-
n
nucleus
-
ps
prosecretory-vesicle
-
R
receptor
-
r
ciliary rootlet
-
rc
caudal ciliary rootlet
-
rr
rostral ciliary rootlert
-
sv
secretory vesicle
-
v
vesicle
-
v
i
central vesicle of multivesicular body
-
v
o
surrounding vesicle of multivesicular body
-
z
cisternae 相似文献
7.
David A. Doe 《Zoomorphology》1982,101(1):39-59
Summary The copulatory organs in Macrostomum sp. and Microstomum sp. contain simple tubular stylets which are intracellular specializations. The stylet in Macrostomum sp. is produced in a syncytium covering part of the prostatic vesicle. The proximal region of the stylet surrounds the vesicle which contains six prostatic gland ducts and six accessory (sensory) cells containing ciliary rootlets. The stylet in Microstomum sp. is produced in an extension of a syncytium which lines the combined seminal-prostatic vesicle. The stylet is connected to the combined vesicle by a narrow bridge of matrix syncytium through which sperm, prostatic gland products and sensory cilia pass from the vesicle to the stylet lumen. In both species the matrix syncytium can be interpreted as a specialized terminal end of the male canal epithelium. Stylets of Turbellaria and other lower Metazoa are discussed in regards to structure (one or several pieces) and location (in separate cells, in a syncytium, or extracellular).Abbreviations used in figures
ac
accessory cell
-
b
basal body
-
c
cilium
-
cv
combined vesicle
-
d
prostatic gland duct
-
dc
degenerative cell
-
di
dictyosome
-
e
epidermis
-
ed
ejaculatory duct
-
g
prostatic gland cell
-
h
hemidesmosome
-
i
intercellular matrix
-
im
internal muscle
-
in
intestine;
-
l
lumen of male canal
-
lm
longitudinal muscle
-
m
matrix syncytium
-
mc
male canal epithelial cell
-
mi
microfilaments
-
mt
microtubules
-
mu
muscle cell
-
mv
microvilli
-
n
nucleus
-
np
nerve process
-
ns
neurosecretory (?) granule
-
p
prostatic vesicle
-
pv
prostatic part of combined vesicle
-
r
rootlet
-
s
stylet
-
sm
stylet material
-
sp
sperm
-
sv
seminal part of combined vesicle 相似文献
8.
Labeled inhibitor autoradiography showed that carbonic anhydrase (CA) occurs in (1) the epithelium, (2) free odontoblasts and fibroblasts, (3) row odontoblasts and their membranes surrounding the calcareous parts and (4) extracellular areas. Extracellular CA occurs in areas where fibroblasts and collagen fibers are abundant. The localization of CA suggests that CA facilitates the movement of CO2 through the membrane and/or extracellular spaces to promote calcification. 相似文献
9.
10.
D. B. Benner 《Genesis (New York, N.Y. : 2000)》1987,8(3):151-163
The fourth chromosome mutant cubitus interruptus-Wallace(ciW) produces leg, wing, and body bristle aberrations. The effect on the wing is similar to that produced by cubitus interruptus-dominant (ciD) which also has an influence on larval segmentation indicating that it has a regulatory function. Leg morphology of haplo-4, ciW, and mosaic haplo-4:diplo-4, ci/ci+ flies was examined in an attempt to distinguish between a structural and a regulatory function by ciW. Aberrations recovered include failure of segment elongation, intersegmental gaps, duplication of bristles, and segments that are shorter than normal and of greater than normal diameter. Many of these effects are localized, suggesting that ciW may act to maintain cell positional reference. Increased local cell proliferation appears to be one manifestation of loss of the normal function. 相似文献
11.
Summary Muscles are generally attached to the skeleton by interconnecting tendons. Each tendon necessarily has a junction with the muscle and another with the skeleton. The ultrastructure of the skeleton is identical in all echinoderm classes. Nevertheless, we found three different types of muscle-skeleton junctions. (1) In Crinoida the muscles are attached almost directly to the calcite trabeculae. (2) Asteroida and Ophiuroida have tendons that arise from the basal laminae of the muscle bundles. They consist of unstriated microfibrils that are attached on the muscle side to electron-dense areas below the sarcolemma of the fingershaped muscle ends. On the skeleton side they embrace the outermost calcite trabeculae. (3) In Echinoida the strong muscles are joined to the skeleton by means of composite tendons. They consist of unstriated tendon cords that adhere to the muscles and of bundles of striated fibrils coiled around the calcite trabeculae. Both kinds of tendons are interconnected in the same way as the links of a chain. Composite tendons are found in junctions that are exposed to multidirectional stress. In Holothuroida there are no true muscle-skeleton junctions and the muscles are apposed to connective tissue.The muscle-tendon junctions in Echinodermata differ fundamentally from the junctions in the protostome Arthropoda or Mollusca, but they were found to be very similar in structure to the muscle-tendon junctions in Vertebrata. This coincidence may refer to a phylogenetic relationship of the two deuterostome phyla. But the tendon-skeleton junctions of the two phyla are dissimilar, for Echinodermata and Vertebrata differ fundamentally in their skeletons. Vertebrate bone consists of extracellular fibrils combined with minute crystals of hydroxylapatite. Echinoderm ossicles are intercellular in origin. They are nothing but the calcified vacuolar system of syncytial sclerocytes, and extracellular fibrils never enter the mineral phase.Abbreviations
bl
basal lamina
-
c
calcite trabecula
-
dp
distal processes of sclerocytes
-
el
electron-dense layer
-
m
muscle
-
sf
striated tendon fibrils
-
uf
unstriated tendon fibrils
-
tc
trabecle coat 相似文献
12.
Beate Sopott-Ehlers 《Zoomorphology》1989,109(3):145-152
Summary The spermiogenesis of Invenusta aestus (Coelogynoporidae) is described based on electron microscopical observations. Special attention is paid to the intercentriolar body and the anchoring apparatus of the cilia. These organelles are differentiated at the beginning of spermatid maturation and undergo striking changes during gametogenesis. The importance of the organelles mentioned for discussion of phylogenetic relationships within the Plathelminthes is considered.Abbreviations
ci
cilium
-
cy
cytophore
-
db
dense bodies
-
go
Golgi complex
-
icb
intercentriolar body
-
mi
mitochondrion
-
mt
microtubules
-
n
nucleus
-
r
rootlet
-
spo
spermatogonia
-
spt
spermatids
-
spy
spermatocytes
-
tb
tubular body
-
zd
zone of differentiation 相似文献
13.
The aleurone of RB-3 shrunken-2 (sh2) maize kernels is deficient in α-amylase activity during germination, but exogenous applications of gibberellic acid (GA3) (0.001–10 μm ) induced low levels of activity. The highest activity was measured in the aleurone of kernels treated with 10 μm GA3 (14,600 ± 945 units), but was lower than untreated Starchy (Su) aleurone tissues (35,280 ± 5,010 units). On isoelectric focusing gels, no α-amylase isozymes were detected in the untreated sh2 aleurone using starch zymograms or immunoblots, but the 1.0 and 10 μm mm GA3 treatments induced nearly all the isozymes (eight to ten) present in the Su aleurone. There was a very low level of α-amylase mRNA in the untreated sh2 aleurone, an intermediate level in the 1.0 μm GA3-treated sh2 aleurone, and the highest level in the untreated Su aleurone. On the confocal microscope, the 1.0 μm GA3-treated aleurone cells had enhanced levels of cytoplasmic membranes and RNA compared to untreated sh2 aleurone cells. The 1.0 μm GA3 treatment also induced shoot elongation in the sh2 seedlings. The data demonstrate that the sh2 aleurone is deficient in its function to produce α-amylases, and exogenous GA3 can partially restore cell function in the sh2 kernels. 相似文献
14.
High-calcifying cells of Emiliania huxleyi were grown on a synthetic seawater medium and the effect of nitrate (NO- 3) concentration on growth, calcite accumulation, calcification rate and DIC (dissolved inorganic carbon) utilisation determined. The stoichiometry between NO- 3 utilisation and calcite production was 1:6·5 (mol/mol). Calcification and growth were tightly coupled: calcite production ceased when cultures entered the stationary phase due to NO- 3 depletion, but by adding a pulse of NO- 3 growth and calcification were restored. The initial C/N ratio in the medium was important in relation to calcification rate. At 20 µM NO- 3 the total DIC (2 mM) was rapidly depleted, the calcification rate subsequently declining, whereas at 5 and 10 µM NO- 3 rates of calcification were constant at 20 g carbon cell-1 × 1014·h-1 throughout culture growth, excess DIC being present relative to the available NO- 3. Calcite production per unit NO- 3 was similar for isolates of E. huxleyi from neritic, oligotrophic and nitrate-rich waters. In laboratory cultures, where the photon flux density is optimised for growth, the initial NO- 3 concentration is a reliable indicator of final calcite yield. 相似文献
15.
E. Bowie Kahle Kenneth G. Butz Streamson C. Chua Erin E. Kershaw Rudolph L. Leibel Terry W. Fenger Carl T. Hansen Otho E. Michaelis 《Obesity (Silver Spring, Md.)》1997,5(2):142-145
The autosomal recessive obesity mutations fatty (fa) and corpulent (cp) arose in separate rat strains, 13M and Koletsky, respectively. By complementation analysis, the two mutations appear to be in the same gene. The somewhat different phenotypes of fa/fa and cp/cp animals probably reflect the fact that the mutations are segregating on different rat strains. The fa mutation has been mapped to the interval between Pgm1 and Glut1 on rat Chr 5, but cp has not been mapped genetically. We mapped cp in 30 obese progeny of a LA/N-BN cp/+ intercross using microsatellite markers for these flanking genes. Cp maps to the same genetic interval as rat fa and mouse db. Cp is flanked by Glut1 and Pgm1: Pgm1——–cp——–Glut1 map distance (cM) 1.67 6.67 Thus, cp and fa map to the same ~8 cM interval of the rat genome. In conjunction with the complementation studies alluded to above, these findings indicate that cp and fa are mutations in the same gene (Lepr). 相似文献
16.
Nutrient-limited productivity of calcareous versus fleshy macroalgae in a eutrophic,carbonate-rich tropical marine environment 总被引:4,自引:0,他引:4
The results of a study of nutrient enrichment with nitrogen (N) and phosphorus (P) on productivity and calcification of fleshy and calcareous algae are reported in this study. Plants were collected from a nearshore eutrophic site in the Florida Keys (USA) and experimentally pulsed during the night with combinations of N and P. After several days of pulsing (7–10 days), net productivity, calcification, and alkaline phosphatase activity (APA), were measured. Productivity of fleshy algae were frequently enhanced by N, P, and N+P, during both summer and winter. Phosphorus limited the productivity of Hydroclathrus clathratus during winter and Ulva spp. during summer, whereas nitrogen limited the productivity of Laurencia intricata during both seasons. During summer, Dictyota cervicornis productivity was not enhanced by any nutrient enrichment. Nitrogen limited the productivity of the three calcareous species Penicillus capitatus, Penicillus dumetosus and Halimeda opuntia during winter and that of H. opuntia during summer. Neither N nor P enrichment increased calcification of calcareous species, and P enrichment greatly inhibited calcification of P. dumetosus during winter. Nutrient enrichment enhanced the productivity of the fleshy species to a greater extent than that of calcareous algae. The seawater DIN:SRP molar ratio was low at our eutrophic study site (molar ratio average of 3:1 during winter and 9:1 during summer) compared to more oligotrophic sites in the Florida Keys, suggesting that in carbonate-rich environments, eutrophication shifts nutrient regulation of productivity from P to N. APA activities of fleshy macroalage were higher than calcareous algae, and rates of all macro algae were 2- to 7-fold higher in summer compared to winter. Productivity was also about 3-fold higher in fleshy compared to calcareous species and about 2-fold higher in summer compared to winter. These results suggest that nutrient enrichment enhances productivity of fleshy algae to a greater extent than that of calcareous algae. Thus, overgrowth of calcareous algae by more opportunistic fleshy forms could reduce carbonate accretion in tropical coastlines experiencing increased eutrophication. 相似文献
17.
Transgenic papaya plants from Agrobacterium-mediated transformation of somatic embryos 总被引:1,自引:0,他引:1
Maureen M. M. Fitch Richard M. Manshardt Dennis Gonsalves Jerry L. Slightom 《Plant cell reports》1993,12(5):245-249
Summary Transgenic papaya (Carica papaya L.) plants were regenerated from embryogenic cultures that were cocultivated with a disarmed C58 strain of Agrobacterium tumefaciens containing one of the following binary cosmid vectors: pGA482GG or pGA482GG/cpPRV-4. The T-DNA region of both binary vectors includes the chimeric genes for neomycin phosphotransferase II (NPTII) and ß-glucuronidase (GUS). In addition, the plant expressible coat protein (cp) gene of papaya ringspot virus (PRV) is flanked by the NPTII and GUS genes in pGA482GG/cpPRV-4. Putative transformed embryogenic papaya tissues were obtained by selection on 150 g·ml–1 kanamycin. Four putative transgenic plant lines were obtained from the cp gene– vector and two from the cp gene+ vector. GUS and NPTII expression were detected in leaves of all putative transformed plants tested, while PRV coat protein expression was detected in leaves of the PRV cp gene+ plant. The transformed status of these papaya plants was analyzed using both polymerase chain reaction amplification and genomic blot hybridization of the NPTII and PRV cp genes. Integration of these genes into the papaya genome was demonstrated by genomic blot hybridizations. Thus, like numerous other dicotyledonous plant species, papayas can be transformed with A. tumefaciens and regenerated into phenotypically normal-appearing plants that express foreign genes.Journal Series no. 3757 of the Hawaii Institute of Tropical Agriculture and Human Resources 相似文献
18.
19.
Kim TH Lee JY Baek JA Lee JC Yang X Taketo MM Jiang R Cho ES 《Biochemical and biophysical research communications》2011,(4):549-555
Wnt/ß-catenin signaling plays an important role in morphogenesis and cellular differentiation during development. Essential roles of Wnt/ß-catenin signaling in tooth morphogenesis have been well known, but the involvement of Wnt/ß-catenin signaling in the dental hard tissue formation remains undefined. To understand roles of Wnt/ß-catenin signaling in dentin and cementum formation, we generated and analyzed the conditional ß-catenin stabilized mice in the dental mesenchyme. The OC-Cre;Catnblox(ex3)/+ mice exhibited malformed teeth characterized by aberrantly formed dentin and excessively deposited cementum. Large amount of dentin was rapidly formed with widened predentin and numerous globular calcifications in the crown. Whereas roots of molars were short and covered with the excessively formed cellular cementum. With age, the coronal pulp chamber and periodontal space were narrowed by the excessively formed dentin and cementum, respectively. To compare the changes of gene expression in the mutant mice, Col1a1 expression was increased but that of Dspp was decreased in the odontoblasts. However, both of Col1a1 and Bsp expression was increased in the cementoblasts. The gene expression changes were consistent with the localization of matrix proteins. Biglycan and PC-1 was increased but Phex was decreased in the odontoblasts and dentin matrix, respectively. TNAP was increased but Dmp1 and FGF23 was decreased in the cementoblasts and cementum matrix, respectively. Our results indicate that persistent stabilization of ß-catenin in the dental mesenchyme leads to premature differentiation of odontoblasts and differentiation of cementoblasts, and induces excessive dentin and cementum formation in vivo. These results suggest that temporospatial regulation of Wnt/ß-catenin signaling plays critical roles in the differentiation of odontoblasts and cementoblasts, and that inhibition of Wnt/ß-catenin signaling may be important for the formation of dentin and cementum during tooth development. Local modulation of Wnt/ß-catenin signaling has therapeutic potential to improve the regeneration of dentin and periodontium. 相似文献
20.
Mei YF Yamaza T Atsuta I Danjo A Yamashita Y Kido MA Goto M Akamine A Tanaka T 《Cell and tissue research》2007,328(1):117-127