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《Arthropod Structure & Development》2014,43(3):193-204
In this paper, the wax secretions and wax glands of Matsucoccus matsumurae (Kuwana) at different instars were investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. The first and second instar nymphs were found to secrete wax filaments via the wax glands located in the atrium of the abdominal spiracles, which have a center open and a series of outer ring pores. The wax gland of the abdominal spiracle possesses a large central wax reservoir and several wax-secreting cells. Third-instar male nymphs secreted long and translucent wax filaments from monolocular, biolocular, trilocular and quadrilocular pores to form twine into cocoons. The adult male secreted long and straight wax filaments in bundles from a group of 18–19 wax-secreting tubular ducts on the abdominal segment VII. Each tube duct contained five or six wax pores. The adult female has dorsal cicatrices distributed in rows, many biolocular tubular ducts and multilocular disc pores with 8–12 loculi secreting wax filaments that form the egg sac, and a rare type wax pores with 10 loculi secreting 10 straight, hollow wax filaments. The ultrastructure and cytological characteristics of the wax glands include wax-secreting cells with a large nucleus, multiple mitochondria and several rough endoplasmic reticulum. The functions of the wax glands and wax secretions are discussed. 相似文献
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Aharoni Y 《Plant physiology》1968,43(1):99-102
Young and unripe oranges and grapefruits stored at 15° or 20° evidenced shortly after harvest a marked increase in respiratory rate, and then a well-defined maximum which was followed by a decrease. 相似文献
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V P Ivanov 《T?Sitologii?a i genetika》1983,17(1):56-60
A study of monozygotic and dizygotic twins from the moment of their birth till 13 years of age showed that differences in twin genesis and conditions of prenatal development exert no statistically significant influence on formation of average indices. At different stages of ontogenesis contribution of the genetic determinant estimated by index H was different as to a degree of manifestation, directivity (+; -) sex-dependent peculiarities of realization. 相似文献
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In order to examine whether the patterns of nuclear and chromatin glycoproteins change during development the glycoproteins of foetal and adult chicken liver were investigated. Nuclear and chromatin proteins from both sources were separated by SDS-PAGE, transferred onto Immobilon-P transfer membrane or nitrocellulose and tested for concanavalin A (Con A), Galanthus nivalis agglutinin (GNA) and Aleuria aurantia agglutinin (AAA) binding. Results revealed a similarity in the profiles of nuclear and chromatin glycoproteins recognized by Con A from 14-, 16-, 18-day foetal and adult chicken liver. Generally GNA and AAA reacted more weakly with glycoproteins from foetal liver compared with the same glycoproteins from adult liver. 相似文献
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Embryo development in vitro of cat oocytes cryopreserved at different maturation stages 总被引:4,自引:0,他引:4
The purpose of this study was to evaluate the ability of cat oocytes, at different stages of maturation, to survive after cryopreservation and to assess their subsequent development following IVM and IVF. In the initial toxicity trial, immature oocytes were exposed to different concentrations of DMSO and ethylene glycol (EG). Resumption of meiosis and metaphase II were evaluated after removal of the cryoprotectant and IVM. The highest rates of resumption of meiosis (51.4%) were achieved after exposure to 1.5 mol l(-1) of cryoprotectants, and no difference was observed with control oocytes. Metaphase II was obtained in 25.7% (P<0.01) and 22.9% (P<0.005) of oocytes exposed to 1.5 mol l(-1) of DMSO and ethylene glycol, although at lower rates than in control oocytes (54.4%). On the basis of this finding, 1.5 mol l(-1) of cryoprotectant was chosen for freezing cat oocytes at the germinal vesicle stage (immature) or at metaphase II stage (mature). Post-thaw viability was assessed by the evaluation of the embryo development in vitro. After fertilization, mature oocytes frozen in ethylene glycol cleaved in better proportions (38.7%) than immature oocytes (6.8%, P<0.001), and no differences were observed in the cleavage rate of oocytes frozen at different maturation stages with DMSO (immature 12.8%; mature 14.1%). Embryonic development beyond the 8-cell stage was obtained only when mature oocytes were frozen with ethylene glycol (11.3%). This study suggests that cryopreserved cat oocytes can be fertilized successfully and that their development in vitro is enhanced when mature oocytes are frozen with ethylene glycol. The stage of maturation may be a key element in improving cat oocyte cryopreservation. 相似文献
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The origin and development of individual size variation in early pelagic stages of fish 总被引:1,自引:0,他引:1
Size variation among individuals born at the same time in a common environment (within cohorts) is a common phenomenon in
natural populations. Still, the mechanisms behind the development of such variation and its consequences for population processes
are far from clear. We experimentally investigated the development of early within-cohort size variation in larval perch (Perca fluviatilis). Specifically we tested the influence of initial variation, resulting from variation in egg strand size, and intraspecific
density for the development of size variation. Variation in egg strand size translated into variation in initial larval size
and time of hatching, which, in turn, had effects on growth and development. Perch from the smallest egg strands performed
on average equally well independent of density, whereas larvae originating from larger egg strands performed less well under
high densities. We related this difference in density dependence to size asymmetries in competitive abilities leading to higher
growth rates of groups consisting of initially small individuals under high resource limitation. In contrast, within a single
group of larvae, smaller individuals grew substantially slower under high densities whereas large individuals performed equally
well independent of density. As a result, size variation among individuals within groups (i.e. originating from the same clutch)
increased under high densities. This result may be explained by social interactions or differential timing of diet shifts
and a depressed resource base for the initially smaller individuals. It is concluded that to fully appreciate the effects
of density-dependent processes on individual size variation and size-dependent growth, consumer feedbacks on resources need
to be considered. 相似文献
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Liisa Kaarina Simola Kristiina Koskimies-Soininen Marja Tomell 《Physiologia plantarum》1985,65(1):23-26
Turions of Utricularia vulgaris L. were germinated in long-day conditions at 15°C for 1,3 and 6 days and their glycolipid composition was compared with that of resting but vernalized turions. Digalactosyldiacylglycerides (DGDG), monogalactosyldiacylglycerides (MGDG) and cerebrosides were present at all stages of development. No great changes were found in the glycolipid classes during sprouting but some differences were noted in the proportions of fatty acids. The most common fatty acids in all three glycolipid classes studied were 16:0, 18:0 and 18:2. MGDG and DGDG also contained relatively much 18:3 and its proportion increased during germination. Young turions and full-grown leaves collected from nature contained the same glycolipid classes as the sprouting turions. The developmental stage of the organs studied is reflected in the fatty acid composition of DGDG and MGDG but is not so evident in the cerebrosides. The 18:2 fatty acid is rather typical of the resting turions, especially in DGDG. 相似文献
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V N Arendariuk 《Ukrainski? biokhimicheski? zhurnal》1987,59(6):78-81
The phospholipid composition and ultrastructure of pulp are found to be qualitatively different at different stages of ontogenetic development (in the first and permanent dentition). An intensified functional load (with higher dental abrasion) prevents completion of the differentiation of cellular and noncellular elements of pulp even in permanent teeth. 相似文献
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The objective of our study was to determine the effect of conditioning media with homologous porcine uterine cells on the developmental rate of porcine embryos. Cell monolayers were prepared by selective dissection and digestion of sections from the uterus of prepuberal gilts that were primed with PMSG and hCG. Conditioned media were used with 2 type of embryos: 4-cell stage (Experiment 1) or blastocyst stage (Experiment 2). In Experiment 1, embryos were collected surgically by flushing the oviducts, 36 to 48 h following the first of 2 inseminations. Embryos were cultured in Whitten's medium containing 1.5% BSA as a protein source until they attained the 4-cell stage. Embryos at the 4-cell stage were cultured randomly in either Whitten's medium with 1.5% BSA or Whitten's medium with 1.5% BSA that was previously conditioned for 24 h with an endometrial epithelial cell monolayer. Embryos were cultured in 50-microl drops covered with oil in a 38.5 degrees C, 5% CO(2) in air incubator. There was no advantage to using the conditioned media with the 4-cell stage embryos. The embryos were less developed than those cultured in nonconditioned Whitten's medium (P <0.001). In Experiment 2, embryos were cultured at the blastocyst stage. They were recovered the same way as in Experiment 1 and then cultured in Whitten's medium containing 1.5% BSA until they reached the blastocyst stage. At the blastocyst stage (Day 6), embryos were randomly assigned to 1 of the 6 following treatments: Whitten's with 1.5% BSA or Whitten's plus 1.5% BSA that was previously conditioned with endometrial epithelial cell monolayer, TCM-199 containing 0.4% BSA or TCM-199 plus 0.4% BSA that was previously conditioned with endometrial epithelial cell monolayer, finally, TCM-199 containing 10% serum or TCM-199 plus 10% serum that was previously conditioned with endometrial epithelial cell monolayer. Results show that initiation of hatching was significantly enhanced by conditioning the Whitten's media. 相似文献
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Fonseca FN Ferreira AJ Sartorelli P Lopes NP Floh EI Handro W Kato MJ 《Phytochemistry》2000,55(6):575-580
Chemical investigations carried out with tissues at different developmental stages of Araucaria angustifolia established the presence of E and Z isomers of octadecyl p-coumarate and octadecyl ferulate in undifferentiated callus; in the seedling stems, the source of explants, three biflavones of the amentoflavone-type were isolated, whereas the diterpene, trans-communic acid, was obtained from the seedling roots. Adult stems accumulated the benzaldehydes, vanillin, p-hydroxybenzaldehyde and coniferaldehyde; the lignans, pinoresinol, eudesmin and lariciresinol; and the isoflavones, cabreuvine and irisolidone. 相似文献