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1.
Compression wood (CW) contains higher quantities of β-1-4-galactan than does normal wood (NW). However, the physiological
roles and ultrastructural distribution of β-1-4-galactan during CW formation are still not well understood. The present work
investigated deposition of β-1-4-galactan in differentiating tracheids of Cryptomeria japonica during CW formation using an immunological probe (LM5) combined with immunomicroscopy. Our immunolabeling studies clearly
showed that differences in the distribution of β-1-4-galactan between NW (and opposite wood, OW) and CW are initiated during
the formation of the S1 layer. At this stage, CW was strongly labeled in the S1 layer, whereas no label was observed in the S1 layer of NW and OW. Immunogold labeling showed that β-1-4-galactan in the S1 layer of CW tracheids significantly decreased during the formation of the S2 layer. Most β-1-4-galactan labeling was present in the outer S2 region in mature CW tracheids, and was absent in the inner S2 layer that contained helical cavities in the cell wall. In addition, delignified CW tracheids showed significantly more labeling
of β-1-4-galactan in the secondary cell wall, suggesting that lignin is likely to mask β-1-4-galactan epitopes. The study
clearly showed that β-1-4-galactan in CW was mainly deposited in the outer portion of the secondary cell wall, indicating
that its distribution may be spatially consistent with lignin distribution in CW tracheids of Cryptomeria japonica. 相似文献
2.
Keiji Sugimoto Sachiko Fujii Masayoshi Kaiho Itsuo Nakamura 《Cell and tissue research》1990,261(3):509-516
Summary Actin-containing cytoplasmic fibers were visualized in the mesenteric mesothelial cells of the large intestine of bullfrog tadpoles by rhodamine-phalloidin staining of en face preparations of mesothelial cells. These fibers were concurrently stained by immunofluorescence using antibodies to myosin or -actinin. Electron microscopy showed the presence of bundles of microfilaments in the basal cytoplasm of the cells. Such fibers in the mesothelial cells may be comparable to the stress fibers present in cultured cells. The mesothelial cells initially formed axially oriented stress fibers when they changed from a rhombic to a slender spindle-like shape. On the other hand, stress fibers disappeared as cells transformed from elongated to polygonal shapes during the period of metamorphic climax. Expression of stress fibers in these cells appears to be related to the degree of tension loaded on the mesentery, which may be generated by mesenteric winding. These stress fibers in the mesothelial cells may serve to regulate cellular transformation. They may also help to maintain cellular integrity by strengthening the cellular attachment to subepithelial tissue against tensile stress exerted on the mesentery. 相似文献
3.
Summary Two laboratory experiments were conducted to examine the ovipositional preferences of the egg parasitoidOoencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) for parasitized and unparasitizedMegacopta punctatissimum Montandon (Hemiptera: Plataspidae). Females that had never oviposited or that had not oviposite for 3 days preferred recently parasitized hosts more than unparasitized hosts. The preference for recently parasitized hosts appeared to be mediated by the punctures in already parasitized hosts made by the ovipositor of the first female. Survival of the parasitoid progeny was lower in recently parasitized hosts than in unparasitized hosts. However, handling time of parasitized hosts was extremely short relative to that of unparasitized hosts, because the superparasitizing female could use the punctures made by the previous females. It is concluded that the females preferred the parasitized hosts over unparasitized hosts because the benefit of saving time and energy for drilling was more than the cost of progeny survival. 相似文献
4.
Prosaposin Facilitates Sciatic Nerve Regeneration In Vivo 总被引:3,自引:0,他引:3
Yasunori Kotani Seiji Matsuda Masahiro Sakanaka Keiji Kondoh Shu-ichi Ueno Akira Sano 《Journal of neurochemistry》1996,66(5):2019-2025
Abstract: Prosaposin, a multifunctional protein, is the precursor of saposins, which activate sphingolipid hydrolases. In addition to acting as a precursor for saposins, prosaposin has been shown to rescue hippocampal CA1 neurons from lethal ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Here we show that prosaposin, when added to a collagen-filled nerve guide after sciatic nerve transection in guinea pigs, increased dramatically the number of regenerating nerve fibers within the guide. To identify the target neurons of prosaposin during peripheral nerve regeneration, we determined the degree of atrophy and chromatolysis of neurons in the spinal anterior horn and dorsal root ganglia on the prosaposin-treated and untreated side. The effect of prosaposin on large spinal neurons and small neurons of the dorsal root ganglion was more conspicuous. Subsequent immunohistochemistry demonstrated that the atrophy of cholinergic large neurons in the anterior horn is prevented to significant extent by prosaposin treatment. These findings suggest that prosaposin promotes peripheral nerve regeneration by acting on α-motor neurons in the anterior horn and on small sensory neurons in the dorsal root ganglion. The present study raises the possibility of using prosaposin as a tool for the treatment of peripheral nerve injuries. 相似文献
5.
S. Shiga H. Numata 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1996,179(5):625-633
The band-legged ground cricket Pteronemobius nigrofasciatus shows a clear photoperiodic response at 25°C with respect to the control of the induction of embryonic diapause. When crickets were reared under a short-day (LD 12 12) photoperiod and then transferred to a long-day (LD 16 8) photoperiod upon adult emergence, the adults mainly laid nondiapause eggs. However, adults maintained continuously under short-day conditions laid dispause eggs. When compound eyes were bilaterally removed after adult emergence, the crickets mainly laid nondiapause eggs, irrespective of the photoperiod. Thus, the adults completely lost their sensitivity to photoperiod after bilateral removal of their compound eyes. Unilateral removal of the compound eye also affected the crickets under a short-day photoperiod, and the incidence of diapause eggs was intermediate between that laid by intact adults and that laid by adults after the bilateral removal of compound eyes. The incidence of diapause eggs in sham-operated crickets was not significantly different from that in intact crickets under both sets of photoperiodic conditions. These results show that P. nigrofasciatus perceives the photoperiod through its compound eyes. 相似文献
6.
Food habits of sika deer on the Boso Peninsula,central japan 总被引:6,自引:0,他引:6
The rumen contents of sika deer (Cervus nippon Temminck) on the Boso Peninsula, central Japan, were analyzed to identify local, sexual and age-specific differences in food
habits. Graminoids and woody plants were the primary foods throughout the year. In winter, the use of evergreen broad leaves
increased. The food habits of sika deer on Boso Peninsula were intermediate between those of populations inhabiting northern
and southern Japan. Acorns, mainlyLithocarpus edulis Nakai, were consumed in fall and winter with a peak in October. Since the availability of acorns is not influenced by foraging
in previous years, it can be regarded as a stable food supply and hence may be important for deer on the Boso Peninsula. The
local difference between the Amatsukominato (AT) area, having a large plantation ofLithocarpus producing acrons, and the Kamogawa-Katsuura (KK) area, having a small plantation ofLithocarpus, was recognized; seeds and fruit were consumed more in AT than in KK in fall and winter. Males consumed more seeds and fruit
than females at both sites in fall. This can be attributed to sexual differences in nutritional requirement. 相似文献
7.
Takeo Uchiyama Masuro Numata Seiji Terada Tsutomu Hosino 《Plant Cell, Tissue and Organ Culture》1993,32(2):153-159
A suspension culture of Mentha was established from callus which formed on the tips of young shoots of a Mentha hybrid (M. arvenis × M. spicata). Changes in growth parameters during a culture cycle were recorded. The general appearance of cells during division and growth, including the changes in cell form, was also represented.Suspension-cultured cells of Mentha hybrid released a large amount of extracellular polysaccharides (ECP) mainly at the logarithmic phase of the growth cycle. The ECP contained galacturonic acid as major components and arabinose, galactose, glucose, xylose, rhamnose and mannose as minor components. The ratio of the uronic acid content to total sugar content in the ECP was below 40% at day 7, but increased up to 90% at day 21. The relative contents of xylose and glucose in the ECP decreased during the culture period, while the arabinose content increased and those of rhamnose, mannose and galactose remained constant.The IR spectrum suggested that the ECP were low-methoxylated pectic polysaccharides. The presence of lignin and related compounds in the ECP was not detected. The protein content of the ECP was about 10% and the main amino acids were alanine, proline, hydroxyproline, valine, asparticacid and serine, in that order. 相似文献
8.
Yoshihiro Takasugi Keiji Kawata Takahiko Okuda Yoshihisa Koga Nobuyuki Mizuguchi Shigeaki Yamanaka Shinsuke Watanabe 《Experimental Animals》2003,52(5):429-432
Age-related alterations and differences of weights and those of amino acid concentrations in the cerebrospinal fluid (CSF) were evaluated between Sprague Dawley (SD) rats and Wistar Kyoto (WKY) rats from eight to twenty weeks of age. The weights of SD rats were heavier than WKY rats at all ages. The age-related alterations of the CSF concentration of many amino acids within each strain were significant but showed no significant trend with age. Between the strains, the concentration differences of excitatory and inhibitory amino acids were not frequent although the concentrations of arginine, alanine and threonine were significantly higher in SD rats than in WKY rats. These results suggest that the different CSF concentrations of amino acids may relate to characteristics of rat strains. 相似文献
9.
10.