We have isolated a human cDNA clone encoding a novel acidic protein of MW 55,000 that we designated “myocilin” since it has homology to myosin and is localized preferentially in the ciliary rootlet and basal body of the connecting cilium of photoreceptor cells. The deduced amino acid sequence of human myocilin showed significant homologies with nonmuscle myosin ofDictyostelium discoideumin the N-terminal region and also with olfactomedin of bullfrog in the C-terminal region. Myocilin contained a leucine zipper-like motif similar to that seen in kinectin and other cytoskeletal proteins. These findings suggest that myocilin is a novel cytoskeletal protein involved in the morphogenesis of ciliated neuroepithelium such as photoreceptor cells. The myocilin gene (MYOC) was mapped to human chromosome 1q23–q24 by fluorescencein situhybridization. 相似文献
Experimental conditions for efficient callus initiation from mangrove plants were investigated. As a source explant, leaf
ofBruguiera sexangula was used. Mangrove plant is one of the most famous woody plants which can grow at the salty area. The initiated callus can
be a suitable material for the investigation of salt tolerant mechanisms of mangrove plants.
Leaf pieces cultured in an Amino Acid medium supplemented with 2 μM 2,4-dichlorophenoxyacetic acid and 2 μMN-(2-chloro-4-pyridyl)-N′-phenylurea at 30 C developed calluses. Microscopic observation suggested that the callus was initiated from the tissue in
the vascular bundles in the leaf.
We also examined the effect of NaCl on callus initiation and short-term culture of the calluses on the leaves. Callus initiation
rate decreased with increasing NaCl concentration higher than 100 mM in the culture media. The medium containing 100 mM NaCl
produced the largest callus on the leaf, compared with higher or lower concentrations of NaCl. 相似文献
Understanding the factors shaping rare species’ current genetic diversity and structure, particularly the impact of recent anthropogenic pressures, is important in order to develop appropriate conservation strategies based on robust predictions. Thus, we have genotyped all 585 surviving individuals of Magnolia stellata from six remnant populations and seven isolated tree sites in northern Mie Prefecture, Japan, using nuclear and chloroplast microsatellites. Three genetic clusters were detected by STRUCTURE analysis, with an oldest divergence time between pairs within 25 generations according to coalescent analysis. We attribute this recent divergence to recent anthropogenic environmental changes. Evidence of only one significant recent migration event between pairs of the six populations was detected, indicating that most of the remnant populations are isolated now. Their future genetic status was predicted using Monte Carlo simulations, under four scenarios. It declined more than twice as rapidly in a scenario assuming variations in fecundity among both female and male parents than in a scenario assuming no fecundity variations, but strongly improved in a scenario including promotion of migrations between adjacent pairs of populations. These predictions indicate that sexual reproduction of the species should be promoted by providing more suitable habitats and migration between populations should be enhanced by restoring remnant isolated tree sites and extinct populations. In addition, all the remnant populations should be conserved because they host current genetic variation that may be important for coping with future climate change, and they could provide important stepping-stones for gene flow. 相似文献
To ensure the persistence of populations and species that maintain unique biodiversity in suburban landscapes, it is necessary to establish an efficient management system for abandoned suburban secondary forests. Thinning operations seem to be an effective management approach to inhibiting the progress of forest succession, which could lower the level of species diversity. To evaluate the effect of thinning operations on the demographic performance (growth, survival, and sexual reproduction) of the rare subtree species Magnolia stellata, we set up a field experiment and monitored the population dynamics over 9 years. The results revealed that stem survival and flower production per genet showed a decreasing trend in the nonthinned site. However, thinning operations increased the demographic performance, in particular the stem growth and survival rates as well as flower and seed production. The findings suggested that thinning operations may decrease the extinction probability of not only the targeted local population but also the metapopulation, because the thinned population serves as a better seed source. Thus, the creation of well-lit sites by thinning operations would be a useful conservation strategy for M.stellata. 相似文献
Endo-β-N-acetylglucosaminidase D from Diplococcus pneumoniae released galactosyl oligosaccharides from IgG glycopeptides treated with β-N-acetylglucosaminidase. The structure of the major oligosaccharide was proposed to be as follows.Since α-mannosidase digestion of the β-N-acetylglucosaminidase-treated glycopeptides made them again resistant to the endoglycosidase, we concluded that an unsubstituted α-mannosyl residue was required for the enzymic action. 相似文献
A temperature-sensitive respiration-deficient mutant of yeast lacks hemoproteins and accumulates coproporphyrin III when cultivated at elevated temperatures. Cells grown at 20 C respired normally and contained cytochromes a, b, and c. Cells grown at 35 C showed respiration-deficient mutant characters; they did not respire, lacked cytochromes, and accumulated coproporphyrin III. Addition of protoporphyrin IX or protohemin IX to the culture medium restored the respiratory activity of this mutant during growth at 35 C. The activities of various enzymes, including succinate-2,6-dichlorophenol indophenol (DCPIP), reduced nicotinamide adenine dinucleotide (NADH(2))-DCPIP, succinate-cytochrome c, and NADH(2)-cytochrome c oxidoreductase, and cytochrome oxidase, and the cytochrome c content of cells cultured in various conditions were determined. Changes in the number and structure of mitochondria were associated with changes in respiratory activity. 相似文献
Summary By direct genomic sequencing, we have delineated the causative mutation in 64 families of European descent with hemophilia B. Six (9%) had a CT transition at base 31008, which substitutes methionine for threonine 296 (T296M) in the catalytic domain of factor IX. Five of the patients had the same haplotype (frequency of 16% in the northern European population). These individuals are of Amish/German descent and they are likely to share a common ancestor. The sixth patient had a different haplotype, which indicates that his mutation had an independent origin. The data highlight the importance of clinical criteria for the classification of hemophilia B. All six patients had clinically mild disease and their factor IX coagulant activities were in the range of 3%–6% when tested simultaneously in one laboratory, yet the factor IX activities provided with patient records varied 40-fold. Due to the high frequency of this mutation, we have utilized the technique of polymerase chain reaction amplification of specific alleles (PASA) to perform rapid and inexpensive carrier diagnoses in the families with this mutation. This is of particular importance for the Amish since the mutation should account for much of, if not all, the mild hemophilia B that is commonly found in this population. 相似文献