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151.
152.
Abstract Mass mortalities of fauna are known to occur in estuarine environments during flood events. Specific factors associated with these mortalities have rarely been examined. Therefore, the effect of exposing, to lowered salinities, an infaunal bivalve that is susceptible to mass mortalities during winter flooding in a southern Australian estuary was tested in the present study. In a laboratory experiment, low salinities (≤6 parts per thousand [ppt]), which mimicked those expected during flood events in the Hopkins River estuary, were shown to affect Soletellina alba, both lethally and sublethally. All bivalves died at 1 ppt, while those at 6 ppt took longer to burrow and exhibited a poorer condition than those at 14 and 27 ppt. The limited salinity tolerance of S. alba suggests that lowered salinities are a likely cause of mass mortality for this species during winter flooding. 相似文献
153.
Yoshihiro Sasaki Yuka Shioyama Wen‐Jie Tian Jun‐ichi Kikuchi Satoshi Hiyama Yuki Moritani Tatsuya Suda 《Biotechnology and bioengineering》2010,105(1):37-43
This paper describes construction of a nanosensory device for amplified detection of biologically important amines as chemical signals. The device was inspired by a biological signal transduction system, and was fabricated on an artificial cell membrane through self‐organization of the molecular components, such as a synthetic receptor and a natural enzyme. Selective recognition of biologically important amines was achieved by a synthetic receptor with a pyridoxal moiety, as evaluated by means of electronic absorption spectroscopy. The selectivity in detecting amines as chemical signals mainly depends on hydrophobicity of the amines. The event upon detecting the chemical signals was transmitted to an enzyme by a metal ion acting as a mediator species, and then the enzyme amplified the event by the catalytic reaction to obtain signal output. This paper is realization of a biomimetic signal transduction system using amines as chemical signals and may provide a useful guidepost for designing integrated nanosystems. Biotechnol. Bioeng. 2010;105: 37–43. © 2009 Wiley Periodicals, Inc. 相似文献
154.
Development of the gametophytes of a rehophytic fernOsmunda lancea and a related dryland speciesO. japonica was examined, and adaptation ofO. lancea gametophytes to rheophytic habitat was discussed. The spores ofO. lancea were larger in size and contained larger oil droplets than those ofO. japonica. The germination rate was similar. In agar culture,O. lancea gametophytes grew more rapidly and reached reprudctive maturity earlier thanO. japonica, although there was no prominent gross-morphological difference in developing and mature gametophytes. Sporophyte formation
ofO. lancea took place at roughly two times higher rate than that ofO. japonica. TheO. lancea gametophytes might be adapted to the periodically flooded habitat by shortening its life, which is a different strategy from
that of the sporophytic generation. 相似文献
155.
156.
An improved method for the detection of genetic variations in DNA with denaturing gradient gel electrophoresis 总被引:5,自引:0,他引:5
We have examined the feasibility of denaturing gradient gel electrophoresis (DGGE) of RNA:DNA duplexes to detect variations in genomic and cloned DNAs. The result has demonstrated that employment of RNA:DNA duplexes makes DGGE much more practical for screening a large number of samples than that of DNA:DNA heteroduplexes originally developed by Lerman et al. (1986), because preparation of RNA probes is easier than that of DNA probes. Three different 32P-labeled RNA probes were produced. Genomic or cloned DNAs were digested with restriction enzymes and hybridized to labeled RNA probes, and resulting RNA:DNA duplexes were examined by DGGE. The presence of mismatch(es) was detected as a difference in mobility of bands on the gel. The experimental conditions were determined using DNA segments from cloned normal and 3 thalassemic human beta-globin genes. The results of the experiments on the cloned DNAs suggest that DGGE of RNA:DNA duplexes will detect nucleotide substitutions and deletions in DNA. In the course of these studies, a polymorphism due to a single-base substitution at position 666 of IVS2 (IVS2-666) of the human beta-globin gene was directly identified using genomic DNA samples. A study of 59 unrelated Japanese from Hiroshima was made in which the frequency of the allele with C at IVS2-666 was 0.48 and that of the allele with T was 0.52. This approach was found to be very effective for the detection of heritable variation and should be a powerful tool for the detection of fresh mutations in DNA, which occur outside the known restriction sites. 相似文献