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971.
C. Anwyl Cooper-Willis Joan C. Olson Mary E. Brewer Gerrie A. Leslie 《Immunogenetics》1985,21(1):1-10
The immune response of the rat to group A streptococcal carbohydrate (SACHO) and an associated idiotype, Id-1, was used to examine the effect of paternal immunity on Id-1 and SACHO-specific antibody expression by the offspring. First litters, conceived before immunization of the father, had significantly higher Id-1 levels than litters conceived by the same parental pairs after hyperimmunization of the father (P > 0.01). Total anti-SACHO levels were not affected. The effect appeared to be independent of the level of Id-1 expressed by the father or grandfather. No significant difference in Id-1 production was found between offspring of actively immune, neonatally Id-1 suppressed fathers and fathers expressing high levels of Id-1. We suggest that the paternal immunoregulatory influence acts via the maternal immune system to modify the idiotype repertoire expressed in the immune response of the offspring, and is not the result of genetic transmission of a trait acquired by the father. Some possible mechanisms of transmission are discussed. 相似文献
972.
Stimulated overflow of dopamine (DA) into the extracellular fluid of the rat caudate nucleus was measured with fast-scan cyclic voltammetry. DA concentrations were sampled in less than 10 ms at 100-ms intervals with a Nafion-coated, carbon-fiber microelectrode. Overflow of DA was induced by electrical stimulation of the medial forebrain bundle with 300-microA pulses of various duration and frequency. Stimulated overflow was measured as a function of stimulus duration before and after administration of benztropine, bupropion, and amphetamine. These results were correlated with simulated curves based on a simple uptake/overflow model. The observed overflow was assumed to be a function of [DA]p, the concentration of DA which overflows per stimulus pulse, and the kinetics of cellular uptake of DA. Correlation of experimental with stimulated results was obtained at the 95% confidence limit for the duration studies; however, it was not possible to distinguish between the effects of pharmacological agents on uptake and overflow. In contrast, modulation of stimulus frequency did permit such distinction. Simulations of an increase in [DA]p fit results following dihydroxyphenylalanine methyl ester at 95% confidence limits, whereas an equivalent change in the apparent Km did not fit. An increase in the apparent value of Km correlated with results obtained at different frequencies following nomifensine and bupropion administration at the 95% confidence limit, whereas an equivalent increase in [DA]p did not fit. The effects of GBR 12909 best correlated with an increase in the DA available for overflow. 相似文献
973.
Salicylic acid inhibited ethylene formation from ACC in self-buffered (pH 3.8) pear (Pyrus communis) cell suspension cultures with a K1app of about 10 micromolar after 1 to 3 hours incubation. Inhibition appeared noncompetitive. Among 22 related phenolic compounds tested, only acetylsalicylic acid showed similar levels of inhibition. Inhibition by salicylic acid was inversely dependent on the pH of the culture medium and did not require a continuous external supply of salicylate. When compared to known inhibitors of the ethylene forming enzyme, cobalt, n-propyl gallate, and dinitrophenol, inhibition by salicylic acid most closely resembled that by dinitrophenol but salicylic acid did not produce the same degree of respiratory stimulation. Results are discussed in terms of other known effects of salicylic acid on plants, pH-dependency, and the possible influence of salicylic acid on electron transport. 相似文献
974.
A E Desjardins R D Plattner D D Shackelford J F Leslie P E Nelson 《Applied and environmental microbiology》1992,58(9):2799-2805
Fumonisins are mycotoxins produced by strains belonging to several different mating populations of Gibberella fujikuroi (anamorphs, Fusarium section Liseola), a major pathogen of maize and sorghum worldwide. We studied the heritability of fumonisin production in mating population A by crossing fumonisin-producing strains collected from maize and sorghum in the United States with fumonisin-nonproducing strains collected from maize in Nepal. Random ascospore and tetrad progeny from three of these crosses were analyzed by gas chromatography-mass spectrometry and high-performance liquid chromatography for their ability to produce fumonisins on autoclaved cracked maize. In all three crosses, the ability to produce fumonisins, predominately fumonisin B1, segregated as a single gene or group of closely linked genes. Intercrosses between appropriate progeny and parents were poorly fertile, so we could not determine if the apparent single genes that were segregating in each of these crosses were allelic with one another. Mating type and spore-killer traits were scored in some crosses, and each segregated, as expected, as a single gene that was unlinked to the ability to produce fumonisins. We conclude that G. fujikuroi mating population A provides a powerful genetic system for the study of this important fungal toxin. 相似文献
975.
Fate of DNA encoding hygromycin resistance after meiosis in transformed strains of Gibberella fujikuroi (Fusarium moniliforme). 总被引:3,自引:2,他引:1
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Stability of foreign DNA transformed into a novel host is an important parameter in decisions to permit the release of genetically engineered microorganisms into the environment. Meiotic instability of transformed DNA has been reported in fungi such as Ascobolus, Aspergillus, and Neurospora. We used strains of Gibberella fujikuroi (Fusarium moniliforme) transformed with the hygr gene from Escherichia coli to study meiotic stability of foreign DNA in this plant pathogenic fungus. Crosses with single-copy transformants segregated hygr:hygs in a 1:1 manner consistent with that expected for a Mendelian locus in a haploid organism. Multicopy transformants, however, segregated hygr:hygs in a 1:2 manner that was not consistent with Mendelian expectations for a chromosomal marker, even though two unrelated auxotrophic nuclear genes were segregating normally. Segregation ratios in crosses in which hygr was introduced via the male parent did not differ significantly from crosses in which the transformed strain served as the female parent. Some of the sensitive progeny from the crosses with the multicopy transformants carried hygr sequences. When these phenotypically sensitive progeny were crossed with a wild-type strain that carried no hygr sequences, some of the progeny were phenotypically hygr. Some progeny from some crosses were more resistant to hygromycin than were their sibs or the transformant strains that served as their parents. Transformants passaged through a maize plant only rarely segregated progeny with the high levels of resistance. The mechanism underlying these genetic instabilities is not clear but may involve unequal crossing over or methylation or both. Further work with cloned genes with homology to sequences already present in the Fusarium genome is warranted. 相似文献
976.
Steven J. Pittler Leslie P. Kozak John E. Wilson 《Biochimica et Biophysica Acta (BBA)/General Subjects》1985,843(3)
Hexokinase (ATP: D-hexose 6-phosphotransferase, EC 2.7.1.1) has been synthesized in the rabbit reticulocyte lysate system directed by poly(A)+ mRNA isolated from rat brain. Identification of the in vitro synthesis product as hexokinase was based on its immunoprecipatation with anti-hexokinase serum as well as the generation of identical peptide maps after partial cleavage of the in vitro product and authentic hexokinase with Staphylococcus aureus V8 proteinase or chymotrypsin. The in vitro product and authentic hexokinase were indistinguishable in molecular weight (SDS-gel electrophoresis); thus, despite the fact that, in situ, much of the hexokinase in brain is found in association with mitochondria, it is not synthesized in the form of a higher molecular weight precursor as is characteristic of other mitochondrial proteins. This is in accord with the view that hexokinase is best considered as a classical ‘soluble’ enzyme which is capable of exhibiting reversible association with mitochondria. The in vitro product cochromatographs (during anion-exchange HPLC) with authentic hexokinase previously shown to have a blocked (presumably acetylated) N-terminus; this procedure is capable of resolving the N-terminally blocked form of the enzyme from a partially proteolyzed form having a free N-terminal amino group. Thus the in vitro product is apparently N-acetylated by an enzyme system previously shown to be present in reticulocyte lysates. A significant fraction of the in vitro synthesized hexokinase attained a conformation characteristic of the native enzyme as judged by the observations that (1) it could be immunoprecipitated by monoclonal antibodies recognizing the native enzyme but not by antibodies recognizing denatured hexokinase, and (2) limited tryptic cleavage of the in vitro product gave fragments identical to those seen with the native enzyme and thought to reflect the organization of structural domains in that enzyme. However, based on these same criteria, the majority of the hexokinase synthesized in vitro appears to exist in a folding state that is not identical to that of either the fully denatured or native enzyme. 相似文献
977.
Measurements of auto‐antibodies to α‐synuclein in the serum and cerebral spinal fluids of patients with Parkinson's disease
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Rizwan S. Akhtar Joseph P. Licata Kelvin C. Luk Leslie M. Shaw John Q. Trojanowski Virginia M.‐Y. Lee 《Journal of neurochemistry》2018,145(6):489-503
978.
Jayanthi Nagappan Chiew Foan Chin Lee Pei Lee Angel Richard M. Cooper Sean T. May Eng-Ti Leslie Low 《Biotechnology letters》2018,40(11-12):1541-1550
979.
RBM10 is an RNA binding motif (RBM) protein expressed in most, if not all, human and animal cells. Interest in RBM10 is rapidly increasing and its clinical importance is highlighted by its identification as the causative agent of TARP syndrome, a developmental condition that significantly impacts affected children. RBM10's cellular functions are beginning to be explored, with initial studies demonstrating a tumor suppressor role. Very recently, however, contradictory results have emerged, suggesting a tumor promoter role for RBM10. In this review, we describe the current state of knowledge on RBM10, and address this dichotomy in RBM10 function. Furthermore, we discuss what may be regulating RBM10 function, particularly the importance of RBM10 alternative splicing, and the relationship between RBM10 and its paralogue, RBM5. As RBM10‐related work is gaining momentum, it is critical that the various aspects of RBM10 molecular biology revealed by recent studies be considered moving forward. It is only if these recent advances in RBM10 structure and function are considered that a clearer insight into RBM10 function, and the disease states with which RBM10 mutation is associated, will be gained. 相似文献
980.
Local and cross‐seasonal associations of climate and land use with abundance of monarch butterflies Danaus plexippus
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Sarah P. Saunders Leslie Ries Karen S. Oberhauser Wayne E. Thogmartin Elise F. Zipkin 《Ecography》2018,41(2):278-290
Quantifying how climate and land use factors drive population dynamics at regional scales is complex because it depends on the extent of spatial and temporal synchrony among local populations, and the integration of population processes throughout a species’ annual cycle. We modeled weekly, site‐specific summer abundance (1994–2013) of monarch butterflies Danaus plexippus at sites across Illinois, USA to assess relative associations of monarch abundance with climate and land use variables during the winter, spring, and summer stages of their annual cycle. We developed negative binomial regression models to estimate monarch abundance during recruitment in Illinois as a function of local climate, site‐specific crop cover, and county‐level herbicide (glyphosate) application. We also incorporated cross‐seasonal covariates, including annual abundance of wintering monarchs in Mexico and climate conditions during spring migration and breeding in Texas, USA. We provide the first empirical evidence of a negative association between county‐level glyphosate application and local abundance of adult monarchs, particularly in areas of concentrated agriculture. However, this association was only evident during the initial years of the adoption of herbicide‐resistant crops (1994–2003). We also found that wetter and, to a lesser degree, cooler springs in Texas were associated with higher summer abundances in Illinois, as were relatively cool local summer temperatures in Illinois. Site‐specific abundance of monarchs averaged approximately one fewer per site from 2004–2013 than during the previous decade, suggesting a recent decline in local abundance of monarch butterflies on their summer breeding grounds in Illinois. Our results demonstrate that seasonal climate and land use are associated with trends in adult monarch abundance, and our approach highlights the value of considering fine‐resolution temporal fluctuations in population‐level responses to environmental conditions when inferring the dynamics of migratory species. 相似文献