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61.
E. Jay DeRocher Francoise Quigley Regis Mache Hans J. Bohnert 《Molecular genetics and genomics : MGG》1993,239(3):450-462
The nucleotide sequences of the entire gene family, comprising six genes, that encodes the Rubisco small subunit (rbcS) multigene family in Mesembryanthemum crystallinum (common ice plant), were determined. Five of the genes are arranged in a tandem array spanning 20 kb, while the sixth gene is not closely linked to this array. The mature small subunit coding regions are highly conserved and encode four distinct polypeptides of equal lengths with up to five amino acid differences distinguishing individual genes. The transit peptide coding regions are more divergent in both amino acid sequence and length, encoding five distinct peptide sequences that range from 55 to 61 amino acids in length. Each of the genes has two introns located at conserved sites within the mature peptide-coding regions. The first introns are diverse in sequence and length ranging from 122 by to 1092 bp. Five of the six second introns are highly conserved in sequence and length. Two genes, rbcS-4 and rbcS-5, are identical at the nucleotide level starting from 121 by upstream of the ATG initiation codon to 9 by downstream of the stop codon including the sequences of both introns, indicating recent gene duplication and/or gene conversion. Functionally important regulatory elements identified in rbcS promoters of other species are absent from the upstream regions of all but one of the ice plant rbcS genes. Relative expression levels were determined for the rbcS genes and indicate that they are differentially expressed in leaves. 相似文献
62.
Arpana Agrawal Sarah J. Brislin Kathleen K. Bucholz Danielle Dick Ronald P. Hart Emma C. Johnson Jacquelyn Meyers Jessica Salvatore Paul Slesinger COGA Collaborators Laura Almasy Tatiana Foroud Alison Goate Victor Hesselbrock John Kramer Samuel Kuperman Alison K. Merikangas John I. Nurnberger Jay Tischfield Howard J. Edenberg Bernice Porjesz 《Genes, Brain & Behavior》2023,22(5):e12864
63.
Jérémy Gauthier Joana Meier Fabrice Legeai Melanie McClure Annabel Whibley Anthony Bretaudeau Hélène Boulain Hugues Parrinello Sam T. Mugford Richard Durbin Chenxi Zhou Shane McCarthy Christopher W. Wheat Florence Piron-Prunier Christelle Monsempes Marie-Christine François Paul Jay Camille Noûs Emma Persyn Emmanuelle Jacquin-Joly Camille Meslin Nicolas Montagné Claire Lemaitre Marianne Elias 《Molecular ecology resources》2023,23(4):872-885
The ithomiine butterflies (Nymphalidae: Danainae) represent the largest known radiation of Müllerian mimetic butterflies. They dominate by number the mimetic butterfly communities, which include species such as the iconic neotropical Heliconius genus. Recent studies on the ecology and genetics of speciation in Ithomiini have suggested that sexual pheromones, colour pattern and perhaps hostplant could drive reproductive isolation. However, no reference genome was available for Ithomiini, which has hindered further exploration on the genetic architecture of these candidate traits, and more generally on the genomic patterns of divergence. Here, we generated high-quality, chromosome-scale genome assemblies for two Melinaea species, M. marsaeus and M. menophilus, and a draft genome of the species Ithomia salapia. We obtained genomes with a size ranging from 396 to 503 Mb across the three species and scaffold N50 of 40.5 and 23.2 Mb for the two chromosome-scale assemblies. Using collinearity analyses we identified massive rearrangements between the two closely related Melinaea species. An annotation of transposable elements and gene content was performed, as well as a specialist annotation to target chemosensory genes, which is crucial for host plant detection and mate recognition in mimetic species. A comparative genomic approach revealed independent gene expansions in ithomiines and particularly in gustatory receptor genes. These first three genomes of ithomiine mimetic butterflies constitute a valuable addition and a welcome comparison to existing biological models such as Heliconius, and will enable further understanding of the mechanisms of adaptation in butterflies. 相似文献
64.
65.
Responses in stomatal conductance to elevated CO2 in 12 grassland species that differ in growth form
Responses in stomatal conductance (g
st
) and leaf xylem pressure potential (
leaf
) to elevated CO2 (2x ambient) were compared among 12 tallgrass prairie species that differed in growth form and growth rate. Open-top chambers (OTCs, 4.5 m diameter, 4.0 m in height) were used to expose plants to ambient and elevated CO2 concentrations from April through November in undisturbed tallgrass prairie in NE Kansas (USA). In June and August,
leaf
was usually higher in all species at elevated CO2 and was lowest in adjacent field plots (without OTCs). During June, when water availability was high, elevated CO2 resulted in decreased g
st
in 10 of the 12 species measured. Greatest decreases in g
st
(ca. 50%) occurred in growth forms with the highest potential growth rates (C3 and C4 grasses, and C3 ruderals). In contrast, no significant decrease in g
st
was measured in the two C3 shrubs. During a dry period in September, reductions in g
st
at elevated CO2 were measured in only two species (a C3 ruderal and a C4 grass) whereas increased g
st
at elevated CO2 was measured in the shrubs and a C3 forb. These increases in g
st
were attributed to enhanced
leaf
in the elevated CO2 plants resulting from increased soil water availability and/or greater root biomass. During a wet period in September, only reductions in g
st
were measured in response to elevated CO2. Thus, there was significant interspecific variability in stomatal responses to CO2 that may be related to growth form or growth rate and plant water relations. The effect of growth in the OTCs, relative to field plants, was usually positive for g
st
and was greatest (>30%) when water availability was low, but only 6–12% when
leaf
was high.The results of this study confirm the importance of considering interactions between indirect effects of high CO2 of plant water relations and direct effects of elevated CO2 on g
st
, particularly in ecosystems such as grasslands where water availability often limits productivity. A product of this interaction is that the potential exists for either positive or negative responses in g
st
to be measured at elevated levels of CO2. 相似文献
66.
M. G. Hilton A. Jay M. J. C. Rhodes P. D. G. Wilson 《Applied microbiology and biotechnology》1995,43(3):452-459
This paper reports studies on the growth and biosynthesis of monoterpenes by transformed shoot cultures of Mentha citrata and Mentha piperita, originally developed 5 years ago and since maintained by regular subculturing. Throughout this time, the M. citrata culture has stably maintained production of an oil closely resembling that of the parent plant in which linalool and linalyl acetate are the predominant components. However, M. piperita, which initially showed a divergence from the parent plant in producing significant amounts of menthofuran in addition to the characteristic oil components menthol and menthone, has now been found to produce pulegone and menthofuran as the major components. The cultures were subjected to different environmental conditions of varying periods of light and temperature in an attempt to restore menthol and menthone production. Increased illumination reduced the yields of pulegone and menthofuran but did not stimulate the production of either menthol or menthone, which remained only at trace levels (below 0.2 g/g fresh weight). Cultures of M. citrata were, however, stimulated by increased illumination, and produced more linalool and linalyl acetate. Shoot cultures of M. citrata and M. piperita were grown in 14–1 fermenters for up to 60 dys during which the biomass increased from approximately 100 g to 2.5 kg and 3.5 kg respectively. Both cultures rapidly consumed sucrose with a concomitant release of glucose, and the uptake of inorganic ions was similar except that M. citrata consumed far less Na+ during the fermentation. The total yields of monoterpenes from the fermentations were 1.16 g (M. piperita) and 0.18 g (M. citrata). *** DIRECT SUPPORT *** AG903062 00005 相似文献
67.
Superoxide dismutase activity of the captopril-iron complex 总被引:2,自引:0,他引:2
With an assay that generates superoxide anion radicals without the intervention of metal ions we investigated the antioxidant properties of captopril, an angiotensin-converting enzyme inhibitor with a sulfhydryl group. Under these conditions, increasing concentrations of the drug were seen not to scavenge O·
2
–
directly. However, a combination of captopril and iron could bring about the breakdown of the superoxide anion; a result that may help to understand the free radical-scavenging properties of captopril. 相似文献
68.
Jay K. Thakkar David R. Janero Haamid M. Sharif Craig Yarwood 《Molecular and cellular biochemistry》1995,145(2):177-183
A sheep antiserum against purified rabbit-heart adenylate deaminase (EC 3.5.4.6) (AMPD) was developed and validated as an immunologic probe to assess the cross-species tissue distribution of the mammalian cardiac AMPD isoform. The antiserum and the antibodies purified therefrom recognized both native and denatured rabbit-heart AMPD in immunoprecipitation and immunoblot experiments, respectively, and antibody binding did not affect native enzyme activity. The immunoprecipitation experiments further demonstrated a high antiserum titer. Immunoblot analysis of either crude rabbit-heart extracts or purified rabbit-heart AMPD revealed a major immunoreactive band with the molecular mass (81 kDa) of the soluble rabbit-heart AMPD subunit. AMPD in heart extracts from mammalian species other than rabbit (including human) was equally immunoreactive with this antiserum by quantitative immunoblot criteria. Although generally held to be in the same isoform class as heart AMPD, erythrocyte AMPD was not immunoreactive either within or across species. Nor was AMPD from most other tissues [e.g., white (gastrocnemius) muscle, lung, kidney] immunoreactive with the cardiac-directed antibody. Limited immunoreactivity was evidenced by mammalian liver, red (soleus) muscle, and brain extracts across species, indicating the presence of a minor cardiac(-like) AMPD isoform in these tissues. The results of this study characterize the tissue distribution of the cardiac AMPD isoform using a molecular approach with the first polyclonal antibodies prepared against homogeneous cardiac AMPD. This immunologic probe should prove useful at the tissue level for AMPD immunohistochemistry. 相似文献
69.
70.
William E. Klunk Chong-Jun Xu Richard J. McClure Kanagasabai Panchalingam Jeff A. Stanley Jay W. Pettegrew 《Journal of neurochemistry》1997,69(1):266-272
Abstract: Increased amounts of β-amyloid (Aβ) peptide deposits are found in Alzheimer's disease brain. These amyloid deposits have been implicated in the pathophysiology of this common dementing illness. Aβ peptides have been shown to be toxic to neurons in cell culture, and this toxicity is critically dependent on the aggregation of the peptide into cross-β-pleated sheet fibrils. Also, in vivo and postmortem NMR studies have shown changes in certain brain membrane phospholipid metabolites in normal aging and more extensive alterations in patients with Alzheimer's disease. The finding that membrane phospholipids affect the aggregation of Aβ suggests that the abnormalities in membrane metabolism found in Alzheimer's disease could affect the deposition of Aβ in vivo. Therefore, we examined the effect of membrane phospholipid metabolites that are altered in Alzheimer's disease brain on the aggregation of Aβ(1–40) using a light scattering method. Certain metabolites (glycerophosphocholine, glycerophosphoethanolamine, and α-glycerophosphate) augment the aggregation of Aβ. Other membrane phospholipid metabolites (phosphocholine, phosphoethanolamine, and inositol-1-phosphate) have no effect. We conclude that increased membrane phospholipid metabolite concentrations may play a role in the deposition of Aβ seen in normal aging and the even greater deposition of Aβ observed in Alzheimer's disease. 相似文献