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61.
Among songbirds, growing evidence suggests that acoustic adaptation of song traits occurs in response to habitat features. Despite extensive study, most research supporting acoustic adaptation has only considered acoustic traits averaged for species or populations, overlooking intraindividual variation of song traits, which may facilitate effective communication in heterogeneous and variable environments. Fewer studies have explicitly incorporated sexual selection, which, if strong, may favour variation across environments. Here, we evaluate the prevalence of acoustic adaptation among 44 species of songbirds by determining how environmental variability and sexual selection intensity are associated with song variability (intraindividual and intraspecific) and short-term song complexity. We show that variability in precipitation can explain short-term song complexity among taxonomically diverse songbirds, and that precipitation seasonality and the intensity of sexual selection are related to intraindividual song variation. Our results link song complexity to environmental variability, something previously found for mockingbirds (Family Mimidae). Perhaps more importantly, our results illustrate that individual variation in song traits may be shaped by both environmental variability and strength of sexual selection. 相似文献
62.
In yeast, DNA polymerase zeta (Rev3 and Rev7) and Rev1, involved in the error-prone translesion synthesis during replication of nuclear DNA, localize also in mitochondria. We show that overexpression of Rev3 reduced the mtDNA extended mutability caused by a subclass of pathological mutations in Mip1, the yeast mitochondrial DNA polymerase orthologous to human Pol gamma. This beneficial effect was synergistic with the effect achieved by increasing the dNTPs pools. Since overexpression of Rev3 is detrimental for nuclear DNA mutability, we constructed a mutant Rev3 isoform unable to migrate into the nucleus: its overexpression reduced mtDNA mutability without increasing the nuclear one. 相似文献
63.
Bruzzone S Bodrato N Usai C Guida L Moreschi I Nano R Antonioli B Fruscione F Magnone M Scarfì S De Flora A Zocchi E 《The Journal of biological chemistry》2008,283(47):32188-32197
Abscisic acid (ABA) is a plant stress hormone recently identified as an endogenous pro-inflammatory cytokine in human granulocytes. Because paracrine signaling between pancreatic beta cells and inflammatory cells is increasingly recognized as a pathogenetic mechanism in the metabolic syndrome and type II diabetes, we investigated the effect of ABA on insulin secretion. Nanomolar ABA increases glucose-stimulated insulin secretion from RIN-m and INS-1 cells and from murine and human pancreatic islets. The signaling cascade triggered by ABA in insulin-releasing cells sequentially involves a pertussis toxin-sensitive G protein, cAMP overproduction, protein kinase A-mediated activation of the ADP-ribosyl cyclase CD38, and cyclic ADP-ribose overproduction. ABA is rapidly produced and released from human islets, RIN-m, and INS-1 cells stimulated with high glucose concentrations. In conclusion, ABA is an endogenous stimulator of insulin secretion in human and murine pancreatic beta cells. Autocrine release of ABA by glucose-stimulated pancreatic beta cells, and the paracrine production of the hormone by activated granulocytes and monocytes suggest that ABA may be involved in the physiology of insulin release as well as in its dysregulation under conditions of inflammation. 相似文献
64.
Oxygen-dependent transcriptional regulator Hap1p limits glucose uptake by repressing the expression of the major glucose transporter gene RAG1 in Kluyveromyces lactis
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Bao WG Guiard B Fang ZA Donnini C Gervais M Passos FM Ferrero I Fukuhara H Bolotin-Fukuhara M 《Eukaryotic cell》2008,7(11):1895-1905
65.
Schadt EE Molony C Chudin E Hao K Yang X Lum PY Kasarskis A Zhang B Wang S Suver C Zhu J Millstein J Sieberts S Lamb J GuhaThakurta D Derry J Storey JD Avila-Campillo I Kruger MJ Johnson JM Rohl CA van Nas A Mehrabian M Drake TA Lusis AJ Smith RC Guengerich FP Strom SC Schuetz E Rushmore TH Ulrich R 《PLoS biology》2008,6(5):e107
66.
Diabetes during pregnancy results in congenital malformations
and long-term postnatal diseases. Experimental
models are still needed to investigate the mechanism
responsible for these alterations. Thus, by the administration
of different doses of streptozotocin (STZ) (0, 25,
30, or 35 mg/kg body weight, intravenous) at the onset
of pregnancy in rats, the present study sought an appropriate
animal model for this pathology. At day 6 of pregnancy,
plasma glucose was progressively higher with an increasing
STZ dose, and in rats receiving the 35-mg dose,
2 subgroups were detected: some animals had plasma glucose
levels above controls but below 200 mg/dL (mildly diabetic,
MD), whereas others had levels above 400 mg/dL
(severely diabetic, SD). At day 20 of pregnancy, the MD
rats had normal glycemia, but after an oral glucose load
(2 g/kg body weight), plasma glucose increased more and
insulin increased less than in controls. The SD rats maintained
their hyperglycemia and had a greatly impaired
oral glucose tolerance. At day 20, fetuses of SD dams were
fewer, weighed less, and had enhanced plasma glucose and
triglycerides and decreased insulin, whereas those from
MD dams did not differ from controls. At birth, newborns
from MD dams had higher body weight, plasma insulin,
and liver triglycerides as well as total body lipid concentrations
than controls, and on day 21, remained macrosomic and showed higher plasma glucose and liver triglyceride
concentrations. At 70 days of age, offspring of MD dams had
impaired oral glucose tolerance but normal plasma insulin
change in the case of females, whereas plasma insulin increased
less in males. These alterations were manifest more
in those offspring from dams that had > 50% macrosomic
newborns than in those from dams that had < 50% macrosomic
newborns. In conclusion, whereas our MD rats mimic
the changes taking place in gestational diabetic women and
show the long-term risk of macrosomia, the SD rats are
more similar to uncontrolled diabetics. Thus these two rat
models, obtained with moderate amounts of STZ, could be
used to study the pathophysiological consequences of these
different diabetic conditions. 相似文献
67.
Marco A. Flores-Méndez Zila Martínez-Lozada Hugo C. Monroy Luisa C. Hernández-Kelly Iliana Barrera Arturo Ortega 《Neurochemical research》2013,38(7):1324-1332
Glutamate (Glu), the major excitatory amino acid, activates a wide variety of signal transduction cascades. Synaptic plasticity relies on activity-dependent differential protein expression. Glu receptors have been critically involved in long-term synaptic changes, although recent findings suggest that Na+-dependent Glu transporters participate in Glu-induced signalling. Within the cerebellum, Bergmann glia cells are in close proximity to glutamatergic synapses and through their receptors and transporters, sense and respond to neuronal glutamatergic activity. Translational control represents the fine-tuning stage of protein expression regulation and Glu modulates this event in glial cells. In this context, we decided to explore the involvement of Glu receptors and transporters in the regulation of the initiation phase of protein synthesis. To this end, Bergmann glia cells were exposed to glutamatergic ligands and the serine 51-phosphorylation pattern of the main regulator of the initiation phase of translation, namely the α subunit of eukaryotic initiation factor 2 (eIF2α), determined. A time and dose-dependent increase in eIF2α phosphorylation was detected. The signalling cascade included Ca2+ influx, activation of the Ca2+/calmodulin-dependent protein kinase II and protein kinase C. These results provide an insight into the molecular targets of the Glu effects at the translational level and strengthen the notion of the critical involvement of glia cells in glutamatergic synaptic function. 相似文献
68.
69.
Atanasova I Kabadjova P Bogatzevska N Moncheva P 《Zeitschrift für Naturforschung. C, Journal of biosciences》2005,60(11-12):893-898
Nine strains of Erwinia amylovora were isolated from new host plants in Bulgaria--chokeberry and strawberry. The strains were characterized morphologically and biochemically using the API 20E and BIOLOG system. It was established that they showed three different API 20E metabolic profiles, not found by previous studies of E. amylovora. All strains were identified as E. amylovora due to their metabolic fingerprint patterns obtained by the BIOLOG system. The identification was confirmed by PCR amplification of a specific region of plasmid pEA29 and genome ams-region. This study is the first characterization and identification of E. amylovora strains isolated from chokeberry and strawberry by the API 20E and BIOLOG system and by polymerase chain reaction. 相似文献
70.
Drees BL Thorsson V Carter GW Rives AW Raymond MZ Avila-Campillo I Shannon P Galitski T 《Genome biology》2005,6(4):R38
We have generalized the derivation of genetic-interaction networks from quantitative phenotype data. Familiar and unfamiliar modes of genetic interaction were identified and defined. A network was derived from agar-invasion phenotypes of mutant yeast. Mutations showed specific modes of genetic interaction with specific biological processes. Mutations formed cliques of significant mutual information in their large-scale patterns of genetic interaction. These local and global interaction patterns reflect the effects of gene perturbations on biological processes and pathways. 相似文献