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21.
Isolation and sequencing of cDNA clones encoding Drosophila chromosomal protein D1. A repeating motif in proteins which recognize at DNA 总被引:10,自引:0,他引:10
C T Ashley C G Pendleton W W Jennings A Saxena C V Glover 《The Journal of biological chemistry》1989,264(14):8394-8401
Drosophila melanogaster D1 is a satellite DNA-associated protein which preferentially binds DNA sequences containing runs of AT base pairs. Clones encoding this polypeptide have been isolated from a lambda gt11 cDNA library by immunological screening with a D1 antiserum. The deduced sequence of the D1 polypeptide is 355 amino acids long and contains 10 copies of a repeating motif consisting of a glycine-arginine-proline (GRP) tripeptide located within a cluster of basic amino acids. Three copies of a similar motif have previously been observed in a mammalian satellite DNA-binding protein, high mobility group protein I (Lund, T., Dahl, K. H., Mork, E., Holtlund, J., and Laland, S. G. (1987) Biochem. Biophys. Res. Commun. 146, 725-730), suggesting that this motif may be a general feature of proteins which bind AT-rich satellite DNA and perhaps other AT-containing DNA as well. 相似文献
22.
We have examined the catecholamine-sensitive adenylate cyclase in the retina of the white perch (Roccus americanus). Both dopamine and the beta-adrenergic agonist isoproterenol stimulate cyclic AMP accumulation in this retina, but serotonin, an indoleamine, and phenylephrine, an alpha-adrenergic agonist, had no effect. The stimulation of adenylate cyclase by isoproterenol is more potent and effective than that of dopamine. The effects of dopamine and isoproterenol are mediated via independent dopamine and beta-adrenergic receptors. Haloperidol, a dopamine antagonist, blocks the stimulatory effect of dopamine but not of isoproterenol. Conversely, propranolol, a beta-adrenergic antagonist, blocks the stimulatory effect of isoproterenol but not of dopamine. The effects of dopamine and isoproterenol are not additive. In fractions of purified horizontal cells we found evidence for dopamine receptors linked to adenylate cyclase but did not find evidence for the presence of cyclase coupled beta-adrenergic receptors. The cellular location of the beta-adrenergic receptors is unknown. Our findings demonstrate the existence of both beta-adrenergic and dopamine receptors coupled to adenylate cyclase in the white perch retina. However, we did not find either epinephrine or norepinephrine, endogenous ligands of the beta-receptor, to be present in retinal extracts subjected to HPLC. 相似文献
23.
Identification of quantitative trait loci for plant height, lodging, and maturity in a soybean population segregating for growth habit 总被引:8,自引:0,他引:8
S. H. Lee M. A. Bailey M. A. R. Mian E. R. Shipe D. A. Ashley W. A. Parrott R. S. Hussey H. R. Boerma 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(5):516-523
The use of molecular markers to identify quantitative trait loci (QTLs) has the potential to enhance the efficiency of trait selection in plant breeding. The purpose of the present study was to identify additional QTLs for plant height, lodging, and maturity in a soybean, Glycine max (L.) Merr., population segregating for growth habit. In this study, 153 restriction fragment length polymorphisms (RFLP) and one morphological marker (Dt1) were used to identify QTLs associated with plant height, lodging, and maturity in 111 F2-derived lines from a cross of PI 97100 and Coker 237. The F2-derived lines and two parents were grown at Athens, Ga., and Blackville, S.C., in 1994 and evaluated for phenotypic traits. The genetic linkage map of these 143 loci covered about 1600 cM and converged into 23 linkage groups. Eleven markers remained unlinked. Using interval-mapping analysis for linked markers and single-factor analysis of variance (ANOVA), loci were tested for association with phenotypic data taken at each location as well as mean values over the two locations. In the combined analysis over locations, the major locus associated with plant height was identified as Dt1 on linkage group (LG) L. The Dt1 locus was also associated with lodging. This locus explained 67.7% of the total variation for plant height, and 56.4% for lodging. In addition, two QTLs for plant height (K007 on LG H and A516b on LG N) and one QTL for lodging (cr517 on LG J) were identified. For maturity, two independent QTLs were identified in intervals between R051 and N100, and between B032 and CpTI, on LG K. These QTLs explained 31.2% and 26.2% of the total variation for maturity, respectively. The same QTLs were identified for all traits at each location. This consistency of QTLs may be related to a few QTLs with large effects conditioning plant height, lodging, and maturity in this population. 相似文献
24.
Molecular markers associated with seed weight in two soybean populations 总被引:10,自引:0,他引:10
M. A. R. Mian M. A. Bailey J. P. Tamulonis E. R. Shipe T. E. Carter Jr. W. A. Parrott D. A. Ashley R. S. Hussey H. R. Boerma 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(7):1011-1016
Seed weight (SW) is a component of soybean, Glycine max (L.) Merr., seed yield, as well as an important trait for food-type soybeans. Two soybean populations, 120 F4-derived lines of YoungxPI416937 (Pop1) and 111 F2-derived lines of PI97100xCoker 237 (Pop2), were mapped with RFLP makers to identify quantitative trait loci (QTLs) conditioning SW across environments and populations. The genetic map of Pop1 consisted of 155 loci covering 973 cM, whereas Pop2 involved 153 loci and covered 1600 cM of map distance. For Pop1, the phenotypic data were collected from Plains, GA., Windblow, N.C., and Plymouth, N.C., in 1994. For Pop2, data were collected from Athens, GA., in 1994 and 1995, and Blackville, S.C., in 1995. Based on single-factor analysis of variance (ANOVA), seven and nine independent loci were associated with SW in Pop1 and Pop2, respectively. Together the loci explained 73% of the variability in SW in Pop1 and 74% in Pop2. Transgressive segregation occurred among the progeny in both populations. The marker loci associated with SW were highly consistent across environments and years. Two QTLs on linkage group (LG) F and K were located at similar genomic regions in both populations. The high consistency of QTLs across environments indicates that effective marker-assisted selection is feasible for soybean SW. 相似文献
25.
26.
27.
Cervical antibodies in patients with oral herpes simplex virus type 1 (HSV-1) infection: local anamnestic responses after genital HSV-2 infection. 总被引:2,自引:0,他引:2 下载免费PDF全文
Herpes simplex virus (HSV)-specific immunoglobulin A, immunoglobulin G, and secretory-component-containing immunoglobulins were identified in cervical and salivary secretions from six subjects with oral HSV type 1 (HSV-1) infections. Anamnestic cervical and salivary antibody responses were detected in two HSV-1-seropositive women with newly acquired genital HSV-2 infections. These data implicate the common mucosal immune system in antibody responses to HSV. 相似文献
28.
F. M. Cowan A. M. Johnson R. Ashley L. Corey A. Mindel 《BMJ (Clinical research ed.)》1994,309(6965):1325-1329
OBJECTIVES--To examine the epidemiology of antibody to herpes simplex virus type 2 and to assess its suitability as a serological marker of sexual behaviour in populations with high and low prevalences. DESIGN--Cross sectional survey. SETTING--Department of genitourinary medicine and blood donation centre in central London. SUBJECTS--Representative sample of 869 patients attending department between November 1990 and December 1991, and 1494 consecutive blood donors attending for donation between February and April 1992. METHOD--Participants had a blood sample taken for antibody testing with a novel type specific assay and completed a questionnaire. RESULTS--Prevalence of antibody differed significantly between the two groups (188/833 (22.7%) clinic attenders; 102/1347 (7.6%) blood donors). In both populations antibody was strongly associated with sex, sexual orientation, years of sexual activity, number of lifetime sexual partners, and past infection with sexually transmitted diseases after other factors were controlled for. Only 130 (45%) of all those with antibody had symptoms suggestive of genital herpes, and 79 (27.4%) had had genital herpes diagnosed. Of those without antibody to herpes simplex viruses type 1 and 2, 8.0% reported genital blisters or sores and 1.1% had had genital herpes diagnosed by a doctor. CONCLUSIONS--The strong relation between herpes simplex virus type 2 and sexual lifestyle suggests that the presence of antibody to the virus may be suitable for use as an objective, serological marker of patterns of sexual behaviour in different populations. These data show that only a minority of those infected with herpes simplex virus type 2 have a diagnosis of genital herpes or express clinical symptoms, making serological determinants of infection essential for epidemiological studies. 相似文献
29.
Single anion channels reconstituted from cardiac mitoplasts 总被引:4,自引:0,他引:4
Ion channels from sheep cardiac mitoplast (inverted inner mitochondrial membrane vesicle) preparations were incorporated into
voltage-clamped planar lipid bilayers. The appearance of anion rather than cation channels could be promoted by exposing the
bilayers to osmotic gradients formed by Cl− salts of large, relatively imperment, cations at a pH of 8.8. Two distinct activities were identified. These comprised a
multisubstate anion channel of intermediate conductance (∼60 pS in 300vs. 50mm choline Cl, ∼100 pS in symmetric 150mm KCl), and a lower-conductance anion channel (∼25 or ∼50 pS in similar conditions), which only displayed two well-defined
substates, at ∼25 and ∼50% of the fully open state. The larger channels were not simple multiples of the lower-conductance
channels, but both discriminated poorly, and to a similar extent, between anions and cations (PCl
−/Pcholine
+ ∼12, PCl
−/PK
+∼8). The lower-conductance channel was only minimally selective between different anions (PNO
3
−
(1.0)=PCl
−>PBr
−>PI
−>PSCN
−(0.8)), and its conductance failed to saturate even in high (>1.0 M) activities of KCl. The channels were not obviously voltage
dependent, and they were unaffected by 0.5 mM SITS, H2O2, propranolol, quinine or amitriptyline, or by 2 mM ATP, or by variations in pH (5.5–8.8). Ca2+ and Mg2+ did not alter single channel activity, but did modify single current amplitudes in the lower-conductance channel. This effect,
together with voltage-dependent substate behavior, is described in the following paper. 相似文献
30.
Jennifer D. Watts Mary Farina John S. Kimball Luke D. Schiferl Zhihua Liu Kyle A. Arndt Donatella Zona Ashley Ballantyne Eugénie S. Euskirchen Frans-Jan W. Parmentier Manuel Helbig Oliver Sonnentag Torbern Tagesson Janne Rinne Hiroki Ikawa Masahito Ueyama Hideki Kobayashi Torsten Sachs Daniel F. Nadeau John Kochendorfer Marcin Jackowicz-Korczynski Anna Virkkala Mika Aurela Roisin Commane Brendan Byrne Leah Birch Matthew S. Johnson Nima Madani Brendan Rogers Jinyang Du Arthur Endsley Kathleen Savage Ben Poulter Zhen Zhang Lori M. Bruhwiler Charles E. Miller Scott Goetz Walter C. Oechel 《Global Change Biology》2023,29(7):1870-1889
Arctic-boreal landscapes are experiencing profound warming, along with changes in ecosystem moisture status and disturbance from fire. This region is of global importance in terms of carbon feedbacks to climate, yet the sign (sink or source) and magnitude of the Arctic-boreal carbon budget within recent years remains highly uncertain. Here, we provide new estimates of recent (2003–2015) vegetation gross primary productivity (GPP), ecosystem respiration (Reco), net ecosystem CO2 exchange (NEE; Reco − GPP), and terrestrial methane (CH4) emissions for the Arctic-boreal zone using a satellite data-driven process-model for northern ecosystems (TCFM-Arctic), calibrated and evaluated using measurements from >60 tower eddy covariance (EC) sites. We used TCFM-Arctic to obtain daily 1-km2 flux estimates and annual carbon budgets for the pan-Arctic-boreal region. Across the domain, the model indicated an overall average NEE sink of −850 Tg CO2-C year−1. Eurasian boreal zones, especially those in Siberia, contributed to a majority of the net sink. In contrast, the tundra biome was relatively carbon neutral (ranging from small sink to source). Regional CH4 emissions from tundra and boreal wetlands (not accounting for aquatic CH4) were estimated at 35 Tg CH4-C year−1. Accounting for additional emissions from open water aquatic bodies and from fire, using available estimates from the literature, reduced the total regional NEE sink by 21% and shifted many far northern tundra landscapes, and some boreal forests, to a net carbon source. This assessment, based on in situ observations and models, improves our understanding of the high-latitude carbon status and also indicates a continued need for integrated site-to-regional assessments to monitor the vulnerability of these ecosystems to climate change. 相似文献