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排序方式: 共有209条查询结果,搜索用时 15 毫秒
11.
MARIA JOSÉ ASINS IRENE VILLALTA MOHAMED M. ALY RAQUEL OLÍAS PAZ ÁLVAREZ DE MORALES RAÚL HUERTAS JUN LI NOELIA JAIME‐PÉREZ ROSARIO HARO VERÓNICA RAGA EMILIO A. CARBONELL ANDRÉS BELVER 《Plant, cell & environment》2013,36(6):1171-1191
The location of major quantitative trait loci (QTL) contributing to stem and leaf [Na+] and [K+] was previously reported in chromosome 7 using two connected populations of recombinant inbred lines (RILs) of tomato. HKT1;1 and HKT1;2, two tomato Na+‐selective class I‐HKT transporters, were found to be closely linked, where the maximum logarithm of odds (LOD) score for these QTLs located. When a chromosome 7 linkage map based on 278 single‐nucleotide polymorphisms (SNPs) was used, the maximum LOD score position was only 35 kb from HKT1;1 and HKT1;2. Their expression patterns and phenotypic effects were further investigated in two near‐isogenic lines (NILs): 157‐14 (double homozygote for the cheesmaniae alleles) and 157‐17 (double homozygote for the lycopersicum alleles). The expression pattern for the HKT1;1 and HKT1;2 alleles was complex, possibly because of differences in their promoter sequences. High salinity had very little effect on root dry and fresh weight and consequently on the plant dry weight of NIL 157‐14 in comparison with 157‐17. A significant difference between NILs was also found for [K+] and the [Na+]/[K+] ratio in leaf and stem but not for [Na+] arising a disagreement with the corresponding RIL population. Their association with leaf [Na+] and salt tolerance in tomato is also discussed. 相似文献
12.
Testosterone administration increases growth hormone (GH) secretion and decreases the plasma leptin concentration in men. We evaluated the effect of increased GH secretion due to short-term testosterone treatment on leptin concentrations. Ten boys aged 14.8 +/- 0.2 (mean +/- SE) years with transient GH deficiency caused by pubertal delay were evaluated before and after (3 months) 4 intramuscular injections of 100 mg testosterone heptylate, given at 15-day intervals. The leptin concentration decreased from 5.4 +/- 1.3 to 3. 6 +/- 1.1 microgram/l (p < 0.001), despite a weight gain of 3.4 +/- 0.5 kg. There were significant increases in body mass index (BMI), from -0.2 +/- 0.5 to 0.2 +/- 0.5 SD, p < 0.005, in GH peak after stimulation test, from 6.3 +/- 0.5 to 21.7 +/- 2.9 microgram/l, p < 0. 0003, in plasma testosterone, from 0.6 +/- 0.1 to 6.5 +/- 1.3 microgram/l, p < 0.001, in insulin-like growth factor-I (IGF-I), from 152 +/- 21 to 330 +/- 30 microgram/l, p < 0.0001, and in IGF-binding protein-3 (IGFBP-3), from 4.2 +/- 0.5 to 5.4 +/- 0.4 mg/l, p < 0.01. But there were no changes in blood glucose (4.7 +/- 0.1 and 4.8 +/- 0.1 mmol/l), or plasma fasting insulin (9.0 +/- 1.2 and 8.1 +/- 1.3 mIU/l). The leptin concentrations were positively correlated with the BMI before (p < 0.03) and after (p < 0.04) testosterone, but not with the GH peak after stimulation, or with plasma testosterone, IGF-I or IGFBP-3. The leptin and insulin concentrations after testosterone treatment were positively correlated (p < 0.04). Thus, short-term testosterone treatment of boys with pubertal delay decreases their leptin concentrations. The lack of correlation with GH secretion or with its changes, despite the dramatic increase in GH secretion, and the lack of change in insulin are additional features suggesting that testosterone increases the leptin concentration mainly by an effect on adipose tissue. 相似文献
13.
Phylogenetic utility of the nuclear gene arginine decarboxylase: an example from Brassicaceae 总被引:10,自引:2,他引:8
Arginine decarboxylase (ADC) is an important enzyme in the production of
putrescine and polyamines in plants. It is encoded by a single or low-copy
nuclear gene that lacks introns in sequences studied to date. The rate of
Adc amino acid sequence evolution is similar to that of ndhF for the
angiosperm family studied. Highly conserved regions provide several target
sites for PCR priming and sequencing and aid in nucleotide and amino acid
sequence alignment across a range of taxonomic levels, while a variable
region provides an increased number of potentially informative characters
relative to ndhF for the taxa surveyed. The utility of the Adc gene in
plant molecular systematic studies is demonstrated by analysis of its
partial nucleotide sequences obtained from 13 representatives of
Brassicaceae and 3 outgroup taxa, 2 from the mustard oil clade (order
Capparales) and 1 from the related order Malvales. Two copies of the Adc
gene, Adc1 and Adc2, are found in all members of the Brassicaceae studied
to data except the basal genus Aethionema. The resulting Adc gene tree
provides robust phylogenetic data regarding relationships within the
complex mustard family, as well as independent support for proposed tribal
realignments based on other molecular data sets such as those from
chloroplast DNA.
相似文献
14.
Norma C. Perez-Rosas Norma L. Gomez-Viquez Adan Dagnino-Acosta Moises Santillan Agustín Guerrero-Hernandez 《PloS one》2015,10(9)
The process of Ca2+ release from sarcoplasmic reticulum (SR) comprises 4 phases in smooth muscle cells. Phase 1 is characterized by a large increase of the intracellular Ca2+ concentration ([Ca2+]i) with a minimal reduction of the free luminal SR [Ca2+] ([Ca2+]FSR). Importantly, active SR Ca2+ ATPases (SERCA pumps) are necessary for phase 1 to occur. This situation cannot be explained by the standard kinetics that involves a fixed amount of luminal Ca2+ binding sites. A new mathematical model was developed that assumes an increasing SR Ca2+ buffering capacity in response to an increase of the luminal SR [Ca2+] that is called Kinetics-on-Demand (KonD) model. This approach can explain both phase 1 and the refractory period associated with a recovered [Ca2+]FSR. Additionally, our data suggest that active SERCA pumps are a requisite for KonD to be functional; otherwise luminal SR Ca2+ binding proteins switch to standard kinetics. The importance of KonD Ca2+ binding properties is twofold: a more efficient Ca2+ release process and that [Ca2+]FSR and Ca2+-bound to SR proteins ([Ca2+]BSR) can be regulated separately allowing for Ca2+ release to occur (provided by Ca2+-bound to luminal Ca2+ binding proteins) without an initial reduction of the [Ca2+]FSR. 相似文献
15.
16.
Admixture in Mexico City: implications for admixture mapping of Type 2 diabetes genetic risk factors
Martinez-Marignac VL Valladares A Cameron E Chan A Perera A Globus-Goldberg R Wacher N Kumate J McKeigue P O'Donnell D Shriver MD Cruz M Parra EJ 《Human genetics》2007,120(6):807-819
Admixture mapping is a recently developed method for identifying genetic risk factors involved in complex traits or diseases
showing prevalence differences between major continental groups. Type 2 diabetes (T2D) is at least twice as prevalent in Native
American populations as in populations of European ancestry, so admixture mapping is well suited to study the genetic basis
of this complex disease. We have characterized the admixture proportions in a sample of 286 unrelated T2D patients and 275
controls from Mexico City and we discuss the implications of the results for admixture mapping studies. Admixture proportions
were estimated using 69 autosomal ancestry-informative markers (AIMs). Maternal and paternal contributions were estimated
from geographically informative mtDNA and Y-specific polymorphisms. The average proportions of Native American, European and,
West African admixture were estimated as 65, 30, and 5%, respectively. The contributions of Native American ancestors to maternal
and paternal lineages were estimated as 90 and 40%, respectively. In a logistic model with higher educational status as dependent
variable, the odds ratio for higher educational status associated with an increase from 0 to 1 in European admixture proportions
was 9.4 (95%, credible interval 3.8–22.6). This association of socioeconomic status with individual admixture proportion shows
that genetic stratification in this population is paralleled, and possibly maintained, by socioeconomic stratification. The
effective number of generations back to unadmixed ancestors was 6.7 (95% CI 5.7–8.0), from which we can estimate that genome-wide
admixture mapping will require typing about 1,400 evenly distributed AIMs to localize genes underlying disease risk between
populations of European and Native American ancestry. Sample sizes of about 2,000 cases will be required to detect any locus
that contributes an ancestry risk ratio of at least 1.5. 相似文献
17.
Background
The analysis of genetic variation in populations of infectious agents may help us understand their epidemiology and evolution. Here we study a model for assessing the levels and patterns of genetic diversity in populations of infectious agents. The population is structured into many small subpopulations, which correspond to their hosts, that are connected according to a specific type of contact network. We considered different types of networks, including fully connected networks and scale free networks, which have been considered as a model that captures some properties of real contact networks. Infectious agents transmit between hosts, through migration, where they grow and mutate until elimination by the host immune system. 相似文献18.
R Moriggi Jr HS Di Mauro SC Dias JM Matos MB Urtado NF Camar?o IV Sousa Neto DC Nascimento RA Tibana CO Assump??o J Prestes CB Urtado 《Biology of sport / Institute of Sport》2015,32(4):289-294
Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances. 相似文献
19.
Polyana C Tizioto Jeremy F Taylor Jared E Decker Caio F Gromboni Mauricio A Mudadu Robert D Schnabel Luiz L Coutinho Gerson B Mour?o Priscila SN Oliveira Marcela M Souza James M Reecy Renata T Nassu Flavia A Bressani Patricia Tholon Tad S Sonstegard Mauricio M Alencar Rymer R Tullio Ana RA Nogueira Luciana CA Regitano 《遗传、选种与进化》2015,47(1)
20.
Research on personality and circadian typology indicates evening-type women are more impulsive and novelty seeking, neither types are more anxious, and morning types tend to be more active, conscientious, and persistent. The purpose of this study is to examine the differences between circadian typologies in the light of the Zuckerman's Alternative Five-Factor Model (AFFM) of personality, which has a strong biological basis, in an adult sample of 412 women 18 to 55 yrs of age. The authors found morning-type women had significant higher scores than evening-type and neither-type women on Activity, and its subscales General Activity and Work Activity. In contrast, evening-type women scored significantly higher than morning-type women on Aggression-Hostility, Impulsive Sensation Seeking, and its subscale Sensation Seeking. In all groups, results were independent of age. These findings are in accordance with those previously obtained in female student samples and add new data on the AFFM. The need of using personality models that are biologically based in the study of circadian rhythms is discussed. 相似文献