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1.
Falke KC Maurer HP Melchinger AE Piepho H Flachenecker C Frisch M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(2):299-297
According to quantitative genetic theory, linkage disequilibrium (LD) can hamper the short- and long-term selection response in recurrent selection (RS) programs. We analyzed LD in two European flint maize populations, KW1265 x D146 (A x B) and D145 x KW1292 (C x D), under modified recurrent full-sib selection. Our objectives were to investigate (1) the decay of initial parental LD present in F(2) populations by three generations of intermating, (2) the generation of new LD in four (A x B) and seven (C x D) selection cycles, and (3) the relationship between LD changes and estimates of the additive genetic variance. We analyzed the F(2) and the intermated populations as well as all selection cycles with 104 (A x B) and 101 (C x D) simple sequence repeat (SSR) markers with a uniform coverage of the entire maize genome. The LD coefficient D and the composite LD measure Delta were estimated and significance tests for LD were performed. LD was reduced by intermating as expected from theory. A directional generation of negative LD between favorable alleles could not be observed during the selection cycles. However, considerable undirectional changes in D were observed, which we attributed to genetic sampling due to the finite population size used for recombination. Consequently, a long-term reduction of the additive genetic variance due to negative LD was not observed. Our experimental results support the hypothesis that in practical RS programs with maize, LD generated by selection is not a limiting factor for obtaining a high selection response. 相似文献
2.
Falke KC Flachenecker C Melchinger AE Piepho HP Maurer HP Frisch M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(5):765-776
Selection and random genetic drift are the two main forces affecting the selection response of recurrent selection (RS) programs
by changes in allele frequencies. Therefore, detailed knowledge on allele frequency changes attributable to these forces is
of fundamental importance for assessing RS programs. The objectives of our study were to (1) estimate the number, position,
and genetic effect of quantitative trait loci (QTL) for selection index and its components in the base populations, (2) determine
changes in allele frequencies of QTL regions due to the effects of random genetic drift and selection, and (3) predict allele
frequency changes by using QTL results and compare these predictions with observed values. We performed QTL analyses, based
on restriction fragment length polymorphisms (RFLPs) and simple sequence repeats (SSRs), in 274 F2:3 lines of cross KW1265 × D146 (A × B) and 133 F3:4 lines of cross D145 × KW1292 (C × D) originating from two European flint maize populations. Four (A × B) and seven (C × D)
cycles of RS were analyzed with SSRs for significant allele frequency changes due to selection. Several QTL regions for selection
index were detected with simple and composite interval mapping. In some of them, flanking markers showed a significant allele
frequency change after the first and the final selection cycles. The correlation between observed and predicted allele frequencies
was significant only in A × B. We attribute these observations mainly to (1) the high dependence of the power of QTL detection
on the population size and (2) the occurrence of undetectable QTL in repulsion phase. Assessment of allele frequency changes
in RS programs can be used to detect marker alleles linked to QTL regions under selection pressure.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Flachenecker C Frisch M Falke KC Melchinger AE 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(6):1113-1120
Selection response of a modified recurrent full-sib (FS) selection scheme conducted in two European flint F2 maize (Zea mays L.) populations was re-evaluated. Our objectives were to (1) determine the selection response for per se and testcross performance in both populations and (2) separate genetic effects due to selection from those due to random genetic drift. Modified recurrent FS selection was conducted at three locations using an effective population size N
e = 32 and a selection rate of 25% for a selection index, based on grain yield and grain moisture. Recombination was performed according to a pseudo-factorial mating scheme. Selection response was assessed using a population diallel including the source population and advanced selection cycles, as well as testcrosses with unrelatesd inbred line testers and the parental F1 generation. Selection response per cycle was significant for grain yield and grain moisture in both populations. Effects of random genetic drift caused only a small reduction in the selection response. No significant selection response was observed for testcrosses, suggesting that for heterotic traits, such as grain yield, a high frequency of favorable alleles in the elite tester masked the effects of genes segregating in the populations. We conclude that our modified recurrent FS selection is an alternative to other commonly applied intrapopulation recurrent selection schemes, and some of its features may also be useful for increasing the efficiency of interpopulation recurrent selection programs. 相似文献
4.
Characterisation and transferability of apple SSRs to two European pear F<Subscript>1</Subscript> populations 总被引:1,自引:0,他引:1
Pierantoni L Cho KH Shin IS Chiodini R Tartarini S Dondini L Kang SJ Sansavini S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(7):1519-1524
European pear (Pyrus communis L.) is among the important fruit species for which only few genetic studies have been carried out. Available evidence indicates that simple sequence repeats (SSR) are very useful as molecular markers because they are codominant, highly polymorphic, abundant and reproducible. The present paper reports more than 100 apple SSR markers in two populations of European pear; a total of 41 SSR markers were then positioned on a genetic linkage map of the cross Passe Crassane × Harrow Sweet and 31 in the map Abbè Fétel × Max Red Bartlett. Syntenic relationships between pear and apple maps have been considered for the chromosomes carrying two or more SSR markers. The alignment among the two maps supports the colinearity of the two genomes with respect both to identification and to orientation of the linkage groups. 相似文献
5.
G. R. Rodríguez L. Sequin G. R. Pratta R. Zorzoli L. A. Picardi 《Biologia Plantarum》2008,52(3):548-552
Pericarp polypeptide profiles were analyzed at three ripening stages in the F1 hybrid and the F2 population from the cross between the accessions: LA1385 (Lycopersicon esculentum var. cerasiforme) and 804627 (L. esculentum, a homozygous genotype for the nor mutant). Six polymorphic polypeptides were observed in LA1385, while no polymorphic polypeptides among ripening stages was
observed in 804627. On the other hand, some polypeptides in the F1 hybrid were not observed in the parents whereas others were present in both parental genotypes and were unnoticeable in the
hybrid genotype. From a cluster analysis on the protein profiles of the F2 population, the differential expression of proteins allowed to distinguish mature green (MG) stage from the others two stages,
while for breaker stage (BR) and red ripe stage, the genetic background was more important in forming groups. The differential
expression of proteins could be associated with fruit morphology traits such as a 72 kDa polypeptide present in MG stage with
fruit diameter, height and mass and a 47 kDa polypeptide found in BR with fruit shelf life. 相似文献
6.
7.
Flachenecker C Frisch M Falke KC Melchinger AE 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(3):483-491
Recurrent selection is a cyclic breeding procedure designed to improve the mean of a population for the trait(s) under selection.
Starting from an F2 population of European flint maize (Zea mays L.) intermated for three generations, we conducted seven cycles of a modified recurrent full-sib (FS) selection scheme. The
objectives of our study were to (1) monitor trends across selection cycles in the estimates of the population mean, additive
and dominance variances, (2) compare predicted and realized selection responses, and (3) investigate the usefulness of best
linear unbiased prediction (BLUP) of progeny performance under the recurrent FS selection scheme applied. Recurrent FS selection
was conducted at three locations using a selection rate of 25% for a selection index, based on grain yield and grain moisture.
Recombination was performed according to a pseudo-factorial mating scheme, where the selected FS families were divided into
an upper-ranking group of parents mated to the lower-ranking group. Variance components were estimated with restricted maximum
likelihood. Average grain yield increased 9.1% per cycle, average grain moisture decreased 1.1% per cycle, and the selection
index increased 11.2% per cycle. For the three traits we observed, no significant changes in additive and dominance variances
occurred, suggesting future selection response at or near current rates of progress. Predictions of FS family performance
in Cn+1 based on mean performance of parental FS families in Cn were of equal or higher precision as those based on the mean additive genetic BLUP of their parents, and corresponding correlations
were of moderate size only for grain moisture. The significant increase in grain yield combined with the decrease in grain
moisture suggest that the F2 source population with use of a pseudo-factorial mating scheme is an appealing alternative to other types of source materials
and random mating schemes commonly used in recurrent selection. 相似文献
8.
Giovanna Lippe Elena Bisetto Marina Comelli Stefania Contessi Francesca Di Pancrazio Irene Mavelli 《Journal of bioenergetics and biomembranes》2009,41(2):151-157
Mitochondria are central to heart function and dysfunction, and the pathways activated by different cardioprotective interventions
mostly converge on mitochondria. In a context of perspectives in innate and acquired cardioprotection, we review some recent
advances in F0F1ATPsynthase structure/function and regulation in cardiac cells. We focus on three topics regarding the mitochondrial F0F1ATPsynthase and the plasma membrane enzyme, i.e.: i) the crucial role of cardiac mitochondrial F0F1ATPsynthase regulation by the inhibitory protein IF1 in heart preconditioning strategies; ii) the structure and function of mitochondrial F0F1ATPsynthase oligomers in mammalian myocardium as possible endogenous factors of mitochondria resistance to ischemic insult;
iii) the external location and characterization of plasma membrane F0F1 ATP synthase in search for possible actors of its regulation, such as IF1 and calmodulin, at cell surface. 相似文献
9.
Silvia Ravera Isabella Panfoli Maria Grazia Aluigi Daniela Calzia Alessandro Morelli 《Cell biochemistry and biophysics》2011,59(2):63-70
FoF1-ATP synthase is the nanomotor responsible for most of ATP synthesis in the cell. In physiological conditions, it carries
out ATP synthesis thanks to a proton gradient generated by the respiratory chain in the inner mitochondrial membrane. We previously
reported that isolated myelin vesicles (IMV) contain functional FoF1-ATP synthase and respiratory chain complexes and are able to conduct an aerobic metabolism, to support the axonal energy
demand. In this study, by biochemical assay, Western Blot (WB) analysis and immunofluorescence microscopy, we characterized
the IMV FoF1-ATP synthase. ATP synthase activity decreased in the presence of the specific inhibitors (olygomicin, DCCD, FCCP, valynomicin/nigericin)
and respiratory chain inhibitors (antimycin A, KCN), suggesting a coupling of oxygen consumption and ATP synthesis. ATPase
activity was inhibited in low pH conditions. WB and microscopy analyses of both IMV and optic nerves showed that the Inhibitor
of F1 (IF1), a small protein that binds the F1 moiety in low pH when of oxygen supply is impaired, is expressed in myelin sheath. Data are discussed in terms of the role
of IF1 in the prevention of the reversal of ATP synthase in myelin sheath during central nervous system ischemic events. Overall,
data are consistent with an energetic role of myelin sheath, and may shed light on the relationship among demyelination and
axonal degeneration. 相似文献
10.
Yao-Dong Song Liang Wang Li-Ming Wu Qiao-Ling Chen Fa-Kun Liu Xiao-Wen Tang 《Journal of molecular modeling》2016,22(2):50
In this paper, we report a study on the structure and first hyperpolarizability of C60Cl2 and C60F2. The calculation results show that the first hyperpolarizabilities of C60Cl2 and C60F2 were 172 au and 249 au, respectively. Compared with the fullerenes, the first hyperpolarizability of C60Cl2 increased from 0 au to 172 au, while the first hyperpolarizability of C60F2 increased from 0 au to 249 au. In order to further increase the first hyperpolarizability of C60Cl2 and C60F2, Li@C60Cl2 and Li@C60F2 were obtained by introducing a lithium atom to C60Cl2 and C60F2. The first hyperpolarizabilities of Li@C60Cl2 and Li@C60F2 were 2589 au and 985 au, representing a 15-fold and 3.9-fold increase, respectively, over those of C60Cl2 and C60F2. The transition energies of four molecules (C60Cl2, Li@C60Cl2, C60F2, Li@C60F2) were calculated, and were found to be 0.17866 au, 0.05229 au, 0.18385 au, and 0.05212 au, respectively. A two-level model explains why the first hyperpolarizability increases for Li@C60Cl2 and Li@C60F2. 相似文献
11.
M. K. Nikolaeva S. N. Maevskaya P. Yu. Voronin 《Russian Journal of Plant Physiology》2017,64(4):536-542
We studied the temporal sequence of changes in the photosynthetic CO2/H2O gas exchange intensity, as well as leaf water status, contents of soluble carbohydrates, starch, proline, pigments, and MDA, in maize seedlings (Zea mays L., cv. Luchistaya) under adaptation to increasing water deficit. The duration of drought was 2, 3, 5, and 6 days. Withholding water from maize plants caused gradual increase in the intensity of water deficit: from mild (2 or 3 days) to moderate (5 days) and nearly severe (6 days) water stress. After 6 days, relative leaf water content decreased by 19.8% as compared to the control. On the second day after the onset of drought, slight reduction in the photosynthetic CO2/H2O gas exchange intensity of the treated plants was observed. After 6 days, photosynthesis and transpiration of leaves synchronously reduced almost threefold due to stomatal closure. The progressive soil drought had substantial impact on the carbohydrate metabolism. After 2 days of water deficit, the content of reducing sugars and sucrose increased slightly, whereas after 6 days, it increased ten and four times, respectively. After 2, 3, and 5 days of drought, the starch content declined slightly; however, under severe drought (6 days), it increased by 30% as compared to the control. Simultaneously with the increase in the content of soluble sugars, proline content increased significantly and it was the highest on the sixth day of drought. At all stages of water deficit, the proline content increased more significantly than the content of reducing carbohydrates and sucrose. Under increasing water deficit (5 and 6 days), the content of MDA was found to rise. At the initial drought stage (2 or 3 days) and under severe water deficit (6 days), no significant changes in the pigment content were observed. Thus, at the initial stages of progressive drought, in the leaves of this maize cultivar, a decline in photosynthetic activity proceeded simultaneously with accumulation of reducing sugars, sucrose, and proline. The results obtained showed that, at the first stages of adaptation of maize seedlings to drought, the changes in carbohydrate and proline metabolism have been observed, which have increased upon further plant dehydration. 相似文献
12.
Bisetto E Picotti P Giorgio V Alverdi V Mavelli I Lippe G 《Journal of bioenergetics and biomembranes》2008,40(4):257-267
The role of the integral inner membrane subunit e in self-association of F0F1ATP synthase from bovine heart mitochondria was analyzed by in situ limited proteolysis, blue native PAGE/iterative SDS-PAGE, and LC-MS/MS. Selective degradation of subunit e, without disrupting
membrane integrity or ATPase capacity, altered the oligomeric distribution of F0F1ATP synthase, by eliminating oligomers and reducing dimers in favor of monomers. The stoichiometry of subunit e was determined
by a quantitative MS-based proteomics approach, using synthetic isotope-labelled reference peptides IAQL*EEVK, VYGVGSL*ALYEK,
and ELAEAQEDTIL*K to quantify the b, γ and e subunits, respectively. Accuracy of the method was demonstrated by confirming
the 1:1 stoichiometry of subunits γ and b. Altogether, the results indicate that the integrity of a unique copy of subunit
e is essential for self-association of mammalian F0F1ATP synthase.
Elena Bisetto and Paola Picotti contributed equally to this work. 相似文献
13.
Zhuo Zhao Jie Zhang Mei-Ling Xu Zhi-Peng Liu Hua Wang Ming Liu Yan-Yan Yu Li Sun Hui Zhang Hai-Yan Wu 《Biotechnology and Bioprocess Engineering》2016,21(1):128-133
In order to adapt port rapid detection of food borne norovirus, presently we developed a new typed detection method based on F0F1-ATPase molecular motor biosensor. A specific probe was encompassed the conservative region of norovirus and F0F1-ATPase within chromatophore was constructed as a molecular motor biosensor through the “ε-subunit antibody-streptomycin-biotin-probe” system. Norovirus was captured based on probe-RNA specific binding. Our results demonstrated that the Limit of Quantification (LOQ) is 0.005 ng/mL for NV RNA and also demonstrated that this method possesses specificity and none cross-reaction for food borne virus. What’s more, the experiment used this method could be accomplished in 1 h. We detected 10 samples by using this method and the results were consistent with RT-PCR results. Overall, based on F0F1-ATPase molecular motors biosensor system we firstly established a new typed detection method for norovirus detection and demonstrated that this method is sensitive and specific and can be used in the rapid detection for food borne virus. 相似文献
14.
Test weight is an important trait in maize breeding. Understanding the genetic mechanism of test weight is important for effective
selection of maize test weight improvement. In this study, quantitative trait loci (QTL) for maize test weight were identified.
In the years 2007 and 2008, a F2:3 population along with the parents Chang7-2 and Zheng58 were planted in Zhengzhou, People’s Republic of China. Significant
genotypic variation for maize test weight was observed in both years. Based on the genetic map containing 180 polymorphic
SSR markers with an average linkage distance of 11.0 cM, QTL for maize test weight were analysed by mixed-model composite
interval mapping. Five QTL, including four QTL with only additive effects, were identified on chromosomes 1, 2, 3, 4 and 5,
and together explained 25.2% of the phenotypic variation. Seven pairs of epistatic interactions were also detected, involving
11 loci distributed on chromosomes 1, 2, 3, 4, 5 and 7, respectively, which totally contributed 18.2% of the phenotypic variation.
However, no significant QTL × environment (Q×E) interaction and epistasis × environment interaction effects were detected.
The results showed that besides the additive QTL, epistatic interactions also formed an important genetic basis for test weight
in maize. 相似文献
15.
Bhatt D Cole SP Grabar TB Claggett SB Cain BD 《Journal of bioenergetics and biomembranes》2005,37(2):67-74
The peripheral stalk of F1F0 ATP synthase is composed of a parallel homodimer of b subunits that extends across the cytoplasmic membrane in F0 to the top of the F1 sector. The stalk serves as the stator necessary for holding F1 against movement of the rotor. A series of insertions and deletions have been engineered into the hydrophilic domain that interacts with F1. Only the hydrophobic segment from {val-121} to {ala-132} and the extreme carboxyl terminus proved to be highly sensitive to mutation. Deletions in either site apparently abolished enzyme function as a result of defects is assembly of the F1F0 complex. Other mutations manipulating the length of the sequence between these two areas had only limited effects on enzyme function. Expression of a b subunit with insertions with as few as two amino acids into the hydrophobic segment also resulted in loss of F1F0 ATP synthase. However, a fully defective b subunit with seven additional amino acids could be stabilized in a heterodimeric peripheral stalk within a functional F1F0 complex by a normal b subunit. 相似文献
16.
Villalta I Bernet GP Carbonell EA Asins MJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(6):1001-1017
Salt tolerance has been analysed in two populations of F7 lines developed from a salt sensitive genotype of Solanum lycopersicum var. cerasiforme, as female parent, and two salt tolerant lines, as male parents, from S. pimpinellifolium, the P population (142 lines), and S. cheesmaniae, the C population (116 lines). Salinity effects on 19 quantitative traits including fruit yield were investigated by correlation,
principal component analysis, ANOVA and QTL analysis. A total of 153 and 124 markers were genotyped in the P and C populations,
respectively. Some flowering time and salt tolerance candidate genes were included. Since most traits deviated from a normal
distribution, results based on the Kruskal–Wallis non-parametric test were preferred. Interval mapping methodology and ANOVA
were also used for QTL detection. Eight out of 15 QTLs at each population were detected for the target traits under both control
and high salinity conditions, and among them, only average fruit weight (FW) and fruit number (FN) QTLs (fw1.1, fw2.1 and fn1.2) were detected in both populations. The individual contribution of QTLs were, in general, low. After leaf chloride concentration,
flowering time is the trait most affected by salinity because different QTLs are detected and some of their QTL×E interactions
have been found significant. Also reinforcing the interest on information provided by QTL analysis, it has been found that
non-correlated traits may present QTL(s) that are associated with the same marker. A few salinity specific QTLs for fruit
yield, not associated with detrimental effects, might be used to increase tomato salt tolerance. The beneficial allele at
two of them, fw8.1 (in C) and tw8.1 (for total fruit weight in P) corresponds to the salt sensitive parent, suggesting that the effect of the genetic background
is crucial to breed for wide adaptation using wild germplasm. 相似文献
17.
We summarize our current view of the reaction mechanism in F1-ATPase as it has emerged from experiment, theory, and computational studies over the last several years. ATP catalysis in
the catalytic binding pockets of F1 takes place without the release of any significant free energy and is efficiently driven by the combined action of two water
molecules utilizing a so-called protein-relay mechanism. The chemical reaction itself is controlled by the spatial position
of a key arginine residue. 相似文献
18.
Prostaglandin F<Subscript>2α</Subscript> identified as a Luteolytic Hormone in Sheep 总被引:3,自引:0,他引:3
J. A. McCRACKEN J. C. CARLSON M. E. GLEW J. R. GODING D. T. BAIRD K. GREEN B. SAMUELSSON 《Nature: New biology》1972,238(83):129-134
Prostaglandin F2α is released from the uterus of the sheep in a cyclic fashion, acts primarily in a local manner on the ovary via a counter-current mechanism and is responsible for the periodic regression of the corpus luteum in this species. 相似文献
19.
20.
In a relatively simple mathematical model we analyze the possibility of auto-oscillatory modes of F1-ATPase during ATP hydrolysis. 相似文献