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1.
The Vh2 and Vh4 scab resistance genes in two differential hosts derived from Russian apple R12740-7A map to the same linkage group of apple 总被引:3,自引:0,他引:3
V.G.M. Bus E.H.A. Rikkerink W.E. van de Weg R.L. Rusholme S.E. Gardiner H.C.M. Bassett L.P. Kodde L. Parisi F.N.D. Laurens E.J. Meulenbroek K.M. Plummer 《Molecular breeding : new strategies in plant improvement》2005,15(1):103-116
Russian apple R12740-7A is the designation for an accession grown from seed collected in Russia, which was found to be highly resistant to apple scab. The resistance has historically been attributed to a naturally pyramided complex involving three major genes: one race-nonspecific gene, Vr, conditioning resistance to all known races, plus two race-specific genes. The race-nonspecific gene was identified as an independently segregating gene by Dayton and Williams (1968) and is referred to in this paper as Vr-DW. The first researchers to study the scab resistance gene complex in Russian apple never described the phenotype conditioned by the race-nonspecific gene. Later, Aldwinckle et al. (1976) associated the name Vr with a scab resistance gene conditioning distinctive stellate necrotic reactions, which we refer to as Vr-A in order to distinguish it from Vr-DW. We show that the segregation ratios in progenies from the scab differential hosts 2 and 4 that are derived from Russian apple, crossed with susceptible cultivars were consistent with a single gene conditioning resistance in each host. The genes have been named Vh2 and Vh4, respectively. Resistant segregants from host 2 showed stellate necrotic reactions, while those from host 4 showed hypersensitive reactions. Both the phenotypes and the genetic maps for the genes in the respective hosts were very similar to those of the genes previously named Vr-A and Vx, respectively, in an F1 family of Russian apple. We showed that race 2 of V. inaequalis isolated from host 2 was able to infect resistant descendants of the non-differential accession PRI 442-23 as well as host 2. The descendants of PRI 442-23 were expected to carry the race-nonspecific Vr-DW gene, but in fact carry Vr-A. We conclude that the Vh2 gene in host 2 and Vr-A are the same, and that the Vh4 gene in host 4 and Vx are the same. However, a major finding of this study is that the latter gene mapped to linkage group 2 of apple instead of linkage group 10 as suggested from previous research. With the two race-specific genes from Russian apple defined now, we discuss the nature of the race-nonspecific Vr-DW gene in this accession. We also report the identification of a new scab resistance gene, VT57, from either Golden Delicious or Red Dougherty, which conditions chlorotic resistance reactions and is linked to Vh2. 相似文献
2.
L. Gianfranceschi B. Koller N. Seglias M. Kellerhals C. Gessler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(1-2):199-204
Large-scale marker-assisted selection requires highly reproducible, consistent and simple markers. The use of genetic markers is important in woody plant breeding in general, and in apple in particular, because of the high level of heterozygosity present in Malus species. We present here the transformation of two RAPD markers, which we found previously to be linked to the major scab resistance gene Vf, into more reliable and reproducible markers that can be applied directly to apple breeding. We give an example of how the use of such markers can speed up selection for the introduction of scab resistance genes into the same plant, reducing labour and avoiding time-consuming test crosses. We discuss the nature and relationship of the scab resistance gene Vf to the one present in Nova Easygro, thought to be Vr. 相似文献
3.
Mariya V. Kovaleva Evgeniya I. Sukhanova Tatyana A. Trendeleva Marina V. Zyl’kova Ludmila A. Ural’skaya Kristina M. Popova Nils-Erik L. Saris Renata A. Zvyagilskaya 《Journal of bioenergetics and biomembranes》2009,41(3):239-249
In this study we used tightly-coupled mitochondria from Yarrowia lipolytica and Dipodascus (Endomyces) magnusii yeasts, possessing a respiratory chain with the usual three points of energy conservation. High-amplitude swelling and collapse
of the membrane potential were used as parameters for demonstrating induction of the mitochondrial permeability transition
due to opening of a pore (mPTP). Mitochondria from Y. lipolytica, lacking a natural mitochondrial Ca2+ uptake pathway, and from D. magnusii, harboring a high-capacitive, regulated mitochondrial Ca2+ transport system (Bazhenova et al. J Biol Chem 273:4372–4377, 1998a; Bazhenova et al. Biochim Biophys Acta 1371:96–100, 1998b; Deryabina and Zvyagilskaya Biochemistry (Moscow) 65:1352–1356, 2000; Deryabina et al. J Biol Chem 276:47801–47806, 2001) were very resistant to Ca2+ overload. However, exposure of yeast mitochondria to 50–100 μM Ca2+ in the presence of the Ca2+ ionophore ETH129 induced collapse of the membrane potential, possibly due to activation of the fatty acid-dependent Ca2+/nH+-antiporter, with no classical mPTP induction. The absence of response in yeast mitochondria was not simply due to structural
limitations, since large-amplitude swelling occurred in the presence of alamethicin, a hydrophobic, helical peptide, forming
voltage-sensitive ion channels in lipid membranes. Ca2+- ETH129-induced activation of the Ca2+/H+-antiport system was inhibited and prevented by bovine serum albumin, and partially by inorganic phosphate and ATP. We subjected
yeast mitochondria to other conditions known to induce the permeability transition in animal mitochondria, i.e., Ca2+ overload (in the presence of ETH129) combined with palmitic acid (Mironova et al. J Bioenerg Biomembr 33:319–331, 2001; Sultan and Sokolove Arch Biochem Biophys 386:37–51, 2001), SH-reagents, carboxyatractyloside (an inhibitor of the ADP/ATP translocator), depletion of intramitochondrial adenine nucleotide
pools, deenergization of mitochondria, and shifting to acidic pH values in the presence of high phosphate concentrations.
None of the above-mentioned substances or conditions induced a mPTP-like pore. It is thus evident that the permeability transition
in yeast mitochondria is not coupled with Ca2+ uptake and is differently regulated compared to the mPTP of animal mitochondria. 相似文献
4.
5.
Conservation strategies for populations of woodland caribou Rangifer tarandus caribou frequently emphasize the importance of predator–prey relationships and the availability of lichen-rich late seral forests,
yet the importance of summer diet and forage availability to woodland caribou survival is poorly understood. In a recent article,
Wittmer et al. (Can J Zool 83:407–418, 2005b) concluded that woodland caribou in British Columbia were declining as a consequence of increased predation that was facilitated
by habitat alteration. Their conclusion is consistent with the findings of other authors who have suggested that predation
is the most important proximal factor limiting woodland caribou populations (Bergerud and Elliot in Can J Zool 64:1515–1529, 1986; Edmonds in Can J Zool 66:817–826, 1988; Rettie and Messier in Can J Zool 76:251–259, 1998; Hayes et al. in Wildl Monogr 152:1–35, 2003). Wittmer et al. (Can J Zool 83:407–418, 2005b) presented three alternative, contrasting hypotheses for caribou decline that differed in terms of predicted differences
in instantaneous rates of increase, pregnancy rates, causes of mortality, and seasonal vulnerability to mortality (Table 1,
p 258). These authors rejected the hypotheses that food or an interaction between food and predation was responsible for observed
declines in caribou populations; however, the use of pregnancy rate, mortality season and cause of mortality to contrast the
alternative hypotheses is problematic. We argue here that the data employed in their study were insufficient to properly evaluate
a predation-sensitive foraging hypothesis for caribou decline. Empirical data on seasonal forage availability and quality
and plane of nutrition of caribou would be required to test the competing hypotheses. We suggest that methodological limitations
in studies of woodland caribou population dynamics prohibit proper evaluation of the mechanism of caribou population declines
and fail to elucidate potential interactions between top-down and bottom-up effects on populations.
An erratum to this article can be found at 相似文献
6.
Patocchi A Bigler B Koller B Kellerhals M Gessler C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(5):1087-1092
Reports from several European countries of the breakdown of the Vf resistance, the most frequently used source of resistance in breeding programs against apple scab, emphasize the urgency of diversifying the basis of apple scab resistance and pyramiding different apple scab resistances with the use of their associated molecular markers. GMAL 2473 is an apple scab resistant selection thought to carry the resistance gene Vr. We report the identification by BSA of three AFLP markers and one RAPD marker associated with the GMAL 2473 resistance gene. SSRs associated with the resistance gene were found by (1) identifying the linkage group carrying the apple scab resistance and (2) testing the SSRs previously mapped in the same region. One such SSR, CH02c02a, mapped on linkage group 2, co-segregates with the resistance gene. GMAL 2473 was tested with molecular markers associated with other apple scab resistance genes, and accessions carrying known apple scab resistance genes were tested with the SSR linked to the resistance gene found in GMAL 2473. The results indicate that GMAL 2473 does not carry Vr, and that a new apple scab resistance gene, named Vr
2, has been identified. 相似文献
7.
A major scab resistance gene called Va1 was identified in the Russian apple cultivar ‘Antonovka’ (accession APF22) conferring scab resistance under conditions of
natural scab infection in the field. After scab scorings over a period of 3 years, a 1:1 segregation was observed in the mapping
population 04/214 (‘Golden Delicious’ × ‘Antonovka’). The Va1 resistance gene provides sufficient broad spectrum resistance that is of use in apple resistance breeding and has been assigned
Rvi17 according the proposal for a new scab nomenclature (Bus et al., Acta Horticulturae 814:739–746, 2009). Analysis of simple sequence repeats (SSRs) located on the apple linkage group (LG) 1 showed that the Va1 locus is closely linked (1 cM) to SSR CH-Vf1 known to cosegregate with the Vf locus. A tight genetic association was also observed between a specific cleaved amplified polymorphic sequence marker (ARD-CAPS)
developed from the HcrVf paralog Vf2ARD present in ‘Antonovka’, but there is no indication yet for a causal relationship with Vf2ARD. Although the whole race spectrum of Va1 is still unknown, it was obvious that it acts against the scab races 6 and 7 which are able to overcome the resistance of
Malus floribunda 821. A second resistance factor (named Va2) was studied by race 1-specific scab tests based on grafted 04/214 clones. A 1:1-segregation ratio was observed, too, but
18 “phenotypic recombinants” were found after comparisons with the field scab data of the same genotypes. Va2 was mapped on LG 1 with a genetic distance of about 15 cM above CH-Vf1. The positions of the newly identified ‘Antonovka’
scab resistance factors are compared with previously reported Va mapping approaches and published results from quantitative trait loci analyses performed with different ‘Antonovka’ genotypes. 相似文献
8.
Genome shuffling of <Emphasis Type="Italic">Streptomyces</Emphasis> sp. U121 for improved production of hydroxycitric acid 总被引:2,自引:0,他引:2
(2S, 3R)-Hydroxycitric acid (HCA) from Hibiscus subdariffa inhibits pancreatic α-amylase and intestine α-glucosidase, leading to reduction of carbohydrate metabolism. In our previous
study, Streptomyces sp. U121 was identified as a producer of (2S, 3R)-HCA [Hida et al. (2005) Bioscience, Biotechnology, and Biochemistry 69:1555–1561]. Here, we applied genome shuffling of Streptomyces sp. U121 to achieve rapid improvement of HCA production. The initial mutant population was generated by nitrosoguanidine
treatment of the spores, and an improved population producing fivefold more HCA over wild type was obtained by three rounds
of genome shuffling. For efficient screening of the mutant library, trans-epoxyaconitic acid (EAA), an antibiotic analog of HCA, was utilized. EAA inhibited the regeneration of nonfused protoplasts,
resulting in selective screening of shuffled strains. Mutant strains with enhanced EAA resistance exhibited significantly
higher HCA production in liquid media. Furthermore, the best mutant showed increased cell growth in flask culture, as well
as increased HCA production. 相似文献
9.
Christina M. Grozinger Gene E. Robinson 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(4):461-470
Pheromones cause dramatic changes in behavior and physiology, and are critical for honey bee colony organization. Queen mandibular
pheromone (QMP) regulates multiple behaviors in worker bees (Slessor et al. in J Chem Ecol 31(11):2731–2745, 2005). We also identified genes whose brain expression levels were altered by exposure to QMP (Grozinger et al. in Proc Natl Acad
Sci USA 100(Suppl 2):14519–14525, 2003). Krüppel-homolog 1 (Kr-h1) RNA levels were significantly downregulated by QMP, and were higher in foragers than in nurses (Whitfield et al. in Science
302(5643):296–299, 2003). Here we report on results of behavioral and pharmacological experiments that characterize factors regulating expression
of Kr-h1. Foragers have higher brain levels of Kr-h1 than in-hive bees, regardless of age and pheromone exposure. Furthermore, forager Kr-h1 levels were not affected by QMP. Since the onset of foraging is caused, in part, by increasing juvenile hormone blood titers
and brain octopamine levels, we investigated the effects of octopamine and methoprene (a juvenile hormone analog) on Kr-h1 expression. Methoprene produced a marginal (not significant) increase in Kr-h1 expression, but Kr-h1 brain levels in methoprene-treated bees were no longer downregulated by QMP. Octopamine did not modulate Kr-h1 expression. Our results demonstrate that the gene expression response to QMP is not hard-wired in the brain but is instead
dependent on worker behavioral state. 相似文献
10.
Genka H Baba T Tsuda M Kanaya S Mori H Yoshida T Noguchi MT Tsuchiya K Sawada H 《Journal of molecular evolution》2006,63(3):401-414
DNA fragments containing argK-tox clusters and their flanking regions were cloned from the chromosomes of Pseudomonas syringae pathovar (pv.) actinidiae strain KW-11 (ACT) and P. syringae pv. phaseolicola strain MAFF 302282 (PHA), and then their sequences were determined. Comparative analysis of these sequences and the sequences
of P. syringae pv. tomato DC3000 (TOM) (Buell et al., Proc Natl Acad Sci USA 100:10181–10186, 2003) and pv. syringae B728a (SYR) (Feil et al., Proc Natl Acad Sci USA 102:11064–11069, 2005) revealed that the chromosomal backbone regions of ACT and TOM shared a high similarity to each other but presented a low
similarity to those of PHA and SYR. Nevertheless, almost-identical DNA regions of about 38 kb were confirmed to be present
on the chromosomes of both ACT and PHA, which we named “tox islands.” The facts that the GC content of such tox islands was 6% lower than that of the chromosomal backbone regions of P. syringae, and that argK-tox clusters, which are considered to be of exogenous origin based on our previous studies (Sawada et al., J Mol Evol 54:437–457,
2002), were confirmed to be contained within the tox islands, suggested that the tox islands were an exogenous, mobile genetic element inserted into the chromosomes of P. syringae strains. It was also predicted that the tox islands integrated site-specifically into the homologous sites of the chromosomes of ACT and PHA in the same direction, respectively,
wherein 34 common gene coding sequences (CDSs) existed. Furthermore, at the left end of the tox islands were three CDSs, which encoded polypeptides and had similarities to the members of the tyrosine recombinase family,
suggesting that these putative site-specific recombinases were involved in the recent horizontal transfer of tox islands.
Electronic Supplementary Material Electronic Supplementary material is available for this article at
and accessible for authorised users. 相似文献
11.
Suk-Jin Ha Sang-Yong Kim Jin-Ho Seo Won-Il Sim Hee-Jung Moon Jung-Kul Lee 《World journal of microbiology & biotechnology》2008,24(6):887-890
By the optimization of nitrogen source for coenzyme Q10 (ubiquinone, CoQ10) production in Agrobacterium tumefaciens KCCM 10413 culture, the highest CoQ10 production was achieved in medium containing corn steep powder (CSP). Components for a stimulatory effect on the production
of CoQ10 in CSP were screened, and lactate was found to increase dry cell weight (DCW) and the specific CoQ10 content. In a fed-batch culture of A. tumefaciens, supplementation with 1.5 g of lactate l−1 further improved DCW, the specific CoQ10 content, and CoQ10 production by 16.0, 5.8, and 22.8%, respectively. It has been reported that lactate stimulates cell growth and acts as an
accelerator driving the tricarboxylic acid (TCA) cycle (Roberto et al. 2002, Biotechnol Let 24:427–431; Matsuoka et al. 1996, Biosci Biotechnol Biochem 60:575–579). In this study, lactate supplementation increased DCW and the specific CoQ10 content in A. tumefaciens culture, probably by accelerating TCA cycle and energy production as reported previously, leading to the increase of CoQ10 production. 相似文献
12.
13.
Akio Shimizu Kagayaki Morishima Masahiro Kobayashi Masahiko Kunimoto Ichiro Nakayama 《Journal of applied phycology》2008,20(1):83-88
Conchospore germlings of Porphyra yezoensis were stained with a fluorescent dye for DNA and observed with confocal laser scanning microscopy (CLSM). Relative DNA values
of the germling nuclei were obtained by measuring fluorescence intensities of nuclear regions of the optically sliced specimens,
using the mean value of the smallest blade cells as a reference of the genomic n value. Such quantification revealed that the nuclear DNA amounts of the one-cell, two-cell, and four-cell-stage germlings
are approximately 4 × n, 2 × n, and n ∼2 × n values respectively; these values agreed well with the expected ones from the hypothesis that meiosis corresponds to the
first successive cell divisions after the conchospore germination. These results are consistent with a previous study on cytogenetic
analysis of the chimaera blade formation (Ohme and Miura 1988, Plant Sci 57:135–140) and not consistent with a recent microscopic study (Wang et al. 2006, Phycol Res 54:201–207) which proposed that the first meiotic division occurs at the conchospore formation and the second
division at the germination. 相似文献
14.
Paolo Galli Giovanni Antonio Lodovico Broggini Markus Kellerhals Cesare Gessler Andrea Patocchi 《Molecular breeding : new strategies in plant improvement》2010,26(4):561-572
The Rvi15 (Vr2) apple scab resistance locus found in the GMAL 2473 accession has been previously mapped to the top of the Linkage Group
2 (LG2) by analyzing 89 progeny plants of a cross between ‘Idared’ and GMAL 2473. A new population of 989 progeny plants,
derived from a cross between ‘Golden Delicious’ and GMAL 2473, has been analyzed with the two SSR markers CH02c02a and CH02f06,
previously found to be associated with Rvi15 (Vr2), and with two published markers derived from NBS sequences (ARGH17 and ARGH37) estimated to map close to the Rvi15 (Vr2) locus. ARGH17 and ARGH37, were found to be the closest markers to the resistance locus, bracketing it within an interval
of 1.5 cM. The SSRs mapped one on each side of Rvi15 (Vr2). CH02f06 mapped at 2.9 cM from ARGH37 while CH02a02a mapped at 1.7 from ARGH17. The position of Rvi15 (Vr2) respect to CH02a02a indicates that Rvi15 (Vr2) and Rvi4 (Vh4), a second apple scab gene mapped on the top of LG2, are two different resistance genes. In order to develop even more tightly
linked markers to Rvi15 (Vr2), ARGH17 was used as the starting point for chromosome walking through the Rvi15 (Vr2) homolog region of the cv. ‘Florina’. A single ‘Florina’ BAC clone, 36I17, was sufficient to span the homologous locus in
the new population’s recombinant progeny. Sequencing of the 36I17 BAC clone allowed identifying seven putative ORFs, including
two showing a TIR-NBS-LRR structure. Ten additional markers could be developed mapping within a 1.8 cM interval around the
Rvi15 (Vr2) resistance gene. ARGH17 and GmTNL1 markers, the latter also derived from NBS-LRR resistance gene homolog sequence, are the
closest markers to Rvi15 (Vr2) bracketing it within a 0.5 cM interval. The availability of 12 markers within the Rvi15 (Vr2) region, all within a small physical distance (kbp) in ‘Florina’, suggests that cloning of the Rvi15 (Vr2) apple scab resistance gene from GMAL 2473 will be possible. 相似文献
15.
In the Baltic Sea, herring (Clupea harengus membras) spawns in the littoral zone, where its eggs are attached to algae or vascular plants. Field studies indicate that egg mortality
can be very high (up to 100%) in eggs that are attached to red algae (Rajasilta et al., 1989, 1993). Because high mortality can be due to allelochemical effects of the algae, we studied the mortality of herring eggs on different
algal substrates experimentally. Four types of substrates were tested: fresh Cladophora and Furcellaria, and Furcellaria that had decomposed six days or 23 days. The incubation time in the experiments was 3 days and incubation temperature 12–13 oC (ca. 700–800 h-degrees). The results were in accordance with observations made in field studies and indicated significant
differences among the substrate types. In eggs attached to fresh Cladophora, mortality was significantly lower (mean=2.8%; n=20) than in those attached to Furcellaria, independently of the treatment of the algae. The highest values of mortality (mean=14.4%; n=20) were found in eggs attached to Furcellaria that had decomposed over a six days’ period. This suggested that Furcellaria contain some chemical substances, which can cause mortality in herring embryos and the effect seems to be dependent on the
state of decomposition of the algae. 相似文献
16.
Sitosterol and stigmasterol are major sterols in vascular plants. An altered stigmasterol:sitosterol ratio has been proposed
to influence the properties of cell membranes, particularly in relation to various stresses, but biosynthesis of stigmasterol
is poorly understood. Recently, however, Morikawa et al. (Plant Cell 18:1008–1022, 2006) showed in Arabidopsis thaliana that synthesis of stigmasterol and brassicasterol is catalyzed by two separate sterol C-22 desaturases, encoded by the genes
CYP710A1 and CYP710A2, respectively. The proteins belong to a small cytochrome P450 subfamily having four members, denoted by CYP710A1-A4, and
are related to the yeast sterol C-22 desaturase Erg5p acting in ergosterol synthesis. Here, we report on our parallel investigation
of the Arabidopsis CYP710A family. To elucidate the function of CYP710A proteins, transgenic Arabidopsis plants were generated overexpressing CYP710A1 and CYP710A4. Compared to wild-type plants, both types of transformant displayed a normal phenotype, but contained increased levels of
free stigmasterol and a concomitant decrease in the level of free sitosterol. CYP710A1 transformants also displayed higher
levels of esterified forms of stigmasterol, cholesterol, 24-methylcholesterol and isofucosterol. The results confirm the findings
of Morikawa et al. (Plant Cell 18:1008–1022, 2006) regarding the function of CYP710A1 in stigmasterol synthesis, and show that CYP710A4 also has this capacity. Furthermore,
our results suggest that an increased stigmasterol level alone is sufficient to stimulate esterification of other major sterols. 相似文献
17.
Development of addiction to alcohol or other substances can be attributed in part to exposure-dependent modifications at synaptic
efficacy leading to an organism which functions at an altered homeostatic setpoint. Genetic factors may also influence setpoints
and the stability of the homeostatic system of an organism. Quantitative genetic analysis of voluntary alcohol drinking, and
mapping of the involved genes in the quasi-congenic Recombinant QTL Introgression strain system, identified Eac2 as a Quantitative Trait Locus (QTL) on mouse chromosome 6 which explained 18% of the variance with an effect size of 2.09 g/kg/day
alcohol consumption, and Grm7 as a quantitative trait gene underlying Eac2 [Vadasz et al. in Neurochem Res 32:1099–1112, 100, Genomics 90:690–702, 102]. In earlier studies, the product of Grm7 mGluR7, a G protein-coupled receptor, has been implicated in stress systems [Mitsukawa et al. in Proc Natl Acad Sci USA 102:18712–18717,
63], anxiety-like behaviors [Cryan et al. in Eur J Neurosci 17:2409–2417, 14], memory [Holscher et al. in Learn Mem 12:450–455, 26], and psychiatric disorders (e.g., [Mick et al. in Am J Med Genet B Neuropsychiatr Genet 147B:1412–1418, 61; Ohtsuki et al. in Schizophr Res 101:9–16, 72; Pergadia et al. in Paper presented at the 38th Annual Meeting of the Behavior Genetics Association, Louisville, Kentucky,
USA, 76]. Here, in experiments with mice, we show that (1) Grm7 knockout mice express increased alcohol consumption, (2) sub-congenic, and congenic mice carrying a Grm7 variant characterized by higher Grm7 mRNA drink less alcohol, and show a tendency for higher circadian dark phase motor activity in a wheel running paradigm,
respectively, and (3) there are significant genetic differences in Grm7 mRNA abundance in the mouse brain between congenic and background mice identifying brain areas whose function is implicated
in addiction related processes. We hypothesize that metabotropic glutamate receptors may function as regulators of homeostasis,
and Grm7 (mGluR7) is involved in multiple processes (including stress, circadian activity, reward control, memory, etc.) which interact
with substance use and the development of addiction. In conclusion, we suggest that mGluR7 is a significant new therapeutic
target in addiction and related neurobehavioral disorders. 相似文献
18.
Screening apples for OPD20/600 using sequence-specific primers 总被引:13,自引:0,他引:13
H. Yang S. S. Korban 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(2):263-266
Apple scab, caused by Venturia inaequalis (Cke.) Wint., is the most serious disease of apple trees in many areas of the world. Resistance to V. inaequalis, derived from the small-fruited species Malus floribunda 821, is determined by a major dominant gene, Vf. Using random decamer primers, we identified a RAPD marker, OPD20/600, which is linked to the Vf gene. OPD20/600 was then cloned and sequenced. Sequence-specific primers based on the marker were used to further screen M. floribunda 821, 7 scab-susceptible apple cultivars, 10 scab-resistant apple cultivars, and 28 scab-resistant Coop selections. The sequence-specific primers allowed identification of polymorphisms of OPD20/600 based on the presence or absence of a single band. The advantages of sequence-specific primers over decamer primers for developing genetic markers are discussed. 相似文献
19.
Hurtado P 《Bulletin of mathematical biology》2008,70(8):2264-2282
Since its introduction into eastern North America in the 1940s, the eastern population of house finches (Carpodacus mexicanus) has become partially migratory, unlike its nonmigratory source population in southern California (Able and Belthoff in Proc.
R. Soc. Lond. 265 (1410), 2063–2071, 1998; Belthoff and Gauthreaux in Condor 93, 374–382, 1991). The infectious disease mycoplasmal conjunctivitis (pathogen Mycoplasma gallisepticum or “MG”), which has been monitored in the house finch population since its appearance around 1993 (Dhondt et al. in J. Wild.
Dis. 34 (2), 265–280, 1998), may induce higher mortality rates among populations in more northerly latitudes relative to more southerly populations.
Here, we investigate the potential impact of this differential disease mortality on the migratory structure of the eastern
house finch population using an epidemic modeling approach. Analytical and computational results suggest the ongoing MG epidemic
in the eastern house finch could lead to increases in the percentage of and the total number of migrating individuals in a
population despite overall population declines, assuming relatively high winter mortality rates in the north eastern part
of their range. These results also suggest that empirical evidence of such a change in migratory structure would be most noticeable
in northerly inland populations that showed significant declines following the initial outbreak of MG in the east. 相似文献
20.
Etzel CJ Chen WV Shepard N Jawaheer D Cornelis F Seldin MF Gregersen PK Amos CI;North American Rheumatoid Arthritis Consortium 《Human genetics》2006,119(6):634-641
Meta-analysis is being increasingly used as a tool for integrating data from different studies of complex phenotypes, because the power of any one study to identify causal loci is limited. We applied a novel meta-analytical approach (Loesgen et al. in Genet Epidemiol 21(Suppl 1):S142–S147, 2001) in compiling results from four studies of rheumatoid arthritis in Caucasians including two studies from NARAC (Jawaheer et al. in Am J Hum Genet 68:927–936, 2001; Jawaheer et al. in Arthritis Rheum 48:906–916, 2003), one study from the UK (MacKay et al. in Arthritis Rheum 46:632–639, 2001) and one from France (Cornelis et al. in Proc Natl Acad Sci USA 95:10746–10750, 1998). For each study, we obtained NPL scores by performing interval mapping (2 cM intervals) using GeneHunter2 (Kruglyak et al. in Am J Hum Genet 58:1347–1363, 1996; Markianos et al. in Am J Hum Genet 68:963–977, 2001). The marker maps differed among the three consortium groups, therefore, the marker maps were aligned after the interval mapping was completed and the NPL scores that were within 1 cM of each other were combined using the method of Loesgen et al. (Genet Epidemiol 21(Suppl 1):S142–S147, 2001) by calculating the weighted average of the NPL score. This approach avoids some problems in analysis encountered by using GeneHunter2 when some markers in the sample are not genotyped. This procedure provided marginal evidence (P<0.05) of linkage on chromosome 1, 2, 5 and 18, strong evidence (P<0.01) on chromosomes 8 and 16, and overwhelming evidence in the HLA region of chromosome 6. 相似文献