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1.
In this study we evaluated the influence of recent landscape fragmentation on the dynamics of remnant fragments from the Brazilian
Atlantic Forest. This biome is one of the richest in the world and has been extensively deforested and fragmented. We sampled
five populations of the threatened Dalbergia nigra, a tree endemic to the Brazilian Atlantic Forest, two located in a large reserve of continuous forest and three in fragments
of different sizes and levels of disturbance. In order to assess historical changes, considering the longevity of the analyzed
species, 119 adults and 116 saplings were genotyped for six microsatellite loci. Lower levels of genetic diversity were found
in the most impacted fragments when compared to the most preserved population located inside the reserve, and there was significant
genetic structure among the populations studied (pairwise F
ST = 0.031–0.152; pairwise D
EST = 0.039–0.301). However, genetic structure among saplings (F
ST = 0.056; D
EST = 0.231) was significantly lower than among adults (F
ST = 0.088; D
EST = 0.275). Estimates of contemporary gene flow based on assignment tests corroborated this result, suggesting that fragmentation
led to an increase in gene flow. This connectivity among remnant fragments could mitigate the loss of genetic diversity through
a metapopulation dynamic, but the high rate of habitat loss and the unknown long-term genetic effects add uncertainty. These
results, taken together with the presence of private alleles in disturbed populations, highlight the importance of preserving
the extant fragments. 相似文献
2.
Miluse Trtikova Sabine Güsewell Matthias Baltisberger Peter J. Edwards 《Biological invasions》2011,13(2):413-422
We investigated whether local adaptation has been important in enabling the invasive apomictic species Erigeron annuus to extend its altitudinal range in the Swiss Alps. We first conducted a field survey along several major roads crossing the
Swiss Alps to study the distribution and growth performance of E. annuus along an altitudinal gradient. We then used amplified fragment length polymorphism to assess genetic variation within and
among populations originating from different altitudes. To complement the molecular analyses, we compared the performance
of genotypes with different distributions (i.e. local, occasional, widespread genotypes) in two common gardens at 400 m and
1,000 m a.s.l. Although E. annuus was seldom found above 1,000 m, plant performance in field populations did not decrease with increasing altitude. However,
there was a significant decline in genotypic diversity within populations, and highland (711–1,100 m) populations were more
differentiated (Gst = 0.55) than lowland (200–530 m) populations (Gst = 0.33). In the common garden experiment, local genotypes
(i.e. those restricted to a single population) grew less vigorously than widespread genotypes, and were less likely to reproduce.
We found no evidence for on-going adaptive changes and conclude that any selection acting on particular genotypes at the altitudinal
limit is weak. This leads us to propose that the patterns in the distribution of genotypic diversity in E. annuus are governed by processes of occasional sexual reproduction, dispersal and extinction that are to a large extent independent
of altitude. 相似文献
3.
Alien chromosome addition lines have been widely used for identifying gene linkage groups, assigning species-specific characters
to a particular chromosome and comparing gene synteny between related species. In plant breeding, their utilization lies in
introgressing characters of agronomic value. The present investigation reports the production of intergeneric somatic hybrids
Brassica
napus (2n = 38) + Orychophragmus violaceus (2n = 24) through asymmetric fusions of mesophyll protoplasts and subsequent development of B. napus-O. violaceous chromosome addition lines. Somatic hybrids showed variations in morphology and fertility and were mixoploids (2n = 51–67) with a range of 19–28 O. violaceus chromosomes identified by genomic in situ hybridization (GISH). After pollinated with B. napus parent and following embryo rescue, 20 BC1 plants were obtained from one hybrid. These exhibited typical serrated leaves of O. violaceus or B. napus-type leaves. All BC1 plants were partially male fertile but female sterile because of abnormal ovules. These were mixoploids (2n = 41–54) with 9–16 chromosomes from O. violaceus. BC2 plants showed segregations for female fertility, leaf shape and still some chromosome variation (2n = 39–43) with 2–5 O. violaceus chromosomes, but mainly containing the whole complement from B. napus. Among the selfed progenies of BC2 plants, monosomic addition lines (2n = 39, AACC + 1O) with or without the serrated leaves of O. violaceus or female sterility were established. The complete set of additions is expected from this investigation. In addition, O. violaceus plants at diploid and tetraploid levels with some variations in morphology and chromosome numbers were regenerated from the
pretreated protoplasts by iodoacetate and UV-irradiation.
Z. Zhao and T. Hu make equal contributions to this work. 相似文献
4.
Wesley K. Savage 《Conservation Genetics》2008,9(6):1707-1710
Habitat loss is the single greatest threat to persistence of the critically threatened California tiger salamander (Ambystoma californiense). To aid management plans that designate critical habitat for this species, I developed and characterized 21 tetranucleotide
microsatellite markers using two native populations in Santa Barbara and Alameda Counties. Allelic variation and average heterozygosities
were lower in the endangered Santa Barbara population (allele range 1–4, mean 2.4; H
O = 0.308 H
E = 0.288) compared with the threatened Alameda population (allele range 2–10, mean 6.7; H
O = 0.712, H
E = 0.722). In-depth population studies using these markers will provide vital information for plans to assign critical habitat
that optimize gene flow among breeding populations, as well as for identifying non-native hybrid genotypes that threaten native
A. californiense stocks. Beyond the conservation goals for A. californiense, the close phylogenetic relationships within the tiger salamander complex also suggest a broad utility for population studies
using these markers. 相似文献
5.
A. A. Echelle J. C. Hackler J. B. Lack S. R. Ballard J. Roman S. F. Fox D. M. LeslieJr. R. A. Van Den Bussche 《Conservation Genetics》2010,11(4):1375-1387
A previous mtDNA study indicated that female-mediated gene flow was extremely rare among alligator snapping turtle populations
in different drainages of the Gulf of Mexico. In this study, we used variation at seven microsatellite DNA loci to assess
the possibility of male-mediated gene flow, we augmented the mtDNA survey with additional sampling of the large Mississippi
River System, and we evaluated the hypothesis that the consistently low within-population mtDNA diversity reflects past population
bottlenecks. The results show that dispersal between drainages of the Gulf of Mexico is rare (F
STmsat
= 0.43, ΦSTmtDNA = 0.98). Past range-wide bottlenecks are indicated by several genetic signals, including low diversity for microsatellites
(1.1–3.9 alleles/locus; H
e = 0.06–0.53) and mtDNA (h = 0.00 for most drainages; π = 0.000–0.001). Microsatellite data reinforce the conclusion from mtDNA that the Suwannee River population might eventually
be recognized as a distinct taxonomic unit. It was the only population showing fixation or near fixation for otherwise rare
microsatellite alleles. Six evolutionarily significant units are recommended on the basis of reciprocal mtDNA monophyly and
high levels of microsatellite DNA divergence. 相似文献
6.
Justine Sulawa Alexandre Robert Ulrich Köppen Peter Hauff Oliver Krone 《Biodiversity and Conservation》2010,19(1):97-112
Understanding the effect of protection measures on recovery of endangered populations is crucial for assessing the efficiency
of management plans. Following the ban of DDT, PCB and other detrimental chemicals in the 1970s, the German white-tailed eagle
population recovered rapidly. Using nest monitoring data, dead recovery data and population dynamics models, we examined both
short and long-term viabilities of the population. Between 1991 and 2005 the proportion of breeding pairs with an active nest
among territorial pairs was α = 0.88 ± 0.007. Annual breeding success was γ = 0.62 ± 0.014. Mean fledged brood size was b = 1.50 ± 0.010 fledged/successful breeding pair. The analysis of dead recovery data of 1,273 individuals ringed as nestling
between 1991 and 2006 allowed survival rates to be estimated. We needed to distinguish between “young” (5 years old) and “old”
(older than 5 years) adults. Furthermore the annual survival rate was higher for juvenile and immature birds (0.921 ± 0.024)
than for adults (s
“young” = 0.760 ± 0.097 and s
“old” = 0.875 ± 0.079), a pattern presumably explained by territorial fights. Finally, an age structured model was used to examine
the joint effect of population regulation, environmental and demographic stochasticities. All results indicated that only
pessimistic scenarios could lead to substantial extinction probabilities within 100 years. We conclude that management measures
were successful in removing the main extinction factors of the population and that future conservation efforts need to focus
on the remaining ultimate extinction causes. 相似文献
7.
We isolated and characterized seven microsatellite loci for the perennial herb Ixeridium dentatum ssp. dentatum, an apomictic triploid distributed throughout the lowland areas of East Asia. The number of alleles ranged from two to seven
in 32 screened individuals of I. dentatum ssp. dentatum from Japan. The observed and expected heterozygosities were 0.000–0.950 and 0.000–0.891, respectively, calculated using genotypes
of 20 individuals of I. dentatum ssp. nipponicum. One locus (msid4) deviated significantly from Hardy–Weinberg equilibrium (P = 0.0001). These microsatellites were also tested for cross-amplification in 11 other taxa of Lactuceae, including five endangered
taxa. These primers should be useful genetic tools not only for Ixeridium but also for other Lactuceae taxa. 相似文献
8.
Fang Liu Zhiyi He Shumin Deng Hui Zhang Nan Li Jialiang Xu 《Molecular biology reports》2011,38(3):1983-1988
Adiponectin is inversely associated with the risk of ischemic stroke through its anti-inflammatory and anti-atherogenic effects.
Genetic variations in the adiponectin gene (ADIPOQ) have been shown to be associated with the risk of ischemic stroke in Caucasians
and Japanese populations. However, it was unknown whether variations in the ADIPOQ gene were associated with the risk of ischemic
stroke in Chinese population. A case-control study was performed among 302 patients with ischemic stroke and 338 unrelated
controls in a Chinese Han population. The single-nucleotide polymorphisms (SNPs) rs266729 (−11377C/G), rs2241766 (+45T/G),
rs1501299 (+276G/T) in the ADIPOQ gene were genotyped by the polymerase chain reaction–restriction fragment length polymorphism
(PCR-RFLP) method. The frequencies of GG genotype and G allele of rs266729 in the patients with ischemic stroke were significantly
higher than those in the controls (P = 0.034, P = 0.010, respectively). In univariate logistic analysis, compared with CC genotype, GG genotype of rs266729 increased the
risk of ischemic stroke (odds ratio (OR) = 2.062, 95% confidence interval (CI) = 1.145–3.715, P = 0.016). After adjustment for potential risk factors by the multivariate logistic analysis, rs266729 remained positive correlation
with ischemic stroke (OR = 2.165; 95% CI = 1.116–4.197, P = 0.022). However, no significant association was observed among rs2241766, rs1501299 and ischemic stroke. In addition, no
significant difference was found in haplotype frequencies between the patients with ischemic stroke and control subjects.
The present study demonstrated that the promoter polymorphism rs266729 of the ADIPOQ gene was associated with an increased
risk of ischemic stroke in the Chinese Han population. 相似文献
9.
Ku70 plays an important role in the DSBR (DNA double-strand breaks repair) and maintenance of genomic integrity. Genetic variations
within human Ku70 have been demonstrated to be associated with increased risk of several types of cancers. In this hospital-based
case–control study, we aimed to investigate whether a single nucleotide polymorphism (SNP) in the promoter region (rs2267437)
of Ku70 gene is associated with susceptibility to breast cancer in Chinese Han population. A total of 293 patients with breast
cancer and 301 age-matched healthy controls were enrolled in this study. The Ku70 −1310C/G polymorphism was determined by
polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) analysis. A significant difference in genotype
distribution and allele frequency was observed between patients and controls. The CG or GG carries were at higher risk of
breast cancer compared with the CC homozygotes (OR = 1.43, 95% CI = 1.02–2.00, P = 0.038 and OR = 3.53, 95% CI = 1.60–7.80, P = 0.002, respectively). Further stratification analysis revealed that G allele was associated with an increased risk of breast
cancer among premenopausal women (OR = 1.68, 95% CI = 1.21–2.33, P = 0.002), but not in postmenopausal women (OR = 1.33, 5% CI = 0.85–2.10, P = 0.216). Our study suggests that the Ku70 −1310C/G promoter polymorphism may be a susceptibility factor for breast cancer
in Chinese Han population. 相似文献
10.
Lu N Yang Y Wang Y Liu Y Fu G Chen D Dai H Fan X Hui R Zheng Y 《Molecular biology reports》2012,39(6):6581-6589
The polymorphisms of angiotensin-converting enzyme 2 (ACE2) gene have been suggested to be linked to increase risk of essential hypertension in multiple populations. However, the
results are still debatable. To assess the association between ACE2 G8970A genetic polymorphism and essential hypertension, we conducted a meta-analysis of case–control studies across different
ethnicity. PubMed, Embase, CBM, Wanfang and VIP databases were searched, and a total of 11 separate studies in females and
nine separate studies in males met the inclusion criteria. Because ACE2 is on the X chromosome, data for each sex were analyzed separately. The selected studies contained 7,251 (4,472 females/2,779
males) hypertensive patients and 3,800 (2,161 females/1,639 males) normotensive controls. A statistically significant association
was observed between the G8970A gene polymorphism and essential hypertension risk in female hypertensive group in the recessive
genetic model (AA vs. GG+GA: P = 0.03, OR = 1.15, 95% CI = 1.02–1.30, P
heterogeneity = 0.40, I
2 = 5%, fixed-effects model). Although no association was shown between the frequency of the A allele and the genetic susceptibility
to essential hypertension in all male patients (A Allele: P = 0.38, OR = 1.10, 95% CI = 0.89–1.38, P
heterogeneity = 0.02, I
2 = 56%, random-effects model), we found that the relationship between carrier of A allele and the essential hypertension risk
in Han-Chinese male patients subgroup (A Allele: P = 0.006, OR = 1.21, 95% CI = 1.06–1.38, P
heterogeneity = 0.10, I
2 = 44%, fixed-effects model). The current meta-analysis provided solid evidence suggesting that ACE2 gene polymorphism G8790A was probably a genetic risk factor for essential hypertension across different ethnic populations
in female subjects and in Han-Chinese male subjects. 相似文献
11.
Łukasz Kruszyna Margarita Lianeri Błażej Rubis Hanna Knuła Maria Rybczyńska Sylwia Grodecka-Gazdecka Paweł P. Jagodziński 《Molecular biology reports》2011,38(2):1263-1267
The contribution of the CCL2 −2518 A>G (rs 1024611) polymorphism in the occurrence and progression of various cancers has been found to be discordant.
We studied the prevalence of the CCL2 −2518 A>G polymorphism in patients with breast cancer (n = 160) and controls (n = 323) in a sample of the Polish population.
There were no significant differences in CCL2 −2518 A>G genotypes between patients with breast tumors and controls. Odds ratio (OR) for patients bearing the GG genotype
was 1.481 (95% CI = 0.7711–2.845, P = 0.2358), and OR of the GG and AG genotypes was 0.7269 (95% CI = 0.4967–1.064, P = 0.1002). There was also no significant distinction in the prevalence of alleles between patients and healthy individuals.
OR for the CCL2 −2518 G allele frequency was 0.8903 (95% CI = 0.6611–1.199, P = 0.4441). Analysis of the association between tumor size, lymph node metastases, histological grade, and distribution of
genotypes and alleles for the CCL2 −2518 A>G polymorphism also did not show significant differences. Our results did not show association of the CCL2 −2518 A>G polymorphism with breast cancer occurrence and clinical characteristics in a sample of the Polish cohort. 相似文献
12.
The association of the two ERCC polymorphisms, Asp312Asn and Lys751Gln, with lung cancer risk remains controversial and inconclusive.
To better evaluate the potential role of the two polymorphisms and interaction with tobacco smoking in lung cancer susceptibility
presented in diverse populations, we have conducted a meta-analysis based on 26 studies from 24 publications which included
analyses of Asp312Asn (7121 cases, 8962 controls) and Lys751Gln (8396 cases, 10510 controls) polymorphisms. Overall, significantly
elevated lung cancer risk was associated with ERCC2 312Asn allele(homozygous model: OR = 1.20[1.05–1.36], P = 0.006; recessive model: OR = 1.20[1.06–1.35], P = 0.004) and 751Gln allele(homozygous model: OR = 1.31[1.17–1.46], P < 0.00001; heterozygous model: OR = 1.11[1.04–1.19], P = 0.003; recessive model: OR = 1.23[1.11–1.37], P < 0.0001; dominant model: OR = 1.15[1.08–1.23], P < 0.0001). In ethnic subgroup analyses, significantly increased risk was associated with ERCC2 312Asn allele for both Caucasians
and Asians, and 751Gln allele for both Caucasians and Latino-Americans. When stratified by smoking status, significantly elevated
risk of both polymorphisms for never-smokers was detected (dominant model, OR = 1.46[1.09–1.95] and 1.57[1.19–2.08], P = 0.01 and 0.002, respectively). In conclusion, this meta-analysis suggests that the two ERCC2 polymorphisms may contribute
to lung cancer susceptibility serving as low-penetrance risk factors. Extremely large-scale evidence would be necessary to
confirm the effects on ethnically specific populations and gene-environment interactions. 相似文献
13.
Wei B Xu Z Ruan J Zhu M Jin K Zhou D Xu Z Hu Q Wang Q Wang Z 《Molecular biology reports》2012,39(2):1997-2002
Epidemiological studies have evaluated the association between MTHFR 677C>T and 1298A>C polymorphisms and risk of male infertility.
However, the results from the published studies on the association between these two MTHFR polymorphisms and male infertility
risk are conflicting. To derive a more precise estimation of association between the MTHFR polymorphisms and risk of male
infertility, we performed a meta-analysis. A comprehensive search was conducted to identify all case–control studies of MTHFR
polymorphisms and male infertility risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength
of the association. Overall, we found that both 677C>T and 1298A>C polymorphisms were not significantly associated with male
infertility risk. However, in stratified analysis by ethnicity, we found that the 677C>T polymorphism was significantly associated
with the risk of male infertility in Asian population (TT vs. CC: OR = 1.57, 95% CI: 1.05–2.37, P = 0.03; TT vs. TC + CC: OR = 1.40, 95% CI: 1.05–1.86, P = 0.02; TT + TC vs. CC: OR = 1.34, 95% CI: 1.01–1.77, P = 0.04). Although some modest bias could not be eliminated, this meta-analysis suggested that the MTHFR 677T allele might
be a low-penetrant risk factor for male infertility, especially in Asian population. 相似文献
14.
Understanding patterns of connectivity in marine species is vital for the management and conservation of marine biodiversity.
Here, the population genetic structure of a common and abundant tropical reef damselfish, Pomacentrus amboinensis, is reported. Using nine polymorphic microsatellite loci, the genetic structure at both small (i.e., around Lizard Island,
Great Barrier Reef [GBR]) and large (GBR and Papua New Guinea [PNG]) spatial and temporal scales (2–1,600 km; 28 days– 6 years;
n = 1,119) was analyzed. Temporal analyses found no evidence of genetic differentiation within or between Lizard Island recruitment
pulses (R
ST = −0.001, P = 0.788), or corresponding established adult populations separated by 6 years of sampling (R
ST = 0.003, P = 0.116). The spatial analysis revealed that P. amboinensis populations are largely panmictic on the GBR and eastern PNG (R
ST = 0.001, P = 0.913), the only genetic discontinuity being between Kimbe Bay to the north of PNG and all populations south of PNG (R
ST = 0.077, P < 0.0001). Despite assumed high levels of self-recruitment based on previous tagging studies (15–60%), data presented here
indicate that enough recruits are dispersing to impede the evolution of genetic structure over distances as great as 1,600 kms
in this species. Data therefore indicate that the temporal genetic stability recorded here is maintained by high levels of
gene flow. 相似文献
15.
Yoshiaki Tsuda Haruo Sawada Takafumi Ohsawa Katsuhiro Nakao Hiroki Nishikawa Yuji Ide 《Tree Genetics & Genomes》2010,6(3):377-387
We evaluated the genetic structure of 16 Betula maximowicziana populations in the Chichibu mountain range, central Japan, located within a 25-km radius; all but two populations were at
altitudes of 1,100–1,400 m. The results indicate the effects of geographic topology on the landscape genetic structure of
the populations and should facilitate the development of local-scale strategies to conserve and manage them. Analyses involving
11 nuclear simple sequence repeat loci showed that most populations had similar intrapopulation genetic diversity parameters.
Population differentiation (F
ST = 0.021, G′ST = 0.033) parameters for the populations examined were low but were relatively high compared to those obtained in a previous
study covering populations in a much larger area with a radius of approximately 1,000 km (F
ST = 0.062, G′ST = 0.102). Three populations (Iriyama, Kanayamasawa, and Nishizawa) were differentiated from the other populations by Monmonier’s
and spatial analysis of molecular variance algorithms or by STRUCTURE analysis. Since a high mountain ridge (nearly 2,000 m)
separates the Kanayamasawa and Nishizawa populations from the other 14 populations and the Kanayamasawa and Nishizawa populations
are themselves separated by another mountain ridge, the genetic structure appears to be partly due to mountain ridges acting
as genetic barriers and restricting gene flow. However, the Iriyama population is genetically different but not separated
by any clear geographic barrier. These results show that the landscape genetic structure is complex in the mountain range
and we need to pay attention, within landscape genetic studies and conservation programs, to geographic barriers and local
population differentiation. 相似文献
16.
The aim of this study was to determine whether the functional mannose-binding lectin (MBL2) exon 1 codon 54 polymorphism (rs1800450) confers susceptibility to systemic lupus erythematosus (SLE) in ethnically different
populations. A meta-analysis was conducted on the MBL2 codon 54 polymorphism across 21 comparative studies. Meta-analysis showed an association between the MBL2 codon 54 B allele and SLE in all study subjects [odds ratio (OR) = 1.298, 95% confidence interval (CI) = 1.154–1.459, P = 1.4 × 10−5]. Analysis after stratification by ethnicity indicated that the MBL2 codon 54 B allele is significantly associated with SLE in Europeans, Asian, and Africans (OR = 1.246, 95% CI = 1.062–1.462,
P = 0.007; OR = 1.268, 95% CI = 1.049–1.532, P = 0.014; OR = 1.939, 95% CI = 1.269–2.962, P = 0.002, respectively). However, African Americans had a much lower prevalence of the T allele (5.8%) than any other populations
studied, whereas Asians had the highest prevalence (16.2%). This meta-analysis confirms that the MBL2 codon 54 polymorphism is associated with SLE susceptibility in different ethnic groups, and that its prevalence is ethnicity
dependent. 相似文献
17.
Xin-Ling Wang Tao Yu Jin-Song Zhang Qi-Chang Yan Ya-Hong Luo 《Cellular and molecular neurobiology》2009,29(4):549-556
Retinal Müller cells (RMCs) hypertrophy and proliferation play a crucial role in epiretinal membrane formation. This study
was designed to analyze the effects of Fibronectin and specific FAK siRNA in cell adhesion and migration in rat Müller cells.
RMCs were cultured and identified by GFAP, Vimentin, and GLAST mAb, respectively. The cells were planted on dishes coated
with Fibronectin at 0, 1, 5, 10, 50, and 100 μg/ml. The attachment and migration assay was applied to characterize the RMCs–Fibronectin
interactions. Cell lysis and Western blotting were utilized to detect β1-integrin, FAK, and GLAST protein expression. Then the cells were treated with FAK siRNA, non-targeting siRNA, and control
medium. The cell cycle and apoptosis rate was determined by flow cytometry. The attachment, migration, and Western blotting
assay were repeated. These data suggested that almost all the cells expressed GFAP, Vimentin, and GLAST, respectively, which
ensured most of the harvested cells were RMCs. In attachment assay, the A570 values increased significantly with time (F = 1105.439, P < 0.001) and Fibronectin concentration (F = 424.683, P < 0.001). There were significant difference between each Fibronectin concentration in RMCs migration (F = 34.703, P < 0.000). The expression ratio of FAK, β1-integrin, and GLAST elevated significantly as Fibronectin concentration increased (F = 54.755, P < 0.000; F = 119.962, P < 0.000; F = 39.287, P < 0.000). The Fibronectin pretreatment was settled on 50 μg/ml for siRNA inhibition assays. The specific FAK siRNA treatment
significantly increased G0/G1 percentage and apoptosis rate compared with NT siRNA and control group (F = 11.526, P = 0.009; F = 64.772, P < 0.000). The apoptotic rate was significantly suppressed by inhibitors of caspase-8 and 3 (F = 10.500, P = 0.011). The A570 values were significantly suppressed in FAK siRNA groups compared with NT siRNA and control group (F = 154.241, P < 0.000), and the mean migratory cells per view field were significantly decreased (F = 10.906, P = 0.001). FAK and GLAST expression ratio decreased significantly after FAK siRNA treatment (F = 5.315, P = 0.047; F = 5.985, P = 0.042). Take together, FAK is involved in β1-integrin mediated adhesive signaling and play a critical role in regulating Müller cell adhesion, migration, and so far as
to glutamate transportation functions. 相似文献
18.
Jorge C. Pereira Raquel Chaves Alexandra Leitão Domitilia Matias Henrique Guedes-Pinto 《Helgoland Marine Research》2011,65(3):361-367
The clam Ruditapes decussatus is commercially important in the south of Portugal. The random amplified polymorphic DNA (RAPD) technique was applied to
assess the genetic diversity and population structure of two Portuguese populations occurring in the Ria Formosa (Faro) and
the Ria de Alvor, respectively. Twenty-five individuals of each population were investigated by RAPD profiles. Genetic diversity
within populations, measured by the percentage of polymorphic loci (%P), varied between 68.57% (Alvor) and 73.88% (Faro). Shannon’s information index (H) and Nei’s gene diversity (h) were 0.281 and 0.176, respectively, for the Alvor population and 0.356 and 0.234 for the Faro population. Overall, genetic
variation within R. decussatus populations was high. The total genetic diversity (H
T) was explained by a low variation between populations (G
ST = 0.145), which is consistent with high gene flow (N
m = 2.9). The analysis of molecular variance (AMOVA) showed that 65% of variability is within populations and 35% between populations
(ΦPT = 0.345; P ≥ 0.001). The value of Nei’s genetic distance was 0.0881, showing a low degree of population genetic distance, despite the
different geographic origin. This is the first study on the population genetics of R. decussatus by RAPD technique. The results may be useful for restocking programs and aquaculture. 相似文献
19.
It is hypothesized that high expression of the excision repair cross-complementation group 1 (ERCC1) gene might be a positive
prognostic factor, but predict decreased sensitivity to platinum-based chemotherapy. Results from the published data are inconsistent.
To derive a more precise estimation of the relationship between ERCC1 and the prognosis and predictive response to chemotherapy
of non-small cell lung cancer (NSCLC), a meta-analysis was performed. An electronic search of the PubMed and Embase database
was performed. Hazard ratio (HR) for overall survival (OS) was pooled in early stage patients received surgery alone to analyze
the prognosis of ERCC1 on NSCLC. HRs for OS in patients received surgery plus adjuvant chemotherapy and in patients received
palliative chemotherapy and relative risk (RR) for overall response to chemotherapy were aggregated to analyze the prediction
of ERCC1 on NSCLC. The pooled HR indicated that high ERCC1 levels were associated with longer survival in early stage patients
received surgery alone (HR, 0.69; 95% confidence interval (CI), 0.58–0.83; P = 0.000). There was no difference in survival between high and low ERCC1 levels in patients received surgery plus adjuvant
chemotherapy (HR, 1.41; 95% CI, 0.93–2.12; P = 0.106). However, high ERCC1 levels were associated with shorter survival and lower response to chemotherapy in advanced
NSCLC patients received palliative chemotherapy (HR, 1.75; 95% CI, 1.39–2.22; P = 0.000; RR, 0.77; 95% CI, 0.64–0.93; P = 0.007; respectively). The meta-analysis indicated that high ERCC1 expression might be a favourable prognostic and a drug
resistance predictive factor for NSCLC. 相似文献
20.
Romolo Caniglia Elena Fabbri Sarah Cubaynes Olivier Gimenez Jean-Dominique Lebreton Ettore Randi 《Conservation Genetics》2012,13(1):53-64
Non-invasive genetic sampling (NGS) is increasingly used to estimate the abundance of rare or elusive species such as the
wolf (Canis lupus), which cannot be directly counted in forested mountain habitats. Wolf individual and familial home ranges are wide, potentially
connected by long-range dispersers, and their populations are intrinsically open. Appropriate demographic estimators are needed,
because the assumptions of homogeneous detection probability and demographic closeness are violated. We compiled the capture–recapture
record of 418 individual wolf genotypes identified from ca. 4,900 non-invasive samples, collected in the northern Italian
Apennines from January 2002 to June 2009. We analysed this dataset using novel capture–recapture multievent models for open
populations that explicitly account for individual detection heterogeneity (IDH). Overall, the detection probability of the
weakly detectable individuals, probably pups, juveniles and migrants (P = 0.08), was ca. six times lower than that of the highly detectable wolves (P = 0.44), probably adults and dominants. The apparent annual survival rate of weakly detectable individuals was lower (Φ = 0.66)
than those of highly detectable wolves (Φ = 0.75). The population mean annual finite rate of increase was λ = 1.05 ± 0.11,
and the mean annual size ranged from N = 117 wolves in 2003 to N = 233 wolves in 2007. This procedure, combining large-scale NGS and multievent IDH demographic models, provides the first
estimates of abundance, multi-annual trend and survival rates for an open large wolf population in the Apennines. These results
contribute to deepen our understanding of wolf population ecology and dynamics, and provide new information to implement sound
long-term conservation plans. 相似文献