共查询到20条相似文献,搜索用时 0 毫秒
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Julie Jacquemin Jetty S.S. Ammiraju Georg Haberer Dean D. Billheimer Yeisoo Yu Liana C. Liu Luis F. Rivera Klaus Mayer Mingsheng Chen Rod A. Wing 《植物生理与分子生物学学报》2014,(4):642-656
In analyzing gene families in the whole-genome sequences available for O. sativa (AA), O. glaberrima (AA), and O. brachyantha (FF), we observed large size expansions in the AA genomes compared to FF genomes for the superfamilies F-box and NB-ARC, and five additional families: the Aspartic proteases, BTB/POZ proteins (BTB), Glutaredoxins, Trypsin a-amylase inhibitor proteins, and Zf-Dof proteins. Their evolutionary dynamic was investigated to understand how and why such important size variations are observed between these closely related species. We show that expansions resulted from both amplification, largely by tandem duplications, and contraction by gene losses. For the F-box and NB-ARC gene families, the genes conserved in all species were under strong purifying selection while expanded orthologous genes were under more relaxed purifying selection. In F-box, NB-ARC, and BTB, the expanded groups were enriched in genes with little evidence of expression, in comparison with conserved groups. We also detected 87 loci under positive selection in the expanded groups. These results show that most of the duplicated copies in the expanded groups evolve neutrally after duplication because of functional redundancy but a fraction of these genes were preserved following neofunctionalization. Hence, the lineage-specific expansions observed between Oryza species were partly driven by directional selection. 相似文献
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The chimpanzees (Pan troglodytes schweinfurthii) of Gombe National Park, Tanzania, were weighed regularly over a period of 33 yr, resulting in 1286 measurements on 31 males and 26 females aged 2–43 yr. Female growth slowed at 10 yr and that of males at 13 yr. Median adult body mass is 39 kg for males and 31.3 kg for females. Body mass varied between years. Chimpanzees were heaviest during a period of frequent banana provisioning. They were also heavier when community range size was large and population density within the range was low. Chimpanzees were heavier in the wet than in the dry season and body mass tracked rainfall in the preceding mo except for May in which mass was anomalously low. Dominance rank is significantly correlated with body mass for females but not males. High-ranking individuals tended to maintain more stable mass. Variability in body mass was greater for young and old individuals than for prime adults. 相似文献
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Background
Rhabdodontid ornithopod dinosaurs are characteristic elements of Late Cretaceous European vertebrate faunas and were previously collected from lower Campanian to Maastrichtian continental deposits. Phylogenetic analyses have placed rhabdodontids among basal ornithopods as the sister taxon to the clade consisting of Tenontosaurus, Dryosaurus, Camptosaurus, and Iguanodon. Recent studies considered Zalmoxes, the best known representative of the clade, to be significantly smaller than closely related ornithopods such as Tenontosaurus, Camptosaurus, or Rhabdodon, and concluded that it was probably an island dwarf that inhabited the Maastrichtian Haţeg Island.Methodology/Principal Findings
Rhabdodontid remains from the Santonian of western Hungary provide evidence for a new, small-bodied form, which we assign to Mochlodon vorosi n. sp. The new species is most similar to the early Campanian M. suessi from Austria, and the close affinities of the two species is further supported by the results of a global phylogenetic analysis of ornithischian dinosaurs. Bone histological studies of representatives of all rhabdodontids indicate a similar adult body length of 1.6–1.8 m in the Hungarian and Austrian species, 2.4–2.5 m in the subadults of both Zalmoxes robustus and Z. shqiperorum and a much larger, 5–6 m adult body length in Rhabdodon. Phylogenetic mapping of femoral lengths onto the results of the phylogenetic analysis suggests a femoral length of around 340 mm as the ancestral state for Rhabdodontidae, close to the adult femoral lengths known for Zalmoxes (320–333 mm).Conclusions/Significance
Our analysis of body size evolution does not support the hypothesis of autapomorhic nanism for Zalmoxes. However, Rhabdodon is reconstructed as having undergone autapomorphic giantism and the reconstructed small femoral length (245 mm) of Mochlodon is consistent with a reduction in size relative to the ancestral rhabdodontid condition. Our results imply a pre-Santonian divergence between western and eastern rhabdodontid lineages within the western Tethyan archipelago. 相似文献7.
Dhanasekaran Vijaykrishna Yi-Mo Deng Yvonne C. F. Su Mathieu Fourment Pina Iannello George G. Arzey Philip M. Hansbro K. Edla Arzey Peter D. Kirkland Simone Warner Kim O'Riley Ian G. Barr Gavin J. D. Smith Aeron C. Hurt 《Journal of virology》2013,87(18):10182-10189
Influenza A H10N7 virus with a hemagglutinin gene of North American origin was detected in Australian chickens and poultry abattoir workers in New South Wales, Australia, in 2010 and in chickens in Queensland, Australia, on a mixed chicken and domestic duck farm in 2012. We investigated their genomic origins by sequencing full and partial genomes of H10 viruses isolated from wild aquatic birds and poultry in Australia and analyzed them with all available avian influenza virus sequences from Oceania and representative viruses from North America and Eurasia. Our analysis showed that the H10N7 viruses isolated from poultry were similar to those that have been circulating since 2009 in Australian aquatic birds and that their initial transmission into Australia occurred during 2007 and 2008. The H10 viruses that appear to have developed endemicity in Australian wild aquatic birds were derived from several viruses circulating in waterfowl along various flyways. Their hemagglutinin gene was derived from aquatic birds in the western states of the United States, whereas the neuraminidase was closely related to that from viruses previously detected in waterfowl in Japan. The remaining genes were derived from Eurasian avian influenza virus lineages. Our analysis of virological data spanning 40 years in Oceania indicates that the long-term evolutionary dynamics of avian influenza viruses in Australia may be determined by climatic changes. The introduction and long-term persistence of avian influenza virus lineages were observed during periods with increased rainfall, whereas bottlenecks and extinction were observed during phases of widespread decreases in rainfall. These results extend our understanding of factors affecting the dynamics of avian influenza and provide important considerations for surveillance and disease control strategies. 相似文献
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John A. Nyakatura Vivian R. Allen Jonas Laustr?er Amir Andikfar Marek Danczak Hans-Jürgen Ullrich Werner Hufenbach Thomas Martens Martin S. Fischer 《PloS one》2015,10(9)
Orobates pabsti, a basal diadectid from the lower Permian, is a key fossil for the understanding of early amniote evolution. Quantitative analysis of anatomical information suffers from fragmentation of fossil bones, plastic deformation due to diagenetic processes and fragile preservation within surrounding rock matrix, preventing further biomechanical investigation. Here we describe the steps taken to digitally reconstruct MNG 10181, the holotype specimen of Orobates pabsti, and subsequently use the digital reconstruction to assess body mass, position of the centre of mass in individual segments as well as the whole animal, and study joint mobility in the shoulder and hip joints. The shape of most fossil bone fragments could be recovered from micro-focus computed tomography scans. This also revealed structures that were hitherto hidden within the rock matrix. However, parts of the axial skeleton had to be modelled using relevant isolated bones from the same locality as templates. Based on the digital fossil, mass of MNG 10181 was estimated using a model of body shape that was varied within a plausible range to account for uncertainties of the dimension. In the mean estimate model the specimen had an estimated mass of circa 4 kg. Varying of the mass distribution amongst body segments further revealed that Orobates carried most of its weight on the hind limbs. Mostly unrestricted joint morphology further suggested that MNG 10181 was able to effectively generate propulsion with the pelvic limbs. The digital reconstruction is made available for future biomechanical studies. 相似文献
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Newcastle Disease Virus (NDV) is a pathogenic strain of avian paramyxovirus (aPMV-1) that is among the most serious of disease threats to the poultry industry worldwide. Viral diversity is high in aPMV-1; eight genotypes are recognized based on phylogenetic reconstruction of gene sequences. Modified live vaccines have been developed to decrease the economic losses caused by this virus. Vaccines derived from avirulent genotype II strains were developed in the 1950s and are in use globally, whereas Australian strains belonging to genotype I were developed as vaccines in the 1970s and are used mainly in Asia. In this study, we evaluated the consequences of attenuated live virus vaccination on the evolution of aPMV-1 genotypes. There was phylogenetic incongruence among trees based on individual genes and complete coding region of 54 full length aPMV-1 genomes, suggesting that recombinant sequences were present in the data set. Subsequently, five recombinant genomes were identified, four of which contained sequences from either genotype I or II. The population history of vaccine-related genotype II strains was distinct from other aPMV-1 genotypes; genotype II emerged in the late 19th century and is evolving more slowly than other genotypes, which emerged in the 1960s. Despite vaccination efforts, genotype II viruses have experienced constant population growth to the present. In contrast, other contemporary genotypes showed population declines in the late 1990s. Additionally, genotype I and II viruses, which are circulating in the presence of homotypic vaccine pressure, have unique selection profiles compared to nonvaccine-related strains. Collectively, these data show that vaccination with live attenuated viruses has changed the evolution of aPMV-1 by maintaining a large effective population size of a vaccine-related genotype, allowing for coinfection and recombination of vaccine and wild type strains, and by applying unique selective pressures on viral glycoproteins. 相似文献
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Jason S. Long Wendy A. Howard Alejandro Nú?ez Olivier Moncorgé Samantha Lycett Jill Banks Wendy S. Barclay 《Journal of virology》2013,87(18):9983-9996
Clade 2.2 Eurasian-lineage H5N1 highly pathogenic avian influenza viruses (HPAIVs) were first detected in Qinghai Lake, China, in 2005 and subsequently spread through Asia, Europe, and Africa. Importantly, these viruses carried a lysine at amino acid position 627 of the PB2 protein (PB2 627K), a known mammalian adaptation motif. Previous avian influenza virus isolates have carried glutamic acid in this position (PB2 627E), commonly described to restrict virus polymerase function in the mammalian host. We sought to examine the effect of PB2 627K on viral maintenance in the avian reservoir. Viruses constructed by reverse genetics were engineered to contain converse PB2 627K/E mutations in a Eurasian H5N1 virus (A/turkey/Turkey/5/2005 [Ty/05]) and, for comparison, a historical pre-Asian H5N1 HPAIV that naturally bears PB2 627E (A/turkey/England/50-92/1991 [50-92]). The 50-92 PB2 627K was genetically unstable during virus propagation, resulting in reversion to PB2 627E or the accumulation of the additional mutation PB2 628R and/or a synonymous mutation from an A to a G nucleotide at nucleotide position 1869 (PB2 A1869G). Intriguingly, PB2 628R and/or A1869G appeared to improve the genetic stability of 50-92 PB2 627K. However, the replication of 50-92 PB2 627K in conjunction with these stabilizing mutations was significantly restricted in experimentally infected chickens, where reversion to PB2 627E occurred. In contrast, no significant effects on viral fitness were observed for Ty/05 PB2 627E or 627K in in vitro or in vivo experiments. Our observations suggest that PB2 627K is supported in Eurasian-lineage viruses; in contrast, PB2 627K carries a significant fitness cost in the historical pre-Asian 50-92 virus. 相似文献
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Paul Baker Karthikeyan Muthumayandi Craig Gerrand Benjamin Kleim Karen Bettinson David Deehan 《PloS one》2013,8(3)
Background
The number of patients presenting for total knee replacement who are classified as obese is increasing. The functional benefits of performing TKR in these patients are unclear.Aim
To assess the influence pre-operative body mass index has upon knee specific function, general health status and patient satisfaction at 3 years following total knee replacement.Design
Retrospective comparative cohort study using prospectively collected data from an institutional arthroplasty register.Methods
1367 patients were assessed using the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Medical Outcomes Trust Short Form-36 (SF-36) scores supplemented by a validated measure of satisfaction pre-operatively and subsequently at 1,2 and 3 year post-operatively. Comparisons were made by dividing the cohort into 4 groups based on body mass index (BMI) 18.5–25.0 kg/m2 (n = 253);>25.0–30.0 kg/m2 (n = 559);>30.0−35.0 kg/m2 (n = 373);>35.0 kg/m2 (n = 182).Results
Despite lower pre-operative, 1 and 3 year WOMAC and SF-36 scores patients with the highest BMIs >35.0 kg/m2 experienced similar improvements to patients with a ‘normal‘ BMI (18.5–25.0 kg/m2) at 1 year (Difference in WOMAC improvement = 0.0 (95%CI −5.2 to 5.2), p = 1.00) and this improvement was sustained at up to 3 years (Difference in 1 year to 3 year improvement = 2.2 (95%CI: −2.1 to 6.5), p = 1.00). This effect was also observed for the SF-36 mental and physical component scores. Despite equivalent functional improvements levels of satisfaction in the >35.0 kg/m2 group were lower than for any other BMI group (>35.0 kg/m2 = 84.6% satisfied versus 18.5–5.0 kg/m2 = 93.3% satisfied,p = 0.01) as was the proportion of patients who stated they would have the operation again (>35.0 kg/m2 = 69.6% versus 18.5–25.0 kg/m2 = 82.2%,p = 0.01).Conclusion
Obese and morbidly obese patients gain as much functional benefit from total knee replacement as patients with lesser body mass indexes. This benefit is maintained for up to 3 years following surgery. However, these patients are less satisfied with their knee replacement and almost a third would not have the operation again. 相似文献12.
Locusts jump by rapidly releasing energy from cuticular springs built into the hind femur that deform when the femur muscle contracts. This study is the first to examine the effect of temperature on jump energy at each life stage of any orthopteran. Ballistics and high-speed cinematography were used to quantify the energy, distance, and take-off angle of the jump at 15, 25, and 35°C in the locust Locusta migratoria. Allometric analysis across the five juvenile stages at 35°C reveals that jump distance (D; m) scales with body mass (M; g) according to the power equation D = 0.35M0.17±0.08 (95% CI), jump take-off angle (A; degrees) scales as A = 52.5M0.00±0.06, and jump energy (E; mJ per jump) scales as E = 1.91M1.14±0.09. Temperature has no significant effect on the exponent of these relationships, and only a modest effect on the elevation, with an overall Q10 of 1.08 for jump distance and 1.09 for jump energy. On average, adults jump 87% farther and with 74% more energy than predicted based on juvenile scaling data. The positive allometric scaling of jump distance and jump energy across the juvenile life stages is likely facilitated by the concomitant relative increase in the total length (Lf+t; mm) of the femur and tibia of the hind leg, Lf+t = 34.9M0.37±0.02. The weak temperature-dependence of jump performance can be traced to the maximum tension of the hind femur muscle and the energy storage capacity of the femur''s cuticular springs. The disproportionately greater jump energy and jump distance of adults is associated with relatively longer (12%) legs and a relatively larger (11%) femur muscle cross-sectional area, which could allow more strain loading into the femur''s cuticular springs. Augmented jump performance in volant adult locusts achieves the take-off velocity required to initiate flight. 相似文献
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Marta Barluenga rés Barbosa & Eulalia Moreno 《Ethology : formerly Zeitschrift fur Tierpsychologie》2003,109(12):971-979
We studied the effect of daily body mass increase on the foraging preferences of two tit species, crested tit, Parus cristatus and blue tit, P. caeruleus, contrasting in morphology and behaviour. We found that both species show a diurnal increase in body mass during winter. Using an experiment with feeders we show that in the crested tit, the proportion of time spent foraging while hanging decreased as body mass increased. In contrast, in the blue tit, foraging behaviour did not change with mass gain. We propose that the species with a morphological design providing a high ecological plasticity in terms of foraging postures can counteract the negative effect of body mass on the ecological options (foraging niche) more than species with a morphological design providing a low ecological plasticity in terms of foraging postures. Our results suggest that blue tits had the advantage of being able to choose to feed on different patches in the habitat throughout the day, which makes resources more predictable for them. In contrast, crested tits might be more restricted in their foraging options as their body mass increases, and this might explain why they hoard food. 相似文献
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Naoyoshi Nagata Kayo Sakamoto Tomohiro Arai Ryota Niikura Takuro Shimbo Masafumi Shinozaki Noriko Ihana Katsunori Sekine Hidetaka Okubo Kazuhiro Watanabe Toshiyuki Sakurai Chizu Yokoi Mikio Yanase Junichi Akiyama Naomi Uemura Mitsuhiko Noda 《PloS one》2015,10(4)
Background
This study aims to investigate the association between body mass index (BMI) or intra-abdominal fat measured by computed tomography (CT) and bowel symptoms.Method
A cohort of 958 Japanese adults who underwent colonoscopy and CT and completed questionnaires after excluding colorectal diseases was analyzed. Six symptoms (constipation, diarrhea, loose stools, hard stools, fecal urgency, and incomplete evacuation) using a 7-point Likert scale were evaluated between baseline and second questionnaire for test-retest reliability. Associations between BMI, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and symptom score were analyzed by a rank-ordered logistic model, adjusting for age, sex, smoking, and alcohol consumption, hypertension, diabetes mellitus, and dyslipidemia.Results
Some bowel symptom scores were significantly (p<0.05) different between the age groups, sexes, smoking, and alcohol consumption. In multivariate analysis, constipation was associated with low BMI (p<0.01), low VAT area (p = 0.01), and low SAT area (p<0.01). Moreover, hard stools was associated with low BMI (p<0.01) and low SAT area (p<0.01). The remaining symptoms were not significantly associated with BMI or intra-abdominal fat. Test-retest reliability of bowel symptom scores with a mean duration of 7.5 months was good (mean kappa, 0.672).Conclusions
Both low BMI and low abdominal fat accumulation appears to be useful indicators of increased risk for constipation and hard stools. The long-term test-retest reliability of symptom score suggests that bowel symptoms relevant to BMI or visceral fat remain consistent over several months. 相似文献15.
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Evolutionary geneticists have increasingly used sequence variation in mitochondrial DNA (mtDNA) as a source of historical information. However, conclusions based on these data remain tentative because a sufficiently clear understanding of the evolutionary dynamics of mtDNA has yet to be developed. In this paper we present the results of computer simulations designed to illustrate the effects of social structure, geographical structure, and population size on the rate of nucleotide substitution and lineage sorting of mtDNA. The model is based in part on the social structure of macaque monkeys. Simulated populations of females were divided into 25 social groups; the animals in each were distributed in a hierarchy of four dominance rank categories. The probabilities for offspring survivorship were varied among dominance ranks to reflect the fitness consequences of social structure. Population size was varied across runs from 100 to 300 females. The pattern of female migration was also varied to mimic either the island model or the stepping-stone model. All these variables are shown to affect the lineage sorting period (LSP), and certain combinations of parameter values can cause the retention of mtDNA polymorphisms for a very long time. In addition, the simulations exhibited a negative relationship between the LSP and substitution rate over a modest and realistic range of LSP values. An important implication of these results is that estimates of time since isolation based on the assumption of a constant molecular clock may be biased and unreliable. 相似文献
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Francisco J. Zamora-Camacho Senda Reguera M. Virtudes Rubiño-Hispán Gregorio Moreno-Rueda 《Evolutionary biology》2014,41(4):509-517
Most animals rely on their escape speed to flee from predators. Here, we test several hypotheses on the evolution of escape speed in the lizard Psammodromus algirus. We test that: (1) Longer limbs should improve speed sprint. (2) Heavier lizards should be impaired regarding their sprint speed ability, suggesting a trade-off between fat storage and escape capability. (3) Males should achieve faster speeds due to their higher exposure to predators. (4) Gravid females, with increased body mass, should perform lower speed than non-gravid females. And (5) there are inter-population differences in sprint speed across an elevational gradient. We measured lizards sprint speed in a lineal raceway in the laboratory, filming races in standardized conditions and then calculating their maximal speed. We found that hind limb length greatly determined maximal sprint speed, lizards with longer limbs being faster. In parallel, higher body masses reduced maximal speed, which points to a trade-off between fat storage and escaping capability. Sexual differences also arose, as males were faster than females, as a consequence of males having longer limbs. Regarding females, gravidity did not impair maximal sprint speed, suggesting adaptations which compensate for the increased body mass. Finally, we found no elevational trend in both limbs length and sprint speed. In any case, this study suggests that selection on escape capacity may cast morphological evolution, and affect other life-history traits, such as fat storage and reproduction. 相似文献
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TRIMCyp is a fusion protein consisting of the TRIM5 gene product and retrotransposed Cyclophilin A (CypA). Two primate TRIMCyp fusion proteins with varying anti-HIV-1 activities independently evolved in owl monkeys and Old World monkeys. In addition, Old World monkey TRIMCyps lack exon7, which encodes amino acids in the Linker2 region. Previous studies on TRIM5α indicated that this region affects anti-retroviral activity, cytoplasmic body formation, and multimerization. The effects of exon7 deletion on the functions of the TRIMCyp are unclear. In this study, we found that the cytoplasmic bodies and multimers of owl monkey TRIMCyp (omTRIMCyp) are different from those of northern pig-tailed macaque TRIMCyp (npmTRIMCyp). In addition, we demonstrated that exon7 deletion affected cytoplasmic body formation and multimerization. Moreover, we unexpectedly found two chimeric proteins of omTRIMCyp and npmTRIMCyp that failed to block HIV-1 replication, despite the presence of CypA in omTRIMCyp. Further studies indicated that the cytoplasmic bodies and spontaneous multimerization were not responsible for TRIMCyp anti-HIV-1 activity. Moreover, potent viral restriction is associated with higher amounts of monomeric TRIMCyp when the CypA domain is able to recognize and bind to the HIV-1 capsid. Our results suggested that the deletion of exon7 during the evolution of TRIMCyp affected its function. 相似文献
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Sujuan Zhang Yi Wu Wenjing Pan Guoyi Li Di Zhang Shuyi Li Qi Huang Zhao-min Liu 《Endocrine practice》2022,28(4):398-404
ObjectiveMaternal overweight or obesity during early pregnancy can increase the subsequent risk of gestational diabetes mellitus (GDM). However, whether these associations are mediated by thyroid hormones and their effect sizes is still unknown. This study aimed to identify the mediating effects of thyroid parameters between prepregnancy body mass index (BMI) or maternal weight gain during early pregnancy on the subsequent risk of GDM.MethodsThis prospective mother-infant cohort study was conducted from 2018 to 2019. A total of 2772 singleton pregnant women were included in the analysis. A questionnaire survey, anthropometric measures, and thyroid function testing were conducted during early pregnancy. Deiodinase activity was evaluated using the free-triiodothyronine-to-free-thyroxine ratio (FT3:FT4). The standard 75-g oral glucose tolerance test was performed during 24 to 28 weeks of gestation to diagnose GDM. A mediation analysis was performed using PROCESS 3.5 to examine the mediating effects of thyroid parameters between prepregnancy BMI or maternal weight gain during early pregnancy on the subsequent risk of GDM.ResultsThe FT3:FT4 ratio was a significant mediator between prepregnancy BMI or maternal weight gain and GDM, accounting for 16.5% and 18.6% of total effects, respectively. FT3 also mediated the association of prepregnancy BMI with GDM, accounting for 3.3% of the total effects. Thyroid-stimulating hormone suppressed the effects of prepregnancy BMI and maternal weight gain on GDM risk, and the proportion of their total effects was 2.4% and 6.4%, respectively.ConclusionDeiodinase activity, as indicated by the FT3:FT4 ratio, was the strongest mediator among thyroid parameters between prepregnancy BMI or maternal early weight gain and GDM. 相似文献