共查询到20条相似文献，搜索用时 15 毫秒
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Daniel Hebenstreit Miaoqing Fang Muxin Gu Varodom Charoensawan Alexander van Oudenaarden Sarah A Teichmann 《Molecular systems biology》2011,7(1)
The expression level of a gene is often used as a proxy for determining whether the protein or RNA product is functional in a cell or tissue. Therefore, it is of fundamental importance to understand the global distribution of gene expression levels, and to be able to interpret it mechanistically and functionally. Here we use RNA sequencing (RNA‐seq) of mouse Th2 cells, coupled with a range of other techniques, to show that all genes can be separated, based on their expression abundance, into two distinct groups: one group comprised of lowly expressed and putatively non‐functional mRNAs, and the other of highly expressed mRNAs with active chromatin marks at their promoters. These observations are confirmed in many other microarray and RNA‐seq data sets of metazoan cell types. 相似文献
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Klara K. Nordn Jaeike W. Faber Frane Babarovi&#x; Thomas L. Stubbs Tara Selly James D. Schiffbauer Petra Peharec &#x;tefani&#x; Gerald Mayr Fiann M. Smithwick Jakob Vinther 《Evolution; international journal of organic evolution》2019,73(1):15-27
Some of the most varied colors in the natural world are created by iridescent nanostructures in bird feathers, formed by layers of melanin‐containing melanosomes. The morphology of melanosomes in iridescent feathers is known to vary, but the extent of this diversity, and when it evolved, is unknown. We use scanning electron microscopy to quantify the diversity of melanosome morphology in iridescent feathers from 97 extant bird species, covering 11 orders. In addition, we assess melanosome morphology in two Eocene birds, which are the stem lineages of groups that respectively exhibit hollow and flat melanosomes today. We find that iridescent feathers contain the most varied melanosome morphologies of all types of bird coloration sampled to date. Using our extended dataset, we predict iridescence in an early Eocene trogon (cf. Primotrogon) but not in the early Eocene swift Scaniacypselus, and neither exhibit the derived melanosome morphologies seen in their modern relatives. Our findings confirm that iridescence is a labile trait that has evolved convergently in several lineages extending down to paravian theropods. The dataset provides a framework to detect iridescence with more confidence in fossil taxa based on melanosome morphology. 相似文献
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Frederico Henning Gonzalo Machado‐Schiaffino Lukas Baumgarten Axel Meyer 《Evolution; international journal of organic evolution》2017,71(5):1297-1312
Genes of major phenotypic effects and strong genetic correlations can facilitate adaptation, direct selective responses, and potentially lead to phenotypic convergence. However, the preponderance of this type of genetic architecture in repeatedly evolved adaptations remains unknown. Using hybrids between Haplochromis chilotes (thick‐lipped) and Pundamilia nyererei (thin‐lipped) we investigated the genetics underlying hypertrophied lips and elongated heads, traits that evolved repeatedly in cichlids. At least 25 loci of small‐to‐moderate and mainly additive effects were detected. Phenotypic variation in lip and head morphology was largely independent. Although several QTL overlapped for lip and head morphology traits, they were often of opposite effects. The distribution of effect signs suggests strong selection on lips. The fitness implications of several detected loci were demonstrated using a laboratory assay testing for the association between genotype and variation in foraging performance. The persistence of low fitness alleles in head morphology appears to be maintained through antagonistic pleiotropy/close linkage with positive‐effect lip morphology alleles. Rather than being based on few major loci with strong positive genetic correlations, our results indicate that the evolution of the Lake Victoria thick‐lipped ecomorph is the result of selection on numerous loci distributed throughout the genome. 相似文献
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Suegene Noh Lauren Christopher Joan E. Strassmann David C. Queller 《Ecology and evolution》2020,10(3):1119-1134
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Profiling multiple omic layers in a single cell enables the discovery and analysis of biological phenomena that are not apparent from analysis of mono‐omic data. While methods for multiomic profiling have been reported, their adoption has been limited due to high cost and complex workflows. Here, a simple method for joint profiling of gene expression and chromatin accessibility in tens to hundreds of single cells is presented. Assessed herein is the quality of resulting single cell ATAC‐ and RNA‐seq data across three cell types, examining the link between accessibility and expression at the CD3G and FTH1 loci in human primary T cells and monocytes, and comparing the accuracy of clustering solutions for mono‐omic and combined data. The new method allows biological laboratories to perform simultaneous profiling of gene expression and chromatin accessibility using standard reagents and instrumentation. This technique, in conjunction with other advances in multiomic profiling, will enable highly resolved cell state classification and more specific mechanistic hypothesis generation than is possible with mono‐omic analysis. 相似文献
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Fan Qiu Seton Bachle Jesse B. Nippert Mark C. Ungerer 《Molecular ecology resources》2020,20(3):681-691
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Javier Terol Francisco Tadeo Daniel Ventimilla Manuel Talon 《Plant biotechnology journal》2016,14(3):938-950
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Pedro Simes Inês Fragata Josiane Santos Marta A. Santos Mauro Santos Michael R. Rose Margarida Matos 《Evolution; international journal of organic evolution》2019,73(9):1839-1849
Evolutionary convergence is a core issue in the study of adaptive evolution, as well as a highly debated topic at present. Few studies have analyzed this issue using a “real‐time” or evolutionary trajectory approach. Do populations that are initially differentiated converge to a similar adaptive state when experiencing a common novel environment? Drosophila subobscura populations founded from different locations and years showed initial differences and variation in evolutionary rates in several traits during short‐term (～20 generations) laboratory adaptation. Here, we extend that analysis to 40 more generations to analyze (1) how differences in evolutionary dynamics among populations change between shorter and longer time spans, and (2) whether evolutionary convergence occurs after 60 generations of evolution in a common environment. We found substantial variation in longer term evolutionary trajectories and differences between short‐ and longer term evolutionary dynamics. Although we observed pervasive patterns of convergence toward the character values of long‐established populations, populations still remain differentiated for several traits at the final generations analyzed. This pattern might involve transient divergence, as we report in some cases, indicating that more generations should lead to final convergence. These findings highlight the importance of longer term studies for understanding convergent evolution. 相似文献
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Biological assay has been based on analysis of all individuals collected from sample populations. Bulked sample analysis (BSA), which works with selected and pooled individuals, has been extensively used in gene mapping through bulked segregant analysis with biparental populations, mapping by sequencing with major gene mutants and pooled genomewide association study using extreme variants. Compared to conventional entire population analysis, BSA significantly reduces the scale and cost by simplifying the procedure. The bulks can be built by selection of extremes or representative samples from any populations and all types of segregants and variants that represent wide ranges of phenotypic variation for the target trait. Methods and procedures for sampling, bulking and multiplexing are described. The samples can be analysed using individual markers, microarrays and high‐throughput sequencing at all levels of DNA, RNA and protein. The power of BSA is affected by population size, selection of extreme individuals, sequencing strategies, genetic architecture of the trait and marker density. BSA will facilitate plant breeding through development of diagnostic and constitutive markers, agronomic genomics, marker‐assisted selection and selective phenotyping. Applications of BSA in genetics, genomics and crop improvement are discussed with their future perspectives. 相似文献
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Havrylenko S Legouis R Negrutskii B Mirande M 《Protein science : a publication of the Protein Society》2010,19(12):2475-2484
Methionyl-tRNA synthetase (MetRS) is a multidomain protein that specifically binds tRNAMet and catalyzes the synthesis of methionyl-tRNAMet. The minimal, core enzyme found in Aquifex aeolicus is made of a catalytic domain, which catalyzes the aminoacylation reaction, and an anticodon-binding domain, which promotes tRNA-protein association. In eukaryotes, additional domains are appended in cis or in trans to the core enzyme and increase the stability of the tRNA-protein complexes. Eventually, as observed for MetRS from Homo sapiens, the C-terminal appended domain causes a slow release of aminoacyl-tRNA and establishes a limiting step in the global aminoacylation reaction. Here, we report that MetRS from the nematode Caenorhabditis elegans displays a new type of structural organization. Its very C-terminal appended domain is related to the oligonucleotide binding-fold-based tRNA-binding domain (tRBD) recovered at the C-terminus of MetRS from plant, but, in the nematode enzyme, this domain is separated from the core enzyme by an insertion domain. Gel retardation and tRNA aminoacylation experiments show that MetRS from nematode is functionally related to human MetRS despite the fact that their appended tRBDs have distinct structural folds, and are not orthologs. Thus, functional convergence of human and nematode MetRS is the result of parallel and convergent evolution that might have been triggered by the selective pressure to invent processivity of tRNA handling in translation in higher eukaryotes. 相似文献
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Avril M. Harder Janna R. Willoughby William R. Ardren Mark R. Christie 《Molecular ecology》2020,29(6):1035-1049
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