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1.
J Integr Plant Biol ; 66(6): 1052-1067, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38501444

RESUMO

ACYL-CoA-BINDING PROTEINs (ACBPs) play crucial regulatory roles during plant response to hypoxia, but their molecular mechanisms remain poorly understood. Our study reveals that ACBP4 serves as a positive regulator of the plant hypoxia response by interacting with WRKY70, influencing its nucleocytoplasmic shuttling in Arabidopsis thaliana. Furthermore, we demonstrate the direct binding of WRKY70 to the ACBP4 promoter, resulting in its upregulation and suggesting a positive feedback loop. Additionally, we pinpointed a phosphorylation site at Ser638 of ACBP4, which enhances submergence tolerance, potentially by facilitating WRKY70's nuclear shuttling. Surprisingly, a natural variation in this phosphorylation site of ACBP4 allowed A. thaliana to adapt to humid conditions during its historical demographic expansion. We further observed that both phosphorylated ACBP4 and oleoyl-CoA can impede the interaction between ACBP4 and WRKY70, thus promoting WRKY70's nuclear translocation. Finally, we found that the overexpression of orthologous BnaC5.ACBP4 and BnaA7.WRKY70 in Brassica napus increases submergence tolerance, indicating their functional similarity across genera. In summary, our research not only sheds light on the functional significance of the ACBP4 gene in hypoxia response, but also underscores its potential utility in breeding flooding-tolerant oilseed rape varieties.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA , Fosforilação , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
2.
Mol Biol Evol ; 39(2)2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35022759

RESUMO

Hybridization and resulting introgression are important processes shaping the tree of life and appear to be far more common than previously thought. However, how the genome evolution was shaped by various genetic and evolutionary forces after hybridization remains unresolved. Here we used whole-genome resequencing data of 227 individuals from multiple widespread Populus species to characterize their contemporary patterns of hybridization and to quantify genomic signatures of past introgression. We observe a high frequency of contemporary hybridization and confirm that multiple previously ambiguous species are in fact F1 hybrids. Seven species were identified, which experienced different demographic histories that resulted in strikingly varied efficacy of selection and burdens of deleterious mutations. Frequent past introgression has been found to be a pervasive feature throughout the speciation of these Populus species. The retained introgressed regions, more generally, tend to contain reduced genetic load and to be located in regions of high recombination. We also find that in pairs of species with substantial differences in effective population size, introgressed regions are inferred to have undergone selective sweeps at greater than expected frequencies in the species with lower effective population size, suggesting that introgression likely have higher potential to provide beneficial variation for species with small populations. Our results, therefore, illustrate that demography and recombination have interplayed with both positive and negative selection in determining the genomic evolution after hybridization.


Assuntos
Genoma de Planta , Populus , Hibridização Genética , Mutação , Populus/genética , Seleção Genética
3.
Mol Ecol ; 31(5): 1543-1561, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34910340

RESUMO

Global climate changes during the Miocene may have created ample opportunities for hybridization between members of tropical and subtropical biomes at the boundary between these zones. Yet, very few studies have explored this possibility. The Yunnan-Guizhou Plateau (YGP) in Southwest China is a biodiversity hotspot for vascular plants, located in a transitional area between the floristic regions of tropical Southeast Asia and subtropical East Asia. The genus Eriobotrya (Rosaceae) comprises both tropical and subtropical taxa, with 12 species recorded in the YGP, making it a suitable basis for testing the hypothesis of between-biome hybridization. Therefore, we surveyed the evolutionary history of Eriobotrya by examining three chloroplast regions and five nuclear genes for 817 individuals (47 populations) of 23 Eriobotrya species (including 19 populations of 12 species in the YGP), plus genome re-sequencing of 33 representative samples. We concluded that: (1) phylogenetic positions for 16 species exhibited strong cytonuclear conflicts, most probably due to ancient hybridization; (2) the YGP is a hotspot for hybridization, with 11 species showing clear evidence of chloroplast capture; and (3) Eriobotrya probably originated in tropical Asia during the Eocene. From the Miocene onwards, the intensification of the Eastern Asia monsoon and global cooling may have shifted the tropical-subtropical boundary and caused secondary contact between species, thus providing ample opportunity for hybridization and diversification of Eriobotrya, especially in the YGP. Our study highlights the significant role that paleoclimate changes probably played in driving hybridization and generating rich species diversity in climate transition zones.


Assuntos
Eriobotrya , Evolução Biológica , China , Humanos , Filogenia , Filogeografia
4.
Mol Phylogenet Evol ; 172: 107485, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35452840

RESUMO

Inferring accurate biogeographic history of plant taxa with an East Asia (EA)-North America (NA) is usually hindered by conflicting phylogenies and a poor fossil record. The current distribution of Chamaecyparis (false cypress; Cupressaceae) with four species in EA, and one each in western and eastern NA, and its relatively rich fossil record, make it an excellent model for studying the EA-NA disjunction. Here we reconstruct phylogenomic relationships within Chamaecyparis using > 1400 homologous nuclear and 61 plastid genes. Our phylogenomic analyses using concatenated and coalescent approaches revealed strong cytonuclear discordance and conflicting topologies between nuclear gene trees. Incomplete lineage sorting (ILS) and hybridization are possible explanations of conflict; however, our coalescent analyses and simulations suggest that ILS is the major contributor to the observed phylogenetic discrepancies. Based on a well-resolved species tree and four fossil calibrations, the crown lineage of Chamaecyparis is estimated to have originated in the upper Cretaceous, followed by diversification events in the early and middle Paleogene. Ancestral area reconstructions suggest that Chamaecyparis had an ancestral range spanning both EA and NA. Fossil records further indicate that this genus is a relict of the "boreotropical" flora, and that local extinctions of European species were caused by global cooling. Overall, our results unravel a complex evolutionary history of a Paleogene relict conifer genus, which may have involved ILS, hybridization and the extinction of local species.


Assuntos
Chamaecyparis , Cupressaceae , Traqueófitas , Evolução Biológica , Filogenia , Traqueófitas/genética
5.
Glob Chang Biol ; 28(16): 4832-4844, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35561010

RESUMO

Global warming has been linked to declines in tree growth. However, it is unclear how the asymmetry in daytime and nighttime warming influences this response. Here, we use 2947 residual tree-ring width chronologies covering 32 species at 2493 sites, between 1901 and 2018, across the Northern Hemisphere, to analyze the effects of daytime and nighttime temperatures, precipitation, and drought stress on the radial growth of trees. We show that drought stress was primarily triggered by daytime rather than nighttime warming. The radial growth of trees was more sensitive to drought stress in warm regions than in cold regions, especially for angiosperms. Our study provides robust evidence that daytime warming is the primary driver of the observed declines in forest productivity related to drought stress and that daytime and nighttime warming should be considered separately when modelling forest-climate interactions and feedbacks in a future, warmer world.


Assuntos
Mudança Climática , Árvores , Clima , Secas , Florestas
6.
Cladistics ; 38(2): 187-203, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34551153

RESUMO

The Eastern Asia (EA) - North America (NA) disjunction is a well-known biogeographic pattern of the Tertiary relict flora; however, few studies have investigated the evolutionary history of this disjunction using a phylogenomic approach. Here, we used 2369 single copy nuclear genes and nearly full plastomes to reconstruct the evolutionary history of the small Tertiary relict genus Thuja, which consists of five disjunctly distributed species. The nuclear species tree strongly supported an EA clade Thuja standishii-Thuja sutchuenensis and a "disjunct clade", where western NA species T. plicata is sister to an EA-eastern NA disjunct Thuja occidentalis-Thuja koraiensis group. Our results suggested that the observed topological discordance among the gene trees as well as the cytonuclear discordance is mainly due to incomplete lineage sorting, probably facilitated by the fast diversification of Thuja around the Early Miocene and the large effective population sizes of ancestral lineages. Furthermore, approximately 20% of the T. sutchuenensis nuclear genome is derived from an unknown ancestral lineage of Thuja, which might explain the close resemblance of its cone morphology to that of an ancient fossil species. Overall, our study demonstrates that single genes may not resolve interspecific relationships for disjunct taxa, and that more reliable results will come from hundreds or thousands of loci, revealing a more complex evolutionary history. This will steadily improve our understanding of their origin and evolution.


Assuntos
Cupressaceae , Thuja , Ásia , Fósseis , Filogenia , Thuja/genética
7.
Plant J ; 103(1): 430-442, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32168389

RESUMO

Species are becoming extinct at unprecedented rates as a consequence of human activity. Hence it is important to understand the evolutionary dynamics of species with already small population sizes. Populus ilicifolia is a vulnerable poplar species that is isolated from other poplar species and is uniquely adapted to the Tropics. It has a very limited size, reproduces partly clonally and is therefore an excellent case study for conservation genomics. We present here the first annotated draft genome of P. ilicifolia, characterize genome-wide patterns of polymorphisms and compare those to other poplar species with larger natural ranges. P. ilicifolia experienced a more prolonged and severe decline of effective population size (Ne ) and signs of genetic erosion than any other poplar species with which it was compared. At present, the species has the lowest genome-wide genetic diversity, the highest abundance of long runs of homozygosity, high inbreeding levels as well as a high overall accumulation of deleterious variants. However, more effective purging of severely deleterious variants and adaptation to the Tropics may have contributed to its survival. Hence, in spite of its limited genetic variation, it is certainly worth pursuing the conservation efforts of this unique species.


Assuntos
Genoma de Planta/genética , Populus/genética , Reprodução Assexuada/genética , Espécies em Perigo de Extinção , Variação Genética/genética , Genoma de Planta/fisiologia , Homozigoto , Endogamia , Polimorfismo Genético/genética , Populus/fisiologia , Clima Tropical
8.
Ann Bot ; 128(7): 903-918, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34472580

RESUMO

BACKGROUND AND AIMS: Understanding the population genetics and evolutionary history of endangered species is urgently needed in an era of accelerated biodiversity loss. This knowledge is most important for regions with high endemism that are ecologically vulnerable, such as the Qinghai-Tibet Plateau (QTP). METHODS: The genetic variation of 84 juniper trees from six populations of Juniperus microsperma and one population of Juniperus erectopatens, two narrow-endemic junipers from the QTP that are sister to each other, was surveyed using RNA-sequencing data. Coalescent-based analyses were used to test speciation, migration and demographic scenarios. Furthermore, positively selected and climate-associated genes were identified, and the genetic load was assessed for both species. KEY RESULTS: Analyses of 149 052 single nucleotide polymorphisms showed that the two species are well differentiated and monophyletic. They diverged around the late Pliocene, but interspecific gene flow continued until the Last Glacial Maximum. Demographic reconstruction by Stairway Plot detected two severe bottlenecks for J. microsperma but only one for J. erectopatens. The identified positively selected genes and climate-associated genes revealed habitat adaptation of the two species. Furthermore, although J. microsperma had a much wider geographical distribution than J. erectopatens, the former possesses lower genetic diversity and a higher genetic load than the latter. CONCLUSIONS: This study sheds light on the evolution of two endemic juniper species from the QTP and their responses to Quaternary climate fluctuations. Our findings emphasize the importance of speciation and demographic history reconstructions in understanding the current distribution pattern and genetic diversity of threatened species in mountainous regions.


Assuntos
Traqueófitas , Biodiversidade , Ecossistema , Variação Genética , Genética Populacional , Filogenia , Tibet
9.
Mol Ecol ; 29(7): 1250-1266, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32150782

RESUMO

Having a comprehensive understanding of population structure, genetic differentiation and demographic history is important for the conservation and management of threatened species. High-throughput sequencing (HTS) provides exciting opportunities to address a wide range of factors for conservation genetics. Here, we generated HTS data and identified 266,884 high-quality single nucleotide polymorphisms from 82 individuals of Cupressus chengiana, to assess population genomics across the species' full range, comprising the Daduhe River (DDH), Minjiang River (MJR) and Bailongjiang River (BLJ) catchments in western China. admixture, principal components analysis and phylogenetic analyses indicated that each region contains a distinct lineage, with high levels of differentiation between them (DDH, MJR and BLJ lineages). MJR was newly distinguished compared to previous surveys, and evidence including coalescent simulations supported a hybrid origin of MJR during the Quaternary. Each of these three lineages should be recognized as an evolutionarily significant unit (ESU), due to isolation, differing genetic adaptations and different demographic history. Currently, each ESU faces distinct threats, and will require different conservation strategies. Our work shows that population genomic approaches using HTS can reconstruct the complex evolutionary history of threatened species in mountainous regions, and hence inform conservation efforts, and contribute to the understanding of high biodiversity in mountains.


Assuntos
Cupressus/genética , Genética Populacional , Hibridização Genética , Núcleo Celular/genética , China , Conservação dos Recursos Naturais , DNA de Cloroplastos/genética , Ecossistema , Espécies em Perigo de Extinção , Evolução Molecular , Fluxo Gênico , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Polimorfismo de Nucleotídeo Único , RNA-Seq , Transcriptoma
10.
New Phytol ; 222(1): 576-587, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30415488

RESUMO

Nonbifurcating divergence caused by introgressive hybridization is continuously reported for groups of closely related species. In this study, we aimed to reconstruct the genome-scale classification of deep lineages of the conifer genus Picea, establish their phylogenetic relationships and test the bifurcating hypothesis between deeply branching lineages based on genomic data. We sequenced the transcriptomes of 35 individuals of 27 taxa covering all main lineages of the genus. Four major lineages, comprising three to 12 taxa each, largely consistent with morphological evidence, were recovered across the coalescent and integrated nuclear phylogeny. However, many of the individual gene trees recovered contradict one another. Moreover, the well-supported coalescent tree inferred here differs from previous studies based on various DNA markers, with respect to topology and inter-lineage relationships. We identified the shared polymorphisms between four major lineages. ABBA-BABA tests confirmed the inter-lineage gene flow and thus violated the bifurcating divergence model. Gene flow occurred more frequently between lineages distributed in the same continent than those disjunct between continents. Our results indicate that introgression and nonbifurcating diversification apply, even between deeply branching lineages of the conifer genus Picea.


Assuntos
Variação Genética , Filogenia , Picea/genética , Polimorfismo Genético , Núcleo Celular/genética , Bases de Dados Genéticas , Fluxo Gênico , Genoma de Planta , Haplótipos/genética
11.
Ann Bot ; 123(1): 153-167, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30124771

RESUMO

Background and Aims: Rapid evolutionary divergence and reticulate evolution may result in phylogenetic relationships that are difficult to resolve using small nucleotide sequence data sets. Next-generation sequencing methods can generate larger data sets that are better suited to solving these puzzles. One major and long-standing controversy in conifers concerns generic relationships within the subfamily Cupressoideae (105 species, approx. 1/6 of all conifers) of Cupressaceae, in particular the relationship between Juniperus, Cupressus and the Hesperocyparis-Callitropsis-Xanthocyparis (HCX) clade. Here we attempt to resolve this question using transcriptome-derived data. Methods: Transcriptome sequences of 20 species from Cupressoideae were collected. Using MarkerMiner, single-copy nuclear (SCN) genes were extracted. These were applied to estimate phylogenies based on concatenated data, species trees and a phylogenetic network. We further examined the effect of alternative backbone topologies on downstream analyses, including biogeographic inference and dating analysis. Results: Based on the 73 SCN genes (>200 000 bp total alignment length) we considered, all tree-building methods lent strong support for the relationship (HCX, (Juniperus, Cupressus)); however, strongly supported conflicts among individual gene trees were also detected. Molecular dating suggests that these three lineages shared a most recent common ancestor approx. 60 million years ago (Mya), and that Juniperus and Cupressus diverged about 56 Mya. Ancestral area reconstructions (AARs) suggest an Asian origin for the entire clade, with subsequent dispersal to North America, Europe and Africa. Conclusions: Our analysis of SCN genes resolves a controversial phylogenetic relationship in the Cupressoideae, a major clade of conifers, and suggests that rapid evolutionary divergence and incomplete lineage sorting probably acted together as the source for conflicting phylogenetic inferences between gene trees and between our robust results and recently published studies. Our updated backbone topology has not substantially altered molecular dating estimates relative to previous studies; however, application of the latest AAR approaches has yielded a clearer picture of the biogeographic history of Cupressoideae.


Assuntos
Cupressaceae/classificação , Cupressaceae/genética , Proteínas de Plantas/análise , Transcriptoma , Filogenia
12.
Ann Bot ; 121(4): 665-679, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29324975

RESUMO

Background and Aims: Glacial refugia and inter-/postglacial recolonization routes during the Quaternary of tree species in Europe and North America are well understood, but far less is known about those of tree species in subtropical eastern Asia. Thus, we have examined the phylogeographic history of Populus adenopoda (Salicaceae), one of the few poplars that naturally occur in this subtropical area. Methods: Genetic variations across the range of the species in subtropical China were surveyed using ten nuclear microsatellite loci and four chloroplast fragments (matK, trnG-psbK, psbK-psbI and ndhC-trnV). Coalescent-based analyses were used to test demographic and migration hypotheses. In addition, species distribution models (SDMs) were constructed to infer past, present and future potential distributions of the species. Key Results: Thirteen chloroplast haplotypes were detected, and haplotype-rich populations were found in central and southern parts of the species' range. STRUCTURE analyses of nuclear microsatellite loci suggest obvious lineage admixture, especially in peripheral and northern populations. DIYABC analysis suggests that the species might have experienced two independent rounds of demographic expansions and a strong bottleneck in the late Quaternary. SDMs indicate that the species' range contracted during the Last Glacial Maximum (LGM), and contracted northward but expanded eastward during the Last Interglacial (LIG). Conclusions: Chloroplast data and SDMs suggest that P. adenopoda might have survived in multiple glacial refugia in central and southern parts of its range during the LGM. Populations of the Yunnan-Guizhou Plateau in the southern part have high chloroplast DNA diversity, but may have contributed little to the postglacial recolonization of northern and eastern parts. The three major demographic events inferred by DIYABC coincide with the initiation of the LIG, start of the LGM and end of the LGM, respectively. The species may have experienced multiple rounds of range contraction during glacial periods and range expansion during interglacial periods. Our study corroborates the importance of combining multiple lines of evidence when reconstructing Quaternary population evolutionary histories.


Assuntos
Populus , China , DNA de Cloroplastos/genética , Demografia , Ecossistema , Variação Genética/genética , Genética Populacional , Haplótipos/genética , Repetições de Microssatélites/genética , Populus/genética , Refúgio de Vida Selvagem , Clima Tropical
13.
BMC Genomics ; 18(1): 176, 2017 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-28209119

RESUMO

BACKGROUND: The family Brassicaceae encompasses diverse species, many of which have high scientific and economic importance. Early diversifications and phylogenetic relationships between major lineages or clades remain unclear. Here we re-investigate Brassicaceae phylogeny with complete plastomes from 51 species representing all four lineages or 5 of 6 major clades (A, B, C, E and F) as identified in earlier studies. RESULTS: Bayesian and maximum likelihood phylogenetic analyses using a partitioned supermatrix of 77 protein coding genes resulted in nearly identical tree topologies exemplified by highly supported relationships between clades. All four lineages were well identified and interrelationships between them were resolved. The previously defined Clade C was found to be paraphyletic (the genus Megadenia formed a separate lineage), while the remaining clades were monophyletic. Clade E (lineage III) was sister to clades B + C rather than to all core Brassicaceae (clades A + B + C or lineages I + II), as suggested by a previous transcriptome study. Molecular dating based on plastome phylogeny supported the origin of major lineages or clades between late Oligocene and early Miocene, and the following radiative diversification across the family took place within a short timescale. In addition, gene losses in the plastomes occurred multiple times during the evolutionary diversification of the family. CONCLUSIONS: Plastome phylogeny illustrates the early diversification of cruciferous species. This phylogeny will facilitate our further understanding of evolution and adaptation of numerous species in the model family Brassicaceae.


Assuntos
Brassicaceae/genética , Cloroplastos/genética , Genoma de Cloroplastos/genética , Filogenia , Teorema de Bayes , Brassicaceae/classificação , Genes de Plantas/genética , Funções Verossimilhança , Alinhamento de Sequência
14.
BMC Plant Biol ; 16: 89, 2016 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-27091174

RESUMO

BACKGROUND: The factors that contribute to and maintain hybrid zones between distinct species are highly variable, depending on hybrid origins, frequencies and fitness. In this study, we aimed to examine genetic origins, compositions and possible maintenance of Populus × jrtyschensis, an assumed natural hybrid between two distantly related species. This hybrid poplar occurs mainly on the floodplains along the river valleys between the overlapping distributions of the two putative parents. RESULTS: We collected 566 individuals from 45 typical populations of P. × jrtyschensis, P. nigra and P. laurifolia. We genotyped them based on the sequence variations of one maternally inherited chloroplast DNA (cpDNA) fragment and genetic polymorphisms at 20 SSR loci. We further sequenced eight nuclear genes for 168 individuals from 31 populations. Two groups of cpDNA haplotypes characteristic of P. nigra and P. laurifolia respectively were both recovered for P. × jrtyschensis. Genetic structures and coalescent tests of two sets of nuclear population genetic data suggested that P. × jrtyschensis originated from hybridizations between the two assumed parental species. All examined populations of P. × jrtyschensis comprise mainly F1 hybrids from interspecific hybridizations between P. nigra and P. laurifolia. In the habitats of P. × jrtyschensis, there are lower concentrations of soil nitrogen than in the habitats occupied by the other two species. CONCLUSIONS: Our extensive examination of the genetic composition of P. × jrtyschensis suggested that it is typical of F1-dominated hybrid zones. This finding plus the low concentration of soil nitrogen in the floodplain soils support the F1-dominated bounded hybrid superiority hypothesis of hybrid zone maintenance for this particular hybrid poplar.


Assuntos
DNA de Cloroplastos/genética , Variação Genética , Repetições de Microssatélites/genética , Populus/genética , Núcleo Celular/genética , DNA de Cloroplastos/química , DNA de Plantas/química , DNA de Plantas/genética , Ecossistema , Inundações , Fluxo Gênico , Genética Populacional , Geografia , Haplótipos , Vigor Híbrido/genética , Hibridização Genética , Polimorfismo Genético , Populus/classificação , Populus/crescimento & desenvolvimento , Rios , Análise de Sequência de DNA , Especificidade da Espécie
15.
Mol Ecol ; 25(11): 2373-86, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27093071

RESUMO

Hybridization and introgression are believed to play important roles in plant evolution. However, few empirical studies have been designed to clarify the ways in which these processes complicate taxonomic delimitation. Recent phylogenetic studies based on a number of different DNA fragments have indicated that Picea brachytyla in the eastern Qinghai-Tibet Plateau is polyphyletic, a finding that contrasts with traditional taxonomy based on morphological traits. We aimed to test this conflict using transcriptomic data from 26 trees collected from multiple localities for this and related species. Our phylogenomic analyses suggest that the sampled trees of P. brachytyla cluster into two distinct lineages corresponding to the two taxonomically recognized intraspecific varieties: var. brachytyla and var. complanata. However, var. complanata nested within Picea likiangensis and was sister to one of its three varieties, while var. brachytyla comprised an isolated lineage. The polyphyletic origin hypothesis was further supported by likelihood tree comparisons using Akaike's information criterion (AIC) and by coalescent analyses under the snapp model. However, our abba-baba and ∂a∂i analyses suggest that gene flow between these two independently evolved lineages has been extensive and bidirectional. Introgression, as well as parallel evolution in the arid habitats common to both lineages, may have given rise to their morphological similarity. Our study highlights the importance of genomic evidence and the use of newly developed coalescent analysis methods for clarifying the evolutionary complexity of certain plant taxa.


Assuntos
Evolução Molecular , Fluxo Gênico , Genética Populacional , Filogenia , Picea/genética , China , Hibridização Genética , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , RNA de Plantas/genética , Tibet , Transcriptoma
16.
Proc Natl Acad Sci U S A ; 109(20): 7793-8, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22550176

RESUMO

Most extant genus-level radiations in gymnosperms are of Oligocene age or younger, reflecting widespread extinction during climate cooling at the Oligocene/Miocene boundary [∼23 million years ago (Ma)]. Recent biogeographic studies have revealed many instances of long-distance dispersal in gymnosperms as well as in angiosperms. Acting together, extinction and long-distance dispersal are likely to erase historical biogeographic signals. Notwithstanding this problem, we show that phylogenetic relationships in the gymnosperm family Cupressaceae (162 species, 32 genera) exhibit patterns expected from the Jurassic/Cretaceous breakup of Pangea. A phylogeny was generated for 122 representatives covering all genera, using up to 10,000 nucleotides of plastid, mitochondrial, and nuclear sequence per species. Relying on 16 fossil calibration points and three molecular dating methods, we show that Cupressaceae originated during the Triassic, when Pangea was intact. Vicariance between the two subfamilies, the Laurasian Cupressoideae and the Gondwanan Callitroideae, occurred around 153 Ma (124-183 Ma), when Gondwana and Laurasia were separating. Three further intercontinental disjunctions involving the Northern and Southern Hemisphere are coincidental with or immediately followed the breakup of Pangea.


Assuntos
Cupressaceae/fisiologia , Demografia/história , Fósseis , Filogenia , Sequência de Bases , Teorema de Bayes , Cupressaceae/genética , Evolução Molecular , Geografia , História Antiga , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , Filogeografia , Análise de Sequência de DNA , Especificidade da Espécie
17.
Mol Phylogenet Evol ; 78: 87-95, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24841538

RESUMO

Haloragaceae are a cosmopolitan plant family with its centre of diversity in Australia. Here, we investigate the historical biogeography of the family and the role of vicariance or dispersal in shaping its current distribution. DNA sequences from ITS, matK and the trnK 5' and trnK 3' introns were obtained for 102 species representing all 8 genera of Haloragaceae for use in Bayesian molecular dating. Molecular dating was conducted using two macrofossils as calibration points for the analyses. Biogeographic history was investigated using a Bayesian dispersal-vicariance analysis and a dispersal-extinction-cladogenesis model. The results suggest that the earliest diversification of the extant Haloragaceae occurred in Australia during the Eocene (37.3-56.3Ma). Early diversification of the family in the Southern Hemisphere is inferred as resulting from vicariance events among Australia, South America and New Zealand. The results also indicate multiple out of Australia dispersal routes, primarily including (1) from Australia to Asia during the Miocene, with subsequent dispersal to Europe and North America; (2) from Australia to New Zealand, then to South America during the Miocene and Pliocene. Most of the inferred dispersal events occurred throughout the Miocene and later, and are biased towards the aquatic Haloragaceae lineages.


Assuntos
Magnoliopsida/genética , Dispersão Vegetal , Austrália , Teorema de Bayes , Especiação Genética , Magnoliopsida/classificação , Filogenia , Filogeografia , Análise de Sequência de DNA
19.
Biochem Genet ; 52(3-4): 181-202, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24292698

RESUMO

Understanding the extent and distribution of genetic diversity is crucial for the conservation and management of endangered species. Cupressus chengiana, C. duclouxiana, C. gigantea, and C. funebris are four ecologically and economically important species in China. We investigated their genetic diversity, population structure, and extant effective population size (35 populations, 484 individuals) employing six pairs of nuclear microsatellite markers (selected from 53). Their genetic diversity is moderate among conifers, and genetic differentiation among populations is much lower in C. gigantea than in the other three species; the estimated effective population size was largest for C. chengiana, at 1.70, 2.91, and 3.91 times the estimates for C. duclouxiana, C. funebris, and C. gigantea, respectively. According to Bayesian clustering analysis, the most plausible population subdivision scheme within species is two groups in C. chengiana, three groups in C. duclouxiana, and a single group for both C. funebris and C. gigantea. We propose a conservation strategy for these cypress species.


Assuntos
Conservação dos Recursos Naturais , Cupressus/genética , Variação Genética , Repetições de Microssatélites , Animais , Teorema de Bayes , China , Análise por Conglomerados , DNA de Plantas/genética , Genética Populacional , Análise de Sequência de DNA
20.
Mitochondrial DNA B Resour ; 9(6): 738-742, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38881576

RESUMO

The present study firstly reported a complete mitochondrial genome of Minois paupera (Alphéraky, 1888), a Satyrinae species endemic to China. This mitogenome is circular, 15,213 bp in length, and consists of 37 typical mitochondrial genes, including 13 protein-coding genes (PCGs), 22 tRNAs, and two rRNAs. The phylogenetic position was inferred using 31 previously published complete mitogenomes, and the results reveal that M. paupera is the most closely related to Minois dryas. The complete mitogenome of M. paupera provides useful genetic information for further research on the phylogeography and phylogeny of the genus Minois.

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