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1.
Nat Commun ; 10(1): 4201, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519986

RESUMO

As Charles Darwin anticipated, living fossils provide excellent opportunities to study evolutionary questions related to extinction, competition, and adaptation. Ginkgo (Ginkgo biloba L.) is one of the oldest living plants and a fascinating example of how people have saved a species from extinction and assisted its resurgence. By resequencing 545 genomes of ginkgo trees sampled from 51 populations across the world, we identify three refugia in China and detect multiple cycles of population expansion and reduction along with glacial admixture between relict populations in the southwestern and southern refugia. We demonstrate multiple anthropogenic introductions of ginkgo from eastern China into different continents. Further analyses reveal bioclimatic variables that have affected the geographic distribution of ginkgo and the role of natural selection in ginkgo's adaptation and resilience. These investigations provide insights into the evolutionary history of ginkgo trees and valuable genomic resources for further addressing various questions involving living fossil species.


Assuntos
Evolução Biológica , Genoma de Planta , Ginkgo biloba/genética , Filogenia , Adaptação Fisiológica , China , Fósseis , Genômica , Sementes/genética , Seleção Genética
2.
Heredity (Edinb) ; 121(6): 594-604, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29479059

RESUMO

Ecological speciation is an important factor in the diversification of plants. The distribution of the woody species Rhododendron indicum, which grows along rivers and is able to withstand water flow when rivers flood (i.e. it is a rheophyte), is disjunct, in contrast to the widespread distribution of its relative, Rhododendron kaempferi. This study aimed to elucidate the phylogenetic relationships between R. indicum and R. kaempferi and the evolutionary processes that gave rise to them. The sequences of three non-coding chloroplast DNA regions (total length 1977 bp) were obtained from 21 populations covering the ranges of the two species. In addition, genome-wide SNPs were genotyped from 20 populations using a genotyping by sequencing method. Leaf morphologies were measured for eight representative populations. Two chloroplast DNA haplotypes, which were detected in R. indicum, were shared between the two species. Genome-wide SNPs identified two lineages in R. indicum and these lineages did not constitute a monophyletic group. Each of these two lineages was related to geographically close populations of R. kaempferi. Leaf morphology, which is a characteristic feature in rheophytes, was not differentiated between the two lineages in R. indicum. The morphological similarity between the two heterogeneous lineages may be a result of parallel evolution from R. kaempferi or of introgressive hybridization between the species due to strong selective pressure imposed by flooding.


Assuntos
Filogeografia , Rhododendron/genética , DNA de Plantas/genética , Haplótipos , Hibridização Genética , Polimorfismo de Nucleotídeo Único , Rhododendron/classificação , Especificidade da Espécie
3.
Appl Plant Sci ; 4(4)2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27144104

RESUMO

PREMISE OF THE STUDY: Microsatellite markers can be used to evaluate population structure and genetic diversity in native populations of Indigofera pseudotinctoria (Fabaceae) and assess genetic disturbance caused by nonnative plants of the same species. METHODS AND RESULTS: We developed 14 markers for I. pseudotinctoria using next-generation sequencing and applied them to test two native populations, totaling 77 individuals, and a transplanted population, imported from a foreign country, of 17 individuals. The mean number of alleles was 3.310, observed heterozygosity was 0.242, and expected heterozygosity was 0.346. The fixation index in the transplanted population was 0.469, which was higher than in the native populations (0.154 and 0.158). In addition, the transplanted population contains one allele that is not shared by the native population. CONCLUSIONS: Microsatellite markers can be useful for evaluating genetic diversity within and between populations and for studying population genetics in I. pseudotinctoria and related species.

4.
Biosci Biotechnol Biochem ; 69(12): 2374-80, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16377896

RESUMO

A lectin named GFL was isolated from the fruiting body of the basidiomycete mushroom Grifola frondosa, which belongs to Aphyllophorales. The lectin had a molecular mass of 24 kDa on SDS-PAGE. The hemagglutinating activity of GFL was not inhibited by any monosaccharide, and inhibited only by porcine stomach mucin so far as tested. The occurrence of GFL was studied at three stages during fruiting body formation. The largest quantity of hemagglutinating activity was found in the fruiting body, and lesser amounts in the mycelial mat and the primordium. The 24-kDa band of GFL was found at all three stages, and the band-intensity corresponded to the level of activity in each sample. By cloning and sequencing the GFL-cDNA, the primary structure of this lectin was determined. GFL is composed of 181 amino acids, having no signal peptide. The amino acid sequence was found to be homologous to those of so-called jacalin-related plant lectins, suggesting that GFL is the first example of a jacalin-related lectin of fungal origin.


Assuntos
Basidiomycota/metabolismo , Grifola/química , Lectinas/química , Lectinas de Plantas/metabolismo , Sequência de Aminoácidos , Basidiomycota/química , Metabolismo dos Carboidratos , Cromatografia por Troca Iônica , Clonagem Molecular , DNA Complementar/biossíntese , DNA Complementar/genética , DNA Fúngico/biossíntese , DNA Fúngico/genética , Bases de Dados Genéticas , Eletroforese em Gel de Poliacrilamida , Testes de Hemaglutinação , Lectinas/biossíntese , Lectinas/genética , Dados de Sequência Molecular , Peso Molecular , Homologia de Sequência
5.
J Plant Res ; 117(4): 265-76, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15170530

RESUMO

The pollen morphology of 11 genera and 11 species of the Hydrocharitaceae and one species of the Najadaceae was studied using scanning and transmission electron microscopies, and the exine structures and sculptures are discussed in relation to pollination mechanisms and the molecular phylogeny. The pollen grains of the Hydrocharitaceae are spherical, inaperturate, and form monads or tetrads, while those of the Najadaceae are elliptical, inaperturate, and form monads. The entomophilous genera Egeria, Blyxa, Ottelia, Stratiotes, and Hydrocharis share pollen grains that have projections like spines or bacula. The anemophilous genus Limnobium has reticulate pollen grains. The hypohydrophilous genera Thalassia and Najas are characterized by pollen grains with reduced exine structures. The pollen-epihydrophilous genera Elodea and Hydrilla have tightly arranged small spinous pollen grains, and the male flower-epihydrophilous genera Enhalus and Vallisneria have reduced reticulate or gemmate exines. Character state reconstruction of the exine structures and sculptures using a molecular phylogenetic tree suggests that variation in the exine is generally correlated with the pollination mechanism; the selective pressures acting on the pollination mechanisms have reduced the exine structure in hypohydrophilous plants and resulted in various exine sculptures that are adapted to the different pollination mechanisms in entomophilous, anemophilous, and pollen-epihydrophilous plants.


Assuntos
Hydrocharitaceae/ultraestrutura , Pólen/ultraestrutura , Evolução Biológica , Hydrocharitaceae/classificação , Hydrocharitaceae/fisiologia , Microscopia Eletrônica de Varredura , Filogenia , Pólen/fisiologia , Especificidade da Espécie
6.
J Plant Res ; 117(3): 229-44, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15138844

RESUMO

The B-class MADS-box genes composed of APETALA3 ( AP3) and PISTILLATA ( PI) lineages play an important role in petal and stamen identity in previously studied flowering plants. We investigated the diversification of the AP3-like and PI-like MADS-box genes of eight species in five basal angiosperm families: Amborella trichopoda (Amborellaceae); Brasenia schreberi and Cabomba caroliniana (Cabombaceae); Euryale ferox, Nuphar japonicum, and Nymphaea tetragona (Nymphaeaceae); Illicium anisatum (Illiciaceae); and Kadsura japonica (Schisandraceae). Sequence analysis showed that a four amino acid deletion in the K domain, which was found in all previously reported angiosperm PI genes, exists in a PI homologue of Schisandraceae, but not in six PI homologues of the Amborellaceae, Cabombaceae, and Nymphaeaceae, suggesting that the Amborellaceae, Cabombaceae, and Nymphaeaceae are basalmost lineages in angiosperms. The results of molecular phylogenetic analyses were not inconsistent with this hypothesis. The AP3 and PI homologues from Amborella share a sequence of five amino acids in the 5' region of exon 7. Using the linearized tree and likelihood methods, the divergence time between the AP3 and PI lineages was estimated as somewhere between immediately after to several tens of millions of years after the split between angiosperms and extant gymnosperms. Estimates of the age of the most recent common ancestor of all extant angiosperms range from approximately 140-210 Ma, depending on the trees used and assumptions made.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Domínio MADS/genética , Magnoliopsida/genética , Filogenia , Sequência de Aminoácidos , Proteínas de Arabidopsis/metabolismo , DNA Complementar/química , DNA Complementar/genética , DNA de Plantas/química , DNA de Plantas/genética , Proteínas de Domínio MADS/metabolismo , Magnoliopsida/química , Dados de Sequência Molecular , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
7.
J Biosci Bioeng ; 98(4): 257-62, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-16233702

RESUMO

By cloning and sequencing cDNA, the primary structure of a mycelial aggregate-specific lectin of Pleurotus cornucopiae was determined. The amino acid sequence was novel and elucidated unique properties of this lectin: It was composed of 373 amino acids, 33 of which constitute a signal sequence. The sequence of the mature lectin consisted of two homologous regions having five glycosylation recognition signals and six cysteine residues. However, the distribution of these elements in the two regions was biased. Expression of cDNA in Escherichia coli and Pichia pastoris revealed the requirement of glycosylation to produce the functional lectin. Gel filtration followed by gel electrophoretic analyses of the purified lectin showed that the active component moved faster than the bulk of the protein, suggesting that the most active lectin formed an oligomer of subunits through disulfide bonds. From these observations, a model for the structure of the active form of this lectin is proposed. Southern hybridization using the cDNA as a probe revealed the presence of several genes. The lectin gene was composed of five exons and five introns.

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