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1.
Nat Plants ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32042158

RESUMO

Hornworts, liverworts and mosses are three early diverging clades of land plants, and together comprise the bryophytes. Here, we report the draft genome sequence of the hornwort Anthoceros angustus. Phylogenomic inferences confirm the monophyly of bryophytes, with hornworts sister to liverworts and mosses. The simple morphology of hornworts correlates with low genetic redundancy in plant body plan, while the basic transcriptional regulation toolkit for plant development has already been established in this early land plant lineage. Although the Anthoceros genome is small and characterized by minimal redundancy, expansions are observed in gene families related to RNA editing, UV protection and desiccation tolerance. The genome of A. angustus bears the signatures of horizontally transferred genes from bacteria and fungi, in particular of genes operating in stress-response and metabolic pathways. Our study provides insight into the unique features of hornworts and their molecular adaptations to live on land.

2.
Mol Phylogenet Evol ; 145: 106729, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31926307

RESUMO

The Cleisostoma-Gastrochilus clades are among the most speciose and diverse groups of Asian orchids and are a taxonomically problematic group. Phylogenetic relationships among the genera of these clades have remained unresolved with traditional sequences from one or a few markers. We present large-scale phylogenomic data sets, incorporating complete chloroplast genome sequences from 53 species (including 41 species sequenced in this study), to compare plastome structure and to resolve the phylogenetic relationships of these clades. The plastomes of Cleisostoma-Gastrochilus clades possessed the quadripartite structure and plastome genes of typical angiosperms with sizes ranging from 142 to 149 kb and encoding a set of 118-120 genes. Unusual structural features were detected in the plastome of Uncifera acuminata, including the presence of a large 17-kb inversion (19 genes) in the Large Single-Copy region and the loss of the rpl32 gene in Cleisostoma fuerstenbergianum. The pseudogenization of ndh genes was widespread in these clades. Phylogenomic analyses, including 68 plastid protein-coding genes, showed that these clades can be subdivided into three major groupings and six subgroupings: Vandopsis undulata, the Gastrochilus clade (including the Trichoglottis and Gastrochilus subclades) and the Cleisostoma clade (including the Vandopsis, Diploprora, Cleisostoma and Schoenorchis subclades). Two genera, Vandopsis and Cleisostoma, were not monophyletic. A new genus, Cymbilabia, was proposed to avoid non-monophyly of Vandopsis. Our results demonstrate the power of plastid phylogenomics to improve the phylogenetic relationships of intricate groups and provide new insight into plastome evolution in Orchidaceae.

3.
Mol Phylogenet Evol ; 143: 106689, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31751610

RESUMO

The Cirrhopetalum alliance is a loosely circumscribed species-rich group within the mega-diverse genus Bulbophyllum (Orchidaceae). The monophyletic status of the alliance has been challenged by previous studies, although established sectional classifications have yet to be tested in a phylogenetic context. We used maximum likelihood and Bayesian analyses of DNA sequence data (cpDNA: matK and psbA-trnH; nrDNA: ITS and Xdh; 3509 aligned characters; 117 taxa), including all sections putatively associated with the Cirrhopetalum alliance, to reconstruct the phylogeny. We mapped 11 selected categorical floral characters onto the phylogeny to identify synapomorphies and assess potential evolutionary transitions across major clades. Our results unequivocally support the recognition of an amended Cirrhopetalum alliance as a well-supported monophyletic group characterized by clear synapomorphies, following the inclusion of sect. Desmosanthes and the exclusion of five putative Cirrhopetalum-allied sections. Most sections within the Cirrhopetalum alliance are demonstrated to be polyphyletic or paraphyletic, necessitating a new sectional classification. The inclusion of sect. Desmosanthes revolutionizes our understanding of the alliance, with significant evolutionary transitions in floral characters detected. We further investigated six continuously variable characters of the sepals and labellum, and detect phylogenetic conservatism in labellum width and the evolutionary lability of lateral sepal length, which can partly be explained by the different functional roles they play in pollination and pollinator trapping.

4.
J Exp Bot ; 70(22): 6611-6619, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31625570

RESUMO

Members of the Orchidaceae, one of the largest families of flowering plants, evolved the crassulacean acid metabolism (CAM) photosynthesis strategy. It is thought that CAM triggers adaptive radiation into new niche spaces, yet very little is known about its origin and diversification on different continents. Here, we assess the prevalence of CAM in Dendrobium, which is one of the largest genera of flowering plants and found in a wide range of environments, from the high altitudes of the Himalayas to relatively arid habitats in Australia. Based on phylogenetic time trees, we estimated that CAM, as determined by δ 13C values less negative than -20.0‰, evolved independently at least eight times in Dendrobium. The oldest lineage appeared in the Asian clade during the middle Miocene, indicating the origin of CAM was associated with a pronounced climatic cooling that followed a period of aridity. Divergence of the four CAM lineages in the Asian clade appeared to be earlier than divergence of those in the Australasian clade. However, CAM species in the Asian clade are much less diverse (25.6%) than those in the Australasian clade (57.9%). These findings shed new light on CAM evolutionary history and the aridity levels of the paleoclimate on different continents.

5.
PLoS One ; 14(7): e0219046, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31310621

RESUMO

Fruit traits affect population genetic diversity by affecting seed protection and dispersal strategies, thereby comprising important components of phenotypic variation. Understanding of the phenotypic variation is an indispensable first step for developing breeding strategies. However, little information is known about the genetic variation in E. japonica-a monotypic species with abundant phenotypes that is mainly distributed in southern China. In this study, we evaluated the phenotypic diversity of 67 E. japonica using 23 phenotypic traits. Our results showed that the Shannon-Wiener (I) index of qualitative traits ranged from 0.55 to 1.26, and the color traits had a relatively high I. The average coefficient of variation of compound leaf traits (14.74%) was higher than that of fruit and seed traits (12.77% and 11.47%, respectively). Principal component analysis also showed that compound leaf and fruit traits were important components of total variation. Furthermore, correlation analysis revealed a significant difference in elevation and fruit color, irregular ribs, leaf margin and texture. The F value within populations was smaller than among populations, indicating the variation in phenotypic traits among populations was much greater than within populations. Dehua and Zunyi populations had the highest coefficients of variation, whereas Wenzhou population had the smallest-which may be attributed to habitat destruction. According to Q-type clustering, 67 samples clustered into four groups, with those having similar phenotypes clustering into the same group. In general, leaf and fruit traits had abundant phenotypic diversity, representing the main sources of phenotypic variation. Combined with clustering results and field surveys, this study suggests that the phenotypes of E. japonica are classified into two main categories: The deciduous E. japonica present at high altitudes; and the evergreen E. japonica present at low altitudes. Excavating E. japonica variations provides a theoretical reference for its classification and diversity, and is of great significance for planning genetic resources and establishing conservation strategies.

6.
Mol Phylogenet Evol ; 139: 106542, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31229601

RESUMO

Goodyerinae are one of the most species-rich and widespread subtribes of Orchidaceae but notorious for their taxonomic difficulty. Here, a comprehensive molecular phylogenetic study of the subtribe is presented based on two nuclear (ITS, Xdh) and five plastid (matK, psaB, rbcL, trnL, trnL-F) regions. A total of 119 species were included representing all clades recovered by previous phylogenetic analyses as well as seven outgroups. Maximum parsimony, maximum likelihood and Bayesian inference methods were used to infer the phylogenetic relationships. The results show that the Goodyerinae subdivided into three major subdivisions and six groupings: Pachyplectron, Goodyera clade (including Goodyera procera, Microchilus subclade and Goodyera subclade) and Cheirostylis clade (including Gonatostylis, Cheirostylis subclade and Ludisia subclade). Four genera, Erythrodes, Goodyera, Myrmechis and Odontochilus, are not monophyletic. The results support Odontochilus s. l. to include Myrmechis and Kuhlhasseltia. The systematic positions of Goodyera procera and two isolated genera, Herpysma and Orchipedum, are difficult to determine.

7.
Mol Plant ; 12(7): 920-934, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902685

RESUMO

Cultivated peanut (Arachis hypogaea) is an allotetraploid crop planted in Asia, Africa, and America for edible oil and protein. To explore the origins and consequences of tetraploidy, we sequenced the allotetraploid A. hypogaea genome and compared it with the related diploid Arachis duranensis and Arachis ipaensis genomes. We annotated 39 888 A-subgenome genes and 41 526 B-subgenome genes in allotetraploid peanut. The A. hypogaea subgenomes have evolved asymmetrically, with the B subgenome resembling the ancestral state and the A subgenome undergoing more gene disruption, loss, conversion, and transposable element proliferation, and having reduced gene expression during seed development despite lacking genome-wide expression dominance. Genomic and transcriptomic analyses identified more than 2 500 oil metabolism-related genes and revealed that most of them show altered expression early in seed development while their expression ceases during desiccation, presenting a comprehensive map of peanut lipid biosynthesis. The availability of these genomic resources will facilitate a better understanding of the complex genome architecture, agronomically and economically important genes, and genetic improvement of peanut.

8.
Elife ; 72018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30558712

RESUMO

The origin of angiosperms has been a long-standing botanical debate. The great diversity of angiosperms in the Early Cretaceous makes the Jurassic a promising period in which to anticipate the origins of the angiosperms. Here, based on observations of 264 specimens of 198 individual flowers preserved on 34 slabs in various states and orientations, from the South Xiangshan Formation (Early Jurassic) of China, we describe a fossil flower, Nanjinganthus dendrostyla gen. et sp. nov.. The large number of specimens and various preservations allow for an evidence-based reconstruction of the flower. From the evidence of the combination of an invaginated receptacle and ovarian roof, we infer that the seeds of Nanjinganthus were completely enclosed. Evidence of an actinomorphic flower with a dendroid style, cup-form receptacle, and angiospermy, is consistent with Nanjinganthus being a bona fide angiosperm from the Jurassic, an inference that we hope will re-invigorate research into angiosperm origins.


Assuntos
Evolução Biológica , Flores/anatomia & histologia , Flores/classificação , Fósseis , Magnoliopsida/classificação , China , Magnoliopsida/anatomia & histologia
9.
Sci Rep ; 8(1): 16765, 2018 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-30425298

RESUMO

A perfect flower in a mid-Cretaceous (early Cenomanian) Myanmar amber is described as Lijinganthus revoluta gen. et sp. nov. The fossil flower is actinomorphic and pentamerous, including calyx, corolla, stamens, and gynoecium. The sepals are tiny, while the petals are large and revolute. The stamens are dorsifixed, filamentous, and each has a longitudinally dehiscing bisporangiate anther. The gynoecium is in the centre of the flower, composed of three fused carpels with a stout style. Lijinganthus revoluta gen. et sp. nov. demonstrates a great resemblance to the flowers of Pentapetalae (Eudicots), adding new information to the enigmatic early evolutionary history of Pentapetalae and Eudicots.


Assuntos
Âmbar , Flores , Magnoliopsida , Evolução Biológica , Fósseis
10.
Int J Mol Sci ; 19(10)2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30336592

RESUMO

Flower and fruit colors are of vital importance to the ecology and economic market value of plants. The mechanisms of flower and fruit coloration have been well studied, especially among ornamental flower plants and cultivated fruits. As people pay more attention to exocarp coloration, the endocarp coloration in some species has often been ignored. Here, we report on the molecular mechanism of endocarp coloration in three development stages of Euscaphis konishii. The results show that endocarp reddening is closely related to anthocyanin accumulation, and a total of 86,120 unigenes were assembled, with a mean length of 893 bp (N50 length of 1642 bp). We identified a large number of differentially expressed genes associated with endocarp coloration, including anthocyanin biosynthesis, carotenoid biosynthesis, and chlorophyll breakdown. The genes participating in each step of the anthocyanin biosynthesis were found in the transcriptome dataset, but a few genes were found in the carotenoid biosynthesis and chlorophyll breakdown. In addition, the candidate R2R3-MYB transcription factors and candidate glutathione S-transferase transport genes, which likely regulate the anthocyanin biosynthesis, were identified. This study offers a platform for E. konishii functional genomic research and provides a reference for revealing the regulatory mechanisms of endocarp reddening.


Assuntos
Frutas/genética , Malvaceae/genética , Pigmentação/genética , Análise de Sequência de RNA , Transcriptoma/genética , Antocianinas/biossíntese , Carotenoides/biossíntese , Clorofila/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genes de Plantas , Anotação de Sequência Molecular , Família Multigênica , Mapas de Interação de Proteínas/genética , Reprodutibilidade dos Testes , Fatores de Transcrição/metabolismo
11.
Int J Mol Sci ; 19(9)2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30200389

RESUMO

Self-incompatibility (SI) is a type of reproductive barrier within plant species and is one of the mechanisms for the formation and maintenance of the high diversity and adaptation of angiosperm species. Approximately 40% of flowering plants are SI species, while only 10% of orchid species are self-incompatible. Intriguingly, as one of the largest genera in Orchidaceae, 72% of Dendrobium species are self-incompatible, accounting for nearly half of the reported SI species in orchids, suggesting that SI contributes to the high diversity of orchid species. However, few studies investigating SI in Dendrobium have been published. This study aimed to address the following questions: (1) How many SI phenotypes are in Dendrobium, and what are they? (2) What is their distribution pattern in the Dendrobium phylogenetic tree? We investigated the flowering time, the capsule set rate, and the pollen tube growth from the representative species of Dendrobium after artificial pollination and analysed their distribution in the Asian Dendrobium clade phylogenetic tree. The number of SI phenotypes exceeded our expectations. The SI type of Dendrobium chrysanthum was the primary type in the Dendrobium SI species. We speculate that there are many different SI determinants in Dendrobium that have evolved recently and might be specific to Dendrobium or Orchidaceae. Overall, this work provides new insights and a comprehensive understanding of Dendrobium SI.


Assuntos
Evolução Biológica , Dendrobium/classificação , Dendrobium/genética , Autoincompatibilidade em Angiospermas/genética , Flores/genética , Flores/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Fenótipo , Filogenia , Tubo Polínico/genética , Tubo Polínico/crescimento & desenvolvimento , Polinização , Sementes/genética , Fatores de Tempo
12.
Sci Rep ; 8(1): 11640, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30076357

RESUMO

Deceptive pollination is key to the species richness of Orchidaceae. However, the genetic basis of species diversification is still under study. Section Trigonopedia is a monophyletic clade of genus Cypripedium distributed in the southwest of China. The species of this section are pollinated by different flies. Pollinator differentiation makes section Trigonopedia an ideal group for studying the genetic basis underlying species diversification. Here, we sequenced the transcriptomes of eight species of the genus Cypripedium, including six co-flowering species of section Trigonopedia and two species outside this section as an outgroup. We reconstructed the phylogeny of the section with the combined 1572 single-copy genes extracted from the eight species and produced a highly resolved tree of the section. Furthermore, we combined substitution rate estimation and differential expression analysis to identify candidate genes, including genes related to floral scent synthesis and environmental adaptation, involved in species differentiation. Field investigations showed that these species have adapted to different habitats. We propose that the species diversification in this section is initiated by floral scent differentiation, followed by habitat differentiation, finally leading to speciation. This study sheds novel light on the diversification of closely related orchid species in the Qinghai-Tibetan region.


Assuntos
Adaptação Fisiológica/genética , Orchidaceae/genética , Polinização/genética , Transcriptoma/genética , Animais , Dípteros/genética , Dípteros/fisiologia , Flores/genética , Flores/crescimento & desenvolvimento , Orchidaceae/crescimento & desenvolvimento , Especificidade da Espécie
13.
IMA Fungus ; 9(1): 1-11, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30018868

RESUMO

Orchids are critically dependent on fungi for seedling establishment and growth, so the distribution and diversity of orchids might depend on the associated fungal communities. We characterised the communities associated with eight orchid species in three Mediterranean protected areas, using a combination of above-ground analyses of sporophores and below-ground molecular analyses of orchid root samples. In three years of sporophore collection in 25 plots around flowering orchid plants, 268 macrofungal species belonging to 84 genera were observed. Statistical analyses indicated a correlation between macrofungal diversity and orchid community variation, regardless of the effect of environmental and spatial factors characterizing the investigated orchid sites. Fungal ITS-DNA PCR amplification, cloning, and sequencing revealed Rhizoctonia-like fungi belonging to Ceratobasidiaceae (26 %), Tulasnellaceae (22.5 %), and Sebacinaceae (3.5 %), as well as other basidiomycetes and ascomycetes, in the roots of 99 orchid plants. Mycorrhizal specificity was low but co-occurring orchid species showed preferences for different partners. The diverse macrofungal communities found in the sites may contribute to orchid community variation without colonizing the orchid roots. Molecular analyses revealed a segregation of associated fungi, which may contribute to Mediterranean orchid coexistence in nature.

14.
Biochem Biophys Res Commun ; 503(2): 888-894, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-29928884

RESUMO

The Warburg effect is a dominant phenotype of most tumor cells. Recent reports have shown that the Warburg effect can be reprogrammed by the tumor microenvironment. Lactic acidosis and glucose deprivation are the common adverse microenvironments in solid tumor. The metabolic reprogramming induced by lactic acid and glucose deprivation remains to be elucidated in glioblastoma. Here, we show that, under glucose deprivation, lactic acid can preserve high ATP levels and resist cell death in U251 cells. At the same time, we find that MCT1 and MCT4 are significantly highly expressed. The metabolic regulation factor HIF-1α decreased and C-MYC increased. Nuclear respiratory factor 1 (NRF1) and oxidative phosphorylation (OXPHOS)-related proteins (NDUFB8, ND1) are all distinctly increased. Therefore, lactic acid can induce lactate transport and convert the dominant Warburg effect to OXPHOS. Through bioinformatics analysis, the high expression of HIF-1α, MCT1 or MCT4 indicate a poor prognosis in glioblastoma. In addition, in glioblastoma tissue, HIF-1α, MCT4 and LDH are highly expressed in the interior region, and their expression is decreased in the lateral region. MCT1 can not be detected in the interior region and is highly expressed in the lateral region. Hence, different regions of glioblastoma have diverse energy metabolic pathways. Glycolysis occurs mainly in the interior region and OXPHOS in the lateral region. In general, lactic acid can induce regional energy metabolic reprogramming and assist tumor cells to adapt and resist adverse microenvironments. This study provides new ideas for furthering understanding of the metabolic features of glioblastoma. It may promote the development of new therapeutic strategies in GBM.


Assuntos
Glioblastoma/metabolismo , Glicólise/efeitos dos fármacos , Lactatos/metabolismo , Ácido Láctico/farmacologia , Fosforilação Oxidativa/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Transporte Biológico/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Glioblastoma/patologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Proteínas Musculares/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Simportadores/metabolismo
15.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(1): 1-7, 2018 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-29737080

RESUMO

OBJECTIVE: To study the regulation of suppressor of cytokine signaling 3 (SOCS3) expression bythe brother of the regulator of the imprinted site (BORIS) in hepatocellular carcinoma cell. METHODS: The expression of SOCS3 mRNA in HCC cell lines was detected by real-time quantitative PCR (qRT-PCR). The expression of SOCS3 protein in knockdown and overexpression BORIS of HCC cell lines was tested by Western blot. The SOCS3 gene promoter methylation statusin the knockdown and overexpression BORIS of hepatocarcinoma cell lines was detected by using methylation specific PCR (MSP-PCR) method.The potential BORIS binding site of SOCS3promoter region was found by UCSC database analysis.The enrichment of BORIS in SOCS3 promoter region in endogenous high expression BORIS of HCC cells was evaluated by using chromatin immunoprecipitation (ChIP)-qPCR (ChIP-qPCR).The SOCS3 promoter region histone methylation status in the knockdown and overexpression BORIS of HCC was detected by ChIP-qPCR. RESULTS: The expression of SOCS3 mRNA in hepatocellular carcinoma cells was higher and SOCS3 protein expression was down-regulated or up-regulated in the knockdown or overexpression of BORIS mRNA hepatocarcinoma cells,so BORIS has a positive regulatory effect on SOCS3 protein expression in hepatocarcinoma cells. MSP-PCR experiments showed that the SOCS3 promoter in SMMC-7721 and HepG2 cells was unmethylated and knockdown of BORIS did not change the methylation status; the SOCS3 promoter region of Huh7 cells was methylated; after overexpression of BORIS,the SOCS3 promoter region was changed to an unmethylated state; the SOCS3 promoter was unmethylated in HCCLM3,overexpression of BORIS did not alter the methylation status. The ChIP-qPCR assay demonstrated that BORIS specifically binds to the SOCS3 promoter region in HCC cells with high expression of BORIS. Histone methylation assay indicated that knockdown of BORIS reduced BORIS enrichment in the SOCS3 promoter region, with decreasing H3K4 me2 and increasing H3K27 me3 in the region of histone,whereas the overexpress BORIS in HCC cells showed the opposite situation. CONCLUSION: BORIS plays a role of epigenetic regulationon SOCS3 gene promoter methylation and histone methylation,modulating the expression of SOCS3,and then involved in the development of hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Metilação de DNA , Histonas/metabolismo , Humanos , Regiões Promotoras Genéticas
16.
Nat Genet ; 50(6): 770-771, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29844433
17.
Neuron ; 98(1): 142-155.e4, 2018 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-29551489

RESUMO

Active forgetting explains the intrinsic instability of a labile memory lasting for hours. However, how such memory maintains stability against unwanted disruption is not completely understood. Here, we report a learning-activated active protection mechanism that enables labile memory to resist disruptive sensory experiences in Drosophila. Aversive olfactory conditioning activates mitogen-activated protein kinase (MAPK) transiently in the mushroom-body γ lobe, where labile-aversive memory is stored. This increased MAPK activity significantly prolongs labile memory retention and enhances its resistance to disruption induced by heat shock, electric shock, or odor reactivation. Such experience-induced forgetting cannot be prevented by inhibition of Rac1 activity. Instead, protection of Rac1-independent forgetting correlates with non-muscle myosin II activity and persistence of learning-induced presynaptic structural changes. Increased Raf/MAPK activity, together with suppressed Rac1 activity, completely blocks labile memory decay. Thus, learning not only leads to memory formation, but also activates active protection and active forgetting to regulate the formed memory.


Assuntos
Proteínas de Drosophila/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Memória/fisiologia , Proteínas Proto-Oncogênicas c-raf/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila , Proteínas de Drosophila/análise , Feminino , Aprendizagem/fisiologia , Masculino , Corpos Pedunculados/química , Corpos Pedunculados/metabolismo , Proteínas Proto-Oncogênicas c-raf/análise , Proteínas rac de Ligação ao GTP/análise
18.
BMC Complement Altern Med ; 18(1): 59, 2018 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-29444668

RESUMO

BACKGROUND: Gigantol is a bibenzyl compound derived from several medicinal orchids. This biologically active compound has been shown to have promising therapeutic potential against cancer cells, but its mechanism of action remains unclear. METHODS: The inhibitory effect of gigantol on Wnt/ß-catenin signaling was evaluated with the SuperTOPFlash reporter system. The levels of phosphorylated low-density lipoprotein receptor related protein 6 (LRP6), total LRP6 and cytosolic ß-catenin were determined by Western blot analysis. The expression of Wnt target genes was analyzed using real-time PCR. Cell viability was measured with a MTT assay. The effect of gigantol on cell migration was examined using scratch wound-healing and transwell migration assays. RESULTS: Gigantol decreased the level of phosphorylated LRP6 and cytosolic ß-catenin in HEK293 cells. In breast cancer MDA-MB-231 and MDA-MB-468 cells, treatment with gigantol reduced the level of phosphorylated LRP6, total LRP6 and cytosolic ß-catenin in a dose-dependent manner, resulting in a decrease in the expression of Wnt target genes Axin2 and Survivin. We further demonstrated that gigantol suppressed the viability and migratory capacity of breast cancer cells. CONCLUSION: Gigantol is a novel inhibitor of the Wnt/ß-catenin pathway. It inhibits Wnt/ß-catenin signaling through downregulation of phosphorylated LRP6 and cytosolic ß-catenin in breast cancer cells.


Assuntos
Antineoplásicos/farmacologia , Bibenzilas/farmacologia , Neoplasias da Mama/metabolismo , Guaiacol/análogos & derivados , Orchidaceae/química , Extratos Vegetais/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/fisiopatologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Guaiacol/farmacologia , Humanos , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Fosforilação/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/genética , beta Catenina/metabolismo
20.
BMC Genet ; 19(1): 12, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29439656

RESUMO

BACKGROUND: Loropetalum subcordatum is an endangered species endemic to China that is characterized by narrow distribution, small population size, and delayed fertilization. However, the genetic diversity of the entire extant natural and ex situ populations has not been assessed to date. In this study, we evaluated the genetic diversity and structure of six natural populations and a single ex situ population (the only known ex situ population of L. subcordatum) using sequence-related amplified polymorphism data. RESULTS: In total, 553 reliable DNA bands, of which 359 (63.28%) were polymorphic, were amplified by polymerase chain reaction with combinations of 15 primers. Low average gene diversity within populations and high genetic differentiation were detected in L. subcordatum. A Mantel test demonstrated that there was a positive correlation between genetic and geographic distances, indicating that significant genetic divergence was likely the result of geographic isolation among natural populations. Furthermore, based on genetic structure patterns, populations of L. subcordatum were divided into three clusters. Group 1 was composed of specimens from Libo, Guizhou Province (GZ) and Huanjiang, Guangxi Zhuang Autonomous Region (GX). Group 2 was composed of Mt. Wuguishan, Guangdong Province (GD). Group 3 was composed of three populations in Hong Kong Special Administrative Region. Additionally, clonal reproduction probably existed in GD population. According to the genetic information analysis and field survey, the ex situ population did not match its source population (GD) in terms of genetics, and its habitat was different from the original natural habitat. We observed that a few individual GD seeds were needed to improve ZS ex situ in the future. CONCLUSIONS: Compared to previous SRAP-based studies of endangered plants, L. subcordatum had extremely low average gene diversity within populations and high genetic differentiation among populations. At present, the unique ex situ population has not been successful due to non-representative samples being taken, a smaller population size, and man-made changes in habitat. Potential strategies are suggested to improve the conservation of this species.


Assuntos
Espécies em Perigo de Extinção , Hamamelidaceae/genética , Filogeografia , Polimorfismo Genético , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados/métodos , China , Hamamelidaceae/classificação , Densidade Demográfica
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