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2.
Nature ; 549(7672): 379-383, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28902843

RESUMO

Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth. Here we report the draft genome sequence of Apostasia shenzhenica, a representative of one of two genera that form a sister lineage to the rest of the Orchidaceae, providing a reference for inferring the genome content and structure of the most recent common ancestor of all extant orchids and improving our understanding of their origins and evolution. In addition, we present transcriptome data for representatives of Vanilloideae, Cypripedioideae and Orchidoideae, and novel third-generation genome data for two species of Epidendroideae, covering all five orchid subfamilies. A. shenzhenica shows clear evidence of a whole-genome duplication, which is shared by all orchids and occurred shortly before their divergence. Comparisons between A. shenzhenica and other orchids and angiosperms also permitted the reconstruction of an ancestral orchid gene toolkit. We identify new gene families, gene family expansions and contractions, and changes within MADS-box gene classes, which control a diverse suite of developmental processes, during orchid evolution. This study sheds new light on the genetic mechanisms underpinning key orchid innovations, including the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism; reveals relationships between the Orchidaceae subfamilies; and helps clarify the evolutionary history of orchids within the angiosperms.


Assuntos
Evolução Molecular , Genoma de Planta/genética , Orchidaceae/genética , Filogenia , Genes de Plantas/genética , Orchidaceae/anatomia & histologia , Orchidaceae/classificação , Transcriptoma
3.
Mol Phylogenet Evol ; 167: 107362, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34775057

RESUMO

Delimitation of the tribe Arethuseae has varied considerably since it was first defined. The relationships within Arethuseae, particularly within the subtribe Arethusinae, remain poorly elucidated. In this study, we reconstructed the phylogeny of Arethuseae, using six plastid markers (matK, ycf1, rbcL rpoc1, rpl32-trnL and trnL-F) from 83 taxa. The ancestral state reconstruction of 11 selected morphological characters was also conducted to identify synapomorphies and assess potential evolutionary transitions. Morphological character comparision between the distinct species Bletilla foliosa and other species are conducted. Our results unequivocally supported the monophyly of Arethuseae, which included highly supported clades and a clear synapomorphy of non-trichome-like lamellae. Furthermore, B. foliosa formed a separate clade in the subtribe Arethusinae, instead of clustering with the other Bletilla species in the subtribe Coelogyninae. The morphological characters comparision further showed that the B. foliosa clade could be distinguished from other genera in Arethuseae by multiple characters, including presence of lateral inflorescence, three lamellae with trichome-like apex and four pollinia. In light of these molecular and morphological evidences, we propose Mengzia as a new genus to accommodate B. foliosa and accordingly provide descriptions of this new genus and combination.


Assuntos
Orchidaceae , DNA de Plantas , Filogenia , Plastídeos
4.
Int J Mol Sci ; 22(23)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34884706

RESUMO

Self-incompatibility affects not only the formation of seeds, but also the evolution of species diversity. A robust understanding of the molecular mechanisms of self-incompatibility is essential for breeding efforts, as well as conservation biology research. In recent years, phenotypic and multiple omics studies have revealed that self-incompatibility in Orchidaceae is mainly concentrated in the subfamily Epidendroideae, and the self-incompatibility phenotypes are diverse, even in the same genus, and hormones (auxin and ethylene), and new male and female determinants might be involved in SI response. This work provides a good foundation for future studies of the evolution and molecular mechanisms of self-incompatibility. We review recent research progress on self-incompatibility in orchids at the morphological, physiological, and molecular levels, provide a general overview of self-incompatibility in orchids, and propose future research directions.


Assuntos
Orchidaceae/fisiologia , Autoincompatibilidade em Angiospermas , Evolução Molecular , Fenótipo , Melhoramento Vegetal
5.
J Biol Chem ; 293(2): 484-496, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29162720

RESUMO

As a sensitive signaling system, the mitotic checkpoint ensures faithful chromosome segregation by delaying anaphase onset even when a single kinetochore is unattached to mitotic spindle microtubules. The key signal amplification reaction for the checkpoint is the conformational conversion of "open" mitotic arrest deficient 2 (O-MAD2) into "closed" MAD2 (C-MAD2). The reaction has been suggested to be catalyzed by an unusual catalyst, a MAD1:C-MAD2 tetramer, but how the catalysis is executed and regulated remains elusive. Here, we report that in addition to the well-characterized middle region of MAD1 containing the MAD2-interaction motif (MIM), both N- and C-terminal domains (NTD and CTD) of MAD1 also contribute to mitotic checkpoint signaling. Unlike the MIM, which stably associated only with C-MAD2, the NTD and CTD in MAD1 surprisingly bound both O- and C-MAD2, suggesting that these two domains interact with both substrates and products of the O-to-C conversion. MAD1NTD and MAD1CTD also interacted with each other and with the MPS1 protein kinase, which phosphorylated both NTD and CTD. This phosphorylation decreased the NTD:CTD interaction and also CTD's interaction with MPS1. Of note, mutating the phosphorylation sites in the MAD1CTD, including Thr-716, compromised MAD2 binding and the checkpoint responses. We further noted that Ser-610 and Tyr-634 also contribute to the mitotic checkpoint signaling. Our results have uncovered that the MAD1NTD and MAD1CTD directly interact with each other and with MAD2 conformers and are regulated by MPS1 kinase, providing critical insights into mitotic checkpoint signaling.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Mad2/metabolismo , Mitose/fisiologia , Proteínas Nucleares/metabolismo , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Humanos , Immunoblotting , Cinetocoros/metabolismo , Cinetocoros/fisiologia , Proteínas Mad2/genética , Mitose/genética , Proteínas Nucleares/genética , Fosforilação , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Fuso Acromático/metabolismo , Fuso Acromático/fisiologia
6.
Zhongguo Zhong Yao Za Zhi ; 44(23): 5102-5108, 2019 Dec.
Artigo em Zh | MEDLINE | ID: mdl-32237344

RESUMO

Metabolic syndrome,a kind of clinical syndrome marked by the presence of symptoms such as hyperglycemia,dyslipidemia and hypertension,has an increasing incidence and comes to be present in younger people. More importantly,prolonged maintenance of this condition can significantly increase the incidence of chronic diseases such as diabetes,cardiovascular disease and cancer.However,the formation mechanism of metabolic syndrome is very complex and has not been fully studied and revealed. Dendrobium officinale is a traditional medicine and food substance with multiple physiological functions. In recent years,D. officinale has attracted much attention from the scholars both at home and abroad due to its functions such as improving blood lipid,lowering blood pressure and regulating blood sugar. However,there is no systematic review on the current studies about D. officinale in intervening metabolic syndrome and its underlying molecular mechanism. In this paper,the biological activity of the main active components,and the research or application status of D. officinale extract in the recent years were reviewed. Then,we analyzed the digestion,absorption and the safety and toxicity of D. officinale and its active components in the body. Finally,we summarized the effects of D. officinale and its active components on metabolic syndrome in animals and human bodies,and discussed its possible molecular mechanisms at the cellular level. This paper provides solid theoretical guidance and reliable molecular basis for further research and advanced development of D. officinale and its active components,especially for its oncoming clinical application.


Assuntos
Dendrobium/química , Síndrome Metabólica/tratamento farmacológico , Preparações de Plantas/farmacologia , Animais , Pressão Sanguínea , Humanos
7.
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
8.
Zhongguo Zhong Yao Za Zhi ; 43(11): 2396-2401, 2018 Jun.
Artigo em Zh | MEDLINE | ID: mdl-29945397

RESUMO

"Jinchai Shihu" were called Jinchai and recoded in "Taishang Zhouhou Yujingfang" of Tang Dynasty, which first clearly documented the name of Shihu in complex Dendrobium medicines and were condiered as superior medicinal articles. Morphological features are one of the naming principles for Chinese medicines. In this paper, botanical origin plants under the names of "Jinchai" and "Jinchai Shihu" were investigated. Based on documents from the local Chronicles and historical accounts, the Chinese characters of Jinchai have the distinctive features of gold color and two hair clasps. Moreover, the hair clasps are usually cylindrical in shape with uniform thickness in middle and upper part, and tapers off to the foot. And its bottom part style is simple and head part is complex. Thus we speculated the herbal "Jinchai" and "Jinchai Shihu" should have similar morphologic features as Chinese characters of Jinchai, including golden color and hairpin shape of stems without braches, short and solid sterm. After comparing the dried vegetative morphology of 10 common medicinal Dendrobium species, we suggested that of Dendrobium flexicaule matches well with the morphological features from historical herbal records.


Assuntos
Dendrobium/anatomia & histologia , Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Plantas Medicinais/anatomia & histologia
9.
Zhongguo Zhong Yao Za Zhi ; 42(10): 2001-2005, 2017 May.
Artigo em Zh | MEDLINE | ID: mdl-29090564

RESUMO

Dendrobium species on the ancient Chinese herbal texts were investigated in this paper, including their dscriptions of original species, producing areas and quality. Our results indicated that the major producing areas were Lu'an, Anhui province and Wenzhou, Taizhou, Zhejiang province. In addition, the sweet flavor, short, thin and solid stems were standing for good quality. Based on the stable producing areas and quality descriptions, D. catenatum (D. officinale) ("Tiepi Shihu") and D. houshanense were high quality medicinal Dendrobium species ("Shihu" ) in ancient China. Besides, there were 3 scientific names for "Tiepi Shihu", including D. candidum, D. officinale, D. catenatum. After textual investigation, We suggest that D. catenatum should be its scientific name, and D. officinale was synonyms published later. However, the name "D. officinale" could be reserved as it is much more popular used in publication and commodities. Moreover, its Chinese name should be "Tiepi Shihu".


Assuntos
Dendrobium/química , Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , China , Dendrobium/classificação , Pesquisa
10.
Zhongguo Zhong Yao Za Zhi ; 42(12): 2223-2227, 2017 Jun.
Artigo em Zh | MEDLINE | ID: mdl-28822173

RESUMO

In view of the significant difficulties of propagation, planting and simple product in Dendrobium catenatum(D. officinale)industry development, a series of research were carried out. Genome study showed that D. catenatum is a specie of diploid with 38 chromosomes and 28 910 protein-coding genes. It was identified that specific genes accumulated in different organs at the transcriptome level. We got an insight into the gene regulation mechanism of the loss of the endospermous seed, the wide ecological adaptability and the synthesis of polysaccharides, which provided a theoretical basis for genetic engineering breeding and development and utilization of active pharmaceutical ingredients. The rapid propagation system was established for applying to industrialized production by overcoming breeding problems on seed setting and sprouting, which laid a foundation for artificial cultivation of D. catenatum. And in order to give a clear explanation of genetic variation of important economic traits, we built up the breeding system. Since special varieties of D. catenatum were bred, it helped solve the problem of trait segregation of seedling progeny and support the improvement of D. catenatum industry. The regulation of dynamic variation of target compounds, together with the mechanism of nutrient uptake, was revealed. The breakthrough of key technologies including culture substrates, light regulation and precisely collection was carried out. Several cultivation modes like facility cultivation, original ecological cultivation, cliff epiphytic cultivation, stereoscopic cultivation and potting cultivation were set up. Above all, the goal of cultivating D. catenatum as well as producing good D. catenatum will be achieved.


Assuntos
Agricultura , Dendrobium/genética , Melhoramento Vegetal , Dendrobium/química , Medicamentos de Ervas Chinesas , Plantas Medicinais/química , Plantas Medicinais/genética , Polissacarídeos/biossíntese
11.
Histochem Cell Biol ; 145(1): 93-104, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26464247

RESUMO

LINE-1 is an autonomous non-LTR retrotransposon in mammalian genomes and encodes ORF1P and ORF2P. ORF2P has been clearly identified as the enzyme supplier needed in LINE-1 retrotransposition. However, the role of ORF1P is not well explored. In this study, we employed loss/gain-of-function approach to investigate the role of LINE1-ORF1P in mouse oocyte meiotic maturation. During mouse oocyte development, ORF1P was observed in cytoplasm as well as in nucleus at germinal vesicle (GV) stage while was localized on the spindle after germinal vesicle breakdown (GVBD). Depletion of ORF1P caused oocyte arrest at the GV stage as well as down-regulation of CDC2 and CYCLIN B1, components of the maturation-promoting factor (MPF). Further analysis demonstrated ORF1P depletion triggered DNA damage response and most of the oocytes presented altered chromatin configuration. In addition, SMAD4 showed nuclear foci signal after Orf1p dsRNA injection. ORF1P overexpression held the oocyte development at MI stage and the chromosome alignment and spindle organization were severely affected. We also found that ORF1P could form DCP1A body-like foci structure in both cytoplasm and nucleus after heat shock. Taken together, accurate regulation of ORF1P plays an essential role in mouse oocyte meiotic maturation.


Assuntos
Elementos Nucleotídeos Longos e Dispersos/genética , Meiose/genética , Oócitos/citologia , Oogênese/fisiologia , Proteínas de Ligação a RNA/metabolismo , Animais , Proteína Quinase CDC2/metabolismo , Ciclina B1/metabolismo , Reparo do DNA/genética , Endorribonucleases/metabolismo , Feminino , Fator Promotor de Maturação/metabolismo , Mesotelina , Camundongos , Camundongos Endogâmicos ICR , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Proteína Smad4/metabolismo , Fuso Acromático/metabolismo , Transativadores/metabolismo
12.
Mol Reprod Dev ; 83(2): 132-43, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26642846

RESUMO

We used etoposide (25-100 µg/mL) to induce DNA double-strand breaks (DSBs) in porcine oocytes at the germinal vesicle (GV) stage to determine how such damage affects oocyte maturation. We observed that DNA damage did not delay the rate of germinal vesicle breakdown (GVBD), but did inhibit the final stages of maturation, as indicated by the failure to extrude the first polar body. Oocytes with low levels of DSBs failed to effectively activate ataxia telangiectasia-mutated (ATM) kinase, while those with severe DNA DSBs failed to activate checkpoint kinase 1 (CHK1)--the two regulators of the DNA damage response pathway--indicating that porcine oocytes lack an efficient G2/M phase checkpoint. DSBs induced spindle defects and chromosomal misalignments, leading to the arrest of these oocytes at meiotic metaphase I. The activity of maturation-promoting factor also did not increase appropriately in oocytes with DNA DSBs, although its abundance was sufficient to promote GVBD and chromosomal condensation. Following parthenogenetic activation, embryos from etoposide-treated oocytes formed numerous micronuclei. Thus, our results indicate that DNA DSBs do not efficiently activate the ATM/CHK1-dependent DNA-damage checkpoint in porcine oocytes, allowing these DNA-impaired oocytes to enter M phase. Oocytes with DNA damage did, however, arrest at metaphase I in response to spindle defects and chromosomal misalignments, which limited the ability of these oocytes to reach meiotic metaphase II.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Quebras de DNA de Cadeia Dupla , Pontos de Checagem da Fase G2 do Ciclo Celular , Pontos de Checagem da Fase M do Ciclo Celular , Oócitos/metabolismo , Proteínas Quinases/metabolismo , Fuso Acromático/metabolismo , Animais , Quinase 1 do Ponto de Checagem , Suínos
13.
Ann Bot ; 117(3): 391-400, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26721904

RESUMO

BACKGROUND AND AIMS: Flowering plants display considerable variation in mating system, specifically the relative frequency of cross- and self-fertilization. The majority of estimates of outcrossing rate do not account for temporal variation, particularly during the flowering season. Here, we investigated seasonal variation in mating and fertility in Incarvillea sinensis (Bignoniaceae), an annual with showy, insect-pollinated, 'one-day' flowers capable of delayed selfing. We examined the influence of several biotic and abiotic environmental factors on day-to-day variation in fruit set, seed set and patterns of mating. METHODS: We recorded daily flower number and pollinator abundance in nine 3 × 3-m patches in a population at Mu Us Sand land, Inner Mongolia, China. From marked flowers we collected data on daily fruit and seed set and estimated outcrossing rate and biparental inbreeding using six microsatellite loci and 172 open-pollinated families throughout the flowering period. KEY RESULTS: Flower density increased significantly over most of the 50-d flowering season, but was associated with a decline in levels of pollinator service by bees, particularly on windy days. Fruit and seed set declined over time, especially during the latter third of the flowering period. Multilocus estimates of outcrossing rate were obtained using two methods (the programs MLTR and BORICE) and both indicated high selfing rates of ∼80 %. There was evidence for a significant increase in levels of selfing as the flowering season progressed and pollinator visitation declined. Biparental inbreeding also declined significantly as the flowering season progressed. CONCLUSIONS: Temporal variation in outcrossing rates may be a common feature of the mating biology of annual, insect-pollinated plants of harsh environments but our study is the first to examine seasonal mating-system dynamics in this context. Despite having large flowers and showy floral displays, I. sinensis attracted relatively few pollinators. Delayed selfing by corolla dragging largely explains the occurrence of mixed mating in I. sinensis, and this mode of self-fertilization probably functions to promote reproductive assurance when pollinator service is limited by windy environmental conditions and competition from co-occurring flowering plants.


Assuntos
Bignoniaceae/fisiologia , Flores/anatomia & histologia , Flores/fisiologia , Estações do Ano , Autofertilização/fisiologia , Alelos , Bignoniaceae/genética , China , Cruzamentos Genéticos , Frutas/crescimento & desenvolvimento , Variação Genética , Heterozigoto , Endogamia , Polinização , Tamanho da Amostra , Sementes/crescimento & desenvolvimento , Vento
14.
Zhongguo Zhong Yao Za Zhi ; 41(10): 1956-1964, 2016 May.
Artigo em Zh | MEDLINE | ID: mdl-28895350

RESUMO

To clear from botanical view the original materials under the traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" within the genus Dendrobium of the family Orchidaceae. Combined of different methods including study of historical records from the local chronicles and historical accounts of past event in Hubei, Sichuan, Chongqing, Henan and Shaanxi provinces, interviewing face to face with the old traditional Chinese workers and folk doctors in 20 downtowns and countrysides, such as, Laohekou, Lichuan, Fangxian, Xixia, Neixiang, and Ankang, and collecting a few plants of "Jinchai" for taxonomic identification. The traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" were widely used by the local people from the eastern Chongqing, western Hubei, northeasten Sichuan, southeastern Shaanxi, western Henan. Those two names were frequently found in the local Chronicles and historical accounts of past event, even in the local daily life such as folk songs and stories. The botanical identification results showed that a endemic species of D. flexicaule is the original materials of the traditional Chinese medicine names "Jinchai" and "Jinchai Shihu", and this species are also called "Longtoujin", "Renzijin", "Huanzijin" and "Longtoufengweijin" by the local people. The dried artifactitious specimens of D. flexicaule are traditionally named as "Jinerhuan". The botanic resource plants of the traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" are the endemic species of D. flexicaule that is distributed mainly in central areas of China including eastern Chongqing, western Hubei, northeasten Sichuan, southeastern Shaanxi, and western Henan, rather than D. nobile as referring in both Chinese and English version of Flora of China, and in official recorded serious versions of The Chinese Pharmacopoeia since 1977. In order to avoid confusion in the traditional Chinese medicine dendrobiums industry, the Chinese name of D. nobile is suggested as "Biancao Shihu", which characterized one stem feature of this species, and the traditional Chinese medicine names "Jinchai" or "JinchaiShihu" is suggested to refer to the species D. flexicaule.


Assuntos
Dendrobium/classificação , Medicamentos de Ervas Chinesas/química , Plantas Medicinais/classificação , China , Medicina Tradicional Chinesa
15.
Biol Reprod ; 92(4): 101, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25740542

RESUMO

Polo-like kinase (PLK) 4 is a unique member of the PLK family that plays vital roles in centriole biogenesis during mitosis. The localization of PLK4 on centrioles must be precisely regulated during mitosis to ensure correct centriole duplication. However, little is known about the function of PLK4 in mammalian oocyte meiosis. We addressed this question by examining the expression and localization of PLK4 in mouse oocytes and using RNA interference and protein overexpression to investigate its function in meiosis. PLK4 expression peaked at the germinal vesicle breakdown (GVBD) stage, and the protein was localized in the cytoplasm throughout meiotic maturation. Depletion of PLK4 caused meiotic arrest at the GV stage and suppressed CYCLINB1 and CDC2 activities. Moreover, PLK4 depletion prevented the de-phosphorylation of CDC2-Tyr15 in nucleus and induced a decrease in the level of the CDC25C protein. PLK1 overexpression failed to rescue GV-stage arrest in PLK4-depleted oocytes, whereas overexpressing PLK4 resulted in normal GVBD in oocytes in which PLK1 activity was inhibited. In addition, PLK4 overexpression did not cause abnormal spindle formation or affect extrusion of the first polar body. These results illustrate the fact that PLK4 is essential for meiotic resumption but may not influence spindle formation in mouse oocytes during meiotic maturation.


Assuntos
Meiose/fisiologia , Oócitos/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Proteína Quinase CDC2/genética , Cromossomos/genética , Feminino , Fertilização/fisiologia , Técnicas In Vitro , Camundongos , Fosforilação , Plasmídeos/genética , Corpos Polares/fisiologia , Gravidez , Proteínas Serina-Treonina Quinases/biossíntese , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Fuso Acromático , Fosfatases cdc25/genética
16.
Mol Hum Reprod ; 21(2): 186-94, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25304979

RESUMO

In mammalian cells, 5-methylcytosine (5-meC) can be transformed into 5-hydroxymethylcytosine (5-hmC) by the methylcytosine dioxygenase TET proteins (TET1, TET2 and TET3). Thymine DNA glycosylase (TDG), a downstream enzyme of TET proteins, not only functions in base excision repair, but also acts as a key enzyme that participates in active DNA demethylation. Here we microinjected exogenous TDG-mCherry mRNAs into germinal vesicle (GV) stage mouse oocytes, and found that initially TDG-mCherry localized in the nucleus. Just before GV breakdown (GVBD), TDG-mCherry was released from the nucleus into the cytoplasm. In contrast with TDG, another active DNA demethylation-associated enzyme, activation-induced cytidine deaminase (AID) became localized in the cytoplasm of GV oocytes, but entered the nucleus of oocytes just before GVBD. However, both TDG and AID could enter the G0 stage nuclei of cumulus cells injected into the ooplasm. To analyze the effects of TDG on oocyte maturation, we over-expressed TDG-mCherry in GV oocytes, and found that the rates of both GVBD and polar body extrusion rate were significantly decreased. When the TDG over-expressed oocytes were blocked at the GV stage, the oocyte chromatin became decondensed, and the histone 3 trimethyl lysine 9 (H3K9me3) and H3K9me2 levels were decreased. We also found that TDG could reduce the 5-meC level of oocyte genomic DNA. All these results indicate that aberrant TDG expression causes epigenetic modifications and meiotic cell cycle arrest of mouse oocytes.


Assuntos
Timina DNA Glicosilase/metabolismo , Animais , Ciclo Celular/genética , Ciclo Celular/fisiologia , Núcleo Celular/metabolismo , Células do Cúmulo/metabolismo , Epigênese Genética/genética , Epigênese Genética/fisiologia , Feminino , Meiose/genética , Meiose/fisiologia , Camundongos , Camundongos Endogâmicos ICR , Oócitos/metabolismo , Timina DNA Glicosilase/genética
17.
Mol Ecol ; 24(11): 2838-55, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25847454

RESUMO

South-East Asia covers four of the world's biodiversity hotspots, showing high species diversity and endemism. Owing to the successive expansion and contraction of distribution and the fragmentation by geographical barriers, the tropical flora greatly diversified in this region during the Tertiary, but the evolutionary tempo and mode of species diversity remain poorly investigated. Paphiopedilum, the largest genus of slipper orchids comprising nearly 100 species, is mainly distributed in South-East Asia, providing an ideal system for exploring how plant species diversity was shaped in this region. Here, we investigated the evolutionary history of this genus with eight cpDNA regions and four low-copy nuclear genes. Discordance between gene trees and network analysis indicates that reticulate evolution occurred in the genus. Ancestral area reconstruction suggests that vicariance and long-distance dispersal together led to its current distribution. Diversification rate variation was detected and strongly correlated with the species diversity in subg. Paphiopedilum (~80 species). The shift of speciation rate in subg. Paphiopedilum was coincident with sea-level fluctuations in the late Cenozoic, which could have provided ecological opportunities for speciation and created bridges or barriers for gene flow. Moreover, some other factors (e.g. sympatric distribution, incomplete reproductive barriers and clonal propagation) might also be advantageous for the formation and reproduction of hybrid species. In conclusion, our study suggests that the interplay of reticulate evolution and sea-level fluctuations has promoted the diversification of the genus Paphiopedilum and sheds light into the evolution of Orchidaceae and the historical processes of plant species diversification in South-East Asia.


Assuntos
Especiação Genética , Orchidaceae/classificação , Sudeste Asiático , Núcleo Celular/genética , DNA de Cloroplastos/genética , DNA de Plantas/genética , Fluxo Gênico , Genes de Plantas , Modelos Genéticos , Dados de Sequência Molecular , Oceanos e Mares , Orchidaceae/genética , Análise de Sequência de DNA
18.
Cancers (Basel) ; 16(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38927905

RESUMO

Effective cancer therapy with limited adverse effects is a major challenge in the medical field. This is especially complicated by the development of acquired chemoresistance. Understanding the mechanisms that underlie these processes remains a major effort in cancer research. In this review, we focus on the dual role that Bid protein plays in apoptotic cell death via the mitochondrial pathway, in oncogenesis and in cancer therapeutics. The BH3 domain in Bid and the anti-apoptotic mitochondrial proteins (Bcl-2, Bcl-XL, mitochondrial ATR) it associates with at the outer mitochondrial membrane provides us with a viable target in cancer therapy. We will discuss the roles of Bid, mitochondrial ATR, and other anti-apoptotic proteins in intrinsic apoptosis, exploring how their interaction sustains cellular viability despite the initiation of upstream death signals. The unexpected upregulation of this Bid protein in cancer cells can also be instrumental in explaining the mechanisms behind acquired chemoresistance. The stable protein associations at the mitochondria between tBid and anti-apoptotic mitochondrial ATR play a crucial role in maintaining the viability of cancer cells, suggesting a novel mechanism to induce cancer cell apoptosis by freeing tBid from the ATR associations at mitochondria.

19.
J Health Popul Nutr ; 43(1): 92, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38909238

RESUMO

BACKGROUND: All the scoring methods for the DLQI miss the moderate impact of the disease on patients, which may underestimate the impact of psoriasis on patients' quality of life. To improve the accuracy of the assessment of the Dermatology Life Quality Index score (DLQI) for patients with psoriasis, this study proposed and validated a new scoring method, the DLQI-NS, which includes the moderate impact option in the self-assessment of each item in psoriasis patients. METHODS: A cross-sectional study was conducted in which patients with psoriasis were enrolled. A total of 425 participants completed the DLQI, DLQI-NS and Skindex-16 questionnaires. Reliability, validity, ceiling and floor effects were evaluated of both DLQI and DLQI-NS questionnaires. RESULTS: About 14.4-32.5% of the patients reported a moderate impact on quality of life. The DLQI-NS allowed 17 more patients (4.0%) to achieve severe disease. The Cronbach's alpha coefficient of the DLQI-NS was 0.90, and that of the DLQI was 0.89. The KMO test results for the DLQI-NS and DLQI were 0.927 and 0.916, respectively. One factor was identified for each questionnaire. The items of the DLQI-NS showed an item-total correlation from 0.52 to 0.82, and the DLQI questionnaire's item-total correlation ranged from 0.47 to 0.83. The DLQI-NS, DLQI total score and Skindex-16 had Spearman's rank correlation coefficients of 0.89 and 0.84, respectively. Both the DLQI-NS and DLQI showed significant moderate correlations with the BSA (0.51 vs. 0.50) and PASI (0.47 vs. 0.46). No ceiling effects were observed for any of the items of both questionnaires. CONCLUSION: The validity and reliability of the DLQI-NS and DLQI were good, but the DLQI-NS was superior to the DLQI. The DLQI-NS is an effective self-assessment tool for assessing quality of life in psoriasis patients.


Assuntos
Psoríase , Qualidade de Vida , Índice de Gravidade de Doença , Humanos , Psoríase/psicologia , Feminino , Masculino , Estudos Transversais , Reprodutibilidade dos Testes , Inquéritos e Questionários/normas , Adulto , Pessoa de Meia-Idade , Idoso
20.
Biol Reprod ; 88(5): 110, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23515676

RESUMO

It is well accepted that oocyte meiotic resumption is mainly regulated by the maturation-promoting factor (MPF), which is composed of cyclin B1 (CCNB1) and cyclin-dependent kinase 1 (CDC2). Maturation-promoting factor activity is regulated by the expression level of CCNB1, phosphorylation of CDC2, and their germinal vesicle (GV) localization. In addition to CCNB1, cyclin O (CCNO) is highly expressed in oocytes, but its biological functions are still not clear. By employing short interfering RNA microinjection of GV-stage oocytes, we found that Ccno knockdown inhibited CDC2 (Tyr15) dephosphorylation and arrested oocytes at the GV stage. To rescue meiotic resumption, cell division cycle 25 B kinase (Cdc25b) and Ccnb1 were overexpressed in the Ccno knockdown oocytes. Unexpectedly, we found that Ccno knockdown did not affect CDC25B entry into the GV, and overexpression of CDC25B was not able to rescue resumption of oocyte meiosis. However, GV breakdown (GVBD) was significantly increased after overexpression of Ccnb1 in Ccno knockdown oocytes, indicating that GVBD block caused by cyclin O knockdown can be rescued by cyclin B1 overexpression. We thus conclude that cyclin O, as an upstream regulator of MPF, plays an important role in oocyte meiotic resumption in mouse oocytes.


Assuntos
Ciclinas/metabolismo , Meiose/genética , Oócitos/metabolismo , Animais , Proteína Quinase CDC2/genética , Proteína Quinase CDC2/metabolismo , Ciclo Celular/genética , Ciclina B1/genética , Ciclina B1/metabolismo , Ciclinas/genética , Feminino , Fator Promotor de Maturação/genética , Fator Promotor de Maturação/metabolismo , Mesotelina , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Microinjeções , Oócitos/citologia , Fosforilação , RNA Interferente Pequeno
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