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1.
Glob Chang Biol ; 30(4): e17271, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613240

RESUMO

Ecological and evolutionary theories have proposed that species traits should be important in mediating species responses to contemporary climate change; yet, empirical evidence has so far provided mixed evidence for the role of behavioral, life history, or ecological characteristics in facilitating or hindering species range shifts. As such, the utility of trait-based approaches to predict species redistribution under climate change has been called into question. We develop the perspective, supported by evidence, that trait variation, if used carefully can have high potential utility, but that past analyses have in many cases failed to identify an explanatory value for traits by not fully embracing the complexity of species range shifts. First, we discuss the relevant theory linking species traits to range shift processes at the leading (expansion) and trailing (contraction) edges of species distributions and highlight the need to clarify the mechanistic basis of trait-based approaches. Second, we provide a brief overview of range shift-trait studies and identify new opportunities for trait integration that consider range-specific processes and intraspecific variability. Third, we explore the circumstances under which environmental and biotic context dependencies are likely to affect our ability to identify the contribution of species traits to range shift processes. Finally, we propose that revealing the role of traits in shaping species redistribution may likely require accounting for methodological variation arising from the range shift estimation process as well as addressing existing functional, geographical, and phylogenetic biases. We provide a series of considerations for more effectively integrating traits as well as extrinsic and methodological factors into species redistribution research. Together, these analytical approaches promise stronger mechanistic and predictive understanding that can help society mitigate and adapt to the effects of climate change on biodiversity.


Assuntos
Biodiversidade , Mudança Climática , Filogenia , Geografia , Fenótipo
2.
Nature ; 629(8010): 114-120, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38538797

RESUMO

Mountain ranges contain high concentrations of endemic species and are indispensable refugia for lowland species that are facing anthropogenic climate change1,2. Forecasting biodiversity redistribution hinges on assessing whether species can track shifting isotherms as the climate warms3,4. However, a global analysis of the velocities of isotherm shifts along elevation gradients is hindered by the scarcity of weather stations in mountainous regions5. Here we address this issue by mapping the lapse rate of temperature (LRT) across mountain regions globally, both by using satellite data (SLRT) and by using the laws of thermodynamics to account for water vapour6 (that is, the moist adiabatic lapse rate (MALRT)). By dividing the rate of surface warming from 1971 to 2020 by either the SLRT or the MALRT, we provide maps of vertical isotherm shift velocities. We identify 17 mountain regions with exceptionally high vertical isotherm shift velocities (greater than 11.67 m per year for the SLRT; greater than 8.25 m per year for the MALRT), predominantly in dry areas but also in wet regions with shallow lapse rates; for example, northern Sumatra, the Brazilian highlands and southern Africa. By linking these velocities to the velocities of species range shifts, we report instances of close tracking in mountains with lower climate velocities. However, many species lag behind, suggesting that range shift dynamics would persist even if we managed to curb climate-change trajectories. Our findings are key for devising global conservation strategies, particularly in the 17 high-velocity mountain regions that we have identified.


Assuntos
Altitude , Migração Animal , Biodiversidade , Mapeamento Geográfico , Aquecimento Global , Animais , África Austral , Brasil , Conservação dos Recursos Naturais , Aquecimento Global/estatística & dados numéricos , Umidade , Indonésia , Chuva , Refúgio de Vida Selvagem , Imagens de Satélites , Especificidade da Espécie , Temperatura , Fatores de Tempo
3.
Proc Biol Sci ; 290(1999): 20230529, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37221845

RESUMO

Deforestation is a major contributor to biodiversity loss, yet the impact of forest loss on daily microclimate variability and its implications for species with different daily activity patterns remain poorly understood. Using a recently developed microclimate model, we investigated the effects of deforestation on the daily temperature range (DTR) in low-elevation tropical regions and high-elevation temperate regions. Our results show that deforestation substantially increases DTR in these areas, suggesting a potential impact on species interactions. To test this hypothesis, we studied the competitive interactions between nocturnal burying beetles and all-day-active blowfly maggots in forested and deforested habitats in Taiwan. We show that deforestation leads to increased DTR at higher elevations, which enhances the competitiveness of blowfly maggots during the day and leads to a higher failure rate of carcass burial by the beetles at night. Thus, deforestation-induced temperature variability not only modulates exploitative competition between species with different daily activity patterns, but also likely exacerbates the negative impacts of climate change on nocturnal organisms. In order to limit potential adverse effects on species interactions and their ecological functions, our study highlights the need to protect forests, especially in areas where deforestation can greatly alter temperature variability.


Assuntos
Biodiversidade , Besouros , Animais , Temperatura , Mudança Climática , Febre , Larva
4.
Sci Total Environ ; 857(Pt 2): 159437, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36244482

RESUMO

Monsoon precipitation affects natural and social systems in East Asia, one of the most densely populated regions in the world. Monsoon precipitation variability is strongly influenced by El Niño-Southern Oscillation (ENSO) and may be related to the phase of the Pacific Decadal Oscillation (PDO). However, a collective understanding of the long-term PDO-ENSO-monsoon relationship remains limited because related studies are almost exclusively based on short instrumental records. Although paleoclimate proxies for PDO and ENSO are currently available, there is a lack of high-quality proxies for East Asian summer monsoon (EASM) precipitation. Moreover, the strengthening of the ENSO-EASM relationship since the 1970s has raised the question of anthropogenic impact. Reconstructing EASM precipitation is thus crucial to understanding its variability under natural and anthropogenic forcings. In this study, we addressed these challenges using tree ring oxygen isotopes of red cypress (Chamaecyparis formosensis Matsum), a long-lived endemic tree species in Taiwan. We developed an annual-resolved and well-validated EASM precipitation proxy from 1533 CE to 2011 which explained 49 % of the variance in instrumental precipitation. In comparison with multiple paleoclimate proxies, we revealed that PDO persistently modulated the ENSO-EASM relationship over the past half-millennium. The ENSO-EASM relationship was enhanced during the positive PDO phases and dynamically weakened during the negative PDO phases, notably in the early-17th, 18th, and early to mid-20th centuries. The strengthened relationship since the 1970s concurred with an unusually high PDO and ENSO and fell within its natural variability. Nevertheless, as the amplitude of the PDO is predicted to weaken under warming, the modulation effects may become less predictable.


Assuntos
Tempestades Ciclônicas , El Niño Oscilação Sul , Estações do Ano , Árvores , Isótopos de Oxigênio/análise
5.
Int J Syst Evol Microbiol ; 70(8): 4767-4773, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32697186

RESUMO

A strictly anaerobic predominant bacterium, designated as strain gm001T, was isolated from a freshly voided faecal sample collected from a healthy Taiwanese adult. Cells were Gram-stain-negative rods, non-motile and non-spore-forming. Strain gm001T was identified as a member of the genus Prevotella, and a comparison of 16S rRNA and hsp60 gene sequences revealed sequence similarities of 98.5 and 93.3 %, respectively, demonstrating that it was most closely related to the type strain of Prevotella copri. Phylogenomic tree analysis indicated that the gm001T cluster is an independent lineage of P. copri DSM 18205T. The average nucleotide identity, digital DNA‒DNA hybridization and average amino acid identity values between strain gm001T and P. copri DSM 18205T were 80.9, 28.6 and 83.8 %, respectively, which were clearly lower than the species delineation thresholds. The species-specific genes of this novel species were also identified on the basis of pan-genomic analysis. The predominant menaquinones were MK-11 and MK-12, and the predominant fatty acids were anteiso-C15 : 0, C15 : 0 and iso-C15 : 0. Acetate and succinate were produced from glucose as metabolic end products. Taken together, the results indicate that strain gm001T represents a novel species of the genus Prevotella, for which the name Prevotella hominis sp. nov. is proposed. The type strain is gm001T (=BCRC 81118T=JCM 33280T).


Assuntos
Fezes/microbiologia , Filogenia , Prevotella/classificação , Adulto , Bactérias Anaeróbias/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Humanos , Hibridização de Ácido Nucleico , Prevotella/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , Taiwan , Vitamina K 2/química
6.
Nat Commun ; 11(1): 3754, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699234

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

7.
Nat Commun ; 11(1): 1398, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32170152

RESUMO

Understanding how phenotypic traits vary among populations inhabiting different environments is critical for predicting a species' vulnerability to climate change. Yet, little is known about the key functional traits that determine the distribution of populations and the main mechanisms-phenotypic plasticity vs. local adaptation-underlying intraspecific functional trait variation. Using the Asian burying beetle Nicrophorus nepalensis, we demonstrate that mountain ranges differing in elevation and latitude offer unique thermal environments in which two functional traits-thermal tolerance and reproductive photoperiodism-interact to shape breeding phenology. We show that populations on different mountain ranges maintain similar thermal tolerances, but differ in reproductive photoperiodism. Through common garden and reciprocal transplant experiments, we confirm that reproductive photoperiodism is locally adapted and not phenotypically plastic. Accordingly, year-round breeding populations on mountains of intermediate elevation are likely to be most susceptible to future warming because maladaptation occurs when beetles try to breed at warmer temperatures.


Assuntos
Aclimatação/fisiologia , Mudança Climática , Besouros/fisiologia , Reprodução/fisiologia , Adaptação Fisiológica , Animais , Ásia , Evolução Biológica , Ecologia , Ecossistema , Feminino , Jardins , Masculino , Ovário , Fenótipo , Temperatura
8.
Nat Commun ; 10(1): 4612, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601806

RESUMO

Both community composition changes due to species redistribution and within-species size shifts may alter body-size structures under climate warming. Here we assess the relative contribution of these processes in community-level body-size changes in tropical moth assemblages that moved uphill during a period of warming. Based on resurvey data for seven assemblages of geometrid moths (>8000 individuals) on Mt. Kinabalu, Borneo, in 1965 and 2007, we show significant wing-length reduction (mean shrinkage of 1.3% per species). Range shifts explain most size restructuring, due to uphill shifts of relatively small species, especially at high elevations. Overall, mean forewing length shrank by ca. 5%, much of which is accounted for by species range boundary shifts (3.9%), followed by within-boundary distribution changes (0.5%), and within-species size shrinkage (0.6%). We conclude that the effects of range shifting predominate, but considering species physiological responses is also important for understanding community size reorganization under climate warming.


Assuntos
Tamanho Corporal/fisiologia , Mariposas/fisiologia , Altitude , Animais , Bornéu , Mudança Climática , Malásia , Mariposas/anatomia & histologia
9.
Ecol Lett ; 22(10): 1668-1679, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31347240

RESUMO

How abiotic and biotic factors constrain distribution limits at the harsh and benign edges of species ranges is hotly debated, partly because macroecological experiments testing the proximate causes of distribution limits are scarce. It has long been recognized - at least since Darwin's On the Origin of Species - that a harsh climate strengthens competition and thus sets species range limits. Using thorough field manipulations along a large elevation gradient, we show the mechanisms by which temperature determines competition type, resulting in a transition from interference to exploitative competition from the lower to the upper elevation limits in burying beetles (Nicrophorus nepalensis). This transition is an example of Darwin's classic hypothesis that benign climates favor direct competition for highly accessible resources while harsh climates result in competition through resources of high rivalry. We propose that identifying the properties of these key resources will provide a more predictive framework to understand the interplay between biotic and abiotic factors in determining geographic range limits.


Assuntos
Altitude , Clima , Besouros , Animais , Cruzamento , China , Comportamento Competitivo , Modelos Estatísticos , Densidade Demográfica , Temperatura
10.
Biol Rev Camb Philos Soc ; 93(1): 284-305, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28568902

RESUMO

Climate change is driving a pervasive global redistribution of the planet's species. Species redistribution poses new questions for the study of ecosystems, conservation science and human societies that require a coordinated and integrated approach. Here we review recent progress, key gaps and strategic directions in this nascent research area, emphasising emerging themes in species redistribution biology, the importance of understanding underlying drivers and the need to anticipate novel outcomes of changes in species ranges. We highlight that species redistribution has manifest implications across multiple temporal and spatial scales and from genes to ecosystems. Understanding range shifts from ecological, physiological, genetic and biogeographical perspectives is essential for informing changing paradigms in conservation science and for designing conservation strategies that incorporate changing population connectivity and advance adaptation to climate change. Species redistributions present challenges for human well-being, environmental management and sustainable development. By synthesising recent approaches, theories and tools, our review establishes an interdisciplinary foundation for the development of future research on species redistribution. Specifically, we demonstrate how ecological, conservation and social research on species redistribution can best be achieved by working across disciplinary boundaries to develop and implement solutions to climate change challenges. Future studies should therefore integrate existing and complementary scientific frameworks while incorporating social science and human-centred approaches. Finally, we emphasise that the best science will not be useful unless more scientists engage with managers, policy makers and the public to develop responsible and socially acceptable options for the global challenges arising from species redistributions.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais/métodos , Ecologia/métodos , Ciências Sociais/métodos , Animais , Humanos , Especificidade da Espécie
11.
Science ; 355(6332)2017 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-28360268

RESUMO

Distributions of Earth's species are changing at accelerating rates, increasingly driven by human-mediated climate change. Such changes are already altering the composition of ecological communities, but beyond conservation of natural systems, how and why does this matter? We review evidence that climate-driven species redistribution at regional to global scales affects ecosystem functioning, human well-being, and the dynamics of climate change itself. Production of natural resources required for food security, patterns of disease transmission, and processes of carbon sequestration are all altered by changes in species distribution. Consideration of these effects of biodiversity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals.


Assuntos
Biodiversidade , Mudança Climática , Animais , Abastecimento de Alimentos , Saúde , Humanos
12.
Science ; 351(6280): 1437-9, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-27013729

RESUMO

The climatic variability hypothesis posits that the magnitude of climatic variability increases with latitude, elevation, or both, and that greater variability selects for organisms with broader temperature tolerances, enabling them to be geographically widespread. We tested this classical hypothesis for the elevational range sizes of more than 16,500 terrestrial vertebrates on 180 montane gradients. In support of the hypothesis, mean elevational range size was positively correlated with the scope of seasonal temperature variation, whereas elevational range size was negatively correlated with daily temperature variation among gradients. In accordance with a previous life history model and our extended versions of it, our findings indicate that physiological specialization may be favored under shorter-term climatic variability.


Assuntos
Clima , Aquecimento Global , Estações do Ano , Temperatura , Vertebrados/fisiologia , Animais
13.
Fertil Steril ; 96(5): 1225-9, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21943726

RESUMO

OBJECTIVE: To investigate the relationship between the Notch 1 signaling pathway and the embryo implantation rate. DESIGN: Mouse embryos were cultured in vitro, and implantation competency was quantified. SETTING: Tertiary fertility center of a university teaching hospital. ANIMAL(S): Outbred ICR strain mouse embryos. INTERVENTION(S): The expression of Notch 1 was altered by adding a γ-secretase inhibitor to the culture medium. We quantified the consequent effect on embryo implantation. MAIN OUTCOME MEASURE(S): We measured the messenger RNA level of Notch 1 gene at different embryonic stages, embryo implantation rate under different culture conditions, the amount of Notch 1, and related implantation competency. RESULT(S): Quantitative polymerase chain reaction showed that the expression of Notch 1 increased during the implantation window. Adding γ-secretase inhibitor in the culture medium decreased the percentage of blastocysts in a dose-dependent manner. A Matrigel invasion assay showed that the competency of implantation required adequate expression of Notch 1 intracellular domain. CONCLUSION(S): Expression of Notch 1 at the proper time is required for the competency of embryo implantation; this effect is mediated through regulation of Notch 1 intracellular domain expression.


Assuntos
Implantação do Embrião , Embrião de Mamíferos/metabolismo , Receptor Notch1/metabolismo , Transdução de Sinais , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Colágeno/metabolismo , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Técnicas de Cultura Embrionária , Implantação do Embrião/efeitos dos fármacos , Embrião de Mamíferos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Laminina/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Proteoglicanas/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptor Notch1/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
14.
Science ; 333(6045): 1024-6, 2011 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-21852500

RESUMO

The distributions of many terrestrial organisms are currently shifting in latitude or elevation in response to changing climate. Using a meta-analysis, we estimated that the distributions of species have recently shifted to higher elevations at a median rate of 11.0 meters per decade, and to higher latitudes at a median rate of 16.9 kilometers per decade. These rates are approximately two and three times faster than previously reported. The distances moved by species are greatest in studies showing the highest levels of warming, with average latitudinal shifts being generally sufficient to track temperature changes. However, individual species vary greatly in their rates of change, suggesting that the range shift of each species depends on multiple internal species traits and external drivers of change. Rapid average shifts derive from a wide diversity of responses by individual species.


Assuntos
Altitude , Comportamento Animal , Mudança Climática , Ecossistema , Meio Ambiente , Animais , Geografia , Dinâmica Populacional , Especificidade da Espécie , Fatores de Tempo
15.
Proc Natl Acad Sci U S A ; 106(5): 1479-83, 2009 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-19164573

RESUMO

Physiological research suggests that tropical insects are particularly sensitive to temperature, but information on their responses to climate change has been lacking-even though the majority of all terrestrial species are insects and their diversity is concentrated in the tropics. Here, we provide evidence that tropical insect species have already undertaken altitude increases, confirming the global reach of climate change impacts on biodiversity. In 2007, we repeated a historical altitudinal transect, originally carried out in 1965 on Mount Kinabalu in Borneo, sampling 6 moth assemblages between 1,885 and 3,675 m elevation. We estimate that the average altitudes of individuals of 102 montane moth species, in the family Geometridae, increased by a mean of 67 m over the 42 years. Our findings indicate that tropical species are likely to be as sensitive as temperate species to climate warming, and we urge ecologists to seek other historic tropical samples to carry out similar repeat surveys. These observed changes, in combination with the high diversity and thermal sensitivity of insects, suggest that large numbers of tropical insect species could be affected by climate warming. As the highest mountain in one of the most biodiverse regions of the world, Mount Kinabalu is a globally important refuge for terrestrial species that become restricted to high altitudes by climate warming.


Assuntos
Altitude , Mariposas/fisiologia , Clima Tropical , Animais , Bornéu , Mariposas/classificação , Especificidade da Espécie
16.
Fertil Steril ; 91(3): 831-7, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18314115

RESUMO

OBJECTIVE: To determine the integrity of the sperm plasma membrane, mitochondria, and DNA, which are essential for accurate transmission of genetic material to offspring, and to quantify possible apoptosis and investigate any relationship between these parameters in ejaculated sperm from men with or without varicoceles. DESIGN: Retrospective study. SETTING: University teaching hospital. PATIENT(S): Twenty-five patients with varicocele and 10 normal, fertile controls. INTERVENTION(S): Apoptosis-related phenotype activations including the plasma membrane translocation of phosphatidylserine, mitochondrial dysfunction, and nuclear DNA damage, were assessed by using the annexin-V/propidium iodide double staining assay, 3,3'-dihexloxacarbocyanine iodide staining assay, and single-cell gel electrophoresis assay (comet assay). MAIN OUTCOME MEASURE(S): Apoptosis-related phenotype. RESULT(S): Patients with varicocele had statistically significantly more annexin V live sperm cells and nuclear DNA fragmentation than did the control men. In contrast, their numbers of 3,3'-dihexloxacarbocyanine iodide live cells were statistically significantly less than those in control men. CONCLUSION(S): The increased externalization of phosphatidylserine, mitochondrial dysfunction, and nuclear DNA damage occurred in the sperm of men with varicoceles, suggesting that certain apoptotic mechanisms may relate to the condition of varicocele, originating in the mitochondria of spermatocytes and then functioning within the nucleus of the cell.


Assuntos
Apoptose , Ejaculação , Espermatogênese , Espermatozoides/patologia , Varicocele/fisiopatologia , Adulto , Anexina A5/metabolismo , Membrana Celular/patologia , Fragmentação do DNA , Humanos , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias/patologia , Fenótipo , Fosfatidilserinas/metabolismo , Estudos Retrospectivos , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Espermatozoides/metabolismo , Varicocele/patologia , Adulto Jovem
17.
Fertil Steril ; 91(6): 2732.e5-7, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19110243

RESUMO

OBJECTIVE: To present male gender preselection after successive gestational hyperandrogenism and female pseudohermaphroditism by pregnancy luteomas. DESIGN: Case report. SETTING: University-based teaching hospital. PATIENT(S): We describe herein a gravida who presented two successive 46, XX disorders of sex development with apparent female genitalia with an enlarged clitoris due to maternal androgen excess from pregnancy luteoma. The maternal hyperandrogenemia returned to a normal level and bilateral luteoma regressed spontaneously postpartum. After gender preselection by Y-bearing spermatozoa for intrauterine insemination at the third gestation, a healthy boy was born in spite of the exaggerated maternal androgen production of pregnancy luteoma to avoid 46, XX disorders of sex development. INTERVENTION(S): Y-bearing spermatozoa for intrauterine insemination as male gender preselection. MAIN OUTCOME MEASURE(S): Boy born after gender preselection for intrauterine insemination and cesarean section. RESULT(S): Healthy boy born without disorder of sex development after antenatal maternal androgen excess of ovarian luteoma. CONCLUSION(S): Successive pregnancy luteomas associated with maternal hyperandrogenism may cause female disorders of sex development. Male preselection ameliorates the insult of external genitalia ambiguity by antenatal androgen excess in this matter of concern.


Assuntos
Transtornos do Desenvolvimento Sexual/genética , Luteoma/complicações , Cesárea , Cromossomos Humanos Y , Feminino , Humanos , Hiperandrogenismo/complicações , Masculino , Gravidez , Complicações Neoplásicas na Gravidez
18.
Biosci Biotechnol Biochem ; 72(11): 3021-4, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18997403

RESUMO

The filamentous fungus Monascus pilosus was genetically transformed with a reporter plasmid, pMS-1.5hp, by aurintricarboxylic acid (ATA) treatment to obtain an efficient red-pigment producing mutant. The transformation efficiency of Monascus pilosus was higher with the ATA-treatment than with either a non-restriction-enzyme-mediated integration (REMI) or a REMI method. This valid and convenient random mutagenesis method shows that ATA can be applied in fungi for efficient genetic transformation.


Assuntos
Ácido Aurintricarboxílico/farmacologia , Monascus/genética , Monascus/metabolismo , Pigmentação , Transformação Genética/efeitos dos fármacos , Animais , Cloreto de Cálcio/farmacologia , Enzimas de Restrição do DNA/metabolismo , Humanos , Monascus/citologia , Plasmídeos/genética , Polietilenoglicóis/farmacologia , Protoplastos/efeitos dos fármacos
19.
J Agric Food Chem ; 56(14): 5639-46, 2008 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-18578535

RESUMO

Monacolin K is a secondary metabolite synthesized by polyketide synthases (PKS) from Monascus, and it has the same structure as lovastatin, which is mainly produced by Aspergillus terreus. In the present study, a bacterial artificial chromosome (BAC) clone, mps01, was screened from the BAC library constructed from Monascus pilosus BCRC38072 genomic DNA. The putative monacolin K biosynthetic gene cluster was found within a 42 kb region in the mps01 clone. The deduced amino acid sequences encoded by the nine genes designated as mokA- mokI, which share over 54% similarity with the lovastatin biosynthetic gene cluster in A. terreus, were assumed to be involved in monacolin K biosynthesis. A gene disruption construct designed to replace the central part of mokA, a polyketide synthase gene, in wild-type M. pilosus BCRC38072 with a hygromycin B resistance gene through homologous recombination, resulted in a mokA-disrupted strain. The disruptant did not produce monacolin K, indicating that mokA encoded the PKS responsible for monacolin K biosynthesis in M. pilosus BCRC38072.


Assuntos
Clonagem Molecular , Lovastatina/biossíntese , Lovastatina/genética , Monascus/genética , Sequência de Aminoácidos , Cromossomos Artificiais Bacterianos , Lovastatina/química , Dados de Sequência Molecular , Monascus/enzimologia , Filogenia , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo
20.
Anim Reprod Sci ; 105(3-4): 272-82, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17434695

RESUMO

This study is to investigate the change of morphology of the meiotic spindle and the extent of zona hardening relating to the morphological survival and developmental competence of thawed oocytes. Four- to 8-week-old female mice (C57BL/6) primed with an intraperitoneal injection of pregnant mare's serum gonadotropin and human chorionic gonadotropin. Cryopreserved oocytes using two protocols: vitrificaton using ethylene glycol (EG) and slow freezing using propanediol (PROH). The freezing oocytes were thawed and were fertilized and subsequently cultured in vitro. Spindle/chromosome imagery, dissolution of zona pellucida, and post-thawing survival and development were comparable between two groups. The vitrification cryopreservation method proved to be better than the slow-freezing protocol when comparing the frequency of normal-shaped spindle development post-thawing. The difference in the time required for the dissolution of the zona pellucida under treatment of pronase that was determined to exist between the two cryopreservation methods was statistically significant (P<0.005). The survival rate of post-thawed mature oocytes was significantly greater for the vitrification group than it was for the slow-freezing cryopreservation group (P=0.005). The vitrification cryopreservation of mature murine oocytes would appear to be more satisfactory than the slow controlled-rate freezing method as regards the post-thawing oocyte survival and also the incidence of the normal spindle apparatus in the ooplasm.


Assuntos
Criopreservação/métodos , Meiose/fisiologia , Oócitos/fisiologia , Fuso Acromático/fisiologia , Zona Pelúcida/fisiologia , Animais , Feminino , Fertilização in vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Oócitos/ultraestrutura , Pronase/metabolismo , Fuso Acromático/ultraestrutura , Estatísticas não Paramétricas , Zona Pelúcida/ultraestrutura
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