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1.
Glob Chang Biol ; 30(4): e17271, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38613240

RESUMEN

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.


Asunto(s)
Biodiversidad , Cambio Climático , Filogenia , Geografía , Fenotipo
2.
Nature ; 629(8010): 114-120, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38538797

RESUMEN

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.


Asunto(s)
Altitud , Migración Animal , Biodiversidad , Mapeo Geográfico , Calentamiento Global , Animales , África Austral , Brasil , Conservación de los Recursos Naturales , Calentamiento Global/estadística & datos numéricos , Humedad , Indonesia , Lluvia , Refugio de Fauna , Imágenes Satelitales , Especificidad de la Especie , Temperatura , Factores de Tiempo
3.
Proc Biol Sci ; 290(1999): 20230529, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37221845

RESUMEN

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.


Asunto(s)
Biodiversidad , Escarabajos , Animales , Temperatura , Cambio Climático , Fiebre , Larva
4.
Sci Total Environ ; 857(Pt 2): 159437, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36244482

RESUMEN

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.


Asunto(s)
Tormentas Ciclónicas , El Niño Oscilación del Sur , Estaciones del Año , Árboles , Isótopos de Oxígeno/análisis
5.
Nat Commun ; 11(1): 3754, 2020 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-32699234

RESUMEN

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

6.
Int J Syst Evol Microbiol ; 70(8): 4767-4773, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32697186

RESUMEN

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).


Asunto(s)
Heces/microbiología , Filogenia , Prevotella/clasificación , Adulto , Bacterias Anaerobias/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Humanos , Hibridación de Ácido Nucleico , Prevotella/aislamiento & purificación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Taiwán , Vitamina K 2/química
7.
Nat Commun ; 11(1): 1398, 2020 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-32170152

RESUMEN

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.


Asunto(s)
Aclimatación/fisiología , Cambio Climático , Escarabajos/fisiología , Reproducción/fisiología , Adaptación Fisiológica , Animales , Asia , Evolución Biológica , Ecología , Ecosistema , Femenino , Jardines , Masculino , Ovario , Fenotipo , Temperatura
8.
Nat Commun ; 10(1): 4612, 2019 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-31601806

RESUMEN

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.


Asunto(s)
Tamaño Corporal/fisiología , Mariposas Nocturnas/fisiología , Altitud , Animales , Borneo , Cambio Climático , Malasia , Mariposas Nocturnas/anatomía & histología
9.
Ecol Lett ; 22(10): 1668-1679, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31347240

RESUMEN

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.


Asunto(s)
Altitud , Clima , Escarabajos , Animales , Cruzamiento , China , Conducta Competitiva , Modelos Estadísticos , Densidad de Población , Temperatura
10.
Biol Rev Camb Philos Soc ; 93(1): 284-305, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28568902

RESUMEN

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.


Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales/métodos , Ecología/métodos , Ciencias Sociales/métodos , Animales , Humanos , Especificidad de la Especie
11.
Science ; 355(6332)2017 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-28360268

RESUMEN

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.


Asunto(s)
Biodiversidad , Cambio Climático , Animales , Abastecimiento de Alimentos , Salud , Humanos
12.
Science ; 351(6280): 1437-9, 2016 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-27013729

RESUMEN

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.


Asunto(s)
Clima , Calentamiento Global , Estaciones del Año , Temperatura , Vertebrados/fisiología , Animales
13.
Fertil Steril ; 96(5): 1225-9, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21943726

RESUMEN

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.


Asunto(s)
Implantación del Embrión , Embrión de Mamíferos/metabolismo , Receptor Notch1/metabolismo , Transducción de Señal , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Animales , Colágeno/metabolismo , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Técnicas de Cultivo de Embriones , Implantación del Embrión/efectos de los fármacos , Embrión de Mamíferos/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Femenino , Regulación del Desarrollo de la Expresión Génica , Laminina/metabolismo , Ratones , Ratones Endogámicos ICR , Proteoglicanos/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptor Notch1/genética , Transducción de Señal/efectos de los fármacos , Factores de Tiempo
14.
Science ; 333(6045): 1024-6, 2011 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-21852500

RESUMEN

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.


Asunto(s)
Altitud , Conducta Animal , Cambio Climático , Ecosistema , Ambiente , Animales , Geografía , Dinámica Poblacional , Especificidad de la Especie , Factores de Tiempo
15.
Proc Natl Acad Sci U S A ; 106(5): 1479-83, 2009 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-19164573

RESUMEN

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.


Asunto(s)
Altitud , Mariposas Nocturnas/fisiología , Clima Tropical , Animales , Borneo , Mariposas Nocturnas/clasificación , Especificidad de la Especie
16.
Fertil Steril ; 91(6): 2732.e5-7, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19110243

RESUMEN

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.


Asunto(s)
Trastornos del Desarrollo Sexual/genética , Luteoma/complicaciones , Cesárea , Cromosomas Humanos Y , Femenino , Humanos , Hiperandrogenismo/complicaciones , Masculino , Embarazo , Complicaciones Neoplásicas del Embarazo
17.
Fertil Steril ; 91(3): 831-7, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18314115

RESUMEN

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.


Asunto(s)
Apoptosis , Eyaculación , Espermatogénesis , Espermatozoides/patología , Varicocele/fisiopatología , Adulto , Anexina A5/metabolismo , Membrana Celular/patología , Fragmentación del ADN , Humanos , Masculino , Potencial de la Membrana Mitocondrial , Mitocondrias/patología , Fenotipo , Fosfatidilserinas/metabolismo , Estudios Retrospectivos , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides/metabolismo , Varicocele/patología , Adulto Joven
18.
Biosci Biotechnol Biochem ; 72(11): 3021-4, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18997403

RESUMEN

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.


Asunto(s)
Ácido Aurintricarboxílico/farmacología , Monascus/genética , Monascus/metabolismo , Pigmentación , Transformación Genética/efectos de los fármacos , Animales , Cloruro de Calcio/farmacología , Enzimas de Restricción del ADN/metabolismo , Humanos , Monascus/citología , Plásmidos/genética , Polietilenglicoles/farmacología , Protoplastos/efectos de los fármacos
19.
J Agric Food Chem ; 56(14): 5639-46, 2008 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-18578535

RESUMEN

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.


Asunto(s)
Clonación Molecular , Lovastatina/biosíntesis , Lovastatina/genética , Monascus/genética , Secuencia de Aminoácidos , Cromosomas Artificiales Bacterianos , Lovastatina/química , Datos de Secuencia Molecular , Monascus/enzimología , Filogenia , Sintasas Poliquetidas/genética , Sintasas Poliquetidas/metabolismo
20.
Anim Reprod Sci ; 105(3-4): 272-82, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-17434695

RESUMEN

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.


Asunto(s)
Criopreservación/métodos , Meiosis/fisiología , Oocitos/fisiología , Huso Acromático/fisiología , Zona Pelúcida/fisiología , Animales , Femenino , Fertilización In Vitro , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Oocitos/ultraestructura , Pronasa/metabolismo , Huso Acromático/ultraestructura , Estadísticas no Paramétricas , Zona Pelúcida/ultraestructura
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