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1.
PLoS Biol ; 17(1): e3000107, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30629605

RESUMEN

Current molecular biology laboratories rely heavily on the purification and manipulation of nucleic acids. Yet, commonly used centrifuge- and column-based protocols require specialised equipment, often use toxic reagents, and are not economically scalable or practical to use in a high-throughput manner. Although it has been known for some time that magnetic beads can provide an elegant answer to these issues, the development of open-source protocols based on beads has been limited. In this article, we provide step-by-step instructions for an easy synthesis of functionalised magnetic beads, and detailed protocols for their use in the high-throughput purification of plasmids, genomic DNA, RNA and total nucleic acid (TNA) from a range of bacterial, animal, plant, environmental and synthetic sources. We also provide a bead-based protocol for bisulfite conversion and size selection of DNA and RNA fragments. Comparison to other methods highlights the capability, versatility, and extreme cost-effectiveness of using magnetic beads. These open-source protocols and the associated webpage (https://bomb.bio) can serve as a platform for further protocol customisation and community engagement.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Ácidos Nucleicos/aislamiento & purificación , Animales , ADN/aislamiento & purificación , Humanos , Campos Magnéticos , Microesferas , ARN/aislamiento & purificación
2.
Mol Phylogenet Evol ; 134: 238-252, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30415023

RESUMEN

Next generation sequencing has revolutionised biology. Restriction-associated DNA sequencing (RADseq) has primarily been used to study infraspecific relationships but has also been applied in multi-species phylogenomic analyses. In this study, we used a combination of phylogenomic (with RADseq data) and phylogenetic (with sequences of the nuclear internal transcribed spacer, ITS) methods to explore relationships within the taxonomically intricate Euphorbia seguieriana s. l., one of the most widespread Euphorbia taxa inhabiting zonal and extrazonal steppes from Iberia to Central Asia. In the inferred phylogenies the southeastern Balkan and Anatolian populations were clearly separated, supporting the distinction of E. niciciana from E. seguieriana at the species level. Within E. seguieriana, the populations from the Caucasus, Iran, and easternmost Anatolia were sister to all other populations based on RADseq, making necessary the description of a new, morphologically divergent subspecies, E. seguieriana subsp. armeniaca. Conversely, additional studies are needed to understand the status of E. seguieriana subsp. hohenackeri, which is sympatric with E. seguieriana subsp. armeniaca. Niche analyses indicated that differences in the climatic niche between E. niciciana and E. seguieriana are relatively small compared with the climatic differences between the regions over which they are distributed. Contrary to previous believes, E. niciciana and E. seguieriana are allopatric and have likely diverged during the Pleistocene in two different glacial refugia as suggested by distribution modelling. Euphorbia niciciana nowadays has a submediterranean distribution, occupying habitats that are slightly warmer, moister, and less seasonal in temperature but more seasonal in precipitation than E. seguieriana, a characteristic species of continental steppes. Using flow cytometry, we demonstrate that the relative genome sizes of E. niciciana and E. seguieriana differ significantly. Additionally, multivariate morphometric analyses of 56 morphological characters indicated clear morphological divergence of the two species. Importantly, we also provide a revised taxonomic treatment including formal nomenclatural changes, an identification key and species descriptions. Our study demonstrates that an integrative approach, combining modern phylogenomic methods with traditional phylogenetic, cytogenetic, environmental and morphological analyses can result in satisfactorily resolved relationships in intricate groups of closely related species. Finally, phylogenetic inference using ITS sequences is still a useful tool for resolving relationships among the taxa at the species level, but the phylogenomic approach based on RADseq data certainly provides better resolution both among and within species.


Asunto(s)
Ecosistema , Euphorbia/genética , Tamaño del Genoma , Genoma de Planta , Modelos Teóricos , Filogenia , ADN Espaciador Ribosómico/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Irán
3.
Plant Cell Environ ; 38(7): 1347-56, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25393014

RESUMEN

The occurrence of chloroplast protrusions (CPs) in leaves of Ranunculus glacialis L. in response to different environmental conditions was assessed. CPs occur highly dynamically. They do not contain thylakoids and their physiological function is still largely unknown. Controlled in situ sampling showed that CP formation follows a pronounced diurnal rhythm. Between 2 and 27 °C the relative proportion of chloroplasts with CPs (rCP) showed a significant positive correlation to leaf temperature (TL; 0.793, P < 0.01), while irradiation intensity had a minor effect on rCP. In situ shading and controlled laboratory experiments confirmed the significant influence of TL. Under moderate irradiation intensity, an increase of TL up to 25 °C significantly promoted CP formation, while a further increase to 37 °C led to a decrease. Furthermore, rCP values were lower in darkness and under high irradiation intensity. Gas treatment at 2000 ppm CO2/2% O2 led to a significant decrease of rCP, suggesting a possible involvement of photorespiration in CP formation. Our findings demonstrate that in R. glacialis, CPs are neither a rare phenomenon nor a result of heat or light stress; on the contrary, they seem to be most abundant under moderate temperature and non-stress irradiation conditions.


Asunto(s)
Cloroplastos/fisiología , Ranunculus/fisiología , Cloroplastos/efectos de la radiación , Cloroplastos/ultraestructura , Oscuridad , Luz , Fotosíntesis , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de la radiación , Hojas de la Planta/ultraestructura , Ranunculus/efectos de la radiación , Ranunculus/ultraestructura , Estrés Fisiológico , Temperatura
4.
Front Public Health ; 9: 808751, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35141190

RESUMEN

The rapid global rise of COVID-19 from late 2019 caught major manufacturers of RT-qPCR reagents by surprise and threw into sharp focus the heavy reliance of molecular diagnostic providers on a handful of reagent suppliers. In addition, lockdown and transport bans, necessarily imposed to contain disease spread, put pressure on global supply lines with freight volumes severely restricted. These issues were acutely felt in New Zealand, an island nation located at the end of most supply lines. This led New Zealand scientists to pose the hypothetical question: in a doomsday scenario where access to COVID-19 RT-qPCR reagents became unavailable, would New Zealand possess the expertise and infrastructure to make its own reagents onshore? In this work we describe a review of New Zealand's COVID-19 test requirements, bring together local experts and resources to make all reagents for the RT-qPCR process, and create a COVID-19 diagnostic assay referred to as HomeBrew (HB) RT-qPCR from onshore synthesized components. This one-step RT-qPCR assay was evaluated using clinical samples and shown to be comparable to a commercial COVID-19 assay. Through this work we show New Zealand has both the expertise and, with sufficient lead time and forward planning, infrastructure capacity to meet reagent supply challenges if they were ever to emerge.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19 , COVID-19 , Humanos , Indicadores y Reactivos/provisión & distribución , SARS-CoV-2
5.
AoB Plants ; 11(2): plz007, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30937158

RESUMEN

Endemism in mountain ranges is considered to be the result of a number of factors, including restriction to refugia during Pleistocene climate fluctuations. However, isolation in glacial refugia cannot explain the origin of narrowly endemic taxa restricted to formerly heavily glaciated areas. Here, we investigate the phylogeny of two narrowly endemic species, Euphrasia inopinata and E. sinuata (Orobanchaceae), found exclusively in formerly heavily glaciated areas of the eastern European Alps. As both species are diploid and very similar to the widespread (allo)polyploid E. minima, we test whether the restricted distributions of E. inopinata and E. sinuata are relictual, i.e. the two species are ancestral diploid remnants of a polyploid complex, or whether they are derived, i.e. the two species are peripheral segregates of a more widespread diploid. Based on internal transcribed spacer (ITS) sequence and amplified fragment length polymorphism (AFLP) fingerprint data it is shown that E. inopinata and E. sinuata, whose diploid ploidy level is confirmed for all analysed individuals via flow cytometry, are phylogenetically closely related to diploid E. alpina s. l. (series Alpinae) instead of E. minima (series Parviflorae). In addition, there is no evidence that these two diploid species participated in the formation of allotetraploid E. minima. Thus, E. inopinata and E. sinuata are interpreted as peripheral segregates of the widespread E. alpina s. l. Shifts in pollination system from allogamy in E. alpina s. l. to autogamy in E. inopinata and E. sinuata, genetic drift in small populations and geographic isolation at the periphery of the range of E. alpina s. str. probably contributed to the morphological and ecological differentiation of E. inopinata and E. sinuata.

6.
Protoplasma ; 252(6): 1613-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25701381

RESUMEN

Chloroplast protrusions (CPs) have frequently been observed in plants, but their significance to plant metabolism remains largely unknown. We investigated in the alpine plant Ranunculus glacialis L. treated under various CO2 concentrations if CP formation is related to photorespiration, specifically focusing on hydrogen peroxide (H2O2) metabolism. Immediately after exposure to different CO2 concentrations, the formation of CPs in leaf mesophyll cells was assessed and correlated to catalase (CAT) and ascorbate peroxidase (APX) activities. Under natural irradiation, the relative proportion of chloroplasts with protrusions (rCP) was highest (58.7 %) after exposure to low CO2 (38 ppm) and was lowest (3.0 %) at high CO2 (10,000 ppm). The same relationship was found for CAT activity, which decreased from 34.7 nkat mg(-1) DW under low CO2 to 18.4 nkat mg(-1) DW under high CO2, while APX activity did not change significantly. When exposed to natural CO2 concentration (380 ppm) in darkness, CP formation was significantly lower (18.2 %) compared to natural solar irradiation (41.3 %). In summary, CP formation and CAT activity are significantly increased under conditions that favour photorespiration, while in darkness or at high CO2 concentration under light, CP formation is significantly lower, providing evidence for an association between CPs and photorespiration.


Asunto(s)
Dióxido de Carbono/farmacología , Catalasa/metabolismo , Cloroplastos/efectos de los fármacos , Hábitos , Calor , Membranas Intracelulares/efectos de los fármacos , Oxígeno/farmacología , Proteínas de Plantas/metabolismo , Ranunculus/efectos de los fármacos , Aclimatación , Altitud , Ascorbato Peroxidasas/metabolismo , Dióxido de Carbono/metabolismo , Cloroplastos/enzimología , Cloroplastos/efectos de la radiación , Cloroplastos/ultraestructura , Oscuridad , Relación Dosis-Respuesta a Droga , Membranas Intracelulares/enzimología , Membranas Intracelulares/efectos de la radiación , Membranas Intracelulares/ultraestructura , Luz , Microscopía de Interferencia , Oxígeno/metabolismo , Fotoperiodo , Fotosíntesis/efectos de los fármacos , Ranunculus/enzimología , Ranunculus/efectos de la radiación , Ranunculus/ultraestructura , Factores de Tiempo
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