Gene replacements at the his-3 locus of Neurospora crassa

We report the construction of pRAUW122, a plasmid capable of directing the integration of gene-constructs by gene replacement at the his-3locus of Neurospora crassa. Gene targeting at his-3 is selected by growing the transformants in histidine-free medium. The elimination of a second selectable marker (Bmlr), flanking the gene construct, is detected by screening for benomyl sensitivity of the his-3+ transformants. Therefore, his-3+ Bmls transformants have a high probability of having arisen by the desired gene replacement event

Culpa y responsabilidad como vertientes de la conciencia moral

If I am not mistaken, our cultural baggage leads us almost automatically to associate guilt with a religious concept. To be more precise this has Judean-Christian roots. At the same time it also tends to lead to the identification of responsibility with strictly legal matters. Guilt is presented in close association with religion or, at most, with psychoanalysis, given that responsibility is usually restricted to criminal law or is associated in terms of protocol with polities. Nevertheless, although the words «guilt» and «responsibility » do not occur very often in dictionaries of ethics, they are key concepts in moral thought. My purpose here is to present them as dimensions or complementary aspects of our moral sense. It is of course possible for anyone to accept a specific responsibility without feeling guilty while, on the other hand, some people will always prefer to wallow in feelings of guilt without feeling responsible for the cause of the same. However, it is correct for both notions to work together with one accord. Guilt should therefore be a symptom of responsibility, while attending to our own responsibilities should be enough to ensure a complete lack of personal guilt.Si no estoy equivocado, nuestro acervo cultural nos hace asociar casi automáticamente a la culpa con un concepto religioso, de raigambre judeocristiana para ser más precisos, mientras que al mismo tiempo tiende a identificar la responsabilidad con una categoría eminentemente jurídica. La culpa se presenta como algo estrechamente vinculado con el pecado y la religión o, a lo sumo, con el psicoanálisis, en tanto que la responsabilidad suele circunscribirse de oficio al ámbito del derecho penal o relacionarse protocolariamente con la esfera política. Sin embargo, aunque las palabras «culpa» y «responsabilidad» no se prodiguen demasiado en los diccionarios consagrados a la ética, sí constituyen conceptos claves de la reflexión moral. Mi propósito aquí es presentarlos como dimensiones o vertientes complementarias de nuestra conciencia. Desde luego, cualquiera puede asumir una determinada responsabilidad sin sentirse culpable y, a la inversa, siempre hay quien prefiere regodearse con su sentimiento de culpabilidad sin sentirse responsable por la causa del mismo, pero lo suyo es que ambas nociones vayan de consuno y la culpa sea un síntoma de responsabilidad o que atender a las propias responsabilidades ahuyente cualquier asomo de culpabilidad por nuestra parte

La paradójica herencia de la Ilustración kantiana en Schopenhauer

El principal objetivo de este artículo es mostrar las coincidencias, a la vez que las discrepancias, de la lectura hecha por Schopenhauer del programa ilustrado propuesto por Kant. En concreto, se considerarán cuatro grandes temas: sus respectivas afirmaciones respecto a la figura de Federico el Grande y a las principales características de la Ilustración; la idea de esperanza, progreso e historia en el panorama ilustrado; la cosa-en-sí kantiana interpretada como voluntad; y la particular lectura schopenhaueriana del famoso lema kantiano sapere aude!The aim of this article is to point at Schopenhauer reading of the Program of the Enlightment as exposed by Kant, its differences and coincidences. It considers four main issues: The figure of Frederich the Great, as considered by both philosophers, the ideas of Hope, Progress and History, the kantian notion of thing-in-itself understood by Schopenhauer as Will and his peculir reading ot the famous kantian dictum sapere aude!Departamento de Filosofí

A gas emitted by Neurospora crassa

We investigated whether gases other than carbon dioxide are produced by N. crassa. A peak corresponding to ethylene has been detected using gas chromatography. Mass spectroscopy, however, indicated that the gas produced might be carbon monoxide which, surprisingly, migrated with the same chromatographic retention time as ethylene. Our results emphasize the need for caution when interpreting results based solely on gas chromatographic data

MutS and MutL Are Dispensable for Maintenance of the Genomic Mutation Rate in the Halophilic Archaeon Halobacterium salinarum NRC-1

BACKGROUND: The genome of the halophilic archaeon Halobacterium salinarum NRC-1 encodes for homologs of MutS and MutL, which are key proteins of a DNA mismatch repair pathway conserved in Bacteria and Eukarya. Mismatch repair is essential for retaining the fidelity of genetic information and defects in this pathway result in the deleterious accumulation of mutations and in hereditary diseases in humans. METHODOLOGY/PRINCIPAL FINDINGS: We calculated the spontaneous genomic mutation rate of H. salinarum NRC-1 using fluctuation tests targeting genes of the uracil monophosphate biosynthesis pathway. We found that H. salinarum NRC-1 has a low incidence of mutation suggesting the presence of active mechanisms to control spontaneous mutations during replication. The spectrum of mutational changes found in H. salinarum NRC-1, and in other archaea, appears to be unique to this domain of life and might be a consequence of their adaption to extreme environmental conditions. In-frame targeted gene deletions of H. salinarum NRC-1 mismatch repair genes and phenotypic characterization of the mutants demonstrated that the mutS and mutL genes are not required for maintenance of the observed mutation rate. CONCLUSIONS/SIGNIFICANCE: We established that H. salinarum NRC-1 mutS and mutL genes are redundant to an alternative system that limits spontaneous mutation in this organism. This finding leads to the puzzling question of what mechanism is responsible for maintenance of the low genomic mutation rates observed in the Archaea, which for the most part do not have MutS and MutL homologs