Ty1 insertions in intergenic regions of the genome of Saccharomyces cerevisiae transcribed by RNA polymerase III have no detectable selective effect

The retrotransposon Ty1 of Saccharomyces cerevisiae inserts preferentially into intergenic regions in the vicinity of RNA polymerase III-transcribed genes. It has been suggested that this preference has evolved to minimize the deleterious effects of element transposition on the host genome, and thus to favor their evolutionary survival. This presupposes that such insertions have no selective effect. However, there has been no direct test of this hypothesis. Here we construct a series of strains containing single Ty1 insertions in the vicinity of tRNA genes, or in the rDNA cluster on chromosome XII, which are otherwise isogenic to strain 337, containing zero Ty1 elements. Competition experiments between 337 and the strains containing single Ty1 insertions revealed that in all cases, the Ty1 insertions have no selective effect in rich medium. These results are thus consistent with the hypothesis that the insertion site preference of Ty1 elements has evolved to minimize the deleterious effects of transposition on the host genome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72266/1/S1567-1356_03_00199-5.pd

Proposed diagnostic criteria for classical CMML, CMML variants and pre-CMML conditions

Chronic myelomonocytic leukemia (CMML) is a myeloid neoplasm characterized by dysplasia, abnormal production and accumulation of monocytic cells and an elevated risk to transform into acute leukemia. Over the past two decades, our knowledge about the pathogenesis and molecular mechanisms in CMML has increased substantially. In parallel, better diagnostic criteria and therapeutic strategies have been developed. However, many questions remain regarding prognostication and optimal therapy. In addition, there is a need to define potential pre-phases of CMML and special CMML variants, and to separate these entities from each other and from conditions mimicking CMML. To address these unmet needs, an international consensus group met in a Working Conference in August 2018 and discussed open questions and issues around CMML, its variants, and pre-CMML conditions. The outcomes of this meeting are summarized herein and include diagnostic criteria and a proposed classification of pre-CMML conditions as well as refined minimal diagnostic criteria for classical CMML and special CMML variants, including oligomonocytic CMML and CMML associated with systemic mastocytosis. Moreover, we propose diagnostic standards and tools to delineate between normal, pre-CMML and CMML entities. These criteria and standards should facilitate diagnostic and prognostic evaluations in daily practice and clinical studies in applied hematology

A method of genetic identification of pine marten (Martes martes) and stone marten (Martes foina) and its application to faecal samples

Reliable identification of species occurring in a given area is a basis of effective wildlife management and conservation. However, discrimination of species is often difficult, especially if two morphologically similar, rare and elusive species occur sympatrically. This is the case with pine marten Martes martes and stone marten Martes foina, two closely related mustelids that have overlapping ranges throughout central Europe. Here we describe a genetic method that allows for distinguishing non-invasively collected samples (faeces or remotely plucked hair) derived from pine martens or stone martens. On the basis of the analysis of tissue samples of 31 pine martens and 26 stone martens, we found that the microsatellite locus Ma18 - developed in another study for American marten Martes americana - differs substantially in allele lengths between pine martens and stone martens, thereby allowing a genetic distinction of these species. We propose combining the use of the locus Ma18 with the second one described in the literature as having the same properties. The simultaneous application of these two markers allows for unequivocal species identification. To test the practical use of this method, we analysed 365 faecal samples collected in the vicinity of the town Rogów (51°48�N, 19°53�E) in central Poland, where pine martens and stone martens occur sympatrically. We successfully identified 78 scats of stone martens and 155 of pine martens. We found that the faeces of both martens occurred inside forest complexes of the study area. Thus, it is impossible to draw any inferences on the marten species solely from the type of habitat where the faeces were found. Genetic identification of faeces or hair provides a reliable and relatively cheap method of determining the presence of two species of European martens. Its application enables the monitoring of changes in their distribution, which is important because of their different demographic trends and conservation status. © 2007 The Zoological Society of London