What Have We Learned in 30 Years of Investigations on Bari Transposons?

Transposable elements (TEs) have been historically depicted as detrimental genetic entities that selfishly aim at perpetuating themselves, invading genomes, and destroying genes. Scientists often co-opt “special” TEs to develop new and powerful genetic tools, that will hopefully aid in changing the future of the human being. However, many TEs are gentle, rarely unleash themselves to harm the genome, and bashfully contribute to generating diversity and novelty in the genomes they have colonized, yet they offer the opportunity to develop new molecular tools. In this review we summarize 30 years of research focused on the Bari transposons. Bari is a “normal” transposon family that has colonized the genomes of several Drosophila species and introduced genomic novelties in the melanogaster species. We discuss how these results have contributed to advance the field of TE research and what future studies can still add to the current knowledge

CPX-351 treatment in secondary acute myeloblastic leukemia is effective and improves the feasibility of allogeneic stem cell transplantation: results of the Italian compassionate use program

Secondary acute myeloid leukemia (sAML) poorly responds to conventional treatments and allogeneic stem cell transplantation (HSCT). We evaluated toxicity and efficacy of CPX-351 in 71 elderly patients (median age 66 years) with sAML enrolled in the Italian Named (Compassionate) Use Program. Sixty days treatment-related mortality was 7% (5/71). The response rate at the end of treatment was: CR/CRi in 50/71 patients (70.4%), PR in 6/71 (8.5%), and NR in 10/71 (19.7%). After a median follow-up of 11 months relapse was observed in 10/50 patients (20%) and 12 months cumulative incidence of relapse (CIR) was 23.6%. Median duration of response was not reached. In competing risk analysis, CIR was reduced when HSCT was performed in first CR (12 months CIR of 5% and 37.4%, respectively, for patients receiving (=20) or not (=30) HSCT, p = 0.012). Twelve-months OS was 68.6% (median not reached). In landmark analysis, HSCT in CR1 was the only significant predictor of longer survival (12 months OS of 100 and 70.5%, for patients undergoing or not HSCT in CR1, respectively, p = 0.011). In conclusion, we extend to a real-life setting, the notion that CPX is an effective regimen for high risk AML patients and may improve the results of HSCT

Critical literacy as a pedagogical goal in English language teaching

In this chapter, the authors provide an overview of the area of critical literacy as it pertains to second language pedagogy (curriculum and instruction). After considering the historical origins of critical literacy (from antiquity, and including in first language education), they consider how it began to penetrate the field of applied linguistics. They note the geographical and institutional spread of critical literacy practice as documented by published accounts. They then sketch the main features of L2 critical literacy practice. To do this, they acknowledge how practitioners have reported on their practices regarding classroom content and process. The authors also draw attention to the outcomes of these practices as well as challenges that practitioners have encountered in incorporating critical literacy into their second language classrooms

Mosquitoes LTR Retrotransposons: A Deeper View into the Genomic Sequence of Culex quinquefasciatus

A set of 67 novel LTR-retrotransposon has been identified by in silico analyses of the Culex quinquefasciatus genome using the LTR_STRUC program. The phylogenetic analysis shows that 29 novel and putatively functional LTR-retrotransposons detected belong to the Ty3/gypsy group. Our results demonstrate that, by considering only families containing potentially autonomous LTR-retrotransposons, they account for about 1% of the genome of C. quinquefasciatus. In previous studies it has been estimated that 29% of the genome of C. quinquefasciatus is occupied by mobile genetic elements

Gene amplification in methotrexate-resistant mouse cells. IV. Different DNA sequences are amplified in different resistant lines.

DNA was purified from double minutes isolated from MTX-resistant EL4/8 mouse lymphoma cells, digested to completion with Bam H1 restriction endonuclease and cloned in lambda-1059. The properties of the library suggest that the DNA from which it was made was not detectably contaminated with non-dm chromosome material, and that the library is essentially complete for sequences contained in Bam H1 restriction fragments between 9 and 19 kb. The inserts of some selected lambda-recombinants were subcloned in pBR328 or pAT153 to separate sequences of differing repetition frequency. Clones representative of different classes of sequences were used as probes to Southern transfers of Bam H1 digested total nuclear DNAs of various MTX-resistant cell lines. The results clearly show that the amplified unit of each cell line has a unique structure, and that different amplified units differ widely in their sequence composition

Segregation Distortion in Drosophila Melanogaster: Genomic Organization of Responder Sequences

The heterochromatic Responder (Rsp) locus of Drosophila melanogaster is the target of the two distorter loci Sd and E(SD). Rsp is located in a specific heterochromatic region of the second chromosome and is made up of AT-rich satellite sequences whose abundance is related to its sensitivity to the distorter chromosomes. Here we report that a cluster of Rsp sequences is also located in the third chromosome. The third-chromosome cluster has the same flanking sequences as the clone originally used to identify the Rsp elements, and one of the flanking sequences is a rearranged 412 retrotrsansposon. The presence of a second, unlinked Rsp-sequence cluster makes re-interpretation necessary for some earlier experiments in which segregation of the third chromosome had not been followed and raises interesing possibilities for the origin of the Rsp locus

Bari-1, a New Transposon-like Family in Drosophila Melanogaster with a Unique Heterochromatic Organization

We have identified a new middle repetitive DNA family in Drosophila melanogaster. This family is composed of a 1.7-kb element, called Bari-1, that shows common characteristics with many transposable elements. Bari-1 is present in a few euchromatic sites that vary in different stocks. However, it is peculiar in that most copies are homogeneously clustered with a unique location in a specific heterochromatic region close to the centromere of the second chromosome. The molecular analysis of different copies coming from the euchromatin and the heterochromatin has revealed that, independent of their location, all possess the same open reading frame. The putative protein encoded by Bari-1 shares similarity with the transposase of the Tc1 transposon of Caenorhabditis elegans. We compare the Bari-1 organization with other mobile DNA families and discuss the possibility of some functional role for the heterochromatic cluster