171 research outputs found

    The future of UK Antarctic science: strategic priorities essential needs and opportunities for international leadership

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    • The Antarctic region has been experiencing rapid change in recent decades due to human induced factors. Most notably, climate heating is causing ice sheet melting, leading to sea level rise and disruption in global ocean heat circulation, with far-reaching global consequences. • At the same time, this region holds unique research potential that can help address a range of critically important scientific priorities, including climate change impacts, ecosystem protection, the likelihood of extra-terrestrial life and monitoring of space debris. • Due to its long and impressive record of Antarctic research and its scientific, engineering and logistical capabilities in the region, the United Kingdom (UK) is strategically well-positioned to lead or play a key role in the delivery of these research priorities. • To achieve this potential, the UK must act collectively and in partnership with others, as the best and most urgent research benefits from collaboration, cooperation and cost sharing. Crucially, it must mobilise experts both from within the UK and internationally from a range of disciplines, including the social sciences. In the twenty-first century, Antarctic research must not exist within its own bubbl

    Genetically tagged TRE5-A retrotransposons reveal high amplification rates and authentic target site preference in the Dictyostelium discoideum genome

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    Retrotransposons contribute significantly to the evolution of eukaryotic genomes. They replicate by producing DNA copies of their own RNA, which are integrated at new locations in the host cell genome. In the gene-dense genome of the social amoeba Dictyostelium discoideum, retrotransposon TRE5-A avoids insertional mutagenesis by targeting the transcription factor (TF) IIIC/IIIB complex and integrating ∼50 bp upstream of tRNA genes. We generated synthetic TRE5-A retrotransposons (TRE5-Absr) that were tagged with a selection marker that conferred resistance to blasticidin after a complete retrotransposition cycle. We found that the TRE5-Absr elements were efficiently mobilized in trans by proteins expressed from the endogenous TRE5-A population found in D. discoideum cells. ORF1 protein translated from TRE5-Absr elements significantly enhanced retrotransposition. We observed that the 5′ untranslated region of TRE5-A could be replaced by an unrelated promoter, whereas the 3′ untranslated region of TRE5-A was essential for retrotransposition. A predicted secondary structure in the RNA of the 3′ untranslated region of TRE5-A may be involved in the retrotransposition process. The TRE5-Absr elements were capable of identifying authentic integration targets in vivo, including formerly unnoticed, putative binding sites for TFIIIC on the extrachromosomal DNA element that carries the ribosomal RNA genes

    The brazilian core collection of cassava.

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    The Brazilian cassava Germplasm Collection is the largest national collection, and contains strategic genetic variation for the deveopment of breeding programs worldwide.Suplemento. Edição dos Resumos do 4 International Scientific Meeting of the Cassava Biotechnology Network, Salvador, nov. 1998

    IKZF1 Deletions with COBL Breakpoints Are Not Driven by RAG-Mediated Recombination Events in Acute Lymphoblastic Leukemia

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    IKZF1 deletion (ΔIKZF1) is an important predictor of relapse in both childhood and adult B-cell precursor acute lymphoblastic leukemia (B-ALL). Previously, we revealed that COBL is a hotspot for breakpoints in leukemia and could promote IKZF1 deletions. Through an international collaboration, we provide a detailed genetic and clinical picture of B-ALL with COBL rearrangements (COBL-r). Patients with B-ALL and IKZF1 deletion (n = 133) were included. IKZF1 ∆1-8 were associated with large alterations within chromosome 7: monosomy 7 (18%), isochromosome 7q (10%), 7p loss (19%), and interstitial deletions (53%). The latter included COBL-r, which were found in 12% of the IKZF1 ∆1-8 cohort. Patients with COBL-r are mostly classified as intermediate cytogenetic risk and frequently harbor ETV6, PAX5, CDKN2A/B deletions. Overall, 56% of breakpoints were located within COBL intron 5. Cryptic recombination signal sequence motifs were broadly distributed within the sequence of COBL, and no enrichment for the breakpoint cluster region was found. In summary, a diverse spectrum of alterations characterizes ΔIKZF1 and they also include deletion breakpoints within COBL. We confirmed that COBL is a hotspot associated with ΔIKZF1, but these rearrangements are not driven by RAG-mediated recombination

    The brazilian core collection of cassava.

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    The size of Germplasm Collections has become an important limitation for theirr use in plant breeding programs. To overcome this limitation the Core Collection concept has been proposed. A Core Collection consists of a set of accessions selected to represent the genetic diversity of the base collection with minimum repetitiveness. This insures the conservation of maximum genetic variation, allowing rapid evaluation of germplasm and better access to the base collection. The brazilian germplasm Collection of Cassava is the largest national collection, and contains strategic genetic variation for the development of breeding programs worldwide. It consists of approximately 3350 accessions conserved in 7 regional Active Germplasm Banks. To develop the Core Collection a hierarchical stratification similar to that proposed by Cordeiro et al (1995) was used. Two key criteria were used for the stratification of the accessions: category and origin. According to category the accessions were classified as landraces or breeding materials. Within the landraces strutum, accessions were classified according to ecogeographical origin using the Geographic Information System. The selection of the members of the Core, was done trying to represent the genetic variability within each ecogeographic zone, incorporating the knowledge and experience of the curators. This Core Collection will be a logical and efficient starting point for studying the Base Collection using biotechnological tools

    Prenatal origin of childhood AML occurs less frequently than in childhood ALL

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    Background While there is enough convincing evidence in childhood acute lymphoblastic leukemia (ALL), the data on the pre-natal origin in childhood acute myeloid leukemia (AML) are less comprehensive. Our study aimed to screen Guthrie cards (neonatal blood spots) of non-infant childhood AML and ALL patients for the presence of their respective leukemic markers. Methods We analysed Guthrie cards of 12 ALL patients aged 2–6 years using immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements (n = 15) and/or intronic breakpoints of TEL/AML1 fusion gene (n = 3). In AML patients (n = 13, age 1–14 years) PML/RARalpha (n = 4), CBFbeta/MYH11 (n = 3), AML1/ETO (n = 2), MLL/AF6 (n = 1), MLL/AF9 (n = 1) and MLL/AF10 (n = 1) fusion genes and/or internal tandem duplication of FLT3 gene (FLT3/ITD) (n = 2) were used as clonotypic markers. Assay sensitivity determined using serial dilutions of patient DNA into the DNA of a healthy donor allowed us to detect the pre-leukemic clone in Guthrie card providing 1–3 positive cells were present in the neonatal blood spot. Results In 3 patients with ALL (25%) we reproducibly detected their leukemic markers (Ig/TCR n = 2; TEL/AML1 n = 1) in the Guthrie card. We did not find patient-specific molecular markers in any patient with AML. Conclusion In the largest cohort examined so far we used identical approach for the backtracking of non-infant childhood ALL and AML. Our data suggest that either the prenatal origin of AML is less frequent or the load of pre-leukemic cells is significantly lower at birth in AML compared to ALL cases

    inv(11)(q13q23)

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    Review on inv(11)(q13q23), with data on clinics, and the genes involved
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