1,721,179 research outputs found

    Identification of a family of SINEs and LINEs in the Pipistrellus kuhli genome: A new structural and functional symbiotic relationship

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    We initially describe a novel tRNA-derived SINE family, abundantly and randomly distributed in the genome of the bat Pipistrellus kuhli. We present evidence that the LINE retrotransposition machinery is recruited for the creation of a new chimerical retrotranscript constituted by the partial LINE reverse transcriptase ORF2, which is interrupted by the SINE15 retrotransposon. Structural homology between SINE15 and Homo sapiens helix 6 7SL RNA allows us to propose multiple genome partners for SINE retrotransposition, such as SRP proteins and LINE enzymatic machinery. Moreover, on the basis of the LINE and SINE/LINE chimerical transcripts, we propose a mutual relationship between SINE and LINE retrotransposons. © 2007 Elsevier Inc. All rights reserved

    A novel repeated sequence DNA originated from a Tc1-like transposon in water green frog Rana esculenta

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    We have identified and characterized a highly repetitive family, called R.e./Tc1 in the genome of the green water frog Rana esculenta. This family consists of tandemly repeated sequences, localized at the centromeric regions of chromosomes as shown by Southern blot and 'in situ' hybridization. The repeat unit contains a residue of a Tc1-like transposon by Haematobia irritans fly, bordered by two short direct repeats of 9 bp. Tc1 remnant lays near a sequence identical to Homo sapiens Werner syndrome gene stretch. These sequence data suggest that R.e./Tc1 element was probably originated from a transposition event and a duplication via DNA mechanism of the R.e./Tc1 unit that could give rise to the observed tandem array. © 2000 Elsevier Science B.V

    Novel methylation at GpC dinucleotide in the fish Sparus aurata genome

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    To date, vertebrate DNA has been found methylated at the 5′ position of cytosine exclusively in dinucleotide CpG or CpNpG stretches. On the the other hand, we determined that cytosine was methylated unusually in dinucleotide GpC at 5′-GGCC-3′ sequences in the teleost Sparus aurata EcoRI satellite DNA family. This finding is the first example of methylated GpC sequences in the eukaryotic genomes. At this regard, we have examined the relative methylation levels at this site of the highly repetitive EcoRI satellite DNA family from Sparus aurata different tissues. The EcoRI repeat was remarkably more methylated in male germ cells but hypomethylated in female germ cells at the Hae III restriction site (GpC). The novel modification and the differential methylation pattern suggest that EcoRI satellite could have a structural and/or functional role at the centromeres of Sparus aurata

    Isolation of Ty1-copia retrotransposon in myrtle genome and development of S-SAP molecular marker

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    Long terminal repeat (LTR)-retrotransposons are mobile genetic elements that are ubiquitous in plants and constitute a major portion of their nuclear genomes. LTR-retrotransposons possess unique properties that make them appropriate for investigating relationships between populations, varieties and closely related species. Myrtus communis L. is an evergreen shrub growing spontaneously throughout the Mediterranean area. Accessions show significant variations for agriculturally important traits, so the development of specific molecular markers for conservation and characterization of myrtle germplasm is desirable to conserve biodiversity. In this study, we isolated the first retrotransposon Ty1-copia-like element (Tmc1) in Myrtus communis L. genome and used this as a molecular marker. We successfully employed the S-SAP marker system to specifically characterize four myrtle accessions belonging to different areas in the province of Caserta (Italy). The high level of polymorphism detected in isolated LTRs, make Tmc1 a good molecular marker for this species. Our findings confirm that retrotransposon-based molecular markers are particularly valuable tools for plant molecular characterization studies. © Springer Science+Business Media B.V. 2011

    Degradation of waste waters from olive oil mills by Yarrowia lipolytica ATCC 20255 and Pseudomonas putida

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    Waste waters from olive oil processing may cause severe pollution in the Mediterranean area, since they have a high level of chemical oxygen demand (GOD) (100-200 g/l) and contain other organic and inorganic compounds. In all olive oil producing countries, the reduction of pollution in olive oil mill waste waters at reasonable costs and using techniques suitable for most industrial applications is an unsolved problem. For this paper, the yeast Yarrowia lipolytica ATCC 20255 was grown on waste waters from an olive oil mill in a 3.51 fermenter under batch culture conditions. The results showed that the yeast was capable of reducing the COD value by 80% in 24 h. In this way, a useful biomass of 22.45 g/l as single cell protein (SCP) and enzyme lipase were produced. During this process, most of the organic and inorganic substances were consumed, only aromatic pollutants were still present in the fermentation effluents. Therefore, we used a phenol degrader, namely Pseudomonas putida, to reduce phenolic compounds in the fermentation effluents after removing Yarrowia lipolytica cells. P. putida was effective in reducing phenols in only 12 h
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