1,720,979 research outputs found
Transcription of two sunflower (Helianthus annuus L.) mitochondrial tRNA genes having different genetic origins.
No full textThe divergent transcription of two tRNA genes encoded in sunflower mitochondrial DNA, proposed as genes of different genetic origin, has been studied in detail. The transcription initiation site (TIS) for both transcript precursors has been identified by hybridization with in vitro 32P-capped total RNAs and primer extension. The location of two TISs and the analysis of distribution of sequence elements (motifs) usually present in higher plant mitochondrial promoters led to the identification of two short regions (about 30–40 bp) which can be proposed as the promoters for the transcription of two genes. This conclusion is supported by the observation that within the short intergenic region included between the 5′ termini of two genes (1924 bp) the distribution of those specific motifs is unique around the TISs, although not identical for the two promoters. Based on specific experimental results the trnE promoter shows a higher efficiency in comparison with that of the trnH promoter. This result is in good agreement with its structure which strictly conforms to those described for mitochondrial genes of dicot plants. Instead the other promoter shows some divergences which could be responsible for its lower efficiency. The context in which trnH lies in the sunflower mitochondrial genome and other features described in the paper may suggest that, despite the high similarity with the chloroplast counterpart, the trnH gene could have a native origin
Different conservation of introns I and II in the mitochondrial coxII genes of several Angiosperms
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Identification and molecular characterization of the sucrose synthase 2 gene in durum wheat.
No full textCharacterization of three members of the multigene family coding for isoforms of the chlorophyll a/b binding protein Lhcb1 in spinach
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PLMltRNA, a database on the heterogeneous genetic origin of mitochondrial tRNA genes and tRNAs in photosynthetic eukaryotes
No full textThe updated version of PLMItRNA reports information and multialignment on 609 genes and 34 tRNA molecules active in the mitochondria of Viridiplantae ( 27 Embryophyta and 10 Chlorophyta), and photosynthetic algae ( one Cryptophyta, four Rhodophyta and two Stramenopiles). Colour- code based tables reporting the different genetic origin of identified genes allow hyper- textual link to single entries. Promoter sequences identified for tRNA genes in the mitochondrial genomes of Angiospermae are also reported. The PLMItRNA database is accessible at http: / / bighost. area. ba. cnr. it/ PLMItRNA/
MAPPATURA E TRASCRIZIONE DI GENI PER t RNA DI TIPO “CP-LIKE” PER LA DEFINIZIONE DELLA LORO ORIGINE
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