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J Terol

Publications and source records attributed to J Terol.

8 recordsLinked to original sources
PubMed2005

Development of a citrus genome-wide EST collection and cDNA microarray as resources for genomic studies.

A functional genomics project has been initiated to approach the molecular characterization of the main biological and agronomical traits of citrus. As a key part of this project, a citrus EST collection has been generated from 25 cDNA libraries covering different tissues, developmental stages and stress conditions. The collection includes a total of 22,635 high-quality ESTs, grouped in 11,836 putative unigenes, which represent at least one third of the estimated number of genes in the citrus genome. Functional annotation of unigenes which have Arabidopsis orthologues (68% of all unigenes) revealed gene representation in every major functional category, suggesting that a genome-wide EST collection was obtained. A Citrus clementina Hort. ex Tan. cv. Clemenules genomic library, that will contribute to further characterization of relevant genes, has also been constructed. To initiate the analysis of citrus transcriptome, we have developed a cDNA microarray containing 12,672 probes corresponding to 6875 putative unigenes of the collection. Technical characterization of the microarray showed high intra- and inter-array reproducibility, as well as a good range of sensitivity. We have also validated gene expression data achieved with this microarray through an independent technique such as RNA gel blot analysis.

Citrus↗
PubMed2001

Structural and evolutionary analysis of the copia-like elements in the Arabidopsis thaliana genome.

The analysis of 460 kb of genomic sequence of Arabidopsis thaliana chromosome III allowed us to identify two new transposable elements named AtC1 and AtC2. AtC1 shows identical long terminal repeats (LTRs) and all the structural features characteristic of the copia-like active elements. AtC2 is also a full copia-like element, but a putative stop codon in the open reading frame (ORF) would produce a truncated protein. In order to identify the copia-like fraction of the A. thaliana genome, a careful computer-based analysis of the available sequences (which correspond to 92% of the genome) was performed. Approximately 300 nonredundant copia-like sequences homologous to AtC1 and AtC2 were detected, which showed an extreme heterogeneity in size and degree of conservation. This number of copies would correspond to approximately 1% of the A. thaliana genome. Seventy-one sequences were selected for further analysis, with 23 of them being full complete elements. Five corresponded to previously described ones, and the remaining ones, named AtC3 to AtC18 are new elements described in this work. Most of these elements presented a putative functional ORF, nearly identical LTRs, and the other elements necessary for retrotransposon activity. Phylogenetic trees, supported by high bootstrap values, indicated that these 23 elements could be considered separate families. In turn, these 23 families could be clustered into six major lineages, named copia I-VI. Most of the 71 analyzed sequences clustered into these six main clades. The widespread presence of these copia-like superfamilies throughout plant genomes is discussed.

Amino Acid Sequence↗
PubMed2000

ZFWD: a novel subfamily of plant proteins containing a C3H zinc finger and seven WD40 repeats.

We describe a new subfamily of WD repeat proteins characterised by the presence of a C3H zinc finger at the N-terminal part of the protein associated with seven WD40 repeats. We have identified four members of this subfamily in Arabidopsis thaliana, one of them with associated expressed sequence tags (ESTs). We have also identified homologous ESTs in rice, cotton, maize, poplar, pine tree and the ice plant. We do not observe animal homologues, suggesting that this subfamily could be specific for plants. Our data suggest an important role for these proteins. Based on the high sequence conservation within the conserved domains, we suggest that these proteins could have a regulatory function.

Amino Acid Sequence↗
PubMed2000

Sequence and analysis of chromosome 3 of the plant Arabidopsis thaliana.

Arabidopsis thaliana is an important model system for plant biologists. In 1996 an international collaboration (the Arabidopsis Genome Initiative) was formed to sequence the whole genome of Arabidopsis and in 1999 the sequence of the first two chromosomes was reported. The sequence of the last three chromosomes and an analysis of the whole genome are reported in this issue. Here we present the sequence of chromosome 3, organized into four sequence segments (contigs). The two largest (13.5 and 9.2 Mb) correspond to the top (long) and the bottom (short) arms of chromosome 3, and the two small contigs are located in the genetically defined centromere. This chromosome encodes 5,220 of the roughly 25,500 predicted protein-coding genes in the genome. About 20% of the predicted proteins have significant homology to proteins in eukaryotic genomes for which the complete sequence is available, pointing to important conserved cellular functions among eukaryotes.

Arabidopsis↗
PubMed1999

The Arabidopsis CBF gene family is composed of three genes encoding AP2 domain-containing proteins whose expression Is regulated by low temperature but not by abscisic acid or dehydration.

We have identified two genes from Arabidopsis that show high similarity with CBF1, a gene encoding an AP2 domain-containing transcriptional activator that binds to the low-temperature-responsive element CCGAC and induces the expression of some cold-regulated genes, increasing plant freezing tolerance. These two genes, which we have named CBF2 and CBF3, also encode proteins containing AP2 DNA-binding motifs. Furthermore, like CBF1, CBF2 and CBF3 proteins also include putative nuclear-localization signals and potential acidic activation domains. The CBF2 and CBF3 genes are linked to CBF1, constituting a cluster on the bottom arm of chromosome IV. The high level of similarity among the three CBF genes, their tandem organization, and the fact that they have the same transcriptional orientation all suggest a common origin. CBF1, CBF2, and CBF3 show identical expression patterns, being induced very rapidly by low-temperature treatment. However, in contrast to most of the cold-induced plant genes characterized, they are not responsive to abscisic acid or dehydration. Taken together, all of these data suggest that CBF2 and CBF3 may function as transcriptional activators, controlling the level of low-temperature gene expression and promoting freezing tolerance through an abscisic acid-independent pathway.

Abscisic Acid↗
PubMed1995

Molecular characterization of the zerknüllt region of the Antennapedia complex of D. subobscura.

We have characterized at the molecular level the zerknüllt (zen) region of the Drosophila subobscura Antennapedia complex. The sequence comparison between D. subobscura and D. melanogaster shows an irregular distribution of the conserved and diverged regions, with the homeobox and a putative activating domain completely conserved. Comparisons of the promoter sequence and pattern of expression of the gene during development suggest that the regulation of zen has been conserved during evolution. The conservation of zen expression in a subpopulation of the polar cells indicates the existence of an important role in such cells. We describe a transitory segmented pattern of expression of zen in both species, suggesting the existence of interactions with a pair rule gene. Some indirect clues indicate that the z2 gene might be absent from the D. subobscura genome. A chromosome walk initiated to reach the proboscipedia gene of D. subobscura reveals that the distance between pb and zen is at least four times the one described for D. melanogaster and for D. pseudoobscura. Finally, we present cytological evidence showing that the ANT-C is inverted in D. subobscura as compared to D. melanogaster.

Amino Acid Sequence↗
PubMed1991

In situ localization of the Antennapedia gene on the chromosomes of nine Drosophila species of the obscura group.

The homeotic Antennapedia gene, cloned from the genomic DNA of D. subobscura, was localized on the polytene chromosomes of nine species of the Drosophila obscura group. In all of them, the probe used hybridized on chromosomes equivalent to the E element of Müller's terminology. These results are consistent with the idea that single copy genes do not move around the genome and that chromosomal elements have conserved their genetic identity during evolution.

Animals↗