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S Cirera

Publications and source records attributed to S Cirera.

14 recordsLinked to original sources
PubMed2006

Molecular characterization of the porcine surfactant, pulmonary-associated protein C gene.

The surfactant, pulmonary-associated protein C (SFTPC) is a peptide secreted by the alveolar type II pneumocytes of the lung. We have characterized the porcine SFTPC gene at genomic, transcriptional, and protein levels. The porcine SFTPC is a single-copy gene on pig chromosome 14. Two transcripts were found in a newborn pig lung cDNA library: a full-length clone and a clone missing exon 5. cDNA sequence comparison revealed four synonymous and two nonsynonymous substitutions and in-frame insertions at the beginning of exon 5. Comparison of the SFTPC coding region between several mammals showed high levels of conservation. Northern blot studies showed lung-specific expression of the full-length SFTPC transcript, appearing in 50-day-old fetus and increasing during lung development. Both SFTPC transcripts were detected mainly in lung by real-time RT-PCR and they were significantly down-regulated in necrotic lungs of pigs infected with Actinobacillus pleuropneumoniae. Additionally, the protein levels were also decreased or absent in the necrotic tissue.

Actinobacillus Infections↗
PubMed2006

Linkage mapping of gene-associated SNPs to pig chromosome 11.

Single nucleotide polymorphisms (SNPs) were discovered in porcine expressed sequence tags (ESTs) orthologous to genes from human chromosome 13 (HSA13) and predicted to be located on pig chromosome 11 (SSC11). The SNPs were identified as sequence variants in clusters of EST sequences from pig cDNA libraries constructed in the Sino-Danish pig genome project. In total, 312 human gene sequences from HSA13 were used for similarity searches in our pig EST database. Pig ESTs showing significant similarity with HSA13 genes were clustered and candidate SNPs were identified. Allele frequencies for 26 SNPs were estimated in a group of 80 unrelated pigs from Danish commercial pig breeds: Duroc, Hampshire, Landrace and Large White. Eighteen of the 26 SNPs genotyped in the PiGMaP Reference Families were mapped by linkage analysis to SSC11. The EST-based SNPs published here are new genetic markers useful for linkage and association studies in commercial and experimental pig populations. This study represents the first gene-associated SNP linkage map of pig chromosome 11 and adds new comparative mapping information between SSC11 and HSA13. Furthermore, our data facilitate future studies aimed at the identification of interesting regions on pig chromosome 11, positional cloning and fine mapping of quantitative trait loci in pig.

Animals↗
PubMed2004

FISH mapping and sequence analysis of 87 porcine BAC clones.

Ninety-one bacterial artificial chromosomes (BAC) clones, selected effectively at random from our library, were used as probes for fluorescence in situ hybridization. Of these, 87 clones gave a specific signal in one, two or three different pair(s) of swine metaphase chromosomes. The ends of 35 BAC clones were sequenced in order to obtain information for comparative mapping. Fifteen of them gave useful comparative mapping information.

Animals↗
PubMed2003

Linkage and comparative mapping of the locus controlling susceptibility towards E. COLI F4ab/ac diarrhoea in pigs.

In 1995, Edfors-Lilja and coworkers mapped the locus for the E. COLI K88ab (F4ab) and K88ac (F4ac) intestinal receptor to pig chromosome 13 (SSC13). Using the same family material we have refined the map position to a region between the microsatellite markers Sw207 and Sw225. Primers from these markers were used to screen a pig BAC library and the positive clones were used for fluorescent in situ hybridization (FISH) analysis. The results of the FISH analysis helped to propose a candidate gene region in the SSC13q41-->q44 interval. Shotgun sequencing of the FISH-mapped BAC clones revealed that the candidate region contains an evolutionary breakpoint between human and pig. In order to further characterise the rearrangements between SSC13 and human chromosome 3 (HSA3), detailed gene mapping of SSC13 was carried out. Based on this mapping data we have constructed a detailed comparative map between SSC13 and HSA3. Two candidate regions on human chromosome 3 have been identified that are likely to harbour the human homologue of the gene responsible for susceptibility towards E. COLI F4ab/ac diarrhoea in pigs.

Animals↗
PubMed2000

Why do we still find anonymous ESTs?

During recent years, there has been an exponential rise in the number of sequences accessible in the public databases. Despite this, a high percentage of partial sequences of cDNA (ESTs) submitted to the databases remain unrecognized (anonymous ESTs). This lack of similarities could be explained by several hypotheses: i) a different part of the transcript is present in the GenBank; ii) the transcript represents a novel gene not yet isolated in other species; iii) alternative splicing of the same gene in different species; iv) inaccurate sequence data; and/or v) the sequence of the transcript has diverged to the extent that it is not recognized as an ortholog. In the present study we selected a sample of 20 ESTs from a pool of 656 anonymous pig small intestine ESTs in order to investigate the possible cause for the lack of similarities with database entries. To test the significant hypotheses we carried out total sequencing of each insert along with zoo-blot and Northern-blot analysis. Extended analyses of the 20 ESTs showed significant matches to seven existing database entries, whereas 13 still did not show significant hits. The results are discussed in the context of the hypothesis listed above.

Animals↗
PubMed2000

Usefulness of the I/D angiotensin-converting enzyme genotype for detecting the risk of left ventricular hypertrophy in pharmacologically treated hypertensive men.

The insertion/deletion polymorphism (I/D) of the angiotensin-converting enzyme (ACE) gene has been associated in some studies with a higher prevalence of left ventricular hypertrophy (LVH), but few of them were performed on pharmacologically treated hypertensive patients. The present study was undertaken to determine whether ACE genotype determination could help in the identification of pharmacologically treated hypertensive patients at a higher risk of LVH. Ninety-six consecutive men with essential hypertension were selected for the study. Left ventricular mass (LVM) was assessed by echocardiography and indexed by body surface area and 82 patients were considered suitable for the study. Three groups of patients were defined on the basis of their I/D ACE genotype: DD (n = 39), ID (n = 33) and II (n = 10). There were no statistically significant differences between the three groups regarding to the severity of hypertension at diagnosis, degree of control of blood pressure or type of antihypertensive drug therapy used. No statistically significant differences were found between the three groups regarding to LVM index (total 124 +/- 31, DD 121 +/- 29, ID 127 +/- 35 and II 122 +/- 18 g/m2), relative wall thickness (total 0.5 +/- 0. 2, DD 0.5 +/- 0.3, ID 0.48 +/- 0.07 and II 0.47 +/- 0.04) or prevalence of LVH (total 34%, DD 31%, ID 39% and II 30% by Cornell criteria and total 39%, DD 33%, ID 45% and II 40% by Framingham criteria). Furthermore, the I and D allele frequency distribution was similar in the whole group of patients, in patients with LVH, and in a control group of healthy volunteers. Our data do not support that the I/D ACE genotype determination helps in identifying treated hypertensive patients at higher risk of LVH. Journal of Human Hypertension (2000) 14, 327-331

Adult↗
PubMed1998

The sex-peptide gene (Acp70A) is duplicated in Drosophila subobscura.

A 3.1-kb region of Drosphila subobscura homologous to the Acp70A region of D. melanogaster, which contains the sex-peptide gene, was cloned and sequenced. This region contains an approximately 600-bp duplication that includes the sex-peptide and its 5' and 3' flanking regions. The preproteins are 54 and 56 amino acids long, respectively (as compared to 55 amino acids in D. melanogaster), and each includes a 19-amino-acid-long signal peptide. The C-terminal part of the mature peptide is highly conserved between D. melanogaster and the two copies of D. subobscura. In this species, both copies of the gene are transcribed and, like in D. melangaster, only expressed in males. The duplicated region includes 300 bp upstream of the gene that would therefore seem sufficient for their expression in males. This region presents at its 5' end a stretch 93-bp that has a high similarity with the corresponding region of D. melanogaster and could be part of a still unidentified regulatory element of these genes.

Amino Acid Sequence↗
PubMed1998

Molecular evolution of a duplication: the sex-peptide (Acp70A) gene region of Drosophila subobscura and Drosophila madeirensis.

In Drosophila melanogaster, the Acp70A gene, which is involved in the postmating reactions of the female, is a single-copy gene. However, in Drosophila subobscura, the gene is duplicated and both copies are transcribed. To study the molecular evolution of the duplication, a 2.1-kb fragment encompassing both copies of the duplication was sequenced for 10 lines of D. subobscura and one line of Drosophila madeirensis. Estimates of the divergence between the two copies of the duplicated region and between the two species studied, D. subobscura and D. madeirensis, revealed that both copies of the Acp70a gene had evolved independently since their duplication. The ratio of nonsynonymous to silent divergence between copies was generally higher than one. The McDonald and Kreitman test revealed an excess of nonsynonymous changes fixed since the duplication and before the split of the D. subobscura and D. madeirensis lineages. These results point to natural selection driving protein evolution after the duplication. Specifically, adaptive evolution appears to have caused the initial differentiation between copies of the N-terminal parts of the proteins, while purifying selection could be responsible for the high conservation of the C-terminal parts.

Amino Acid Sequence↗
PubMed1998

Molecular diagnosis of lecithin: cholesterol acyltransferase deficiency in a presymptomatic proband.

We report the molecular diagnosis of a lecithin : cholesterol acyltransferase deficiency in a 12-year old proband with a high-density lipoprotein deficiency. The increased percentage of free cholesterol in plasma and high-density lipoprotein indicated an inherited lecithin : cholesterol acyltransferase deficiency as the underlying cause. This diagnosis was confirmed by a low plasma lecithin : cholesterol acyltransferase activity and a combination of genetic analyses which demonstrated compound heterozygosity for two mutations in the lecithin : cholesterol acyltransferase gene of the proband. One was a previously unreported 2 bp deletion leading to a stop signal in codon 77 and the other a point mutation causing Arg 135-->Gln transition. To our knowledge, this is the first diagnosis of lecithin : cholesterol acyltransferase deficiency in a pre-symptomatic patient. Whether the proband will develop signs of complete lecithin : cholesterol acyltransferase deficiency or the milder form (Fish Eye Disease) is uncertain, although the former possibility is more likely. The risk of premature atherosclerosis conferred by lecithin : cholesterol acyltransferase deficiency is not well established. The proband will need to be carefully monitored in the future.

Child↗
PubMed1997

Evolutionary history of the sex-peptide (Acp70A) gene region in Drosophila melanogaster.

In Drosophila the products of the seminal fluid stimulate oviposition and suppress remating in the female. Of all the accessory gland peptides (Acp's) involved in these two responses, the sex-peptide (coded by the Acp70A gene) is among the best characterized at the functional level. A 1.2-kb fragment encompassing the Acp70A gene of nine lines from a natural population of D. melanogaster and one allele of D. sechellia was sequenced to study the forces shaping nucleotide variation within and between species. The coding region of D. simulans and D. mauritiana was also sequenced. A Ser to Ala replacement polymorphism at the last position of the signal peptide was detected in D. melanogaster. The Ser and Ala alleles are at intermediate frequencies. The level of nucleotide variation is lower for the derived Ala allele, which is compatible with a recent origin and an increase in frequency due to positive selection. Variation at the 5' flanking region is structured in two major highly differentiated haplotypes, whose distribution does not conform to neutral expectations. Selective and/or historical factors could contribute to the observed overall patterning of nucleotide variation at the Acp70A region.

Amino Acid Sequence↗
PubMed1995

Molecular characterization of the breakpoints of an inversion fixed between Drosophila melanogaster and D. subobscura.

The two breakpoints of a chromosomal inversion fixed since the split of Drosophila melanogaster and D. subobscura lineages have been isolated and sequenced in both species. The regions spanning the breakpoints initially were identified by the presence of two signals after interspecific in situ hybridization on polytene chromosomes. Interspecific comparison of the sequenced regions allowed us to delineate the location of the breakpoints. Close to one of these breakpoints a new transcription unit (bcn92) has been identified in both species. The inversion fixed between D. melanogaster and D. subobscura does not seem to have broken any transcription unit. Neither complete nor defective transposable elements were found in the regions encompassing the breakpoints. Short thymine-rich sequences (30-50 bp long) have been found bordering the breakpoint regions. Although alternating Pur-Pyr sequences were detected, these putative target sites for topoisomerase II were not differentially clustered in the breakpoints.

Animals↗