RESUMO
Despite decades of research, there is no specific therapy for acute pancreatitis (AP). In the current study, we have evaluated the efficacy of pirfenidone, an antiinflammatory and antifibrotic agent that is approved by the FDA for treatment of idiopathic pulmonary fibrosis (IPF), in ameliorating local and systemic injury in AP. Our results suggest that treatment with pirfenidone in therapeutic settings (e.g., after initiation of injury), even when administered at the peak of injury, reduces severity of local and systemic injury and inflammation in multiple models of AP. In vitro evaluation suggests that pirfenidone decreases cytokine release from acini and macrophages and disrupts acinar-macrophage crosstalk. Therapeutic pirfenidone treatment increases IL-10 secretion from macrophages preceding changes in histology and modulates the immune phenotype of inflammatory cells with decreased levels of inflammatory cytokines. Antibody-mediated IL-10 depletion, use of IL-10-KO mice, and macrophage depletion experiments confirmed the role of IL-10 and macrophages in its mechanism of action, as pirfenidone was unable to reduce severity of AP in these scenarios. Since pirfenidone is FDA approved for IPF, a trial evaluating the efficacy of pirfenidone in patients with moderate to severe AP can be initiated expeditiously.
Assuntos
Células Acinares/metabolismo , Fibrose , Interleucina-10/imunologia , Macrófagos/metabolismo , Pâncreas , Pancreatite , Piridonas/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Células Cultivadas , Citocinas/classificação , Citocinas/imunologia , Modelos Animais de Doenças , Fibrose/etiologia , Fibrose/prevenção & controle , Camundongos , Pâncreas/efeitos dos fármacos , Pâncreas/imunologia , Pâncreas/lesões , Pâncreas/patologia , Pancreatite/tratamento farmacológico , Pancreatite/imunologia , Comunicação Parácrina/imunologia , Transdução de Sinais/imunologiaRESUMO
The genome of the yeast Saccharomyces cerevisiae has been completely sequenced through a worldwide collaboration. The sequence of 12,068 kilobases defines 5885 potential protein-encoding genes, approximately 140 genes specifying ribosomal RNA, 40 genes for small nuclear RNA molecules, and 275 transfer RNA genes. In addition, the complete sequence provides information about the higher order organization of yeast's 16 chromosomes and allows some insight into their evolutionary history. The genome shows a considerable amount of apparent genetic redundancy, and one of the major problems to be tackled during the next stage of the yeast genome project is to elucidate the biological functions of all of these genes.
Assuntos
Mapeamento Cromossômico , Genes Fúngicos , Genoma Fúngico , Saccharomyces cerevisiae/genética , Sequência de Aminoácidos , Sequência de Bases , Cromossomos Fúngicos/genética , Redes de Comunicação de Computadores , DNA Fúngico/genética , Evolução Molecular , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/fisiologia , Biblioteca Gênica , Cooperação Internacional , Família Multigênica , Fases de Leitura Aberta , RNA Fúngico/genética , Análise de Sequência de DNARESUMO
The bakers' yeast, Saccharomyces cerevisiae, a microorganism of major importance for bioindustries, and one of the favored model organisms for basic biological research, is the first eukaryote whose genome is entirely sequenced. Beyond the wealth of novel biological information, it is the extent of what remains to be understood in the genome of a simple unicellular organism that is the most striking result: a significant proportion of yeast genes are orphans of unpredictable function. Offering the possibility of large-scale reverse genetics, yeast will be a powerful model for post-sequencing studies. But geneticists are now faced with the difficulty of asking novel questions.
Assuntos
Genoma Fúngico , Saccharomyces cerevisiae/genética , Análise de Sequência de DNA , Cromossomos/genética , Células Eucarióticas/química , Regulação Fúngica da Expressão Gênica , Proteínas/genética , RNA/genética , Análise de Sequência de DNA/psicologiaRESUMO
The mitochondrial intron-encoded endonuclease I-SceI of Saccharomyces cerevisiae has an 18-bp recognition sequence and, therefore, has a very low probability of cutting DNA, even within large genomes. We demonstrate that double-strand breaks can be initiated by the I-SceI endonuclease at a predetermined location in the mouse genome and that the breaks can be repaired with a donor molecule homologous regions flanking the breaks. This induced homologous recombination is approximately 2 orders of magnitude more frequent than spontaneous homologous recombination and at least 10 times more frequent than random integration near an active promoter. As a consequence of induced homologous recombination, a heterologous novel sequence can be inserted at the site of the break. This recombination can occur at a variety of chromosomal targets in differentiated and multipotential cells. These results demonstrate homologous recombination involving chromosomal DNA by the double-strand break repair mechanism in mammals and show the usefulness of very rare cutter endonucleases, such as I-SceI, for designing genome rearrangements.
Assuntos
Reparo do DNA/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Recombinação Genética/genética , Saccharomyces cerevisiae/enzimologia , Células 3T3 , Animais , Northern Blotting , Southern Blotting , Cromossomos/metabolismo , DNA/metabolismo , Dano ao DNA , Camundongos , Mutagênese Insercional , Proteínas de Saccharomyces cerevisiae , Especificidade por SubstratoRESUMO
The Comprehensive Yeast Genome Database (CYGD) compiles a comprehensive data resource for information on the cellular functions of the yeast Saccharomyces cerevisiae and related species, chosen as the best understood model organism for eukaryotes. The database serves as a common resource generated by a European consortium, going beyond the provision of sequence information and functional annotations on individual genes and proteins. In addition, it provides information on the physical and functional interactions among proteins as well as other genetic elements. These cellular networks include metabolic and regulatory pathways, signal transduction and transport processes as well as co-regulated gene clusters. As more yeast genomes are published, their annotation becomes greatly facilitated using S.cerevisiae as a reference. CYGD provides a way of exploring related genomes with the aid of the S.cerevisiae genome as a backbone and SIMAP, the Similarity Matrix of Proteins. The comprehensive resource is available under http://mips.gsf.de/genre/proj/yeast/.
Assuntos
Bases de Dados Genéticas , Genoma Fúngico , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Sítios de Ligação , Genômica , Proteínas de Membrana/análise , Proteínas de Membrana Transportadoras/análise , Proteínas de Membrana Transportadoras/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Análise de Sequência de Proteína , Fatores de Transcrição/metabolismo , Interface Usuário-ComputadorRESUMO
We describe a genome-wide characterization of mRNA transcript levels in yeast grown on the fatty acid oleate, determined using Serial Analysis of Gene Expression (SAGE). Comparison of this SAGE library with that reported for glucose grown cells revealed the dramatic adaptive response of yeast to a change in carbon source. A major fraction (>20%) of the 15,000 mRNA molecules in a yeast cell comprised differentially expressed transcripts, which were derived from only 2% of the total number of approximately 6300 yeast genes. Most of the mRNAs that were differentially expressed code for enzymes or for other proteins participating in metabolism (e.g., metabolite transporters). In oleate-grown cells, this was exemplified by the huge increase of mRNAs encoding the peroxisomal beta-oxidation enzymes required for degradation of fatty acids. The data provide evidence for the existence of redox shuttles across organellar membranes that involve peroxisomal, cytoplasmic, and mitochondrial enzymes. We also analyzed the mRNA profile of a mutant strain with deletions of the PIP2 and OAF1 genes, encoding transcription factors required for induction of genes encoding peroxisomal proteins. Induction of genes under the immediate control of these factors was abolished; other genes were up-regulated, indicating an adaptive response to the changed metabolism imposed by the genetic impairment. We describe a statistical method for analysis of data obtained by SAGE.
Assuntos
Carbono/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Citosol/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Biblioteca Gênica , Técnicas Genéticas , Glucose/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Microcorpos/genética , Microcorpos/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Modelos Estatísticos , Mutação , Ácido Oleico/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
Systematic sequencing of the genome of Saccharomyces cerevisiae has demonstrated the existence of many novel genes, whose functions need to be studied. Entire chromosome sequences also offer the possibility to examine functional properties of the genome at a higher hierarchical level than the genes themselves. We used ordered DNA fragments of chromosome XI to systematically probe yeast DNA and total RNA extracted from MAT a, MAT alpha and diploid cells grown under three different conditions. Taking into account transcript sizes and uniqueness of probes, we attributed 94 transcripts to sequence-predicted open reading frames (ORFs) or tRNA genes; another 83 being tentatively assigned. The remaining 187 ORFs on chromosome XI do not correspond to transcripts detected under our conditions. More than 80% of transcripts are constitutively expressed, others are regulated by medium composition or cell type, the most frequent regulations being determined by carbon source (glycerol/glucose) or rich versus synthetic medium. Moreover, we show that transcript levels and regulation patterns are not statistically different between ORFs of unknown function, which constitute ca. 40% of the total, and previously identified genes (ca. 30%) or their structural homologues.
Assuntos
Regulação Fúngica da Expressão Gênica , RNA Fúngico/genética , RNA Mensageiro/genética , Saccharomyces cerevisiae/genética , Mapeamento Cromossômico , Sondas de DNA , Família MultigênicaRESUMO
The Saccharomyces cerevisiae mitochondrial endonuclease I-SceI creates a double-strand break as the initiating step in the gene conversional transfer of the omega+ intron to omega- DNA. We have expressed a galactose-inducible synthetic I-SceI gene in the nucleus of yeast that also carries the I-SceI recognition site on a plasmid substrate. We find that the galactose-induced I-SceI protein can be active in the nucleus and efficiently catalyze recombination. With a target plasmid containing direct repeats of the Escherichia coli lacZ gene, one copy of which is interrupted by a 24-bp cutting site, galactose induction produces both deletions and gene conversions. Both the kinetics and the proportion of deletions and gene conversions are very similar to analogous events initiated by a galactose-inducible HO endonuclease gene. We also find that, in a rad52 mutant strain, the repair of double-strand breaks initiated by I-SceI and by HO are similarly affected: the formation of deletions is reduced, but not eliminated. Altogether, these results suggest either that the two endonucleases act in the same way after double-strand break formation or that the two endonucleases are not involved in subsequent steps.
Assuntos
Núcleo Celular/enzimologia , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Mitocôndrias/enzimologia , Recombinação Genética , Sequência de Bases , Southern Blotting , Deleção Cromossômica , Clonagem Molecular , Dano ao DNA , Reparo do DNA , DNA Fúngico/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Escherichia coli/genética , Conversão Gênica , Expressão Gênica , Íntrons , Dados de Sequência Molecular , Mutação , Plasmídeos , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiaeRESUMO
The survival of the rho(+) factor and of Drug(R) mitochondrial genetic markers after exposure to ethidium bromide has been studied. A technique allowing the determination of Drug(R) genetic markers among a great number of both grande and petite colonies has been developed. The results have been analyzed by the target theory. The survival of the rho(+) factor is always less than the survival of any Drug(R) genetic marker. The survivals of C(R) and E(R) are similar to each other, while that of O(R) is greater than that of the other two Drug(R) markers. All possible combinations of Drug(R) markers have been found among the rho(-) petite cells induced, while the only type found among the grande colonies is the preexisting one. The loss of the C(R) and E(R) genetic markers was found to be the most frequently concomitant, while the correlation between the loss of the O(R) marker and the other two Drug(R) markers is less strong. Similar results have been obtained after U.V. irradiation. Interpretations concerning the structure of the yeast mitochondrial genome are given and hypotheses on the mechanism of petite mutation discussed.
Assuntos
Resistência Microbiana a Medicamentos , Mitocôndrias , Mutação , Saccharomyces cerevisiae , Etídio/farmacologia , Genótipo , Mutagênicos , Efeitos da Radiação , Recombinação Genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos da radiação , Raios UltravioletaRESUMO
We have isolated 15 spontaneous mutants resistant to one or several antibiotics like chloramphenicol, erythromycin and spiramycin. We have shown by several criteria that all of them result from mutations localized in the mitochondrial DNA. The mutations have been mapped by allelism tests and by two- and three-factor crosses involving various configurations of resistant and sensitive alleles associated in cis or in trans with the mitochondrial locus omega which governs the polarity of genetic recombination. A general mapping procedure based on results of heterosexual (omega(+)x omega(-)) crosses and applicable to mutations localized in the polar segment is described and shown to be more resolving than that based on results of homosexual crosses. Mutations fall into three loci which are all linked and map in the following order: omega-R(I)-R(II)-R(III). The first locus is very tightly linked with omega while the second is less linked to the first. Mutations of similar resistance phenotype can belong to different loci and different phenotypes to the same locus. Mutations confer antibiotic resistance on isolated mitochondrial ribosomes and delineate a ribosomal segment of the mitochondrial DNA. Homo- and hetero-sexual crosses between mutants of the ribosomal segment and those belonging to the genetically unlinked ATPase locus, O(I), have been performed in various allele configurations. The polarity of recombination between R(I), R(II), R(III) and O(I) decreases as a function of the distance of the R locus from the omega locus rather than as a function of the distance of the R locus from the O(I) locus.
Assuntos
Cloranfenicol/farmacologia , DNA Mitocondrial , Eritromicina/farmacologia , Leucomicinas/farmacologia , Mutação , Saccharomyces cerevisiae/efeitos dos fármacos , Adenosina Trifosfatases/metabolismo , Sequência de Bases , Mapeamento Cromossômico , Cruzamentos Genéticos , DNA Bacteriano , Resistência Microbiana a Medicamentos , Teste de Complementação Genética , Genética Microbiana , Fenótipo , RNA Ribossômico , Recombinação Genética , RibossomosRESUMO
Group I introns form a structural and functional group of introns with widespread but irregular distribution among very diverse organisms and genetic systems. Evidence is now accumulating that several group I introns are mobile genetic elements with properties similar to those originally described for the omega system of Saccharomyces cerevisiae: mobile group I introns encode sequence-specific double-strand (ds) endoDNases, which recognize and cleave intronless genes to insert a copy of the intron by a ds-break repair mechanism. This mechanism results in: the efficient propagation of group I introns into their cognate sites; their maintenance at the site against spontaneous loss; and, perhaps, their transposition to different sites. The spontaneous loss of group I introns occurs with low frequency by an RNA-mediated mechanism. This mechanism eliminates introns defective for mobility and/or for RNA splicing. Mechanisms of intron acquisition and intron loss must create an equilibrium, which explains the irregular distribution of group I introns in various genetic systems. Furthermore, the observed distribution also predicts that horizontal transfer of intron sequences must occur between unrelated species, using vectors yet to be discovered.
Assuntos
Elementos de DNA Transponíveis , Íntrons , Splicing de RNA , Sequência de Bases , Chlamydomonas/genética , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Proteínas Fúngicas/genética , Conformação de Ácido Nucleico , Nucleotidiltransferases/genética , Physarum/genética , RNA Fúngico/genética , RNA Viral/genética , Saccharomyces cerevisiae/genética , Fagos T/genética , TransposasesRESUMO
In yeast, the fate of linear DNA molecules upon transformation is determined by the existence of sequence homology between chromosomes and the ends of the transforming molecule. To understand the mechanism of integration of transforming DNA, we have studied the influence of DNA concentration on the frequency and type of transformants obtained, using either non-replicative or replicative plasmids. In both cases, increasing DNA concentration results in multiple tandem repeats integrated into the chromosome containing the homologous target sequence. When a diploid strain is transformed, multiple tandem repeats occur in only one of the two homologous chromosomes at a time. The frequency distribution of the different types of integrants observed indicates non-independent integration events likely to result from plasmid-plasmid interaction prior to chromosome integration. In addition, our results define the proper conditions for optimized gene targetting or gene rescue experiments.
Assuntos
Cromossomos Fúngicos , DNA Fúngico/genética , Recombinação Genética , Saccharomyces cerevisiae/genética , Transformação Genética , Sequência de Bases , Diploide , Haploidia , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , PlasmídeosRESUMO
We have examined the distribution of trinucleotide repeats in the yeast genome. Perfect and imperfect repeats, ranging from four to 130 triplets were recognized and the repartition of different triplet combinations was found to differ between Open Reading Frames and Intergenic Regions. Examination of different laboratory strains, revealed polymorphic size variations for all perfect repeats studied, compared to an absence of variation for the imperfect ones. Size variations were found discrete in the range of 6-18 triplets, each strain showing one allelic form for a given repeat array. The distribution and stability of trinucleotide repeats in the yeast genome resembles that of humans and may provide an experimental approach to study the mechanisms of their expansion.
Assuntos
Genoma Fúngico , Saccharomyces cerevisiae/genética , Repetições de Trinucleotídeos , Sequência de Bases , Dados de Sequência Molecular , Polimorfismo Genético , Análise de Sequência de DNARESUMO
The complete sequence of the yeast Saccharomyces cerevisiae reveals the presence of many new genes, many of which are without homologs in databases. Characterisation of these genes by novel methods includes systematic deletion followed by phenotypic analysis of mutant strains. We have developed a hierarchical strategy for such a functional analysis of genes, in which the primary phenotypic screening is performed on groups of contiguous genes which are then reinvestigated down to the single gene level. This strategy is applied to the whole chromosome XI as part of EUROFAN (the EUROpean Functional ANalysis) program, and we present here our results on a group of 22 genes from this chromosome. This sample is representative of the results that are emerging for the whole chromosome. Out of the 22 genes deleted, three were shown to be essential, and another three genes confer a mutant growth phenotype to cells when deleted. All phenotypes have been complemented. These figures are in accordance with the previously published fraction of lethal and growth-defective deletions of single genes. We have found no synthetic phenotypes resulting from a combination of deleted genes and have always been able to attribute a mutant phenotype to a single gene.
Assuntos
Cromossomos , Técnicas Genéticas , Fases de Leitura Aberta , Saccharomyces cerevisiae/genética , Deleção de Genes , Teste de Complementação Genética , Genoma Fúngico , Mutação , FenótipoRESUMO
A number of introns in mitochondrial, chloroplast, nuclear or prokaryotic genes have recently been shown to encode double-strand sequence-specific endonucleases. Such introns are mobile genetic elements that insert themselves at or near the cleaved sites. A uniform nomenclature to designate the molecular elements involved in the phenomenon of intron mobility is proposed.
Assuntos
Elementos de DNA Transponíveis , Íntrons , Sequência de Bases , Endodesoxirribonucleases/genética , Nucleotidiltransferases/genética , Terminologia como Assunto , TransposasesRESUMO
We have studied the transcript levels of YGR260w and YLR004c, two genes encoding members of the yeast Dal5p subfamily of the major facilitator family, and we show that they increase when extracellular nicotinic acid and thiamine, respectively, are absent. The deletion of YGR260w in a bna1 auxotrophic mutant for nicotinic acid prevents growth at low nicotinic acid concentration. This suggests that YGR260w is necessary for nicotinic acid import into the cell. The direct measurement of nicotinic acid uptake on whole cells demonstrates that YGR260w encodes the yeast high affinity nicotinic acid permease. Its apparent K(m) of 1.7 microM is low enough to allow the uptake of the low concentrations of nicotinic acid normally secreted by wild type cells.
Assuntos
Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Proteínas de Membrana Transportadoras/genética , Saccharomyces cerevisiae/genética , Sequência de Bases , Proteínas de Membrana Transportadoras/metabolismo , Dados de Sequência Molecular , Niacina/metabolismo , Saccharomyces cerevisiae/metabolismo , Transcrição GênicaRESUMO
The genome of the diploid hemiascomycetous yeast Candida tropicalis, an opportunistic human pathogen and an important organism for industrial applications, was explored by the analysis of 2541 Random Sequenced Tags (RSTs) covering about 20% of its genome. Comparison of these sequences with Saccharomyces cerevisiae and other species permitted the identification and the analysis of a total of more than 1000 novel genetic elements of C. tropicalis. Moreover, the present study confirms that in C. tropicalis, the rare CUG codon is read as a serine and not a leucine. The sequences have been deposited at EMBL with the accession numbers AL438875-AL441602.
Assuntos
Candida/genética , Genoma Fúngico , Ascomicetos/genética , Códon , Elementos de DNA Transponíveis , DNA Mitocondrial , DNA Ribossômico , Proteínas Fúngicas/genética , Código Genético , Íntrons , Dados de Sequência Molecular , Família Multigênica , Análise de Sequência de DNA , Spliceossomos/genéticaRESUMO
A genomic exploration of Kluyveromyces thermotolerans was performed by random sequence tag (RST) analysis. We sequenced 2653 RSTs corresponding to inserts sequenced from both ends. We performed a systematic comparison with a complete set of proteins from Saccharomyces cerevisiae, other completely sequenced genomes and SwissProt. We identified six mitochondrial genes and 1358-1496 nuclear genes by comparison with S. cerevisiae. In addition, 25 genes were identified by comparison with other organisms. This corresponds to about 24% of the estimated gene content of this organism. A lower level of conservation is observed with orthologues to genes of S. cerevisiae previously classified as orphans. Gene order was found to be conserved between S. cerevisiae and K. thermotolerans in 56.5% of studied cases.
Assuntos
Genoma Fúngico , Kluyveromyces/genética , Sequência de Aminoácidos , Ascomicetos/genética , Mapeamento Cromossômico , Cromossomos Fúngicos , DNA Mitocondrial , DNA Ribossômico , Bases de Dados Factuais , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Ordem dos Genes , Código Genético , Dados de Sequência Molecular , RNA de Transferência/genética , Saccharomyces cerevisiae/genética , Homologia de Sequência de AminoácidosRESUMO
As part of the comparative genomics project 'GENOLEVURES', we studied the Kluyveromyces marxianus var. marxianus strain CBS712 using a partial random sequencing strategy. With a 0.2 x genome equivalent coverage, we identified ca. 1300 novel genes encoding proteins, some containing spliceosomal introns with consensus splice sites identical to those of Saccharomyces cerevisiae, 28 tRNA genes, the whole rDNA repeat, and retrotransposons of the Ty1/2 family of S. cerevisiae with diverged Long Terminal Repeats. Functional classification of the K. marxianus genes, as well as the analysis of the paralogous gene families revealed few differences with respect to S. cerevisiae. Only 42 K. marxianus identified genes are without detectable homolog in the baker's yeast. However, we identified several genetic rearrangements between these two yeast species.
Assuntos
Mapeamento Cromossômico , Genoma Fúngico , Kluyveromyces/genética , Ascomicetos/genética , Sequência de Bases , Cromossomos Fúngicos , Códon , Sequência Conservada , Mapeamento de Sequências Contíguas , DNA Mitocondrial , DNA Ribossômico , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Código Genético , Íntrons , Família Multigênica , Proteínas Nucleares/genética , Fases de Leitura Aberta , RNA de Transferência , Retroelementos , SpliceossomosRESUMO
As part of a comparative genomics project on 13 hemiascomycetous yeasts, the Pichia angusta type strain was studied using a partial random sequencing strategy. With coverage of 0.5 genome equivalents, about 2500 novel protein-coding genes were identified, probably corresponding to more than half of the P. angusta protein-coding genes, 6% of which do not have homologs in Saccharomyces cerevisiae. Some of them contain one or two introns, on average three times shorter than those in S. cerevisiae. We also identified 28 tRNA genes, a few retrotransposons similar to Ty5 of S. cerevisiae, solo long terminal repeats, the whole ribosomal DNA cluster, and segments of mitochondrial DNA. The P. angusta sequences were deposited in EMBL under the accession numbers AL430961 to AL436044.