RESUMO
Diversity and differentiation among three populations representing the geographical domains commonly recognized within the natural distribution area of Picea abies were analysed by using a set of 292 AFLP (amplified fragment length polymorphism), SSR (single sequence repeat) and ESTP (expressed sequence tags polymorphism) markers. As usually observed in forest trees, results showed high within-population diversity (H(S) reaching 0.79) and low among-population differentiation (G(ST) approximately 2%). The genomic organization of differentiation was then investigated on the basis of a subsample of 150 AFLP, SSR and ESTP mapped markers. The number of the loci differentiating the Baltico-Nordic from the central European populations (25 loci) and, within the central European populations, the Alpine from the Hercyno-Carpathian populations (12 loci), were different. These 37 differentiated loci, with individual G(ST) values ranging from 0.008 to 0.20, were evenly distributed on all linkage groups and mostly followed the neutral expectations, suggesting genome-wide effects on differentiation. Nine of them however behave as 'outlier' loci indicating possible locus-specific selective effects. Contribution of ongoing evolutionary forces and historical effects to the geographical differentiation of the species are discussed.
Assuntos
Evolução Molecular , Genoma de Planta , Picea/genética , Mapeamento Cromossômico , DNA de Plantas/química , DNA de Plantas/genética , Ecossistema , Etiquetas de Sequências Expressas , França , Variação Genética , Repetições de Microssatélites , Filogenia , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Técnica de Amplificação ao Acaso de DNA PolimórficoRESUMO
Based on an F(1) progeny of 73 individuals, two parental maps were constructed according to the double pseudo-test cross strategy. The paternal map contained 16 linkage groups for a total genetic length of 1,792 cM. The maternal map covered 1,920 cM, and consisted of 12 linkage groups. These parental maps were then integrated using 66 intercross markers. The resulting consensus map covered 2,035 cM and included 755 markers (661 AFLPs, 74 SSRs, 18 ESTPs, the 5S rDNA and the early cone formation trait) on 12 linkage groups, reflecting the haploid number of chromosomes of Picea abies. The average spacing between two adjacent markers was 2.6 cM. The presence of 39 of the SSR and/or ESTP markers from this consensus map on other published maps of different Picea and Pinus species allowed us to establish partial linkage group homologies across three P. abies maps (up to five common markers per linkage group). This first saturated linkage map of P. abies could be therefore used as a support for developing comparative genome mapping in conifers.
Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas/genética , Etiquetas de Sequências Expressas , Marcadores Genéticos/genética , Picea/genética , Polimorfismo Genético/genética , RNA Ribossômico 5S/genética , DNA Ribossômico/genética , Genoma de Planta , Genômica , Cariotipagem , Repetições de Microssatélites/genética , Fenótipo , Picea/fisiologiaRESUMO
A mosaic minisatellite region has been identified in the mitochondrial genome of Norway spruce (Picea abies). The array was composed of three tandem repeats PaTR1 (32 bp), PaTR2a (26 bp) and PaTR2b (26 bp). PaTR2a and PaTR2b differed by one base substitution. The analysis of 92 trees covering the whole natural distribution area of the species allowed detection of 11 length variants ranging from 131 bp to 447 bp. This high intra-specific polymorphism relies on variation in the number of the tandem repeats. Population genetic parameters estimated among 14 populations suggested high population differentiation (Gst=0.749). The phylogenetic analysis of the 11 sequenced length variants has been performed using a parsimony approach. The topology of the tree showed a good association of groups with geographical origin and a low level of size homoplasy. The phylogenetic reconstruction also suggests that this minisatellite locus has mainly evolved by an increase in the repeat copy number.
Assuntos
DNA Mitocondrial/genética , Genética Populacional , Repetições Minissatélites/genética , Filogenia , Picea/genética , Sequência de Bases , Primers do DNA , Eletroforese em Gel de Ágar , Geografia , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
The 5S ribosomal DNA unit structure and organization have been investigated in Larix decidua and Larix kaempferi using selective amplification of gene and spacer, sequence analysis and homologous probe hybridization. Two highly divergent unit size classes of approximately 650 and 870 bp were detected in both species. Sequence analysis in Larix decidua revealed that length variations occur in the middle spacer region and are the result of duplications (in the long spacers) and considerable sequence heterogeneity. Conversely, the transcribed region is of uniform length (120 bp), and the nucleotide sequence of one Larix decidua clone is similar to that reported for other gymnosperms. Sequence comparison of the larch spacers with two other Pinaceae species (Pinus radiata and Picea glauca) showed that the 5' and 3' regions flanking the gene (40 and 60 bp, respectively) are quite conserved, suggesting a regulatory role. Moreover, a small element of about 70 bp located in the middle spacer region was found to be common to the larch long units and the six Pinus radiata spacer clones previously sequenced (64% sequence identity). The short and long unit size classes are mainly organized in composite tandem array(s) with evidence of extensive zones of strict alternation in both species. Mechanisms underlying this unusual association of divergent units in larch 5S rDNA arrays are discussed.
Assuntos
Cycadopsida/genética , DNA de Plantas/genética , DNA Ribossômico/genética , RNA Ribossômico 5S/genética , Sequência de Bases , Clonagem Molecular , Variação Genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência do Ácido Nucleico , Sequências de Repetição em TandemAssuntos
Reanimação Cardiopulmonar/estatística & dados numéricos , Adolescente , Reanimação Cardiopulmonar/métodos , Reanimação Cardiopulmonar/mortalidade , Criança , Pré-Escolar , Cuidados Críticos/estatística & dados numéricos , Hospitais Urbanos , Humanos , Lactente , Recém-Nascido , Admissão do Paciente/estatística & dados numéricos , Estudos Retrospectivos , SuíçaRESUMO
Compact calli with a potential for somatic embryogenesis were obtained from complete or split mature zygotic embryos or from cotyledons and hypocotyls of in vitro grown seedlings of Sequoia sempervirens. Somatic embryos which showed a typical bipolar structure, were formed together with adventitious buds. When placed on filter paper supports they developed into complete plantlets. Of the various combinations tested, culture medium adapted from Murashige and Skoog mineral solution complemented with 6-benzylaminopurine (2 µM), kinetin (2 µM) and 2,4-dichlorophenoxyacetic acid (2.5 µM) was established as the optimal for somatic embryo production.
RESUMO
General anaesthesia with intubation is preferable for emergency Caesarean section, whilst epidural anaesthesia should be reserved for elective Caesarean section. The case of a patient who required emergency Caesarean section following uterine rupture is discussed. The management was complicated by a cervical spine injury which had occurred four months previously. Because an epidural catheter had already been inserted at an early stage of labour, this was the anaesthetic technique chosen for the emergency section. This avoided tracheal intubation and the possibility of worsening the cervical fracture. The end result was satisfactory, both for the mother and the child.
