RESUMO
Two new species and a new combination of Hypoxylon from Texas were identified and described based on morphological, multigene phylogenetic (ITS [nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2], 28S [5' 1200 bp of nuc 28S rDNA], RPB2 [partial second largest subunit of the DNA-directed RNA polymerase II], TUB2 [partial ß-tubulin]), and chemotaxonomic data. Hypoxylon olivaceopigmentum is characterized by its pulvinate to glomerate stromata, olivaceous KOH-extractable pigments, equilateral ascospores, and indehiscent perispore. Hypoxylon texense can be distinguished from morphologically similar species by its rust to dark brick KOH-extractable pigments and the high-performance liquid chromatography (HPLC) profile of its stromatal secondary metabolites. Hypoxylon hinnuleum is proposed as the sexual morph of Nodulisporium hinnuleum, featuring dark vinaceous glomerate stromata with dark brick KOH-extractable pigments composed of cohaerin-type azaphilones and smooth equilateral ascospores with indehiscent perispore. Based on these diagnostic characters, H. hinnuleum forms a complex with H. croceum and H. minicroceum. More than 50 ITS sequences with high identity originating from North American and East Asian environmental isolates formed a well-supported clade with the type of N. hinnuleum, demonstrating the widespread distribution of the species complex. In addition, updated descriptions and comprehensive illustrations with detailed information on the diagnostic features of H. fendleri and H. perforatum are provided. The multilocus phylogenetic reconstruction of Hypoxylon supported the status of the new species and broadened the knowledge about intergeneric relationships.
Assuntos
Microbiologia Ambiental , Filogenia , Esporos Fúngicos/citologia , Xylariales/classificação , Xylariales/isolamento & purificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Microscopia , Pigmentos Biológicos/análise , RNA Polimerase II/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Texas , Tubulina (Proteína)/genética , Xylariales/genética , Xylariales/fisiologiaRESUMO
In the bone marrow cavity, hematopoietic stem cells (HSC) have been shown to reside in the endosteal and subendosteal perivascular niches, which play specific roles on HSC maintenance. Although cells with long-term ability to reconstitute full hematopoietic system can be isolated from both niches, several data support a heterogenous distribution regarding the cycling behavior of HSC. Whether this distinct behavior depends upon the role played by the stromal populations which distinctly create these two niches is a question that remains open. In the present report, we used our previously described in vivo assay to demonstrate that endosteal and subendosteal stromal populations are very distinct regarding skeletal lineage differentiation potential. This was further supported by a microarray-based analysis, which also demonstrated that these two stromal populations play distinct, albeit complementary, roles in HSC niche. Both stromal populations were preferentially isolated from the trabecular region and behave distinctly in vitro, as previously reported. Even though these two niches are organized in a very close range, in vivo assays and molecular analyses allowed us to identify endosteal stroma (F-OST) cells as fully committed osteoblasts and subendosteal stroma (F-RET) cells as uncommitted mesenchymal cells mainly represented by perivascular reticular cells expressing high levels of chemokine ligand, CXCL12. Interestingly, a number of cytokines and growth factors including interleukin-6 (IL-6), IL-7, IL-15, Hepatocyte growth factor (HGF) and stem cell factor (SCF) matrix metalloproteases (MMPs) were also found to be differentially expressed by F-OST and F-RET cells. Further microarray analyses indicated important mechanisms used by the two stromal compartments in order to create and coordinate the "quiescent" and "proliferative" niches in which hematopoietic stem cells and progenitors reside.
Assuntos
Medula Óssea/fisiologia , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Células Estromais/fisiologia , Animais , Medula Óssea/metabolismo , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Osso e Ossos/fisiologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Perfilação da Expressão Gênica/métodos , Hematopoese/genética , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fator de Células-Tronco/genética , Fator de Células-Tronco/metabolismo , Nicho de Células-Tronco/genética , Nicho de Células-Tronco/fisiologia , Células Estromais/citologia , Células Estromais/metabolismoRESUMO
BACKGROUND: The gene encoding acyloxyacyl hydrolase (AOAH), an enzyme that hydrolyzes secondary fatty acyl chains of LPS, is localised on chromosome 7p14-p12, where evidence for linkage to total IgE (tIgE) concentrations and asthma has been previously reported. OBJECTIVE: We hypothesized that variants in AOAH are associated with asthma and related phenotypes. Because both AOAH and soluble CD14 respond to LPS, we tested for gene-gene interaction. METHODS: We investigated the association between 28 single nucleotide polymorphisms throughout the AOAH gene and asthma, concentrations of tIgE, the ratio of IL-13/IFN-y, and soluble CD14 levels among 125 African Caribbean, multiplex asthmatic pedigrees (n=834). Real-time PCR was used to assess whether AOAH cDNA expression differed with AOAH genotype. RESULTS: Significant effects were observed for all 4 phenotypes and AOAH markers in 3 distinct regions (promoter, introns 1-6, and the intron 12/exon 13 boundary/intron 13 region) by means of single-marker and haplotype analyses, with the strongest evidence for a 2-single-nucleotide-polymorphism haplotype and log [tIgE] (P=.006). There was no difference in AOAH expression levels by AOAH genotype for any of the markers. Comparing genotypic distributions at both the AOAH marker rs2727831 and CD14(-260)C>T raises the possibility of gene-gene interaction (P=.006-.036). CONCLUSION: Our results indicate that polymorphisms in markers within the AOAH gene are associated with risk of asthma and associated quantitative traits (IgE and cytokine levels) among asthmatic subjects and their families in Barbados, and there is an interactive effect on tIgE and asthma concentrations between an AOAH marker and the functional CD14(-260)C>T polymorphism. CLINICAL IMPLICATIONS: AOAH is a novel innate immunity candidate gene associated with asthma and related phenotypes in an African ancestry population.