Assuntos
Mapeamento Cromossômico , Proteínas de Ligação a DNA/genética , Glutaminase/genética , Transativadores/genética , Animais , Clonagem Molecular , Endonucleases , Ligação Genética/genética , Marcadores Genéticos/genética , Hibridização in Situ Fluorescente , Camundongos , Proteínas Nucleares , Polimorfismo Genético/genética , Fator de Transcrição STAT1 , Análise de Sequência de DNA , Fatores de TranscriçãoRESUMO
In an effort to produce a more complete transcription map of the short (approximately 5 Mb) arm of the mouse Y chromosome, we have initiated exon trapping from Yp-derived YACs. Sequence analysis of the trapped products has identified exons of previously cloned mouse Y-located genes Zfy and SSty and potential exons homologous to the human Y-located Tspy gene family. In addition, a family of three Yp-located transcripts that show close homology to human RHOA (locus designation ARHA), a member of the Ras family of small GTPases, has been identified. To determine whether these Yp sequences had been transposed from an autosomal ancestor, we used this trapped product to isolate a full-length autosomal mouse RhoA cDNA that is 80% identical at the nucleotide level and 98% identical at the amino acid level to human RHOA and maps to mouse Chromosome 2 (locus designation ArhA). Sequence analysis indicates that the Y-linked copies have diverged from the autosomal form, with small deletions precluding maintenance of a significant open reading frame in all Yp copies. Yet RT-PCR analysis indicates that two of these pseudogenes, RhoAy1 and 3, are expressed in a testis-specific manner, in sharp contrast to the nearly ubiquitous expression pattern of the autosomal ancestor. The data indicate that the Y copies of RhoA have been transposed from an autosome, followed by subsequent duplication, sequence divergence, and acquisition of a testis-specific promoter/enhancer.
Assuntos
Proteínas de Ligação ao GTP/genética , Cromossomo Y/genética , Animais , Southern Blotting , Criança , Mapeamento Cromossômico , Cromossomos Artificiais de Levedura/genética , Clonagem Molecular , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Proteína rhoA de Ligação ao GTPRESUMO
The adhesiveness of isolated canine cardiac myocytes for neutrophils is greatly increased by stimulation with cytokines such as tumor necrosis factor alpha (TNF alpha). Since this adhesion is significantly inhibited by an anti-CD18 MAb, experiments were performed to test the hypothesis that the newly expressed adhesion molecule on the cardiac myocytes was intercellular adhesion molecule-1 (ICAM-1). A newly developed MAb, CL18/6, was found to exhibit the functional and binding characteristics with canine neutrophils and canine jugular vein endothelial cells expected of an antibody recognizing ICAM-1. MAb CL18/6 also bound to isolated cardiac myocytes after stimulation of the myocytes with cytokines, and it blocked by greater than 90% the adhesion of neutrophils to stimulated myocytes. A partial cDNA clone for canine ICAM-1 was isolated, and ICAM-1 mRNA was found to be increased in both endothelial cells and cardiac myocytes after cytokine stimulation. Cytokines that both increased the CL18/6-inhibitable adhesion of neutrophils to myocytes and induced expression of ICAM-1 were IL-1 beta, TNF alpha, and LPS. These results are consistent with the conclusion that canine endothelial cells and cardiac myocytes express ICAM-1 in response to cytokine stimulation, and that ICAM-1 functions as an adhesive molecule for neutrophils on both cell types.