Ocular retardation (or) is a murine eye mutation causing microphthalmia, a thin hypocellular retina and optic nerve aplasia. Here we show that mice carrying the OrJ allele have a premature stop codon in the homeobox of the Chx10 gene, a gene expressed at high levels in uncommitted retinal progenitor cells and mature bipolar cells. No CHX10 protein was detectable in the retinal neuroepithelium of orJ homozygotes. The loss of CHX10 leads both to reduced proliferation of retinal progenitors and to a specific absence of differentiated bipolar cells. Other major retinal cell types were present and correctly positioned in the mutant retina, although rod outer segments were short and retinal lamination was incomplete. These results indicate that Chx10 is an essential component in the network of genes required for the development of the mammalian eye, with profound effects on retinal progenitor proliferation and bipolar cell specification or differentiation. off
Bordetellae, pathogenic to mammals, produce an immunomodulatory adenylate cyclase toxin–hemolysin (CyaA, ACT or AC-Hly) that enables them to overcome the innate immune defense of the host. CyaA subverts host phagocytic cells by an orchestrated action of its functional domains, where an extremely catalytically active adenylyl cyclase enzyme is delivered into phagocyte cytosol by a pore-forming repeat-in-toxin (RTX) cytolysin moiety. By targeting sentinel cells expressing the complement receptor 3, known as the CD11b/CD18 (αMβ2) integrin, CyaA compromises the bactericidal functions of host phagocytes and supports infection of host airways by Bordetellae. Here, we review the state of knowledge on structural and functional aspects of CyaA toxin action, placing particular emphasis on signaling mechanisms by which the toxin-produced 3′,5′-cyclic adenosine monophosphate (cAMP) subverts the physiology of phagocytic cells.
2007: A city in motion: Time-space activity and mobility patterns of suburban inhabitants and the structuration of the spatial organization of the Prague metropolitan area. Geogr. Ann., 89 B (2): 147-167.ABSTRACT. This contribution attempts to reveal the relations between new suburban areas and other parts of the Prague metropolitan area by investigating the time-space activity and mobility patterns of the inhabitants of newly built suburban districts. The focus on some aspects of the everyday life of people in new suburbs helps us to identify the impact of suburbanization on the changing geography of the metropolitan region and to better understand how the spatial organization of the Prague metropolitan area is produced, reproduced and transformed. We use several interrelated concepts, which serve the theoretical foundation of our work, namely time geography, structuration theory and the postcommunist city. The empirical data utilized are primarily based on 262 diaries completed by eighty-eight individuals from thirtyeight households, accompanied by household questionnaires and interviews with the heads of households. The research confirmed the implicit, generally unspoken view that new suburbs in the Prague metropolitan region are heavily dependent on the core of the metropolitan area for the provision of jobs and services. However, newly built suburban shopping facilities to some extent disrupt this pattern, keeping some daily activities of inhabitants within the suburban zone. In addition to empirical observations, the key purpose of this contribution has been to discuss and apply time geography concepts and methods to the research of urban restructuring, and to understand the structuration of metropolitan spatial organization.
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