Sox13 functionally complements the related Sox5 and Sox6 as important developmental modulators in mouse spinal cord oligodendrocytes

The role of transcription factor Sox13, which together with Sox5 and Sox6 belongs to the SoxD family, is only poorly characterized in central nervous system development. Therefore, we analysed whether Sox13 expression and function overlaps with or differs from that of its close relatives Sox5 and Sox6. In the developing mouse spinal cord, we found Sox13 predominantly expressed in neuroepithelial precursors, oligodendroglial and astroglial cells. The substantially overlapping expression with Sox5 and Sox6 in oligodendroglial cells prompted us to study potential roles during specification, lineage progression and differentiation of oligodendrocytes. In contrast to Sox5 and Sox6, Sox13 expression continues after differentiation and even increases in myelinating oligodendrocytes. Sox13 deletion did not interfere with oligodendroglial development, which was normal in Sox13-deficient mice. However, the premature differentiation of oligodendrocyte precursors triggered by loss of Sox6 was slightly more prominent in Sox6/Sox13 double-deficient mice. Sox13 can bind to the same sites in myelin gene promoters as Sox5 and Sox6 in vitro. Reporter gene assays furthermore reveal a similar antagonizing effect on Sox10-dependent transactivation of myelin gene promoters as previously shown for Sox5 and Sox6. This argues that Sox13 is functionally redundant with the other SoxD proteins and complements Sox5 and Sox6 in their role as important modulators of oligodendrocyte development. The transcription factor Sox13 is co-expressed with the related Sox5 and Sox6 in cells of the oligodendroglial lineage. By itself, it has little impact on oligodendrocyte development but supports Sox5 and Sox6 during the process as a functionally redundant transcription factor.

Variable methylation and differential replication of genomic DNA in cultured carrot root expiants during growth induction as influenced by hormonal treatments

The methylation and amplification pattern of genomic DNA of carrot root expiants (Daucus carota L.) undergoes transitory changes during the cultural cycle. A high degree of variation was observed as early as 36 h after the incubation of fresh expiants in the nutrient medium and, depending on the hormonal treatment significant modifications occurred during 14 days of culture. Proliferative tissue conditioned by kinetin showed an extensive reduction in DNA methylation. Changes in the DNA amplification pattern were not necessarily linked to methylation.

An epidemiological, clinical and microbiological follow-up study of incident meningococcal disease cases in Norway, winter 1981-1982. Material and epidemiology in the MenOPP project

To investigate the relative importance of the many possible influencing factors and developmental traits of systemic meningococcal disease (MCd) in the practical Norwegian context, a comprehensive multipurpose case control study was carried out during the winter of 1981-1982 on incident cases in the whole country. The design of the study, the MenOPP project, is outlined. The main inclusion criteria for patients were suspected bacterial meningitis and/or septicemia on referral to hospital. This resulted in 115 verified or probable cases of MCd and 61 patient controls. Randomly drawn from three age strata, 320 population controls were actually approached and 293 (92%) of these responded to the "environmental questionnaire". So did most of the patients (98%). The clinical data mainly comprised information from the commencement of the disease to a sequelae check about six weeks after hospital admission. Laboratory data on strain and serum characteristics were, and still are, collected. The results are to be published in several papers. Here, some epidemiological characteristics of the material are given. Regional, seasonal, and age/sex differences in case fatality are reported and discussed.