The major locus for multifactorial nonsyndromic cleft lip maps to mouse Chromosome 11

Cleft lip with or without cleft palate, CL(P), a common human birth defect, has a genetically complex etiology. An animal model with a similarly complex genetic basis is established in the A/WySn mouse strain, in which 20% of newborn have CL(P). Using a newly created congenic strain, AEJ.A, and SSLP markers, we have mapped a major CL(P)-causing gene derived from the A/WySn strain. This locus, here named clf1 (cleft lip) maps to Chromosome (Chr) 11 to a region having linkage homology with human 17q21-24, supporting reports of association of human CL(P) with the retinoic acid receptor alpha (RARA) locus.     

Coordinating conservation: global networking for species survival

The Species Survival Commission (SSC) of IUCN—the World Conservation Union is the largest, most comprehensive and diverse professional conservation network in existence today. It brings together over 6000 volunteers from more than 160 countries to contribute to the conservation of biological diversity by developing and executing programmes to study, save, restore, and manage wisely species and their habitats. The SSC is organized primarily along taxonomic lines, with members distributed in 96 Specialist Groups focusing on distinct groups of species. These groups are a source of the most current and expert information on the conservation status and priorities for action for species in the wild. As such, they provide an invaluable resource in setting priorities for captive propagation and in linking ex situ actions. In addition, the SSC has five disciplinary Specialist Groups that provide expertise to both the zoo community and field conservationists in areas such as reintroductions, veterinary medicine, captive breeding as a conservation tool, and the impact of invasive species on native flora and fauna. The effectiveness of the SSC is greatly enhanced by the close connections within its network between zoo professionals, academic scientists, field conservationists, and managers of natural resources. Challenges to the SSC currently include better information management, organization at the national level, and extending coverage in areas such as marine biodiversity.     

Oxidative stress responses in transgenic tobacco containing altered levels of glutathione reductase activity

A pea glutathione reductase cDNA was expressed in tobacco. Three classes of construct were used which gave a range of elevated levels of glutathione reductase (GR) activity in the cytosol (GR32), chloroplasts (GR36), or in both chloroplasts and mitochondria (GR46). In some transgenic progeny (T₂) from self-fertilized GR32 and GR36 primary transformants, having approximately twofold elevation of GR activity as compared with recessive siblings, there was an amelioration of the effect on leaf discs of up to 15 µM paraquat. However, lines with similarly elevated levels of GR activity showed no decreased sensitivity to the herbicide. None of the GR32 and GR36 lines was less sensitive to ozone. Conversely, T₂ progeny of GR46 lines, with greater than 4.5-fold elevations of GR activity, showed no reduced sensitivity to paraquat but two out of four of these lines were less sensitive to ozone fumigation. The differential response to stress co-segregated with the presence of the transgene but there was no relationship between the degree of stress response and the level of GR activity. There was an elevation in the total glutathione pool in all lines showing increased GR activity but there was no change in the ratio of oxidized to reduced glutathione. These results demonstrate that the mechanisms of protection against ozone and paraquat are different although both can be mediated by elevated GR activity.