Arabidopsis T-DNA Insertional Lines For CDC25 Are Hypersensitive to Hydroxyurea But Not to Zeocin or Salt Stress.

Background and Aims In yeasts and animals, cyclin-dependent kinases are key regulators of cell cycle progression and are negatively and positively regulated by WEE1 kinase and CDC25 phosphatase, respectively. In higher plants a full-length orthologue of CDC25 has not been isolated but a shorter gene with homology only to the C-terminal catalytic domain is present. The Arabidopis thaliana;CDC25 can act as a phosphatase in vitro. Since in arabidopsis, WEE1 plays an important role in the DNA damage/DNA replication checkpoints, the role of Arath;CDC25 in conditions that induce these checkpoints or induce abiotic stress was tested. Methods arath;cdc25 T-DNA insertion lines, Arath;CDC25 over-expressing lines and wild type were challenged with hydroxyurea (HU) and zeocin, substances that stall DNA replication and damage DNA, respectively, together with an abiotic stressor, NaCl. A molecular and phenotypic assessment was made of all genotypes Key Results There was a null phenotypic response to perturbation of Arath;CDC25 expression under control conditions. However, compared with wild type, the arath;cdc25 T-DNA insertion lines were hypersensitive to HU, whereas the Arath;CDC25 over-expressing lines were relatively insensitive. In particular, the over-expressing lines consistently outgrew the T-DNA insertion lines and wild type when challenged with HU. All genotypes were equally sensitive to zeocin and NaCl. Conclusions Arath;CDC25 plays a role in overcoming stress imposed by HU, an agent know to induce the DNA replication checkpoint in arabidopsis. However, it could not enhance tolerance to either a zeocin treatment, known to induce DNA damage, or salinity stress.

Animism in Rainforest and Tundra: Personhood, Animals, Plants and Things in Contemporary Amazonia and Siberia (Book Review)

Animism is a form of traditional spiritual belief that receives welcome treatment here. The observations of Victorian ethnologist travellers on the local peoples they regarded as primitive was analysed by Sir Edward (E. B.) Tylor, in Primitive Culture (1871) which established the working definition of animism followed by later generations of scholars. This came from the observation that non-scientific people did not always draw sharp distinctions between human persons and other entities such as animals, trees and even rocks but imbued these with soul. The latin anima, ‘soul, spirit’ provided the title of what was assumed to be a primitive religion, animism. The study being reviewed recognizes apparent connections within deep history between Siberia and the Amazon, and uses contemporary social anthropology to clarify assumptions about animism. This book on animism in two shamanic cultures explores personhood and the relations in pre-scientific human thought between humans and non-humans, in contexts where non-humans can be regarded as social persons (p.2).