Translocations are being increasingly proposed as a way of conserving biodiversity, particularly in the management of threatened and keystone species, with the aims of maintaining biodiversity and ecosystem function under the combined pressures of habitat fragmentation and climate change. Evolutionary genetic considerations should be an important part of translocation strategies, but there is often confusion about concepts and goals. Here, we provide a classification of translocations based on specific genetic goals for both threatened species and ecological restoration, separating targets based on ‘genetic rescue’ of current population fitness from those focused on maintaining adaptive potential. We then provide a framework for assessing the genetic benefits and risks associated with translocations and provide guidelines for managers focused on conserving biodiversity and evolutionary processes. Case studies are developed to illustrate the framework.

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Oxygen free radicals are highly reactive species generated by many cellular oxidation-reduction processes. These radicals damage cellular constituents and have been causally implicated in the pathogenesis of many human diseases. We report here that oxygen free radicals generated by Fe2+ in aqueous solution are mutagenic. Aerobic incubation of 4X174 am3 (amber 3 mutation) DNA with Fe2+ results in decreased phage survival when the treated DNA is transfected into Escherichia coli spheroplasts. Transfection of the treated DNA into SOS-induced spheroplasts results in an increase in mutagenesis as great as 50-fold. Both killing and mutagenesis can be prevented by binding of Fe2+ with deferoxamine or by the addition of catalase or mannitol. These results suggest that DNA damage and mutagenesis brought about by Fe2+ are likely to occur by a Fenton-type mechanism that involves the generation of (i) hydrogen peroxide by the autoxidation of iron and (ii) hydroxyl radicals by the interaction of the hydrogen peroxide with Fe2+. DNA sequence analysis of the Fe2+-induced mutants indicates that reversion of the phage phenotype to wild type occurs largely by a transversion type of mutation involving substitution of deoxyadenosine for thymidine opposite a template deoxyadenosine. Mutagenesis is not abolished by incubation of Fe22+-treated 4X174 am3 DNA with an apurinic endonuclease and only partially abolished by incubation with alkali, suggesting that a large fraction of the mutagenesis by oxygen free radicals is not caused by formation of apurinic sites but instead involves an as-yet-to-be-defined alteration in deoxyadenosine. These fmdings raise the possibility that free iron localized in cellular DNA may cause mutations by the generation of oxygen free radicals.A portion of the total cellular oxygen metabolism proceeds by a sequence of one-electron reductions that result in oxygen free-radical intermediates. Processes reported to yield oxygen free radicals include phagocytosis, ischemic cell injury, and drug toxicity (1-4). The resultant free radicals have been hypothesized to be causative factors in aging (5), carcinogenesis (5, 6), and radiation injury (7) and to be a contributory factor in tumor promotion (8)(9)(10) with the overall reaction being the iron-catalyzed interaction between 02 and H202 to form OH-or a similarly reactive species (Haber-Weiss reaction):

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Aim To investigate the relationships between species attributes and genetic parameters in Australian plant species and to determine the associations in relation to predictions from population theory and previous global analyses.Location Continent of Australia. MethodsWe assembled a dataset of all known population genetic analyses of Australian plants based on neutral markers and catalogued them according to key species attributes, including range, abundance, range disjunction, biome and growth form; and genetic parameters, mean number of alleles per locus, observed and expected heterozygosity and population differentiation. We determined relationships between species attributes and genetic parameters using a maximum-likelihood, multimodel inference approach. Results We found many associations that were consistent with predictions. Species attributes with greatest effect on genetic diversity were range size, growth form, abundance and biome. The most important attributes influencing genetic differentiation were range disjunction and abundance. We found unexpected results in the effects of biome and growth form on genetic diversity, with greater diversity in the eastern biome of Australia, and lower diversity in shrubs compared to trees.Main conclusions Our analysis of genetic diversity of Australian plants showed associations consistent with predictions based on population genetics theory, with strong effects of range size, abundance and growth form. We identified a striking effect of range disjunction on population genetic differentiation, an effect that has received little attention in the literature. We also found some notable differences to global predictions, which were most likely explained by confounding effects across variables. This highlights that caution is needed when extrapolating trends from global analyses to regional floras. Identifying associations between species attributes and patterns of genetic diversity enables broadscale predictions to facilitate the inclusion of genetic considerations into conservation decision-making.

The results highlight that management strategies involving interpopulation crosses can improve reproductive output in small, isolated populations of rare plants, but guidelines need to be developed on a population by population basis.

The protein from a mutant clone of staphylococcal nuclease with a cysteine substituting for a lysine at position 78 was prepared and labeled with a cysteine-specific fluorescent probe 5-[[2-[(iodoacetyl)-amino]ethyl]amino]naphthalene-1-sulfonic acid (IAEDANS). Time-resolved nonradiative energy-transfer studies were done using the single tryptophan at position 140 as the energy donor and the IAEDANS as the receptor. Changes in distance and distance distributions were observed as a function of increasing guanidinium (GuHCl) concentration (0-2 M) and in the presence or absence of Ca2+ and inhibitor 2'-deoxythymidine 3',5'-diphosphate (pdTp). In the native state, both the ternary complex and the noncomplexed protein are best fit with one population having an average donor-acceptor distance of approximately 23 A and an "apparent" full width at half-maximum (fwhm) of distance distribution of approximately 18 A. Besides the contribution of linker arm of the acceptor, it appears that there are some conformational heterogeneties either due to the disordering of the tryptophan region or due to the whole protein in the native state. During GuHCl unfolding, the average distance remains relatively constant up to GuHCl concentrations where both the ternary complex and the ligand-free protein are denatured (1-1.3 M). The compact denatured states persist up to 2 M GuHCl. At 2 M GuHCl, the heterogeneity of the denatured state in the ternary complex is much larger than that of the ligand-free nuclease. The results show that the denatured states of staphylococcal nuclease mutant K78C by GuHCl are compact and these compact denatured states are likely due to residual structures or incompletely disrupted hydrophobic cores under these conditions.

Rare plant species are often restricted to small and/or isolated populations that can have reduced reproductive output and adaptive potential, resulting in an increased probability of extinction. Nevertheless, evolutionary changes might occur in such populations that increase their likelihood of persisting. In Australia, many threatened species from the ecologically important genus Grevillea (Proteaceae) are found in disjunct populations and these often display varied modes of reproduction from sexual to exclusively clonal. Here we use microsatellite markers to show that isolated populations across the entire range of G. repens have developed diverse patterns of genetic variation. The largest population has a relatively low level of genetic variation, one small population displays inbreeding, two populations show evidence of clonal reproduction and two contain both triploids and diploids. The global estimate of F ST was moderately high (0.272) suggesting limited gene flow between populations and historical isolation. These findings indicate that the genetically distinct G. repens populations exhibit very different patterns of genetic variation and we propose that the development of clonality and polyploidy in small or isolated populations may allow persistence but also reduces the effective size of the sexual population. Grevillea repens populations from its eastern and western/western central centres of distribution should be viewed as separate units for conservation management.