Dispersal and establishment of Huon pine (Lagarostrobos franklinii)

Huon pine had a mast year in 1989 resulting in massive seedfall. It was found that Huon pine had extremely limited lateral seed dispersal by wind, although the chances of dispersal by water appear extremely good, due to its flotation capabilities. Green rosellas (Platycercus caledonicus Gmelin) were observed feeding on the seed and may play some role both as predators and dispersers of seed. A low percentage of successful germination was achieved and germination rate was slow. Seedlings appear to establish mostly on soil substrates but also occur on logs and trunks. Colonisation, even downstream, can take a considerable period of time and may partly explain the restricted distribution of Huon pine. The implications of these results for conservation and management are discussed

Development and characterization of microsatellite loci for Ocotea species (Lauraceae) threatened with extinction

The Atlantic rainforest species Ocotea catharinensis, Ocotea odorifera, and Ocotea porosa have been extensively harvested in the past for timber and oil extraction and are currently listed as threatened due to overexploitation. To investigate the genetic diversity and population structure of these species, we developed 8 polymorphic microsatellite markers for O. odorifera from an enriched microsatellite library by using 2 dinucleotide repeats. The microsatellite markers were tested for cross-amplification in O. catharinensis and O. porosa. The average number of alleles per locus was 10.2, considering all loci over 2 populations of O. odorifera. Observed and expected heterozygosities for O. odorifera ranged from 0.39 to 0.93 and 0.41 to 0.92 across populations, respectively. Cross-amplification of all loci was successfully observed in O. catharinensis and O. porosa except 1 locus that was found to lack polymorphism in O. porosa. Combined probabilities of identity in the studied Ocotea species were very low ranging from 1.0 x 10-24 to 7.7 x 10-24. The probability of exclusion over all loci estimated for O. odorifera indicated a 99.9% chance of correctly excluding a random nonparent individual. The microsatellite markers described in this study have high information content and will be useful for further investigations on genetic diversity within these species and for subsequent conservation purposes13351385142COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçã

PGC-1alpha Down-Regulation Affects the Antioxidant Response in Friedreich's Ataxia

BACKGROUND: Cells from individuals with Friedreich's ataxia (FRDA) show reduced activities of antioxidant enzymes and cannot up-regulate their expression when exposed to oxidative stress. This blunted antioxidant response may play a central role in the pathogenesis. We previously reported that Peroxisome Proliferator Activated Receptor Gamma (PPARgamma) Coactivator 1-alpha (PGC-1alpha), a transcriptional master regulator of mitochondrial biogenesis and antioxidant responses, is down-regulated in most cell types from FRDA patients and animal models. METHODOLOGY/PRINCIPAL FINDINGS: We used primary fibroblasts from FRDA patients and the knock in-knock out animal model for the disease (KIKO mouse) to determine basal superoxide dismutase 2 (SOD2) levels and the response to oxidative stress induced by the addition of hydrogen peroxide. We measured the same parameters after pharmacological stimulation of PGC-1alpha. Compared to control cells, PGC-1alpha and SOD2 levels were decreased in FRDA cells and did not change after addition of hydrogen peroxide. PGC-1alpha direct silencing with siRNA in control fibroblasts led to a similar loss of SOD2 response to oxidative stress as observed in FRDA fibroblasts. PGC-1alpha activation with the PPARgamma agonist (Pioglitazone) or with a cAMP-dependent protein kinase (AMPK) agonist (AICAR) restored normal SOD2 induction. Treatment of the KIKO mice with Pioglitazone significantly up-regulates SOD2 in cerebellum and spinal cord. CONCLUSIONS/SIGNIFICANCE: PGC-1alpha down-regulation is likely to contribute to the blunted antioxidant response observed in cells from FRDA patients. This response can be restored by AMPK and PPARgamma agonists, suggesting a potential therapeutic approach for FRDA.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Phylogenomics and the rise of the angiosperms

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade

Conservation genetics of rare and threatened Romnalda (Xanthorrhoeaceae) from Australia and Papua New Guinea

No abstract available

Novel microsatellite markers for conservation of Australian native Samadera bidwillii

Ashwath, N ORCiD: 0000-0002-4032-4507; Naik, VM ORCiD: 0000-0002-6223-5484Microsatellite markers were developed for Samadera bidwillii, a nationally listed vulnerable shrub or small tree, to enable investigation of its genetic structure and diversity within and among populations from its known distribution throughout coastal areas mainly in fragmented and disturbed lands from Mackay to Gympie, Queensland, Australia. The loci were tested for cross-amplification in related Samadera species. Ten polymorphic microsatellite markers were isolated and characterised from an enriched library of S. bidwillii, which exhibited di- and trinucleotide repeats. The mean number of alleles per locus ranged from 1.3 to 2.5 and mean expected and observed heterozygosities ranged from 0.06 to 0.33 and from 0.03 to 0.26, respectively in five populations. All loci successfully amplified in six other closely associated Samadera species also reported from Australia. Developed loci can be used in genetic diversity, population structure and gene flow studies with an emphasis on the conservation of S. bidwillii and related species