Patterns of genotype-by-environment interaction in diameter at breast height at age 3 for eucalypt hybrid clones grown for reafforestation of lands affected by salinity

The commercial viability of plantations established for the recovery of saline lands may be supported by the deployment of improved genetic material matched to these particularly challenging environments. Patterns of genotype-by-environment interaction were investigated in a highly unbalanced data set of diameter at breast height at approximately 3 years for a total of 841 genotypes from ten Eucalyptus camaldulensis × Eucalyptus globulus and Eucalyptus camaldulensis × Eucalyptus grandis hybrid families assessed across 21 trials grown on a range of saline and non-saline low rainfall sites from southeast Queensland through central NSW, Victoria, Tasmania and southeast South Australia to southwest Western Australia using factor-analytic mixed-model methods. There was significant heterogeneity among trials in estimates of family variance, genotype-within-family variance, the ratio of family variance to total genetic variance and individual broad-sense heritability. Cluster analyses indicated that family effects were highly correlated across a main group of 19 trials and that most trials fell into two major groups for genotype-within-family effects, with an average correlation among trials within these groups of 0.55. There was, however, no obvious geographical or other explanation for the patterns, suggesting that genotypes should be deployed on the basis of broad-scale adaptation.     

The pigments from Pinnacle Point Cave 13B, Western Cape, South Africa

Earth pigments from the three excavations at Pinnacle Point Cave 13B (Western Cape Province, South Africa), spanning the terminal middle Pleistocene and earlier late Pleistocene, are described and analyzed. Qualitative geological categorization primarily rested on textural, fabric, and iron enrichment attributes. Comprehensive recovery allowed identification of non-anthropic pigmentaceous materials, questionable pigments, and 380 pigments (1.08?kg). Less chemically altered pigments were typically fine-grained sedimentary (FGS) rocks, tending to be soft, highly micaceous, prone to laminar fragmentation, and with reddish-brown streaks of intermediate nuance. More iron-enriched forms tended to be harder, denser, poorly micaceous, and with redder streaks of more saturated nuance. Some still qualified as FGS forms, but a large number were categorized as sandstone or iron oxide. Despite some temporal change in raw material profiles, circumstantial evidence suggests primarily local procurement from one outcrop throughout the sequence. Definitely utilized pieces (12.7%) were overwhelmingly ground. Unusual forms of modification include several notched pieces and a deliberately scraped 'chevron.' Controlling for fragmentation, streak properties of utilized versus unutilized pieces were used to investigate selective criteria. There was robust evidence for preferential grinding of the reddest materials, strongly suggestive evidence for saturation and darkness being subordinate selective criteria, and some indication of more intensive grinding of materials with the reddest, most saturated, and darkest streaks, and for some deliberate heating of pigments. These findings challenge the initial stages of color lexicalization predicted by the various versions of the basic color term (BCT) hypothesis, they provide grounds for rejecting hafting as a general explanatory hypothesis, and they cannot be accounted for by incidental heating. The results are more consistent with agreed upon canons of ornamentation than with individual display. It is concluded that the material was processed to produce saturated red pigment powders. On theoretical grounds, these are presumed to have served primarily as body paints in ritual performance.     

A novel statin-mediated “prenylation block-and-release” assay provides insight into the membrane targeting mechanisms of small GTPases

Ras super-family small GTPases regulate diverse cellular processes such as vesicular transport and signal transduction. Critical to these activities is the ability of these proteins to target to specific intracellular membranes. To allow association with membranes Ras-related GTPases are post-translationally modified by covalent attachment of prenyl groups to conserved cysteine residues at or near their C-terminus. Here we used the HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase (HMGCR) inhibitor mevastatin to develop a ‘prenylation block-and-release’ assay that allows membrane targeting of prenylated proteins to be visualized in living cells. Using this assay we investigated the cytosol to membrane targeting of several small GTPases to compartments of the secretory and endocytic pathways. We found that all Rabs tested were targeted directly to the membrane on which they reside at steady-state and not via an intermediate location as reported for Ras and Rho proteins. However, we observed that the kinetics of cytosol to membrane targeting differed for each Rab tested. Comparison of the mevastatin sensitivity and kinetics of membrane targeting of Rab23, Rab23 prenylation motif mutants and H-Ras revealed that these parameters are strongly dependent upon the prenyl transferase with Rab geranylgeranyl transferase substrates exhibiting higher sensitivity and requiring greater time to recover from mevastatin inhibition than farnesyl transferase substrates. We propose that this assay is a useful tool to investigate the kinetics, biological functions and the mechanisms of membrane targeting of prenylated proteins.     

Characterization and multiplexing of EST-SSR primers in Cynodon (Poaceae) species1

? Premise of the study: Cynodon species are multiple-use grasses that display varying levels of adaptation to biotic and abiotic stress. Previously identified EST-SSR primers were characterized and multiplexed to assess the level of genetic diversity present within a collection of almost 1200 Cynodon accessions from across Australia. ? Methods and Results: Two multiplex reactions were developed comprising a total of 16 EST-SSR markers. All SSR markers amplified across different Cynodon species and different levels of ploidy. The number of alleles ranged from one to eight per locus and the total number of alleles for the germplasm collection was 79. ? Conclusions: The 16 markers show sufficient variation for the characterization of Cynodon core collections and analysis of population genetic diversity in Cynodon grasses.     

Leaf economic traits from fossils support a weedy habit for early angiosperms

Many key aspects of early angiosperms are poorly known, including their ecophysiology and associated habitats. Evidence for fast-growing, weedy angiosperms comes from the Early Cretaceous Potomac Group, where angiosperm fossils, some of them putative herbs, are found in riparian depositional settings. However, inferences of growth rate from sedimentology and growth habit are somewhat indirect; also, the geographic extent of a weedy habit in early angiosperms is poorly constrained. Using a power law between petiole width and leaf mass, we estimated the leaf mass per area (LMA) of species from three Albian (110-105 Ma) fossil floras from North America (Winthrop Formation, Patapsco Formation of the Potomac Group, and the Aspen Shale). All LMAs for angiosperm species are low (<125 g/m(2); mean = 76 g/m(2)) but are high for gymnosperm species (>240 g/m(2); mean = 291 g/m(2)). On the basis of extant relationships between LMA and other leaf economic traits such as photosynthetic rate and leaf lifespan, we conclude that these Early Cretaceous landscapes were populated with weedy angiosperms with short-lived leaves (<12 mo). The unrivalled capacity for fast growth observed today in many angiosperms was in place by no later than the Albian and likely played an important role in their subsequent ecological success.     

Superresolution Localization of Single Functional IP3R Channels Utilizing Ca Flux as a Readout

The subcellular localization of membrane Ca²⁺ channels is crucial for their functioning, but is difficult to study because channels may be distributed more closely than the resolution of conventional microscopy is able to detect. We describe a technique, stochastic channel Ca²⁺ nanoscale resolution (SCCaNR), employing Ca²⁺-sensitive fluorescent dyes to localize stochastic openings and closings of single Ca²⁺-permeable channels within <50 nm, and apply it to examine the clustered arrangement of inositol trisphosphate receptor (IP₃R) channels underlying local Ca²⁺ puffs. Fluorescence signals (blips) arising from single functional IP₃Rs are almost immotile (diffusion coefficient <0.003 μm² s⁻¹), as are puff sites over prolonged periods, suggesting that the architecture of this signaling system is stable and not subject to rapid, dynamic rearrangement. However, rapid stepwise changes in centroid position of fluorescence are evident within the durations of individual puffs. These apparent movements likely result from asynchronous gating of IP₃Rs distributed within clusters that have an overall diameter of ∼400 nm, indicating that the nanoscale architecture of IP₃R clusters is important in shaping local Ca²⁺ signals. We anticipate that SCCaNR will complement superresolution techniques such as PALM and STORM for studies of Ca²⁺ channels as it obviates the need for photoswitchable labels and provides functional as well as spatial information.