Primary cilia and basal bodies are evolutionarily conserved organelles that mediate communication between the intracellular and extracellular environments. Here we show that bbs1, bbs4 and mkks (also known as bbs6), which encode basal body proteins, are required for convergence and extension in zebrafish and interact with wnt11 and wnt5b. Suppression of bbs1, bbs4 and mkks transcripts results in stabilization of beta-catenin with concomitant upregulation of T-cell factor (TCF)-dependent transcription in both zebrafish embryos and mammalian ciliated cells, a defect phenocopied by the silencing of the axonemal kinesin subunit KIF3A but not by chemical disruption of the cytoplasmic microtubule network. These observations are attributable partly to defective degradation by the proteasome; suppression of BBS4 leads to perturbed proteasomal targeting and concomitant accumulation of cytoplasmic beta-catenin. Cumulatively, our data indicate that the basal body is an important regulator of Wnt signal interpretation through selective proteolysis and suggest that defects in this system may contribute to phenotypes pathognomonic of human ciliopathies.

Epistatic interactions have an important role in phenotypic variability, yet the genetic dissection of such phenomena remains challenging. Here we report the identification of a novel locus, MGC1203, that contributes epistatic alleles to Bardet-Biedl syndrome (BBS), a pleiotropic, oligogenic disorder. MGC1203 encodes a pericentriolar protein that interacts and colocalizes with the BBS proteins. Sequencing of two independent BBS cohorts revealed a significant enrichment of a heterozygous C430T mutation in patients, and a transmission disequilibrium test (TDT) showed strong over-transmission of this variant. Further analyses showed that the 430T allele enhances the use of a cryptic splice acceptor site, causing the introduction of a premature termination codon (PTC) and the reduction of steady-state MGC1203 messenger RNA levels. Finally, recapitulation of the human genotypes in zebrafish shows that modest suppression of mgc1203 exerts an epistatic effect on the developmental phenotype of BBS morphants. Our data demonstrate how the combined use of biochemical, genetic and in vivo tools can facilitate the dissection of epistatic phenomena, and enhance our appreciation of the genetic basis of phenotypic variability.

No abstract

No abstract

No abstract

No abstract

Hardwood tree species in forest, plantation, and urban environments (temperate regions of the world) are important biological resources that play a significant role in the economy and the ecology of terrestrial ecosystems, and they have aesthetic and spiritual value. Because of these many values of hardwood tree species, preserving forest tree biodiversity through the use of biotechnological approaches should be an integral component in any forestry program in addition to large-scale ecologically sustainable forest management and preservation of the urban forest environment. Biotechnological tools are available for conserving tree species as well as genetic characterization that will be needed for deployment of germplasm through restoration activities. This review concentrates on the biotechnological tools available for conserving, characterizing, evaluating, and enhancing hardwood forest tree biodiversity. We focus mainly on species grown for lumber and wood products, not species grown mainly for fiber (pulp and paper production). We also present a brief summary of the importance of non-wood forest products from temperate hardwood tree species (a research area that needs further development using biotechnological techniques) and a few case studies for preserving forest tree biodiversity.

Limiting the juvenile phase and reducing tree size are the two main challenges for breeders to improve most fruit crops. Early maturation and dwarf cultivars have been reported for many fruit species. “Early mature” and low vigor walnut genotypes were found among seedlings of Persian walnut. Nine microsatellite markers were used to evaluate genetic diversity among “Early Mature” Persian walnut accessions and provide a comparison with “normal growth” accessions. Six maturation related characteristics were also measured in “Early Mature” samples. Phenotypic traits and diversity indices showed relatively high levels of genetic diversity in “Early Mature” seedlings and indicated high differentiation between individuals. Seedling height, the most diverse phenotypic trait, has an important role in the clustering of “Early Mature” accessions. The “Early Mature” type had higher number of alleles, number of effective allele, and Shannon index compared to the “Normal Growth” group. The two types of studied walnuts had different alleles, with more than half of produced alleles specific to a specific group. “Early Mature” and “Normal Growth” walnuts had 27 and 17 private alleles, respectively. Grouping with different methods separated “Early Mature” and “Normal Growth” samples entirely. The presence of moderate to high genetic diversity in “Early Mature” walnuts and high genetic differentiation with “Normal Growth” walnuts, indicated that “Early Mature” walnuts were more diverse and distinct from “Normal Growth” samples. Moreover, our results showed SSR markers were useful for differentiating between “Early Mature” and “Normal Growth” walnuts. A number of identified loci have potential in breeding programs for identification of “Early Mature” walnuts at the germination phase.