Project description:Oryza longistaminata is an African wild rice species that possesses special traits for breeding applications. Self-incompatibility is the main cause of sterility in O. longistaminata, but here we demonstrated that its pollen fertility and vitality are normal. Lipid and carbohydrate metabolism were active throughout pollen development. In this study, transcriptomics quantitative analysis was used to investigate the profiles of genes related to lipid and carbohydrate metabolism in 4-, 6- and 8.5-mm O. longistaminata spikelets before flowering. We documented cytological changes throughout important stages of anther development, including changes in reproductive cells as they formed mature pollen grains through meiosis and mitosis. RNA-seq and proteome association analysis indicated that fatty acids were converted to sucrose after the 6-mm spikelet stage, based on the abundance of most key enzymes of the glyoxylate cycle and gluconeogenesis. In conclusion, our study provides novel insights into the pollen viability of O. longistaminata at the transcriptome level, which can be used to improve the efficiency of male parent pollination in hybrid rice breeding applications.
Project description:Eucalyptus urophylla is a commercially important wood crop plantation species due to its rapid growth, biomass yield, and use as bioenergy feedstock. We characterized the genetic diversity and population structure of 332 E. urophylla individuals from 19 geographically defined E. urophylla populations with a reliability of 14,468 single nucleotide polymorphisms (SNPs). We compared the patterns of genetic variation among these 19 populations. High levels of genetic diversity were observed throughout the 19 E. urophylla populations based on genome-wide SNP data (HE=0.2677 to 0.3487). Analysis with STRUCTURE software, Principal component analysis (PCA) and a neighbor-joining (NJ) tree indicated that E. urophylla populations could be divided into three groups, and moderate and weak population structure was observed with pairwise genetic differentiation (FST) values ranging from −0.09 to 0.074. The low genetic diversity and shallow genetic differentiation found within the 19 populations may be a consequence of their pollination system and seed dispersal mechanism. In addition, 55 core germplasms of E. urophylla were constructed according to the genetic marker data. The genome-wide SNPs we identified will provide a valuable resource for further genetic improvement and effective use of the germplasm resources.
Project description:The conservation and development of chicken has considerably affected human activities, but the admixture history of chicken breeds has so far been poorly demonstrated especially for Chinese indigenous breeds. Using genotypes from 580961 single nucleotide polymorphism markers scored in 1201 animals, we evaluate the genetic diversity (heterozygosity and proportion of polymorphic markers), Linkage disequilibrium (LD) decay, population structure (principal component analysis and neighbor-joining tree), genetic differentiation (FST and genetic distance) and migration events (Treemix and f-statistics) of eight domesticated chicken breeds. All population analytical methods reveal patterns of hybridization which occurred after divergence in Tibetan chicken. We argue that chicken migration and admixture followed by trade have been important forces in shaping modern Chinese chicken genomic variation. Moreover, isolation by distance may play critical role in the shaping genomic variation within Eurasia continent chicken breeds.
Project description:In this work, we evaluated the genetic stabilization process, of the intra- (Saccharomyces cerevisiae) and interspecific (S. cerevisiae x Saccharomyces kudriavzevii) hybrids obtained by different non-GMO techniques, under fermentative conditions. Large-scale transitions in genome size, detected by measuring total DNA content, and genome reorganizations in both nuclear and mitochondrial DNA, evidenced by changes in molecular markers, were observed during the experiments. Interspecific hybrids seem to need fewer generations to reach genetic stability than intraspecific hybrids. The largest number of molecular patterns among the derived stable colonies was observed for intraspecific hybrids, particularly for those obtained by rare-mating in which the total amount of initial DNA was larger. Finally, a representative intraspecific stable hybrid underwent a normal industrial process to obtain active dry yeast production as an important point at which inducing changes in genome composition was possible. No changes in hybrid genetic composition after this procedure were confirmed by comparative genome hybridization. According to our results, fermentation steps 2 and 5 –comprising between 30 and 50 generations- suffice to obtain genetically stable interspecific and intraspecific hybrids, respectively. This work aimed to develop and validate a fast genetic stabilization method for newly generated Saccharomyces hybrids under selective enological conditions. A comparison of the whole stabilization process in intra- and interspecific hybrids showing different ploidy levels, as a result of using different hybridization methodologies, was also made.
2015-03-30 | GSE46192 | GEO
Project description:Genetic diversity and population structure of H. compressa