Project description:Oleaginous yeasts are valuable systems for biosustainable production of hydrocarbon-based chemicals. Yarrowia lipolytica is one of the best characterized of these yeast with respect to genome annotation and flux analysis of metabolic processes. Nonetheless, progress is hampered by a dearth of genomewide tools enabling functional genomics. The Hermes DNA transposon was expressed to achieve saturation mutagenesis of the Y. lipolytica genome. Over 535 thousand independent insertions were identified by next-generation sequencing. Poisson analysis of insertion density classified ~22% of genes as essential. As expected, most essential genes not only have homologues in Saccharomyces cerevisiae and Schizosaccharomyces pombe, but the majority of those are also essential. As an obligate aerobe, Y. lipolytica has significantly more respiration - related genes that are classified as essential than do S. cerevisiae and S. pombe. The findings provide insights into biosynthetic pathways, compartmentalization of enzymes, and distinct functions of paralogs. Contributions of nonessential genes to fitness were determined in log growth cultures with glucose and glycerol carbon sources. Fluorescence-activated cell sorting identified mutants in which lipid accumulation is increased. Biological contributions of genes to growth were used to evaluate two recent genome-scale models Y. lipolytica metabolism. This study is the first functional genomic analysis of an oleaginous yeast and provides an important resource for modeling and bioengineering of Y. lipolytica.
Project description:We compared genetic profiles of planktonic stage to biofilm stage of deep sea bacterium Pseudoalteromonas sp. SM9913 and revealed genetic features during switch from planktonic to pellicle stage in Pseudoalteromonas sp. SM9913.
Project description:One of the most distinct features of Pseudoalteromonas sp. SCSIO 11900 is its ability to form a very robust pellicle than most Pseudoalteromonas strains. Thus we want to identify the genes essential for the pellicle formation of SCSIO 11900. We compared transcriptom profiles of planktonic cells, initial pellicle and mature pellicle of coral Pseudoalteromonas sp. SCSIO 11900 and revealed that some unique genes from horizontal gene transfer is involved in the pellicle formation of SCSIO 11900.
Project description:Investigation of whole genome gene expression level changes in a Yarrowia lipolytica Y4184 snf1 mutant, compared to the Y4184U+. The Y4184 is an engineered strain to produce eicosapentaenoic acid (EPA) via expression of a Δ9 elongase/Δ8 desaturase pathway, and is derived from Yarrowia lipolytica ATCC#20362.
Project description:We compared genetic profiles of planktonic stage to biofilm stage of deep sea bacterium Pseudoalteromonas sp. SM9913 and revealed genetic features during switch from planktonic to pellicle stage in Pseudoalteromonas sp. SM9913. mRNA profiles of Pseudoalteromonas sp. SM9913 planktonic cells, initial pellicle cells and mature pellicle cells were generated by Illumina Hiseq2000.
Project description:Investigation of whole genome gene expression level changes in a Yarrowia lipolytica Y4184 snf1 mutant, compared to the Y4184U+. The Y4184 is an engineered strain to produce eicosapentaenoic acid (EPA) via expression of a M-NM-^T9 elongase/M-NM-^T8 desaturase pathway, and is derived from Yarrowia lipolytica ATCC#20362. A six chip study using total RNA recovered from three separate cultures of Yarrowia lipolytica Y4184Ura+ strains and three separate cultures of Y4184 snf1 mutant strains in which YlSNF1 gene is deleted entirely. Each chip measures the expression level of 6708 genes from Yarrowia lipolytica ATCC#20362 with fourteen 24-mer probe pairs (PM/MM) per gene, with three-fold technical redundancy.
