Project description:L. helveticus is used to modulate cheese flavor and as a starter organism in certain cheese varieties. Our group has compiled a draft (4x) sequence for the 2.4 Mb genome of an industrial strain L. helveticus CNRZ32. The primary aim was to investigate expression of 168 completely sequenced genes during growth in milk and MRS medium using microarrays. Oligonucleotide probes against each of the completely sequenced genes were compiled on maskless photolithography-based DNA microarrays. Additionally, the entire draft genome sequence was used to produce tiled microarrays where the non-interrupted sequence contigs were covered by consecutive 24-mer probes. Keywords: growth conditions response
Project description:The long-tailed macaque, also referred to as cynomolgus monkey (Macaca fascicularis), is one of the most important non-human primate animal models in basic and applied biomedical research. To improve the predictive power of primate experiments for humans, we determined the genome sequence of a Macaca fascicularis female of Mauritian origin using a whole-genome shotgun sequencing approach. We applied a template switch strategy which employs either the rhesus or the human genome to assemble sequence reads. The 6-fold sequence coverage of the draft genome sequence enabled discovery of about 2.1 million potential single-nucleotide polymorphisms based on occurrence of a dimorphic nucleotide at a given position in the genome sequence. Homology-based annotation allowed us to identify 17,387 orthologs of human protein-coding genes in the M. fascicularis draft genome and the predicted transcripts enabled the design of a M. fascicularis-specific gene expression microarray. Using liver samples from 36 individuals of different geographic origin, we identified 718 genes with highly variable expression in liver, whereas the majority of the transcriptome shows relatively stable and comparable expression. Knowledge of the M. fascicularis draft genome is an important contribution to both the use of this animal in disease models and the safety assessment of drugs and their metabolites. In particular, this information allows high-resolution genotyping and microarray-based gene expression profiling for animal stratification, thereby allowing the use of well-characterized animals for safety testing. Finally, the genome sequence presented here is a significant contribution to the global "3R" animal welfare initiative, which has the goal to reduce, refine and replace animal experiments.
Project description:Some phages and microbes employ Diversity-Generating Retroelements (DGRs) to achieve rapid targeted adaptation. DGRs mutagenize a specific gene without harming the rest of the genome. Mutagenesis relies on the DGR reverse transcriptase (dRT), which is highly error-prone when transcribing adenines of an RNA template. The resulting mutagenized cDNA then alters the target gene through a poorly understood mechanism. Transplanting DGRs into a tractable organism, like Escherichia coli, holds promise for creating a powerful system for gene-targeted editing. Here, we successfully reconstituted the archetypal BPP DGR in E. coli, demonstrating that DGRs are "plug-and-play" systems adaptable to non-native hosts. Systematic analysis of reconstituted DGR established principles for target mutagenesis. Our results revealed that cytosine misincorporation is the most common error when dRT transcribes adenines. However, error rates peak in 5'-AAC-3' and 5'-ACC-3' contexts, driven by elevated adenine and guanosine misincorporations, respectively. Using high-throughput genetics, we discovered that cells lacking the single-stranded DNA exonuclease ExoI exhibit 15-fold higher DGR activity. Our evidence indicates that ExoI inhibits DGRs by binding a limited cellular factor, rather than through direct cDNA degradation. Finally, by profiling DGR targets across thousands of chromosomal loci, we discovered that DGRs preferentially edit targets near the replication origin and oriented in the same direction as replication. We showed that the directionality of replication underlies this bias, possibly through unwinding the target to facilitate base-pairing with incoming cDNA. These findings establish a reconstituted DGR system in E. coli and provide a foundation for optimizing targeted gene-editing applications in the future.
Project description:Since CNVs play a vital role in genomic studies, it is an imperative need to develop a comprehensive, more accurate and higher resolution porcine CNV map with practical significance in follow-up CNV functional analyses To detect CNV of pigs, we performed high density aCGH data of diverse pig breeds in the framework of the pig draft genome sequence (Sscrofa10.2)
Project description:Since CNVs play a vital role in genomic studies, it is an imperative need to develop a comprehensive, more accurate and higher resolution porcine CNV map with practical significance in follow-up CNV functional analyses To detect CNV of pigs, we performed high density aCGH data of diverse pig breeds in the framework of the pig draft genome sequence (Sscrofa10.2)
Project description:Acetic acid bacteria are obligately aerobic alphaproteobacteria that have a unique ability to incompletely oxidize various alcohols and sugars to organic acids. The ability of these bacteria to incompletely oxidize ethanol to acetate has been historically utilized for vinegar production. The mechanism of switching between incomplete oxidation and assimilatory oxidation and the control of energy and carbon metabolism in acetic acid bacteria are not fully understood. To understand the physiology and molecular biology of acetic acid bacteria better, we determined the draft genome sequence of Acetobacter aceti NBRC 14818, which is the type strain of the genus. Based on this draft genome sequence, the transcriptome profiles in A. aceti cells grown on ethanol, acetate, glucose, or mix of ethanol and glucose was determined by using NimbleGen Prokaryotic Expression array (4x72K).