Biomedical subjects

Yingyao Zhou

Publications and source records attributed to Yingyao Zhou.

4 recordsLinked to original sources

PubMed2003

Genetic diversity in yeast assessed with whole-genome oligonucleotide arrays.

The availability of a complete genome sequence allows the detailed study of intraspecies variability. Here we use high-density oligonucleotide arrays to discover 11,115 single-feature polymorphisms (SFPs) existing in one or more of 14 different yeast strains. We use these SFPs to define regions of genetic identity between common laboratory strains of yeast. We assess the genome-wide distribution of genetic variation on the basis of this yeast population. We find that genome variability is biased toward the ends of chromosomes and is more likely to be found in genes with roles in fermentation or in transport. This subtelomeric bias may arise through recombination between nonhomologous sequences because full-gene deletions are more common in these regions than in more central regions of the chromosome.

Chromosome Mapping↗

PubMed2002

Excess polymorphisms in genes for membrane proteins in Plasmodium falciparum.

The detection of single-nucleotide polymorphisms in pathogenic microorganisms has normally been carried out by trial and error. Here we show that DNA hybridization with high-density oligonucleotide arrays provides rapid and convenient detection of single-nucleotide polymorphisms in Plasmodium falciparum, despite its exceptionally high adenine-thymine (AT) content (82%). A disproportionate number of polymorphisms are found in genes encoding proteins associated with the cell membrane. These genes are targets for only 22% of the oligonucleotide probes but account for 69% of the polymorphisms. Genetic variation is also enriched in subtelomeric regions, which account for 22% of the chromosome but 76% of the polymorphisms.

Animals↗

PubMed2002

Match-only integral distribution (MOID) algorithm for high-density oligonucleotide array analysis.

BACKGROUND: High-density oligonucleotide arrays have become a valuable tool for high-throughput gene expression profiling. Increasing the array information density and improving the analysis algorithms are two important computational research topics. RESULTS: A new algorithm, Match-Only Integral Distribution (MOID), was developed to analyze high-density oligonucleotide arrays. Using known data from both spiking experiments and no-change experiments performed with Affymetrix GeneChip arrays, MOID and the Affymetrix algorithm implemented in Microarray Suite 4.0 (MAS4) were compared. While MOID gave similar performance to MAS4 in the spiking experiments, better performance was observed in the no-change experiments.MOID also provides a set of alternative statistical analysis tools to MAS4. There are two main features that distinguish MOID from MAS4. First, MOID uses continuous P values for the likelihood of gene presence, while MAS4 resorts to discrete absolute calls. Secondly, MOID uses heuristic confidence intervals for both gene expression levels and fold change values, while MAS4 categorizes the significance of gene expression level changes into discrete fold change calls. CONCLUSIONS: The results show that by using MOID, Affymetrix GeneChip arrays may need as little as ten probes per gene without compromising analysis accuracy.

Algorithms↗

PubMed2002

Monitoring the chromosome 2 intraerythrocytic transcriptome of Plasmodium falciparum using oligonucleotide arrays.

To test the feasibility of using short oligonucleotide probes to monitor transcript levels in Plasmodium falciparum, a microarray was manufactured containing 4,167 (25 base single-stranded) probes derived from the predicted coding region of P. falciparum chromosome 2. RNA samples from three asexual stages (rings, trophozoites, and schizonts) were labeled and hybridized to the arrays. These results were reproducible, and transcripts were detected for 69% of the 210 genes on chromosome 2. In addition, of the 145 expressed genes, 1/3 appeared to be differentially transcribed during the asexual cycle. Some regions of the chromosome appeared to be transcriptionally silent. Results were confirmed by Northern blot analysis and by quantitative reverse transcriptase-polymerase chain reaction. These data validate the use of relatively short 25-mers for monitoring the expression of a genome that is 82% AT rich.

Animals↗