A method of integrating large data sets of <i>S. cerevisiae</i> was developed here to select novel genes that possess characteristics implying their involvement in DNA processing. Form this method 54 genes were selected and mutants of these genes were screened for phenotype abnormalities associated with both meiotic and mitotic DNA processing. Eleven mutants were found to be sensitive to hydroxyurea (<i>Δsoh1, Δrtt101, Δfyv6, Δhur1Δ/pmr1, Δbre5, Δmms22, Δbrel, Δvid21, Δsgf73, Δrmd11, Δdef1, </i>and <i>Δlgel; </i>20.4%) and two (<i>Δdef1 </i>and <i>Δmms</i>22; 3.7%) were found to be sensitive to methyl methanesulfonate during vegetative growth. Six mutants were found to have low levels of nuclear division during meiosis (<i>Δbre1, Δvid21, Δsg73, Δarmd11, Δdef1, </i>and <i>Δlgel; </i>11.1%), four mutants displayed reductions in heteroallelic recombination in meiosis (<i>Δsoh1, Δbre5, Δhda2 </i>and <i>Δygl250w</i>; 7.4%) and higher levels of nondisjunction in meiosis was observed in two mutants (<i>Δsoh1, </i>and <i>Δyp1107</i>; 3.7%). Genes that were required for normal meiotic nuclear division (MND genes) were further assessed by analysing pre-meiotic DNA replication. One mutant (<i>Δvid21)</i> failed to initiate pre-meiotic DNA replication ; the other five mutants (<i>Δbre1, Δsgf73, Δrmd11, Δdef1, </i>and <i>Δlge1) </i> were observed to have a delay in entry and lengthened time to complete pre-meiotic DNA replication. From cytological analysis of the MND mutants able to undergo pre-meiotic DNA replication it was shown that a <i>Δdef1 </i>strain homologous chromosomes associate during meiosis I but chromosome synapsis is abnormal. Finally a mutation that interrupts <i>PMR1</i> was shown to over-replicate its genome during meiosis and form asci with greater then the normal four spores that are mostly inviable.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:653155 |
| Date | January 2006 |
| Creators | Jordan, Philip |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12320 |
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