Characterization and Genetic Analysis of The Morphological Mutant <em>Crisp-5</em> of <em>Neurospora crassa</em>

<p>The <em>crisp-5</em> (<em>cr-5</em>) mutant (allele 123 CJ13-6A) of <em>Neurospora crassa</em> was isolated in the Georgia Southern Neurospora Laboratory and was found to be linked to <em>ad-4 </em>in LG III. The present study mapped <em>cr-5</em> to the right of <em>ad-4</em> with the gene order <em>pro-1 ad-4 cr-5</em> with 1.3% to 5% recombination between <em>ad-4</em> and <em>cr-5</em>. Reciprocal crosses of <em>cr-5 pro-la</em> double mutant and the <em>leu-1A</em> marker strain supported the gene order <em>pro-1 cr-5 leu-1</em>, successfully bracketing the <em>cr-5</em> locus. There was 12% to 18% recombination between <em>pro-1</em> and <em>cr-5</em> and 9% to 19% recombination between <em>cr-5</em> and <em>leu-1</em>.</p> <p>Both <em>cr-5</em> and wild type 74A were grown on minimal medium in which the carbon source was 2% sucrose, 2% glucose, 2% fructose, 2% lactose, 2% mannitol. 2% glycerol, 2% sorbitol or 2% sorbose. The <em>cr-5</em> mutant grew better on glucose and fructose separately than it did on sucrose. Both the mutant and wild type grew very poorly on lactose, mannitol, sorbitol and glycerol. The pattern of growth of <em>cr-5</em> was different on media with lactose, mannitol, glycerol, and sorbitol. Although <em>cr-5</em> grew poorly on media with some carbon sources, it was found to be a fertile female on all carbon sources tested. Neither strain tested grew on sorbose as the sole carbon source.</p> <p>Observations utilizing SEM indicated that, compared to wild type 74, <em>cr-5</em> has a reduced mycelium containing clusters of conidia formed by highly branched conidiophores carried on short aerial hyphae. The mutant <em>cr-5</em> conidiates early and profusely.</p> <p>The time and percent germination of wild type 74A and <em>cr-5</em> conidia were determined. Conidia of <em>cr-5</em> consistently germinated earlier than those of wild type but the percent of conidia germinating one hour after the first observation of germination was higher for wild type.</p> <p>Conidia of <em>cr-5</em> were tested for thermotolerance at 60^oC heat shock temperature. The mutant <em>cr-5</em> exhibited thermotolerance. Therefore, when performing crosses with new mutants, it would be advisable to test the heat shock effect to avoid skewed results when scoring progeny of the crosses.</p>

Name thesis:degree_name

Master of Science in Biology

Level thesis:degree_level

Thesis (restricted to Georgia Southern)

Discipline thesis:degree_discipline

Department of Biology

Year dc:date.available

2002

Author dc:creator

• Cathcart, Heather Marie

Contributors dc:contributor

• Wayne A. Krissinger
• Oscar J. Pung

• ETD
• Neurospora crassa
• Morphology
• Genetic analysis
• Biochemistry, Biophysics, and Structural Biology
• Biology

Repository record dc:identifier

https://digitalcommons.georgiasouthern.edu/etd_legacy/68

OAI identifier oai:identifier

oai:digitalcommons.georgiasouthern.edu:etd_legacy-1079