There were no GO terms that survived FDR correction between mycelia and day 2 spherules but a large number of significant terms were identified between
mycelia and day 8 spherules (Additional file 6: Figure S3). The most significant enriched GO term was “small molecule metabolic process” (corrected p = 0.004). Thirty-one members of this heterogeneous set of genes were upregulated and 75 were downregulated. Twelve of the downregulated genes coded for nucleotide synthesis or DNA replication. For example, a homeobox domain-containing protein was downregulated −8.68 fold (CIMG_09071); thymidylate synthase was down −3.57 fold (CIMG_08646); cell division control protein Cdc6 was down −3.05 fold (CIMG_07523) and DNA topoisomerase 2 was down −3.09 fold (CIMG_02836). This suggests Selleck AZD1480 that the rate of DNA synthesis is slower in the day 8 spherules than in mycelia.
10 genes coding for amino acid buy S63845 synthesis were downregulated as well. This suggests that not only is DNA synthesis relatively slow compared to mycelia but protein synthesis is too. Other genes involved in vitamin synthesis and energy generation were also downregulated. This is consistent with the notion that day 8 spherules have produced their endospores. Rupturing and releasing endospores should not be a metabolically expensive process. The observation that MFS-1 sugar transporters are upregulated
suggests that that the low metabolic needs may not be universal. The most strongly upregulated genes in day 8 spherules with the GO term “small metabolic process” included glutamate decarboxylase (21.47), three ABC transporters and parasitic phase specific protein-1 (6.66) previously described by Delgado . The PSP-1 gene is also upregulated in day 2 spherules and in day 4 spherules as reported by Whiston et al. . PSP-1 contains a RTA-1 domain, which is involved in resistance to 7-aminocholesterol . This family of proteins has multiple membrane spanning domains and is thought to be involved in binding Montelukast Sodium 7-aminocholesterol and related substances and preventing toxicity. They are not thought to be I-BET151 mw efflux pumps . A group of genes assigned the GO term “carbohydrate metabolic processes” was also enriched in the day 8 spherules dataset. 15 genes were upregulated and 17 genes were downregulated. The upregulated genes included polysaccharide deacetylase (CIMG_02628, 34.82) and 1,4 (α)-amylase (CIMG_03529, 2.70). The most striking downregulated gene in this group is calmodulin (CIMG_04786, -10.38). Two other genes coding for calmodulin (CIMG_02413 and CIMG_08162) are not differentially expressed in day 8 spherules. We looked for differential expression of six calmodulin-dependent kinases and found that they were not up- or downregulated.