RT Journal Article SR Electronic(1) A1 Toffaletti, Dena L. A1 Del Poeta, Maurizio A1 Rude, Thomas H. A1 Dietrich, Fred A1 Perfect, John R.YR 2003 T1 Regulation of cytochrome c oxidase subunit 1 (COX1) expression in Cryptococcus neoformans by temperature and host environment JF Microbiology, VO 149 IS 4 SP 1041 OP 1049 DO https://doi.org/10.1099/mic.0.26021-0 PB Microbiology Society, SN 1465-2080, AB In the study of differential gene expression of Cryptococcus neoformans, a transcript of COX1 (cytochrome oxidase c subunit 1) was identified in a serotype A strain. The transcript was upregulated at 37 °C compared to 30 °C and expressed by yeasts infecting the central nervous system. Northern analysis of COX1 from the serotype A strain revealed two polycistronic transcripts, a temperature-upregulated 2·3 kb transcript and a 1·9 kb transcript that was not affected by temperature. In contrast, COX1 in a serotype D strain showed only a 1·9 kb polycistronic transcript plus a 1·6 kb monocistronic message, and temperature had no effect on the transcripts. The sequence of COX1 revealed similar coding regions between the two strains, but the serotype D strain had five introns whereas no introns were found in the serotype A strain. The serotype D strain had reduced growth rates compared to the serotype A strain at 37 °C, but in an AD hybrid strain the serotype D COX1 gene could support efficient high temperature growth. These studies have revealed mitochondrial molecular differences between serotype A and D strains which show evolutionary divergence. It will be important to determine whether differences in mitochondrial structure and function can influence cryptococcosis., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.26021-0