Patcharee KammarnjassadakulWatcharin RangsipanuratnMethee SriprapunPopchai NgamsakulrungrujTanapat PalagaKallaya SritunyalucksanaAriya ChindampornSiriraj HospitalChulalongkorn UniversityMahidol UniversityHuachiew Chalermprakiat University2022-08-042022-08-042021-01-01Walailak Journal of Science and Technology. Vol.18, No.8 (2021)2228835X168639332-s2.0-85105214306https://repository.li.mahidol.ac.th/handle/20.500.14594/79399This study aimed to investigate the real-time fluctuation of temperature-sensitive gene expression in a Pythium insidiosum growing at human body temperature (37 ºC) when it can cause life-threatening disease, whereas its natural habitat is in agricultural water sources with lower temperature. Genes encoding cytochrome oxidase 2 (COX2), β-tubulin (TUB), and chitin synthase subunit 2 (CHS2) were tested for their expression at the infection temperature (37 ºC) and natural habitat temperature (27 ºC) using real-time RT-PCR. Sixteen strains of P. insidiosum, representing 3 phylogeographic preferences, were analyzed. The subculturing process at 27 ºC was repeated at least 2-3 cycles. The results showed that at 37 ºC, the COX2 was expressed 2.5-fold higher than that of 27 ºC (p = 0.0347) while the level of TUB and CHS2 mRNA disclosed indistinguishable profiles. These results suggested that these genes were suitable to be used as housekeeping genes for temperature-susceptible gene expression studies. This work was likely to be the 1st study examining the gene expression levels of the Thai strain of P. insidiosum under thermal stress conditions. Follow-up studies for the COX2 genes may useful to provide valuable insight into the pathogenesis, diagnostic, or therapeutic targets for further investigation.Mahidol UniversityMultidisciplinaryArticleSCOPUS10.48048/wjst.2021.9433