trachomatis transcriptome was altered in response to both hormones.

Using a 2-fold change as a cut-off, 63 genes (7%) were up-regulated in response to estradiol while 151 genes (17%) were down-regulated (Table 2). A similar percentage (but different subset) of the transcriptome was altered under progesterone exposure, with 85 genes (10%) being up-regulated and 135 genes (15%) Dorsomorphin being down-regulated. This represents around 25% of the transcriptome as a whole, being altered by either hormone alone. When the cut-off was set at 3-fold, 18-20% of the transcriptome was still changed in response to the sex hormones, but this level dropped to 12% when a 5-fold cut-off is used. The full microarray dataset is provided in the GEO database. Table 2 Summary of Chlamydia trachomatis up-regulated and down-regulated genes in response to estradiol or progesterone exposure.   Estradiol Progesterone   No. of genes/% of genome No. of genes/% of genome Up regulated     A: > 2-fold, change 63 (7%) 85 (10%) B: > 3-fold

change 52 (6%) 77 (9%) C: > 5-fold change 22 (2.5%) 49 (5.5%) Down regulated     A: > 2-fold, change 151 (17%) 135 (15%) B: > 3-fold change 138 (15.7%) 117 (13%) C: > 5-fold change 98 (11%) 81 (9%) (A) 2-fold cut-off, (B) 3-fold cut-off, (C) 5-fold cut-off. Estradiol exposure results in the specific down-regulation of lipid and nucleotide metabolism pathways In the estradiol-exposed cultures, 151 genes were down-regulated more than 2-fold, while 63 genes were up-regulated more than 2-fold during the same period. Of these 213 altered Doramapimod cost genes, more than 52% were hypothetical proteins, with no known homologues outside all the chlamydiae. Even though nearly 30% of the chlamydial genome is composed of hypothetical genes, the

fact that 52% of these genes altered their expression by more than 2-fold in response to estradiol exposure suggests that many of the key changes are uniquely associated with Chlamydia. The five top up-regulated genes (ie. showing the largest fold change) included the Nqr2 subunit of Na-translocating NADH-quinone reductase complex (nqr2) [9.26 fold], UDP-N-acetylmuramoylalanine-D-glutamate ligase, putative (murC/ddlA) [9.31 fold], V-type ATPase, subunit D, putative (atpD) [10.23 fold], arginine transport system substrate-binding protein (artJ) [10.96 fold], and putative GDC-973 glycerol-3-phosphate acyltransferase (plsX) [16.53 fold]. In addition, the five genes that showed the largest down-regulation of mRNA expression profile include cell division protein FtsI (pbp3) [35.54 fold], nucleoside-triphosphatase (yggV) [31.84 fold], ribonucleoside-diphosphate reductase alpha chain (nrdA) [30.06 fold], GTP-dependent nucleic acid-binding protein (ychF) [21.29 fold], and succinate dehydrogenase iron-sulfur subunit (sdhB) [18.82 fold]. When the up- and down-regulated genes were input into the KEGG Pathway database http://​www.​genome.​jp/​kegg/​pathway.