Euo is a developmental regulator that represses late genes and activates midcycle genes in .

In this study, we developed a correlative approach that combined DNA immunoprecipitation-seq and RNA-seq analyses to define the regulon of the transcription factor Euo. We confirmed the proposed role of Euo as a transcriptional repressor of late chlamydial genes but also showed that Euo activates transcription of a subset of midcycle genes and autoregulates its own expression via negative feedback. This study validates and expands the role of Euo as an important developmental regulator in . In addition, this genome-wide correlative approach can be applied to study transcription factors in other pathogenic bacteria.