I'm reading this article and I'm having difficulty understanding some of the terminology. It says the following:
"We show that endometrial PRL expression is a derived feature of placental mammals and that the episode of positive selection in HoxA-11 occurred coincident with the origin of its ability to interact functionally with another transcription factor protein (FOXO1A) and thereby up-regulate PRL from the promoter used in endometrial cells."
I kind of understand what they're trying to say here but I don't understand how all of what they said = "nd thereby up-regulate PRL from the promoter used in endometrial cells" How does the coincident of the two = that. I don't understand.