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.
In order to understand how the authors of the article concluded that the HoxA-11 gene's positive selection coincided with its ability to up-regulate PRL expression from the endometrial cells' promoter, we need to break down that sentence into smaller parts.
First, let's clarify some concepts. "PRL" refers to prolactin, a hormone involved in various reproductive processes, including pregnancy and lactation. "Endometrial cells" are the cells that line the inner surface of the uterus.
Now, let's break down the sentence:
1. "We show that endometrial PRL expression is a derived feature of placental mammals": This means that the production of PRL in endometrial cells is a characteristic specific to placental mammals (a group of mammals that includes humans).
2. "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)": Here, the authors are stating that the HoxA-11 gene went through a period of positive selection (a process that leads to the increase in frequency of beneficial genetic variants) at the same time or during the origin of its ability to interact with another protein called FOXO1A. This interaction is crucial for the subsequent event.
3. "And thereby up-regulate PRL from the promoter used in endometrial cells": In this part of the sentence, the authors are saying that as a result of the coincident positive selection and the interaction with FOXO1A, the HoxA-11 gene gained the ability to up-regulate (increase the expression of) PRL from the promoter (a region of DNA) specific to endometrial cells.
Overall, the sentence suggests that the positive selection in the HoxA-11 gene and its ability to interact with FOXO1A occurred at the same time as the origin of its function to up-regulate PRL expression from the specific promoter used in endometrial cells. The authors are proposing that these events are connected and led to the derived feature of endometrial PRL expression observed in placental mammals.