{"cells": [{"cell_type": "markdown", "metadata": {}, "source": ["# Homework 2.2: Autoregulation in a C1-FFL (55 pts)\n", "\n", "*This problem is based off of problem 4.3 from the first edition of Alon's book.*\n", "\n", "
"]}, {"cell_type": "markdown", "metadata": {}, "source": ["The type 1 coherent feedforward loop (C1-FFL) is a motif that is found in large numbers in naturally occurring networks. In the figure below, we show two C1-FFL networks in which the regulator Y is autoregulated. In the C1-FFL with AND logic, Y shows autorepression, and in the C1-FFL with OR logic, it shows autoactivation. These \"decorations\" on C1-FFLs often occur in nature.\n", "\n", "\n", " \n", "\n", "\n", "
\n", "\n", "
\n", "\n", "**a)** As we learned in lecture, the C1-FFL with AND logic shows sign-sensitive delay. Specifically, if X is suddenly turned on, the response of Z is delayed, but if X is suddenly turned off, the response of Z is instantaneous. Analyze the left circuit in the above figure, and compare its dynamics to the canonical C1-FFL circuit with AND logic. Specifically address how the delay time changes. Assume that the regulation of Y follows AND logic.\n", "\n", "**b)** The C1-FFL with OR logic also shows sign-sensitive delay. With OR logic, though, there is no delay when X is suddenly turned on, but rather delay when X is suddenly turned off. Analyze the right circuit in the above figure and compare its dynamics to the canonical C1-FFL circuit with OR logic. Again, address how the delay time changes, this time assuming that the regulation of Y follows OR logic."]}, {"cell_type": "markdown", "metadata": {}, "source": ["
"]}], "metadata": {"anaconda-cloud": {}, "kernelspec": {"display_name": "Python 3", "language": "python", "name": "python3"}, "language_info": {"codemirror_mode": {"name": "ipython", "version": 3}, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.7.7"}}, "nbformat": 4, "nbformat_minor": 4}