Date of Award
Avery Del Grosso
Senescence, Muscle Aging, Hawk Moth, Protein-Protein Interaction, Cytoscape, cytoHubba, MCODE
Muscle aging negatively affects overall organismal function, performance, and metabolism, which are essential for the health and survival of all animals. In humans, such adverse changes increase the likelihood of injuries and illness, but the regulation of muscle senescence is not known. To examine the regulatory aspects of muscle aging, the hawk moth (Manduca sexta) was used as a model organism because it has flight muscles comparable to vertebrate skeletal muscles. The focus of this study will be on the progressive changes in protein-protein interactions (PPI) that occur in muscle of middle age to advanced age male moths. A previous study used time series RNA-Seq data to analyze the progressive changes in genes throughout the lifespan. Here, I use the Cytoscape program to construct PPI networks, and further use the plug-ins MCODE and cytoHubba to determine progressive changes in candidate hub genes from the significant genes detected in the RNA-Seq data set. MCODE clusters the data to determine the most highly interconnected regions, as these regions are likely to represent similar pathways, whereas cytoHubba utilizes eleven analysis methods to analyze the data and assign scores to each node based off the connections the node makes. Using these methods, candidate hub genes of muscle aging can be identified in Manduca sexta. The resultant PPI networks indicated that male moths breakdown stored fatty acids from their larval state for energy, but transition to breaking down protein complexes as they advance in age. These results corroborate previous findings because male moths do not eat compared to female moths. Examining progressive changes in female moths should advance the regulatory understanding of the muscle aging process in higher animals.
Christiansen, Kylie N., "Analysis of Protein-Protein Interaction Networks in Aging Flight Muscle of the Male Hawk Moth, Manduca sexta" (2022). Honors Thesis. 270.