An investigation into small RNAs’ role in the genomic gymnastics that take place during macronuclear
Physical and Biological Sciences
Molecular Biology
All organisms use a set of instructions, typically composed of DNA, to build everything that they need to live and grow. Understanding how these instructions are created and proliferated is essential in understanding how life works; this project aims to elucidate a small part of that deeper understanding. In most organisms, including humans, genetic instructions are passed from generation to generation in a form that is immediately usable. Tiny single celled organisms called ciliates have a unique way of passing instructions down generations. Instead of passing a fully functional set, they pass a set of instructions that are interspersed with junk DNA. Tetrahymena thermophila’s non-functional set of instructions contains 30% junk and each instruction is in the correct order. Tetrahymena must delete the junk and push the resulting fragments together to form their functional instructions. Oxytricha trifallax, a closely related species, faces a more complicated problem in forming their functional instructions. Their non-functional set of instructions contains 95% junk and most instructions are scrambled. That means that instead of the non-functional set going (Coding region 1)-junk-(Coding region 2)-junk-3-junk-4, it might go 3-junk-1-junk-4-junk-2. Oxytricha must not only delete a larger portion of their DNA but they must move the remaining pieces into the correct order to form their functional instructions. This makes them a more interesting model for investigating how organisms pass instructions to future generations.
This project looks at a collection of short copies of the functional set of instructions, called 27nt RNAs, which are thought to play a role in Oxytricha’s formation of their functional instructions. My project's goal is to isolate proteins that interact with the 27nt RNAs. I isolated a small number of proteins that associate with the 27nt RNAs, one of which is a protein previously discovered to interact with 27nt RNAs. Subsequent identification of the other proteins contained in these samples may provide clues to the role the 27nt RNAs play in the genetic remodeling necessary for Oxytricha to form a functional set of instructions.
