id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-007819-51h2jrsy	Schommer, Susan K.	Use of a PRRSV Infectious Clone to Evaluate in Vitro Quasispecies Evolution	2006		.txt	text/plain	1393	82	52	Use of the infectious clone also allows us to begin with a single DNA sequence, providing a well-defined starting point for studying PRRSV evolution. 8 The ORF3 protein has the greatest percentage of amino acid changes between the modified live vaccine (Ingelvac) and its parent strain, VR-2332, the isolate from which the infectious clone used in this study was derived. These sequences were then compared to a low passage VR-2332 cell culture propagated stock to determine if the use of an infectious clone was able to decrease the quasispecies variation as compared to a viral stock. The master sequence for each sample derived from the infectious clone was the same as the original plasmid for all genetic regions investigated. Generation of an infectious clone of VR-2332, a highly virulent North American-type isolate of porcine reproductive and respiratory syndrome virus	./cache/cord-007819-51h2jrsy.txt	./txt/cord-007819-51h2jrsy.txt