id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-310748-ao29zx1u	Banner, Lisa R.	Random nature of coronavirus RNA recombination in the absence of selection pressure	1991-11-30		.txt	text/plain	2839	155	52	Our results showed that within a 1-kb region of the peplomer gene, RNA recombination occurred at almost every potential crossover site. To study RNA recombination in the absence of selection pressure, we developed a polymer-ase chain reaction (PCR) assay using two primers specific for the potential recombinant viruses which have a crossover site between the two primers. Only recombinant RNAs which had a crossover between the two primers and contained A59-specific sequences on the 5'-side and JHM-DL-specific sequences on the 3'-side could be detected by this PCR approach. DNA sequence analysis of 35 cloned PCR products showed that the crossover sites were almost randomly distributed throughout the nearly 1-kb region of the peplomer gene studied ( Fig. 2A) . Analysis of 53 recombinant clones revealed that, similar to the intracellular recombinants, the crossover sites in the viral recombinant RNAs were almost randomly distributed over the 1 -kb region of the peplomer gene (Fig. 2B) .	./cache/cord-310748-ao29zx1u.txt	./txt/cord-310748-ao29zx1u.txt