id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-262868-wanbz1et	Varki, Ajit	Loss of N‐glycolylneuraminic acid in humans: Mechanisms, consequences, and implications for hominid evolution	2002-01-04		.txt	text/plain	10931	514	47	This review discusses one of the few known apehuman genetic differences with a clear-cut biochemical consequence, the selective inactivation of the CMP-N-acetylneuraminic acid (CMP-Neu5Ac) hydroxylase gene in the human lineage Irie et al., 1998; Chou et al., 1998) . A microbial organism approaching a mammalian cell surface would likely first encounter members of a family of sugars called sialic acids, which tend to be the outermost units on the glycan chains attached to the proteins and lipids below (Fig. 1) . However, based on current knowledge of the functions of sialic acids (see above), one can propose some possible scenarios to explain the human loss of Neu5Gc. The most likely one is selection of a randomly occurring CMAH gene mutation by a lethal microbial pathogen that required cell-surface Neu5Gc for effective infection (see below for some examples of such current-day pathogens).	./cache/cord-262868-wanbz1et.txt	./txt/cord-262868-wanbz1et.txt