sentence: The exact complement of ohnologs retained in duplicates varies across species and is likely to reflect particular physiological differences.A noteworthy example comes from central carbon metabolism : it has been suggested that the six ohnologous gene pairs encoding glycolytic enzymes , such as ENO1 / ENO2 , and PYC1 / PYC2 , conserved in S. cerevisiae and C. glabrata , play an important role in the Crabtree effect , ie fermentation even in the presence of high glucose and oxygen [ 32 ] , a trait shared by all Nakaseomyces [ 33,34 ] .