Allelic expression in intergeneric fox hybrids (Alopex lagopus � Vulpes vulpes). II. Erythrocyte glucose-6-phosphate dehydrogenase in arctic and silver foxes: Purification and properties

Abstract

The functional properties of purified glucose-6-phosphate dehydrogenase (G6PD) from the erythrocytes of Artic foxes (Alopex lagopus) and silver foxes (Vulpes vulpes) were investigated. It was found that pH optima for G6P D range from 8.15 to 8.25 in Arctic foxes and from 10.2 to 10.4 in silver foxes. For G6P, the estimated Km values were 74 X 10(-6) M (at pH 8.2) and 166 X 10(-6) M (at pH 10.2) in Artic foxes and 58 X 10(-6) M (at pH 10.2) and 40 X 10(-6) M (at pH 8.2) in silver foxes. The Km values for NADP were estimated as 62 X 10(-6) M (at pH 8.2) and 86 X 10(-6) M (at pH 10.2) in the Artic foxes and 15 X 10(-6) M (at pH 10.2) and 12 X 10(-6) M (at pH 8.2) in the silver foxes. It was found that Mg2+ ions exert a significant activating effect on G6P D in the Arctic fox and do not affect appreciably its activity in the silver fox. The experimental data indicate that slight differences in the electrophoretic mobility of G6P D are associated with considerable functional differences in this enzyme between the two fox species.

Heterochromatin as a factor affecting X-inactivation in interspecific female vole hybrids (Microtidae, Rodentia)

“…Electrophoretic conditions and preparation of the samples for assaying G6PD and GALA, as well as the staining techniques for their visualization, were all as described elsewhere (Zakijan et al 1984). Determination of the specific activity of G6PD in the erythrocytes of all the studied vole species was based on a previously described method (Serov & Zakijan, 1977). Extraembryonic tissues and embryonic organs were taken from hybrids on the 14 days after fertilization.…”