Dosage compensation of the sex-linked enzyme phosphoglucomutase in the orthoptera

Abstract

Sex-linkage of phosphoglucomutase (PGM) is widespread in the Orthoptera. For each of three species studied (representing the two suborders), the specific activity of PGM in males (the heterogametic sex) is almost identical to that in females, providing direct evidence that the difference in gene dose of a sex-linked locus in males and females is compensated in the Orthoptera. The Orthoptera is only the third group for which compensation has been demonstrated. Dosage compensation has been investigated in three orders of insects: it is present in Orthoptera and Diptera but absent in Lepidoptera. It is postulated that dosage compensation arose or was present in related archopteran ancestors and has been secondarily lost in Lepidoptera, possibly in association with female heterogamety in this group. © 1984 The Genetical Society of Great Britain.