An Ubiquitous Interspersed DNA Sequence Family in an Insect

Abstract

The genome of the African migratory locust, Locusta migratoria (Class Insecta, Order Orthoptera, Family Acrididae) contains an interspersed DNA sequence family, designated the Lm1 family. This family consists of short (∼195-bp), widely dispersed, highly reiterated (∼6 × 105 copies/haploid genome) repeat units, which account for about 2% of the locust genome. Lm1 repeats contain regions that closely resemble internal promoter sequences for RNA polymerase III, and they are structurally very similar to RNA polymerase III templates. Family members are flanked by short direct repeats, and are closely linked to structural genes. These features are reminiscent of the Alu family of man and other repeat sequence families, until now documented only in higher vertebrates.