Flies of the 'abnormal abdomen' strain have a higher level of Dmer\bb units with Dmer\R1-element and Dmer\R2-element insertions than wild-type flies. Uninserted Dmer\bb units do not undergo general underreplication in contrast to wild-type, although differential underreplication of the inserted Dmer\bb units does occur in the 'abnormal abdomen' strain.
Elements R1 and R2 are subject to the same recombinational forces that give rise to the concerted evolution of the rDNA units. Molecular phylogenetic analysis of elements from 16 Drosophila species suggests these elements have been stable components of the rDNA locus for the 50-70 million year history of the Drosophila genus.
Flies of the 'abnormal abdomen' strain have a higher level of Dmer\bb units with Dmer\R1-element and Dmer\R2-element insertions than wild-type flies. Uninserted Dmer\bb units do not undergo general underreplication in contrast to wild-type, although differential underreplication of the inserted Dmer\bb units does occur in the 'abnormal abdomen' strain.
Elements R1 and R2 are subject to the same recombinational forces that give rise to the concerted evolution of the rDNA units. Molecular phylogenetic analysis of elements from 16 Drosophila species suggests these elements have been stable components of the rDNA locus for the 50-70 million year history of the Drosophila genus.