This strain is homozygous for the w allele of white. It is distinguished by a deletion of several kb including the 5' end of the gene. It has a wild-type restriction pattern and does not differ from wild type by PCR analysis. Since this recessive mutation is lethal and the location unknown, it is maintained in a polymorphic state by inbreeding families exhibiting the character. Although present in several black stocks, the frequency is highest in the strain named simply 'eyeless'.
Death often occurs in the fourth instar, however a few individuals survive to adulthood.
This strain is maintained by family selection. This homozygous-lethal pericentric inversion is maintained in repulsion to a c DlS chromosome. A good recombination suppressor for the second chromosome. A second chromosome balancer consisting of the above inversion in repulsion to a multiple marker chromosome that carries an uncharacterized recessive lethal. Mos Dark is an X chomosome marker with variable penetrance and expressivity.