A premature stop codon has been introduced into the SuUR sequences (at codon 600), resulting in the expression of a truncated protein from the construct.
Expression of SuUR1-599.Scer\UAS under the control of Scer\GAL4AB1 results in the disappearance of weak points in the polytene chromosomes of salivary glands.
Expression of SuUR1-599.Scer\UAS under the control of Scer\GAL4Sgs3.PD in a SuURES background results in large swellings in the chromocenter and intercalary heterochromatin regions of polytene chromosomes in the salivary glands. The chromosomes spread poorly in squashes, because of numerous ectopic contacts.