These two genes have similar pan-neural expression patterns but encode unrelated proteins. Loss of function of either of these genes alone does not lead to obvious morphological disruption of the embryonic nervous system. Under optimal conditions, animals homozygous null for each of these genes occasionally complete development and eclose. In contrast, animals null for both genes never hatch and frequently exhibit a dramatic reduction of the nervous system. In addition, axon projections are frequently disorganized.
Double mutants have missing and disorganized longitudinal and commissural axon tracts.
Specificity of CNS and PNS regulatory subelements comprising pan-neural enhancers of the deadpan and scratch genes is achieved by repression. 3549-3560 Medline abstract Roark, M., et al.