A series of overlapping deficiencies of the X chromosomes of Drosophila melanogaster. All deficiencies lack the 3C7 band, and females heterozygous for the deficiency show distal notches of the wing. Hemizygous males die as embryos. The wild-type allele of Notch is essential for the proper differentiation of ectoderm. Mutations at the Notch locus result in a hypertrophy of the embryonic nervous system at the expense of hypodermal structures. N + encodes a transmembrane protein containing 2,703 amino acids. Built into the molecule are 36 EGF repeats, some of which bind calcium while others facilitate the formation of Notch protein dimers. See Chronology, 1938, Slizynska; epidermal growth factor.
Subjects: Medicine and Health — Genetics and Genomics.