Contains a small deletion between 280 and 296bp of the chn gene that causes a frameshift mutation after amino acid residue 94.
chn1 clones that are induced within or behind the morphogenetic furrow show normal ommatidium assembly and morphogenetic furrow progression.
Large chn1 clones induced in the eye disc before morphogenetic furrow initiation result in a reduction in the number of photoreceptor cells in the disc and a reduction in eye size at the adult stage.
A few chn1/chn9 transheterozygote escapers survive until the late third instar larval stage. These larvae have abnormally small eye discs and show no morphogenetic furrow.
