Imprecise excision of the progenitor insertion. The mutant allele carries multiple changes in the 5'UTR relative to the progenitor.
Multiple nucleotide substitutions and indels in the region just upstream of the BigH1 ATG.
Embryos derived from a cross between heterozygous parents show a shorter nucleosome repeat length compared to wild-type control embryos.
Homozygous embryos show highly asynchronous divisions and altered nuclei distribution during the blastoderm stage and show signs of intense DNA damage. The embryos show more than 92% lethality prior to the cellular blastoderm stage. No homozygous larvae are obtained.
BigH1100 is partially rescued by Scer\GAL4nanos.PG/BigH1UAS.cPa
BigH1100 is not rescued by Scer\GAL4nanos.PG/BigH1G18579
Expression of BigH1Scer\UAS.cPa under the control of Scer\GAL4nos.PG can significantly rescue the lethality of BigH1100 homozygotes: approximately 19.4% adult viability is seen. This rescue is only seen when BigH1Scer\UAS.cPa is supplied paternally.
Expression of BigH1G18579 under the control of Scer\GAL4nos.PG (both provided maternally) does not rescue the lethality of BigH1100 homozygotes.