Wild-type His3 gene in the context of a histone gene repeat tandem array.
Df(2L)HisC, His3HisTA.wt has viable phenotype
Df(2L)HisC, His3HisTA.wt has fertile phenotype
Df(2L)HisC, His3.3A2X1, His3.3BK9R, His3HisTA.wt/His3[+] has partially lethal - majority die phenotype
His3HisTA.wt rescues Df(2L)HisC
His3HisTA.wt rescues Df(2L)HisC homozygotes to adulthood, and individuals are viable and without morphological defects.
Expression of a transgene containing 12 copies of the histone gene repeat unit (PBac{12xHisTA.wt} - comprised of His1HisTA.wt, His2AHisTA.wt, His2BHisTA.wt, His3HisTA.wt and His4HisTA.wt) is able to fully rescue the embryonic cell cycle arrest and lethality seen in a deletion lacking the histone gene complex (Df(2L)HisC). The rescued flies are viable and no developmental delays are observed, either in the timing of larval hatching or adult eclosion. Fertility is reduced in flies carrying either one or two copies of PBac{12xHisTA.wt}. Transgenes bearing four copies of the histone repeat unit (PBac{4xHisTA.wt}) or six copies (PBac{6xHisTA.wt}) are insufficient to rescue the lethality seen in Df(2L)HisC.
Flies carrying either one or two copies of PBac{12xHisTA.wt} in a Df(2L)HisC mutant background show no increased sensitivity to the DNA-replication inhibiting agent hydroxyurea.
