The Mon1¹⁵⁶ mutation was identified as an amber mutation within the Mon1 coding sequence on the chromosome carrying the pog¹ mutant allele. Lethality of the chromosome in transheterozygous combination with the Mon1^Δ181 mutant can be rescued by overexpression of Mon1, confirming that Mon1 gene function is disrupted by the Mon1¹⁵⁶ mutation. However, the homozygous lethality of this chromosome cannot be rescued by overexpression of Mon1, indicating that the chromosome also carries a second site mutation that contributes to the lethality of the chromosome. FlyBase curator comment: it is not yet clear whether the 'poor gastrulation' phenotype for which the unmapped pog¹ mutation was named is due to disrupted function of the Mon1 gene (caused by the Mon1¹⁵⁶ mutation) and/or due to the second site mutation on the chromosome, thus the pog¹ allele and parent pog gene have been kept as separate entities in FlyBase from Mon1¹⁵⁶ and Mon1 until more information becomes available [date: 200812].

The pog¹ mutation was initially incorrectly ascribed to 'CG31660'/'smog' (in FBrf0208913) - FBrf0231092 shows that pog¹ complements the smog^null deletion of CG31660.