Electroretinogram (ERG) recordings of 10-d-old PAPLA1^KO mutants show decreased sensitivity of the photoreceptor cells to light signal. The amplitude of response of the mutant is less than half of wild-type at all light intensities tested by ERG.

The susceptibility of the mutants to starvation is very significant by day 10 and gets worse until about day 30 from when the difference remains the same.

30-d-old PAPLA1^KO flies fare poorly in a negative geotaxis assay compared with age-matched controls.

PAPLA1^KO mutant flies show a 20% decrease in life span compared with wild-type.

PAPLA1^KO mutant are male sterile. The testes of males are small compared with heterozygous and wild-type controls. Elongated spermatid bundles are observed in both wild-type and mutant testes. However, the individual needle-shaped nuclear staining of sperm cells found in the wild-type seminal vesicle are absent in the mutants, indicating a defect in the individualisation process of spermatogenesis. Electron microscopic examination of testis shows that early stages of spermatogenesis, including the generation of the 64-cell spermatid bundle, seems to occur in the mutant. The clear formation of the major and minor mitochondrial derivatives and the formation of the axonemal structures in the bundles are observed in the mutants. However, closer examination of the spermatid bundles reveals that the mitochondrial derivative and the process of individualization of the spermatids into sperms are defective in the mutants. In many, the mitochondrial derivatives are not individualised and remain bridged between two spermatids. These defects lead to degeneration of the spermatids in the distal en of the testis.

PAPLA1^KO is an enhancer of endoplasmic reticulum phenotype of ninaA³