The P{lacW}Jarid2^j2B8 insertion is located in the intergenic region between the promoters of the divergently transcribed Uch-L5 and Jarid2 genes. Expression of Uch-L5 mRNA is unaffected in P{lacW}Jarid2^j2B8 homozygotes (when analysed by RT-PCR), while mRNA expression of both Jarid2 and the pall gene (located downstream of Jarid2) is abolished, indicating that the insertion results in a double loss of function, of both Jarid2 and pall. Genetic analysis indicates that the phagocytosis-defective phenotype seen in P{lacW}Jarid2^j2B8 homozygotes is caused by the insertion (precise excision of the insertion reverts this phenotype) and is due to the loss of function of pall (the phenotype can be fully rescued by expression of a UAS transgene encoding a full-length pall cDNA).

FlyBase curator comment: P{lacW}Jarid2^j2B8 results in loss of function of both the Jarid2 and pall genes (represented in FlyBase by the Jarid2^j2B8 and pall^j2B8 alleles respectively), and it has been shown that the phagocytosis-defective phenotype seen in P{lacW}Jarid2^j2B8 homozygotes is due to the loss of function of pall (FBrf0202092). The P{lacW}Jarid2^j2B8 chromosome also shows homozygous lethality, and it has been shown that the lethality maps to the insertion (FBrf0126832). A knock-out of the Jarid2 open reading frame is homozygous lethal (FBrf0236101), while a knock-out of the pall open reading frame is homozygous viable (FBrf0227703). This suggests that the lethality caused by the P{lacW}Jarid2^j2B8 insertion is due to an effect on Jarid2; information relating to the lethal phenotype (and the l(3)j2B8 symbol) has thus been assigned to the Jarid2^j2B8 allele in FlyBase.