Fragment containing bam promoter and coding sequence, encoding a frameshift mutation in the coding region that changes the identity of 7aa and deletes 22 more subsequent amino acids (removing most of the PEST sequence and the rest of the C-terminus).
Mutant males carrying one copy of bamΔPEST in a wild-type background show premature spermatocyte differentiation of germline cysts at the 8-cell stage in 9-18% of cysts. 40% of cysts prematurely differentiate at the 8-cell stage in males carrying one copy of bamΔPEST in a bamΔ86/+ background. Males carrying two copies of bamΔPEST in a wild-type background show premature differentiation of germline cysts at the 8-cell stage in 68% of cysts. In these cases, the 8-cell cysts have large cells with typical spermatocyte morphology. Post-meiotic cysts are observed with 32 instead of 64 elongating spermatids.
bamΔPEST is a suppressor | partially of male germline cyst phenotype of mei-P26mfs1
bamΔPEST is a suppressor of nucleolus phenotype of mei-P26mfs1
Expression of bamΔPEST completely rescues the overproliferation defects seen in the testes of mei-P26mfs1 males and 43% of the cysts in the spermatocyte region have 16 spermatocytes per cyst. The enlarged nucleolus phenotype seen in mei-P26mfs1 testes is also suppressed. The spermatocyte and spermatid differentiation defects are not rescued: 30% of cysts from the spermatocyte region have differentiation defects in the rescued males.