Imprecise excision of the P{SUPor-P} element results in deletion of 574 bp, removing most of the 5' UTR of the 65kDa isoform with only 10 residues upstream of the first initiator ATG remaining.
The cellular phenotypes detected in yuriF64 mutant testis include the defective accumulation of dense complex components, failure of basal body positioning, and failure of actin cone formation.
yuriF64 mutants have no motile sperm. Curled structures (thicker than individual sperm) with aberrant coiling are observed in the basal region of the testis.
In yuriF64 mutants highly elongated spermatid cysts are observed and there is a failure of sperm individualisation.
In yuriF64 mutants the basal bodies of round spermatids are in disarray, with some positioned at the rostral nuclear tip rather than the apical nuclear tip, as seen in controls.
In yuriF64 mutant sperm, the 64 axonemal 'triads' all share a single cytoplasm. Terminal differentiation of the minor mitochondrial derivatives is imperfect, and less condensed than normal. Axoneme structure is normal, but aberrant arrangements of axoneme-mitochondrial deriviate triads is observed in a very small number of sperm.
In yuriF64/+ mutant testes, ~90% of cysts show a small number of imperfect individualised triads. Some of the sperm tails are still in syncytial cytoplasm and have individualisation defects.
