Insertion of a P{lacW} element within the first intron.
aster & meiotic cell cycle | male
cleavage furrow & spermatocyte
spindle & meiotic cell cycle | male
The central spindle initially forms normally in mutant spermatocytes, but no cleavage furrow is initiated. Plasma membrane addition in the mutant cells initially occurs with similar kinetics as in control cells, until premature disassembly of the central spindle.
Homozygous adults have abnormal bristles. Female fertile in transheterozygous combination with chic8A. Slightly less than half of onion-stage spermatids contain a single Nebenkern of larger than normal size, associated with two or more normal-sized nuclei (23.2% of spermatids have 2 nuclei). The central spindle is irregular and less dense than wild-type in the first meiotic division in homozygous males. 31.5% of asters show irregular positioning and delayed migration during meiotic divisions in homozygous males.
Precise excision of the P{lacW} element results in reversion of the mutant phenotype.