Polytene chromosomes normal.
Over 50% of egg chambers from 2 day old spnoA42/spnorev6 females contain more than 15 nurse cells, some contain more than 30 of these cells. The nurse cells are variable in size. Some chambers appear necrotic, with condensed and pycnotic chromosomes, the frequency of necrotic chambers increases with age. Stalk cells between successive chambers are not always apparent. Microtubule distribution within the egg chamber is abnormal. spnoA42/spnorev6 males have reduced fertility. The testes of spnoA42/spnorev6 males contain large numbers of primary spermatocytes which show no distinct organisation into cysts, and the testis tip is often expanded to accommodate these cells. Groups of 16 cells undergoing meiosis are not seen, suggesting that there is a loss of synchronous entry into meiosis. Smaller numbers of spermatids than normal are seen.
Many variably sized nuclei scattered in blastoderm embryo cytoplasm. 90% of eggs from spnoA42/spnorev6 females fail to hatch. Phenotype of non-hatchers is milder than for spno2-210/Df(3R)sbd105, with embryos reaching germ band shortening before development ceases.
Three other "revertants" (rev2, rev3 and rev4, selected on basis of being ry- and sterile over Df(3R)sbd105) were isolated in the same screen, but as they complemented spnoA42 for fertility it is not clear that they are mutant at the spno locus.