HIPP1 is not essential for spermatogenesis. A. Quantification of the male fertility in wild type (1, Canton S and 2, yw), two Hipp1−/−, two heteroallelic Hipp1-/+, su(Hw)-/+ mutants, and one Hipp1−/−, su(Hw) −/− double mutant background. The number of males tested is shown above each data set. Bars indicate standard deviation from a minimum of three replicates. Significant changes in fertility between groups and over time were determined using repeated-measures ANOVA (#, not significant; ** P < 0.01; *** P < 0.001). B. Representative confocal images of 3-day-old wild type (Canton S), su(Hw)2/Pb and Hipp1Δ37/ΔDsR testis stained with antibodies against polyglycylated Tubulin (red, marks sperm tails), cleaved Caspase 3 (yellow, marks ICs) and phalloidin (blue, marks actin in ICs and elsewhere in the testis). Scale bars: 200 μm. Asterisk marks anterior of testis. S.V. denotes the seminal vesicle. C. Western blot of proteins extracted from 1-to 3-day old ovaries and <1 day-old testes from Hipp1+/+ and Hipp1Δ37/ΔDsR animals probed with a pan α-crotonyl-lysine (panKcr) antibody and an antibody against Histone H3 (α-H3). A nuclear HeLa cell extract was run as a positive control.