Figure 1
Absence of AU040320 leads to male infertility. (A) Average number of pups born from matings with males wild-type (n = 10), heterozygous (+/−; n = 12) and homozygous (−/−; n = 12) for the AU040320 KO allele. (B) Analysis by Western blotting demonstrating expression of AU040320 in testis of wild-type (+/+) and its absence in AU040320 KO mice (−/−). The protein is also detected in wild-type lysates of the epididymis but not in isolated spermatozoa. Actin was used as loading control. The cropped blots are displayed; full-length blots and Ponceau staining of membranes are shown in Supplementary Fig. S5A. 20 µg loaded per lane. (C) X-gal staining of testis sections of AU040320 −/− mice carrying the lacZ reporter gene. Representative image shows the ß-galactosidase activity (blue dots) resulting from the reporter gene which can be seen in the majority of cells of seminiferous tubules (inset, C’). As expected, wild-type control samples do not display any signal in seminiferous tubules, although some likely unspecific signal is detected in the interstitial region corresponding to the Leydig cells (C”). Nuclei are counterstained with Nuclear FastRed. Tubules are outlined in KO samples (C, C’). (D) Images of testes of wild-type and AU040320 −/− mice show no major morphological abnormalities or differences in size. (E) Average weight of individual testis is comparable between wild-type and mutant mice (n = 8). (F) Quantification of sperm number (x106 cells/ml) revealed a reduction in the number of spermatozoa released from the cauda epididymis of AU040320 KOs (*denotes p < 0.05; n = 3 per genotype). (G–J) Bouins-fixed, H&E-stained histological sections of wild-type and AU040320 KO mice from testis (G,H) and epididymis (I,J), with selected individual tubules shown at larger magnification (G’-J’), including seminiferous tubules containing spermatids in late stages (13–16) of development (G’, H’). Scale bars: 25 μm for all panels.
