All Phenotypes Tex44<em1Sbbx> MGI Mouse

reproductive system phenotype ( J:354514 )

N	• homozygous females breed normally; homozygous males show normal testis histology and cauda epididymal sperm counts

abnormal sperm flagellum morphology ( J:354514 )

• 65% of testicular sperm show a thinning between the midpiece and the principal piece of the flagellum

• cauda epididymal sperm exhibit a disorganized junction (disjunction) between the midpiece and the principal piece

• however, immunostaining of cauda epididymal sperm with an anti-SEPT4 antibody showed that an annulus is present despite the abnormal flagellum structure

abnormal outer dense fiber morphology ( J:354514 )

• sperm flagella often show lack of some outer dense fibers in the principal piece

abnormal sperm axoneme morphology ( J:354514 )

• sperm flagella often show lack of some axonemal microtubule doublets in the principal piece

abnormal sperm mitochondrial morphology ( J:354514 )

• EM analysis of longitudinal sections of sperm flagella showed rare cases of abnormal mitochondrial structures, including abnormal mitochondrial size and supernumerary mitochondria

abnormal sperm principal piece morphology ( J:354514 )

• 63.6 +/- 0.06% of sperm exhibit abnormalities in the principle piece versus 4.2 +/- 0.01% in wild-type sperm; EM analysis of crosssections often showed lack of some microtubule doublets and their associated outer dense fibers

hairpin sperm flagellum ( J:354514 )

• cauda epididymal sperm show a severe 180 hairpin bending in the region between the midpiece and the principal piece

• proportion of severe hairpin bending progresses from 12% in the caput to 58% in the corpus and to 80% in the cauda epididymis

• however, no severe bending is noted in testicular sperm

abnormal spermiogenesis ( J:354514 )

decreased litter size ( J:354514 )

• when bred with adult wild-type females, 8- to 14-week-old homozygous males produce significantly fewer pups per litter than control males (2.9 +/- 0.75 versus 7.1 +/- 0.38, respectively)

• although rare, offspring of homozygous males are viable and normal

reduced male fertility ( J:354514 )

• sexually mature (8 to 14 weeks) homozygous males are severely subfertile

impaired fertilization ( J:354514 )

• homozygous males show impaired fertilization both in vivo and in vitro

decreased fertilization frequency ( J:354514 )

• an in vivo fertilization assay using adult homozygous males mated with superovulated wild-type females showed a significantly lower fertilization rate (FR) than in wild-type control males (19.6 +/- 0.04% versus 96.1 +/- 0.02%, respectively)

• in IVF assays using cumulus-intact oocytes from superovulated wild-type females, the FR is only 0.8 +/- 0.01% versus 44.4 +/- 0.04% for wild-type males

• in IVF assays using zona-free oocytes, the fertilization index (FI: average number of fused sperm per oocyte) is 0.15 +/- 0.04 versus 1.06 +/- 0.09 for wild-type males

• however, FI can be restored to control values by inseminating the oocytes with 10X more sperm in zona-free IVF assays

abnormal sperm physiology ( J:354514 )

• Mitotracker CMTMRos staining of cauda epididymal sperm showed a significantly lower fluorescence intensity than in wild-type sperm, suggesting decreased sperm mitochondrial activity

asthenozoospermia ( J:354514 )

• CASA analysis shows a drastic reduction in sperm motility (8.7 +/- 0.01%) relative to that of wild-type sperm (63.2 +/- 0.02%)