All Phenotypes Hook1<azh> MGI Mouse

• some focal spermatozoa formation, decreased efficiency in transition from round to elongated spermatids, and spermatozoa with abnormal head shapes are found

teratozoospermia ( J:13990 , J:77010 )

• all sperm in homozygous males are affected, having a characteristic ladle shape (J:13990)

• spermatozoa are often club-shaped or crescent formed, looped in the midpiece of the flagellum and detached tails are often seen (J:77010)

absent sperm flagellum ( J:13990 )

• up to 40% lack a flagella

detached sperm flagellum ( J:77010 )

abnormal sperm nucleus morphology ( J:19242 )

• in many step 8-10 spermatids, nuclear invaginations and evaginations are observed, always in association with abnormal positioning of some of the manchette microtubules

• 100% of the sperm nuclei produced display abnormal shapes

abnormal spermatid morphology ( J:19242 , J:19269 , J:77010 )

• distorted acrosome (J:19242)

(J:19269)

(J:77010)

abnormal manchette morphology ( J:19242 )

• abnormal positioning of many manchette microtubules in step 8-9 spermatids

• microtubules are directed towards regions of the plasma membrane not normally associated with manchette formation

ectopic manchette ( J:19242 )

• in step 10-12 spermatids, sheets of manchette microtubules are often located in ectopic positions along the plasma membrane, rather than in association with the nuclear membrane

abnormal spermiogenesis ( J:19242 )

• nuclear invaginations, nuclear evaginations, abnormal positioning of the microtubules, and ectopic manchette

arrest of spermatogenesis ( J:77010 )

• histology shows arrest of spermatogenesis at variable stages in 25% of seminiferous tubules

decreased litter size ( J:13990 )

reduced male fertility ( J:13990 )

• most males breed and litter sizes are more than half as large as those of unaffected litter mates