Analysis Tools
reproductive system
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• a hairpin phenotype is gradually observed as sperm transit through the epididymis
• many sperm flagella display hairpin bending at the annulus as they arrive at the distal corpus and cauda epididymidis
• by the time sperm reach the cauda, 56% of sperm exhibit hairpin bending
• however, spermatozoa obtained from testis are morphologically normal
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• sperm isolated from the caput and proximal corpus epididymidis exhibit a sharp bend at the junction between the midpiece and principal piece
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• at 8-12 weeks of age, epididymal sperm count is significantly lower than that in wild-type males
• however, sperm count is normal at 8-10 months of age, and the ratio of sperm count to testis weight is normal in both age groups
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• during a 2-hr incubation in capacitating medium, epididymal spermatozoa show a significant reduction in the % of total sperm motility, path velocity, linear velocity, and track velocity relative to wild-type controls
• neither 8-Bromo-cAMP nor IBMX is able to rescue the reduction in motility parameters
• however, sperm viability is similar to that in wild-type sperm cells, as shown by a normal response to external calcium ions
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• at 8-12 weeks of age, testis weight is significantly lower than that in wild-type males
• however, testis weight is normal at 8-10 months of age
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• when spermatozoa are capacitated in vitro, the expected time-dependent rise of capacitation-associated protein tyrosine phosphorylation is nearly abolished and PKA substrate phosphorylation is significantly reduced
• CTC staining showed a significant increase in the % of uncapacitated spermatozoa (F pattern) whereas the % of capacitated cells (B pattern) is significantly decreased, indicating that sperm capacitation is inhibited
• however, the time-dependent increase of protein tyrosine phosphorylation is completely rescued by the addition of 8-Bromo-cAMP or IBMX
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• female mice exhibit reduced fertility
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• when mated with wild-type females over a period of 3 months, male mice yield no offspring indicating complete male sterility
• however, seminal plugs are observed, indicating normal copulation
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• IVF assays show that spermatozoa are incapable of fertilizing ZP-intact or ZP-free oocytes
• however, intracytoplasmic sperm injection rescues the fertilization defect
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• the % of spontaneous acrosome-reacted spermatozoa is significantly decreased
• in addition, spermatozoa fail to respond to acrosome reaction inducers A23187 or progesterone
• however, the sperm intracellular Ca2+ level is not significantly altered in either Ca2+-free medium or Ca2+-containing medium, suggesting that impaired acrosome reaction is not due to cytosolic calcium
• neither 8-Bromo-cAMP nor IBMX is able to rescue the acrosome reaction defect
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cellular
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• a hairpin phenotype is gradually observed as sperm transit through the epididymis
• many sperm flagella display hairpin bending at the annulus as they arrive at the distal corpus and cauda epididymidis
• by the time sperm reach the cauda, 56% of sperm exhibit hairpin bending
• however, spermatozoa obtained from testis are morphologically normal
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• sperm isolated from the caput and proximal corpus epididymidis exhibit a sharp bend at the junction between the midpiece and principal piece
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• at 8-12 weeks of age, epididymal sperm count is significantly lower than that in wild-type males
• however, sperm count is normal at 8-10 months of age, and the ratio of sperm count to testis weight is normal in both age groups
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• during a 2-hr incubation in capacitating medium, epididymal spermatozoa show a significant reduction in the % of total sperm motility, path velocity, linear velocity, and track velocity relative to wild-type controls
• neither 8-Bromo-cAMP nor IBMX is able to rescue the reduction in motility parameters
• however, sperm viability is similar to that in wild-type sperm cells, as shown by a normal response to external calcium ions
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homeostasis/metabolism
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• HCO3--induced increase in intracellular pH is significantly inhibited in spermatozoa both before or after 1 h of capacitation
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• spermatozoa exhibit a significantly higher intracellular Na+ concentration than wild-type sperm
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• Na/K-ATPase enzyme is inactivated; both ATP1A4 and ATP1B3, the alpha and beta subunits of Na/K-ATPase, are nearly absent, leading to increased intracellular Na+ concentration in spermatozoa
• male infertility is likely due to Na+ imbalance caused by Na/K-ATPase deficiency
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endocrine/exocrine glands
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• at 8-12 weeks of age, testis weight is significantly lower than that in wild-type males
• however, testis weight is normal at 8-10 months of age
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