Mouse Sperm Phenotyping
Functional sperm are produced through a complicated process within the testes called spermatogenesis and progress to the epididymis where the gametes mature and are stored until ejaculation. A breakdown at any one of these stages can lead to male infertility. With mutant mouse model creation, unexpected male infertility phenotypes are often observed. Our mouse sperm phenotyping services can help you identify, characterize, and define the male infertility phenotype caused by the genetic modification.
- Sperm Motility Assessment: Computer assisted sperm analysis system is used for assessments of cauda epididymal sperm total motility (% of motile sperm), rapid sperm motility (% of motile sperm with VAP ≥10 µm/s), and progressive motility (% of motile sperm with VAP ≥ 50 µm/s and STR ≥50%) at 37 °C. (VAP: The average cell path velocity in µm/s; VSL: The straight line velocity in µm/s; STR: The Straightness ratio of VSL/VAP, expressed as a percent.)
- Sperm Morphology Assessment: Cauda epididymal sperm are assessed for the percentage of sperm with abnormal morphology and the percentage of sperm with abnormal tails, using a phase contrast microscope. Digital pictures included to visualize the different types of abnormal sperm.
- Sperm Production Measurement: One testis per male is decapsulated, weighed and homogenized. Spermatids are then counted using a hemocytometer using a phase contrast microscope. The values for the number of spermatids per testis and spermatids per gram of tissue are divided by 4.84, respectively, to obtain daily sperm production (per testis) and efficiency of sperm production (per gram testis) (vom Saal et al. 1998).
- Measurements of epididymal sperm count: One whole epididymis is weighted and homogenized. Sperm are then counted using a hemocytometer using a phase contrast microscope.
- Sperm viability, membrane integrity and acrosome integrity assessments: (with digital pictures)
- Sperm viability assessment
- Hypo-osmotic swelling test for evaluation of sperm membrane integrity
- Sperm acrosome integrity assessment
- Sperm in vitro fertility assessment: This service is essential to identifying the cause of male infertility (sperm-cumulus penetration defect, sperm-zona binding defect, sperm-zona penetration defect and or sperm-oolemma fusion defect) by comparing fertilization rates of regular IVF, cumulus-free IVF, and laser-assisted IVF plus a sperm-zona binding assay.
- Regular IVF rate
- Cumulus-free IVF rate
- Laser-assisted IVF rate
- Sperm-zona binding assay
vom Saal FS, Cooke PS, Buchanan DL, et al. A physiologically based approach to the study of bisphenol A and other estrogenic chemicals on the size of reproductive organ s, daily sperm production, and behavior. Toxicology and Industrial Health 1998; 14:239-260.
Li MW, and Lloyd KCK et al. Safety, efficacy and efficiency of laser-assisted IVF in subfertile mutant mouse strains. Reproduction 2013; 145: 245-54.
Li MW and Lloyd KCK et al. (2014) IVF recovery of mutant mouse lines using sperm cryopreserved with MTG in cryovials. CryoLetters 2014; CryoLetters 35:145-153.