S. A. Christ

Objective analysis of sperm motility in the lake sturgeon, Acipenser fulvescens: activation and inhibition conditions

Abstract An objective analysis of the duration of motility of sperm from the lake sturgeon, Acipenser fulvescens , has been performed using computer-assisted sperm motion analysis at 200 frames/s. Motility was measured in both 1993 and 1994. The percentage of activated motile sperm and their velocities ([1993] curvilinear velocity: 313 μm/s; straight-line velocity: 129 μm/s) were unchanged after 5 min in Tris/glycine buffer, pH 9.0, with 10 mM added Na + . Qualitative, visual measurements revealed motility lasting for 30 min in this medium. The percentage of motile cells, but not the velocities of the motile cells, was reduced by the addition of potassium to the Tris/glycine buffer. The percentage of motile sperm was inhibited by 50% at 0.5 mM added K + . Elemental analysis of seminal plasma revealed the following concentrations: P (3.02 mM); K (5.78 mM); Ca (0.16 mM); Mg (0.21 mM); Na (25.6 mM); Zn (0.76 μM); and Cl (5.41 mM). Differences between two years of milt collection were not significant.

Effect of cryopreservation and theophylline on motility characteristics of lake sturgeon ( Acipenser fulvescens ) spermatozoa

Computer-assisted motility analysis (CASA) was used to evaluate the effect of cryopreservation and theophylline treatment on sperm motility of lake sturgeon (Acipenser fulvescens ). Motility was recorded at 0 and 5 min postactivation. The effect of cryopreservation on sperm acrosin-like activity was also measured. Cryopreservation led to a decline in the percentage of motile spermatozoa, while other parameters of sperm motion, curvilinear and straight line velocities, linearity and amplitude of lateral head displacement were unchanged. Reductions in straight line velocity observed with fresh and cryopreserved spermatozoa and in linearity with cryopreserved spermatozoa 5 min postactivation were not seen in the presence of 5 mM theophylline at this time point. Frozen-thawed spermatozoa retained acrosin-like activity, and it correlated with the percentage of post-thaw motility (r = 0.95 and r = 0.90, P < 0.05, for 0 and 5 min post-activation time, respectively).

Effects of extenders and time of storage before freezing on motility and fertilization of cryopreserved muskellunge spermatozoa

Abstract The usefulness of five extenders for cryopreservation of muskellunge semen was studied in fertilization trials and computer-assisted semen analysis (CASA) of postthaw sperm motility. The effect of prefreezing storage time before cryopreservation on success of cryopreservation was also analyzed. A 50% fertilization rate (compared with fresh semen) of the extender containing 10% dimethyl sulfoxide (DMSO) in seminal-plasma-mimicking medium (SPMM) supplemented by 10% egg yolk was significantly higher than in extenders consisting of 10% DMSO, 0.6 M sucrose, and 10% egg yolk or 20% glycerol and 0.3 M glucose. Spermatozoa cryopreserved with DMSO–SPMM–egg yolk extender had the highest values of straight-line velocity and linearity of movement. Significantly lower fertilizing ability and curvilinear velocity were found for semen specimens stored on ice for 5 h before freezing compared with specimens stored for 1 h. Although spermatozoa cryopreserved with extender containing 10% methanol had only traces of...

The developmental toxicity of bromochloroacetonitrile in pregnant long‐evans rats

Bromochloroacetonitrile (BCAN) is a by‐product of the chlorine disinfection of water containing natural organic material. Adverse effects of BCAN in an in vivo teratology screen (i.e. neonatal survival assay) gave reason for further investigation into the developmental toxicity of this compound. BCAN was administered orally to pregnant Long‐Evans rats on gestation days 6–18 (vaginal plug = day 0). Four groups of approximately 20 females received BCAN at 5, 25, 45 or 65 mg/kg/day in a tricaprylin vehicle. Endpoints assessed at necropsy (day 20) included maternal organ weights, number of corpora lutea and uterine contents (number of implants and fetuses); live fetuses were weighed, measured and subsequently examined for external, skeletal and soft tissue malformations. Gestational maternal weight gain was reduced at 45 and 65 mg kg‐1. Maternal toxicity, manifested as increased organ weights and deaths, occurred at 65 mg kg‐1. Postimplantation loss was elevated at 45 mg kg‐1 while total litter loss was obser...

Quality assurance considerations for use of the FluorImager SI∖R and FragmeNT Analysis software

The FluorImager SI® (FSI) from Molecular Dynamics is one of several scanning instruments available for the detection of fluorescent emissions associated with DNA samples in a variety of matrices (agarose and polyacrylamide gels, membranes and microplates). In our laboratory, we measured the electrophoretic mobility of randomly amplified polymorphic DNA (RAPD) fragments stained with ethidium bromide in agarose using the FSI to scan gels and the associated Molecular Dynamics software (ImageQuaNT®, and FragmeNT Analysis) for analysis. Initial scans and analyses resulted in inconsistent band detection across the same gel and across several scans of the same gel. To determine the best types of calibration for the instrument, several factors were considered and then evaluated. Tests of calibration acceptability were also evaluated. Band detection by FragmeNT Analysis was improved following optimization of matrices and parameters used in calibration and experimental scans. In addition, use of software templates for analysis and modifications in the staining procedure, which have resulted in decreased instrument associated variance, are discussed.