The ability to successfully fertilize ova relies upon the swimming ability of spermatozoa. Both in humans and in animals, sperm motility has been used as a metric for the viability of semen samples. Recently, several studies have examined the efficacy of low dosage red light exposure for cellular repair and increasing sperm motility. Of prime importance to the practical application of this technique is the absence of DNA damage caused by radiation exposure. In this study, we examine the effect of 633 nm coherent, red laser light on sperm motility using a novel wavelet-based algorithm that allows for direct measurement of curvilinear velocity under red light illumination. This new algorithm gives results comparable to the standard computer-assisted sperm analysis (CASA) system. We then assess the safety of red light treatment of sperm by analyzing, (1) the levels of double-strand breaks in the DNA, and (2) oxidative damage in the sperm DNA. The results demonstrate that for the parameters used there are insignificant differences in oxidative DNA damage as a result of irradiation.
Precise determination of the time of ovulation will greatly enhance the success rate of artificial insemination and timed breedings of captive marine mammals. Because daily samples are necessary to effectively monitor the estrous cycle, behavioral conditioning of blood and urine collection has greatly facilitated the development of reproductive hormone profiles of the bottlenose dolphin (Tursiops truncatus). Measuring luteinizing hormone (LH) in urine obviates the need for blood collection and increases the frequency with which samples can be obtained. This non-invasive method has the potential to elucidate the temporal associations between the fall of circulating estrogen, the surge of LH, and the time of ovulation. Daily urine samples were collected from one female bottlenose dolphin during an ovulatory estrous cycle. Urine was concentrated and normalized by osmolality before application to an immunochromatographic assay (ICG) designed to detect canine serum LH. Centrifuging urine samples to remove insoluble components enhanced the definition and visibility of LH assay bands, concentrating urine increased the speed and intensity of test band development, and normalization of samples by osmolality ensured the application of a standard concentration of urine to each assay. In this single animal cycle follow-up trial, the urinary LH profile corresponded with serum LH, estrogen, and progesterone profiles, demonstrating the possible efficacy of this method for monitoring LH.
Snake populations are declining worldwide, but research devoted to the development of sperm cryopreservation techniques for this taxon is very limited. Spermatozoa were collected postmortem from snakes of four squamate families (Elapidae, Colubridae, Viperidae and Pythonidae). Viability assessment was performed before and after cryopreservation. Spermatozoa were extended in TES and Tris (TEST) yolk buffer with 12% dimethylsulfoxide (DMSO) or 12% glycerol and frozen at a rate of 0.3°Cmin−1. The sperm quality index (SQI), representing three viability parameters (motility, plasma membrane and acrosome integrity), was determined. Despite some species differences, glycerol was a more effective cryoprotectant for Colubridae, whereas DMSO provided greater cryoprotection for spermatozoa of members of the other three families.
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