Relationship Between the Characteristics of Epididymal Red Deer Spermatozoa and Penetrability Into Zona‐Free Hamster Ova

Abstract

A heterologous (zona-free hamster oocytes) in vitro fertilization (IVF) system was used to evaluate the relationship between sperm factors and penetration capacity of epididymal red deer spermatozoa. The sperm parameters evaluated in 36 sperm samples obtained postmortem from stags selectively shot during the rutting season were sperm motility, functional integrity of plasma membrane by means of the hypo-osmotic swelling test (HOST), and, simultaneously, viability and acrosomal status via a triple-stain technique. Zona-free hamster oocytes were used to evaluate the capacity of the different sperm assays to predict in vitro penetration. In order to increase the variability in sperm quality, we recovered samples from stags at different intervals between the death of the male and the collection of the genitalia. All measures of sperm quality declined progressively (P <.001) with increasing intervals between death and sample collection. In addition, many sperm parameters were related to penetration ability in vitro. Subsequently, sperm samples were rearranged in 2 categories according to the interval that had elapsed between death and the collection of the genitalia (group 1, short interval = 0-12 h; group 2, large interval = 18-40 hours). When samples were grouped, less correlation achieved significance, especially for group 1, than when samples were not divided. Also, correlation between the number of sperm per oocyte and sperm parameters for group 1, which had the highest values of sperm quality, failed to reach significance. It is concluded that the classical parameters accepted in assessing the viability of deer spermatozoa can be good predictors of the penetrating ability of the spermatozoa when satisfactory in vitro conditions are used for the development of the IVF system. Also, this study demonstrates that compatible heterologous gamete interaction allows thorough assessment of sperm function in a wild deer.

Heterologous In Vitro Fertility Evaluation of Cryopreserved Iberian Red Deer Epididymal Spermatozoa with Zona‐intact Sheep Oocytes and its Relationship with the Characteristics of Thawed Spermatozoa

“…Similar results have been shown by Van der Ven et al. (1986); Soler and Garde (2003) and Tartaglione and Ritta (2004) in men, red deer and bull respectively. Therefore, the membrane integrity assessed by this method is a good indicator of in vitro fertility.…”

“…Thus, in our study the males with a less responsive acrosome react after incubation at 37°C for 2 h in a non‐capacitating medium and are less likely to fertilize sheep oocytes. In a similar previous study carried out by us with Iberian red deer epididymal sperm, a positive relationship was found between acrosome integrity and percentage of penetrated eggs (Soler and Garde 2003). These differences with this work can be due to differences in the treatment of the sperm.…”

“…1982; Brahmkshtri et al. 1999; Soler and Garde 2003). In this study, we used heterologous IVF with zona‐intact matured sheep oocytes derived from slaughterhouse ovaries, because we can obtain a high number of the same ones and avoid killing a large number of animals for experimental purposes.…”

Characteristics and in vitro fertilizing ability of giant panda (Ailuropoda melanoleuca) frozen‐thawed epididymal spermatozoa obtained 4 hours postmortem: A case report

“…Additionally, the fertilizing ability in thawed samples was evaluated by a sperm penetration assay (SPA) [Yanagimachi et al, 1976]. This test was performed following procedures recently described for deer sperm [Soler and Garde, 2003]. The occurrence of penetration was determined according the criteria described by Yanagimachi et al [1976].…”

Inbreeding and Reproduction in Endangered Ungulates: Preservation of Genetic Variation through the Organization of Genetic Resource Banks

“…Its use has not been much explored in wildlife species (e.g. Soler and Garde 2003) and, in general terms, is now a less favoured assay because it only evaluates one step (sperm–oolema fusion) in the series of events during sperm–egg interaction. Furthermore, in order to bind to the oolema, spermatozoa have to undergo the acrosome reaction either spontaneously (and this itself is a questionable parameter of sperm function) or in response to some natural stimulus or molecular probe.…”