Flow cytometric evaluation of acrosome function/dysfunction in the stallion /

Bibliographic Details
Main Author: Bosard, Tegan S.
Other Authors: Love, Charles C. (Thesis advisor), Varner, Dickson D. (Thesis advisor)
Format: Thesis eBook
Language:English
Published: [College Station, Tex.] : [Texas A&M University], [2010]
Subjects:
Online Access:Link to OAK Trust copy
Description
Abstract:The objective of this study was to establish a rapid and efficient assay that would assess acrosomal status and function of the stallion acrosome. Ejaculates from fertile and subfertile stallions were extended to 25x10⁶/mL and divided into aliquots (1mL) treated with no ionophore (control) or 10[mu]M A23187 and incubated at 37°C for 0, 1, 2, and 3h. Following incubation, samples were fixed with 2% paraformaldehyde for 10 minutes at room temperature; then stored at 4°C in Dulbecco's Phosphate-buffered saline (DPBS) for 0, 24, and 72 hours (i.e. post-fixation storage). After post-fixation storage samples were then permeabilized with 95% ethanol at -20°C for 10 minutes. Samples were resuspended in 20% fetal bovine serum in DPBS, labeled with fluorescein isothiocyanate for 10 minutes, and analyzed by flow cytometry. Post-fixation storage produced fewer (P<0.05) acrosome intact (AI) spermatozoa and a higher (P<0.05) fluorescence intensity than respective fresh samples. Regardless of incubation time or treatment, cool-stored samples averaged ~6% lower (P<0.001) AI spermatozoa than the corresponding fresh semen; however, cooled storage did not alter (P>0.2) the overall fluorescence properties as compared to fresh semen (730±8.08 vs. 734±8.01 fluorescence intensity units, respectively). For fertile stallions, the percentage of AI spermatozoa was higher (p<0.01) in control samples than A23187 samples at incubation times 1, 2, and 3h (Control-59, 56, and 51% vs. A23187- 46, 29, and 23%, respectively), but not at Time 0. For subfertile stallions, the percentage of AI spermatozoa was not affected by ionophore treatment (P>0.05) or incubation period (P>0.05). The results suggest that post-fixation storage in DPBS for up to three days is still representative of the acrosomal competence of the original sample. In addition, spermatozoa stored for 24 hours in an Equitainer[trade mark] exhibited a small (~6%) but significant decrease in the percentage AI spermatozoa. Storage conditions may therefore, affect acrosomal integrity and contribute to reduced fertility when cooled-semen is used. Subfertile stallions exhibited little response [<11% acrosome reacted (AR)] after 3h of A23187 exposure, while the fertile stallions demonstrated a substantial response (>̲ 36% AR) as soon as 1h after ionophore exposure. This assay diagnosed acrosomal dysfunction in stallions with unexplained subfertility.
Item Description:"Major Subject: Veterinary Medicine"
Title from author supplied metadata (automated record created 2010-03-12 12:08:51).
Electronic resource.
Physical Description:1 online resource.
Bibliography:Includes bibliographical references.