267 DIFFERENCES IN BULL SPERM NUCLEAR SHAPE BETWEEN FLOW-SORTED AND NON-SORTED SPERM USING FOURIER HARMONIC ANALYSIS
J. R. Schindler A , R. L. Monson A , K. L. Willenburg A and J. J. Parrish ADepartment of Animal Sciences, University of Wisconsin, Madison, WI
Reproduction, Fertility and Development 21(1) 231-231 https://doi.org/10.1071/RDv21n1Ab267
Published: 9 December 2008
Abstract
The objective of the study was to evaluate sperm nuclear shape in sex-sorted and non-sorted semen using Fourier Harmonic Amplitudes (FHA). Frozen semen was obtained from a single commercially available source. Mature bulls (n = 15) from the same breed with an average age of 4.42 ± 2.08 years were collected and the semen was either frozen or X-chromosome sorted using a flow cytometer and then frozen. Frozen straws were transported to the lab and analyzed for FHA. Briefly, straws were thawed and cells were incubated with 1.6 μm Hoechst 33342. Cells were then washed, fixed, dried to a slide and analyzed for nuclear head shape. Harmonic amplitudes 0 to 5 (HA0–HA5), derived from FHA, were previously shown to be an accurate, objective, and repeatable measure of sperm nuclear shape. HA0 describes the overall nuclear size of the sperm, whereas HA1 describes the anterior head, HA2 the length of the sperm along the longitudinal axis, and HA3 to 5 the distal, post-nuclear curvature of the sperm head. Each unit of semen was evaluated for motility and FHA. There was a significant decrease in motility in the sorted group (77 ± 1% v. 54 ± 3%; P < 0.0001). Multivariate ANOVA showed that there were differences between the sorted and non-sorted groups in HA1 to 4 (P < 0.02). Harmonic amplitude means ± SD (microns) for sorted and non-sorted treatments are as follows: HA1 (0.117 ± 0.003 v. 0.109 ± 0.003), HA2 (1.087 ± 0.005 v. 1.063 ± 0.005), HA3 (0.139 ± 0.003 v. 0.130 ± 0.003), and HA4 (0.201 ± 0.004 v. 0.191 ± 0.004), respectively. The nuclear shape of X-sorted sperm is longer and more pinched in both the anterior and posterior head. Interestingly there was no difference in HA0 (P = 0.119) indicating that the overall size of the sperm head is not affected by the sorting process. The differences in harmonic amplitudes may be due to the size and a restricted location of the X v. Y chromosome in the sperm nucleus.
