From a Sperm’S Eye View – Revisiting Our Perception of This Intriguing Cell

Introduction

The stallion represents one-half of the breeding equation; yet, apportioned time and funding has been considerably less for efforts to advance the discipline of stallion reproduction, as compared to that of mare reproduction. Modern-day fathers of stallion reproduction, such as Robert M. Kenney, Bill W. Pickett, and Marion Tischner, made significant strides in our understanding of stallion reproductive physiology and clinical disease, but this fascinating area of study begs for individuals with the aptitude and tenacity required to take the discipline to new heights. In recent years, the level of interest in research directed toward the breeding stallion has increased noticeably, as evidenced by the 2006 Congress of the International Society of Equine Reproduction (ISER). The stallion was represented in the largest section of papers presented and published at this meeting, a first since the inception of the ISER in 1975.

This paper will be directed primarily at the male gamete, the spermatozoon, and all the fascination that it bestows upon those of us that have dedicated a large portion of our professional lives eavesdropping on its microcosm. We will begin with a detailed overview of spermatozoal structure and function and the events that accompany a spermatozoon’s sojourn through the female reproductive tract, followed by a discussion of some potential clinical ramifications. The lecture that accompanies this text will be directed, almost exclusively, to practical applications and advancements in the discipline of stallion reproduction. Not all published work could be represented in this short review, and we preface this reading with an apology for unintentional exclusion of pertinent data. While we direct the reader to some relevant studies conducted in equids, most of the information provided in this manuscript stems from investigations conducted in other species, where the process of discovery has been most pronounced. Although this comparative approach can be quite enlightening, a drawback is that the relevance to stallions of findings unveiled in other species will require documentation. [...]