Cytometric solutions in veterinary andrology: Developments, advantages, and limitations

Abstract

Cytometric methodologies are becoming increasingly important in veterinary andrology as means of assessing sperm function. However, as yet, flow cytometric techniques in veterinary andrology have not kept up in sophistication with those in other areas of biology and medicine. In this brief review, we consider the present state of cytometry in andrological procedures for evaluating the fertility of domestic animal sires. We outline the aspects of sperm physiology, paying particular attention to the changes that take place during the process known as capacitation, which prepares the sperm for interaction with the egg. We then examine briefly but critically the cytometric techniques that are currently in commercial use or are being established in research laboratories for testing sperm characteristics. Current limitations and potential developments in semen assessment are discussed. Recent research knowledge offers possibilities for applying more subtle flow cytometric approaches to distinguish different levels of fertilizing potential in semen samples. For example, linking field fertility data to multiparametric kinetic studies of sperm capacitational changes rather than ''single parameter-single time point'' estimations may reveal that slower rather than rapid changes indicate high fertility. Moreover, the development of multicolor flow cytometric procedures as a means of evaluating multiple functional parameters in individual cells would reduce the uncertainties always inherent in predicting fertility from in vitro sperm evaluation tests. ' 2011 International Society for Advancement of Cytometry Key terms fertility; sperm evaluation; heterogeneity; subpopulations; multicolour cytometry THE main focus of an andrological assessment in veterinary medicine is to ascertain the fertility of a potential sire. Although the most obvious and indeed frequently used general veterinary test is to quantify the number of offspring born to the sire, this is a lengthy and very expensive process. For ''accuracy,'' many inseminations must be carried out, and results must await gestation and birth. Obviously, therefore, development of rapid tests that can be carried out in the laboratory has for long been important. However, as research into the reproductive process has advanced, it has become clear that the life of the fertilizing sperm between its release from the testis and its fusion with the egg is far from simple. Moreover, the population of sperm ejaculated into the female has been revealed as being heterogeneous in functional ability, even if morphologically normal [c.f. reviews (1,2)]. As a result of these findings, tests are being developed to examine functional ability within a heterogeneously responding population (3-5).Given that a normal male ejaculate contains many millions of individual sperm cells, it is natural that these tests are based on cytometry. In this short review, we will outline and comment upon a range of modern and still-developing cytometric methodologies in use or potentially useful for sperm...

Cluster analysis reveals a binary effect of storage on boar sperm motility function

“…This underlines the need for more sensitive methods to detect storage-associated changes in sperm function, particularly those focusing on responses to stimuli at the molecular level (c.f. Petrunkina et al 2005Petrunkina et al , 2007Petrunkina and Harrison 2011). It has been shown that bicarbonate stimulates boar sperm motility via a cAMPdependent pathway involving protein kinase A (Holt and Harrison 2002).…”

In vitro studies of Norwegian Red bovine semen immobilized and cryopreserved in alginate solid gel network

“…Additionally, the sperm DNA must be of high quality to be able to support sustained embryo development after fertilization (Evenson, ; Evenson, Larson, & Jost, ). Flow cytometry assays have been developed to analyse viability, acrosome integrity (Hossain et al., ; Martínez‐Pastor et al., ; Petrunkina & Harrison, ) and DNA quality assessed by sperm chromatin structure assay (SCSA) (Evenson et al., ).…”

Antioxidant supplementation and purification of semen for improved artificial insemination in livestock species

“…Substantial progress has been achieved in the optimization of female reproductive performance through better estrous detection and management of female reproductive functions (1)(2)(3). While modest additional gains can be made by further improving female fertility (4), the largest gains depend on improving the reproductive management of sires (5). Such progress can be made through improvement of semen collection, analysis, and cryopreservation, incorporating new biomarker-based andrological evaluations and state-of-the art instrumentation for automated, objective, and highthroughput semen analysis and processing (6,7).…”