Seasonal changes have been observed in stallion sperm morphology. Since carbohydrates of sperm glycocalyx play a key role in the sperm-egg recognition and zona binding, the aim of this study was to evaluate the distribution of carbohydrates in stallion ejaculates collected in two different periods of the year using lectin histochemistry. Semen from two fertile trotters was collected in winter (January) and summer (July) (3 ejaculates for each time), diluted in Tyrode’s medium, fixed in 4% (w/v) neutral formalin, smeared on slides and incubated with appropriate dilutions of 12 lectins. The spermatozoa from winter ejaculates reacted with 1) MAL II, SNA, HPA, Con A, WGA and GSA II in the whole cell surface, 2) PNA, RCA120 and SBA in the acrosomal region, 3) GSA I-B4 in the entire head, 4) DBA and UEA I in the post-acrosomal region and tail. The spermatozoa contained in summer ejaculates did not show GSA I-B4 reactivity, whereas they displayed SBA affinity also in post-acrosomal region which was unreactive to UEA I. In addition, the tail of July collected spermatozoa did not contain binding sites for UEA I and GSA II. These results suggest that the expression of oligosaccharide sequences of stallion sperm glycocalyx is time-dependent and that the acrosomal region shows a more stable glycoconjugate pattern with respect to other regions. Lastly, carbohydrate pattern of the glycocalyx could be important in the assessment of semen quality in stallions.
Influence of season on the glycoconjugates surface of stallion ejaculated spermatozoa
VENTRIGLIA G;DESANTIS, Salvatore;VALENTINI, Luisa;LACALANDRA, Giovanni Michele;
2006-01-01
Abstract
Seasonal changes have been observed in stallion sperm morphology. Since carbohydrates of sperm glycocalyx play a key role in the sperm-egg recognition and zona binding, the aim of this study was to evaluate the distribution of carbohydrates in stallion ejaculates collected in two different periods of the year using lectin histochemistry. Semen from two fertile trotters was collected in winter (January) and summer (July) (3 ejaculates for each time), diluted in Tyrode’s medium, fixed in 4% (w/v) neutral formalin, smeared on slides and incubated with appropriate dilutions of 12 lectins. The spermatozoa from winter ejaculates reacted with 1) MAL II, SNA, HPA, Con A, WGA and GSA II in the whole cell surface, 2) PNA, RCA120 and SBA in the acrosomal region, 3) GSA I-B4 in the entire head, 4) DBA and UEA I in the post-acrosomal region and tail. The spermatozoa contained in summer ejaculates did not show GSA I-B4 reactivity, whereas they displayed SBA affinity also in post-acrosomal region which was unreactive to UEA I. In addition, the tail of July collected spermatozoa did not contain binding sites for UEA I and GSA II. These results suggest that the expression of oligosaccharide sequences of stallion sperm glycocalyx is time-dependent and that the acrosomal region shows a more stable glycoconjugate pattern with respect to other regions. Lastly, carbohydrate pattern of the glycocalyx could be important in the assessment of semen quality in stallions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
