Mugnier Sylvie, Boittin Stéphane, Douet Cécile, Monget Philippe, Magistrini Michèle, Goudet Ghylène
INRA, UMR85 Physiologie de la Reproduction et des Comportements, CNRS, Haras Nationaux, Université de Tours, Nouzilly, France.
Reprod Biol Endocrinol. 2008 Nov 14;6:51. doi: 10.1186/1477-7827-6-51.
In human and rodents, sperm-zona pellucida binding is mediated by a sperm surface Galactosyltransferase that recognizes N-Acetylglucosamine residues on a glycoprotein ZPC. In large domestic mammals, the role of these molecules remains unclear: in bovine, they are involved in sperm-zona pellucida binding, whereas in porcine, they are not necessary. Our aim was to clarify the role of Galactosyltransferase and N-Acetylglucosamine residues in sperm-zona pellucida binding in ungulates. For this purpose, we analyzed the mechanism of sperm-zona pellucida interaction in a third ungulate: the horse, since the Galactosyltransferase and N-Acetylglucosamine residues have been localized on equine gametes.
We masked the Galactosyltransferase and N-Acetylglucosamine residues before the co-incubation of gametes. Galactosyltransferase was masked either with an anti-Galactosyltransferase antibody or with the enzyme substrate, UDP Galactose. N-Acetylglucosamine residues were masked either with a purified Galactosyltransferase or with an anti-ZPC antibody.
The number of spermatozoa bound to the zona pellucida did not decrease after the masking of Galactosyltransferase or N-Acetylglucosamine. So, these two molecules may not be necessary in the mechanism of in vitro sperm-zona pellucida interaction in the horse.
The involvement of Galactosyltransferase and N-Acetylglucosamine residues in sperm-zona pellucida binding may have been lost during evolution in some ungulates, such as porcine and equine species.
在人类和啮齿动物中，精子与透明带的结合是由精子表面的半乳糖基转移酶介导的，该酶识别糖蛋白ZPC上的N - 乙酰葡糖胺残基。在大型家养哺乳动物中，这些分子的作用仍不清楚：在牛中，它们参与精子与透明带的结合，而在猪中则并非必需。我们的目的是阐明半乳糖基转移酶和N - 乙酰葡糖胺残基在有蹄类动物精子与透明带结合中的作用。为此，我们分析了第三种有蹄类动物——马的精子与透明带相互作用的机制，因为半乳糖基转移酶和N - 乙酰葡糖胺残基已定位在马的配子上。
在配子共孵育前，我们对半乳糖基转移酶和N - 乙酰葡糖胺残基进行了封闭。半乳糖基转移酶用抗半乳糖基转移酶抗体或酶底物UDP半乳糖进行封闭。N - 乙酰葡糖胺残基用纯化的半乳糖基转移酶或抗ZPC抗体进行封闭。
封闭半乳糖基转移酶或N - 乙酰葡糖胺后，与透明带结合的精子数量并未减少。因此，这两种分子可能在马的体外精子与透明带相互作用机制中并非必需。
在某些有蹄类动物（如猪和马）的进化过程中，半乳糖基转移酶和N - 乙酰葡糖胺残基在精子与透明带结合中的作用可能已经丧失。
