The micropyle: a sperm guidance system in teleost fertilization.
The micropyle: a sperm guidance system in teleost fertilization.
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作者：
D. Amanze;A. Iyengar
玫瑰倒钩（Barbus conchonius）卵的珠孔区由7-10个沟和脊组成，直接流入漏斗形前庭，这是受精过程中实现精卵接触的唯一点。对精子在珠孔区运动模式的延时视频显微镜研究和计算机辅助分析的结果表明，精子通常最先进入珠孔区，总是优先沿着沟进入珠孔坑。随后，86%的精子在30 s内到达珠孔区优先沿着沟进入珠孔坑附近。计算出精子在珠孔区的引导作用，一旦精子进入珠孔区，可能对来自卵的某种形式的化学引诱物作出反应，则可将卵穿透/受精的机会提高多达99.7%。受精后精子凝集也被发现优先发生沿着沟。我们的体外受精实验的结果表明，精子进入点和胚盘形成之间的关联：胚盘直接形成在所有未受干扰的卵子的珠孔下方。
The micropylar region of the Rosy barb, Barbus conchonius, egg consists of 7-10 grooves and ridges, which drain directly into a funnel-shaped vestibule, the only point on the chorion through which sperm-egg contact is achieved during fertilization. Results of time-lapse video microscope study and computer-aided analysis of sperm motility pattern in the micropylar region showed that the fertilizing sperm, usually the first to enter the micropylar region, always travelled preferentially along the grooves into the micropylar pit. Subsequently, 86% of sperm arriving the micropylar region within 30 s travelled preferentially along the grooves into the immediate vicinity of the micropylar pit. The sperm guidance role of the micropylar region was calculated to enhance chances of egg penetration/fertilization by as much as 99.7% once sperm were within the micropylar region, possibly in response to some form of chemo-attractant(s) from the egg. Sperm agglutination post-fertilization was also found to occur preferentially along the grooves. Results of our in vitro fertilization experiments showed association between point of sperm entry and blastodisc formation: the blastodisc formed directly beneath the micropyle in all undisturbed eggs.