| 释义 |
sperm-aster Biol.|ˈspɜːmæstə(r)|
Also spermaster, sperm aster.
[f. sperm n. + aster 4.]
A star-shaped configuration which in some species forms ahead of the sperm nucleus as it enters the egg in fertilization, and which develops into the amphiaster.
1904Biol. Bull. VI. 226 One is the growth and division of the sperm aster, the other the growth of the nucleus. 1925E. B. Wilson Cell (ed. 3) v. 400 In almost all cases the sperm-nucleus, as it advances within the egg, is typically preceded by a sperm-aster which sooner or later divides to form an amphiaster that is the forerunner of the cleavage-amphiaster. 1946Nature 17 Aug. 239/1 Colchicine treatment..inhibits spindle formation as well as the appearance of the spermaster in fertilized eggs and of the monaster in parthenogenesis. 1977Jrnl. Embryol. & Exper. Zool. XL. 194 It would be of the utmost interest to establish whether a causal relationship does also exist between sperm aster formation and the movement and directionality of the female pronucleus. |