Abstract
We investigated the electrical properties of the egg of the nemertean worm (Cerebratulus, and found evidence that an electrically-mediated polyspermy block operates for a period of about 1 hr after fertilization. At fertilization, in natural or artificial sea water, the membrane potential shifts from its resting level of about -66 mV to a peak of about +43 mV, and in most cases remains greater than 0 mV for more than 1 hr. The average potential during the first 30 min is +22 ± 8 mV (SD, n = 12), When the external Na+ concentration is reduced from 486 to 51 mM (choline substituted) the fertilization potential amplitude is reduced; the average potential during the first 30 min is -27 ± 21 mV (SD, n = 5). Eggs inseminated in 51 mM Na+ sea water become polyspermic, indicating that polyspermy prevention depends on an electrically-mediated mechanism. The electrical block is required for about 60 min, since transfer to 51 mM Na+ sea water during this period results in polyspermy. During the first hour following fertilization, the egg is also developing a permanent, nonelectrical block; the degree of polyspermy which results upon transfer to low Na+ sea water decreases progressively with time. The permanent block appears to be at the level of the egg plasma membrane or glycocalyx, since the egg envelope is not a barrier to sperm penetration, nor does its removal induce polyspermy. Electron micrographs show no obvious changes in the morphology of the extracellular layers, plasma membrane or cortex of the egg after fertilization.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 45-52 |
| Number of pages | 8 |
| Journal | Journal of Experimental Zoology |
| Volume | 236 |
| Issue number | 1 |
| State | Published - 1985 |
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ASJC Scopus subject areas
- Animal Science and Zoology
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Fertilization potential and polyspermy prevention in the egg of the nemertean, Cerebratulus lacteus. / Kline, D.; Jaffe, L. A.; Tucker, Richard P.
In: Journal of Experimental Zoology, Vol. 236, No. 1, 1985, p. 45-52.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fertilization potential and polyspermy prevention in the egg of the nemertean, Cerebratulus lacteus
AU - Kline, D.
AU - Jaffe, L. A.
AU - Tucker, Richard P
PY - 1985
Y1 - 1985
N2 - We investigated the electrical properties of the egg of the nemertean worm (Cerebratulus, and found evidence that an electrically-mediated polyspermy block operates for a period of about 1 hr after fertilization. At fertilization, in natural or artificial sea water, the membrane potential shifts from its resting level of about -66 mV to a peak of about +43 mV, and in most cases remains greater than 0 mV for more than 1 hr. The average potential during the first 30 min is +22 ± 8 mV (SD, n = 12), When the external Na+ concentration is reduced from 486 to 51 mM (choline substituted) the fertilization potential amplitude is reduced; the average potential during the first 30 min is -27 ± 21 mV (SD, n = 5). Eggs inseminated in 51 mM Na+ sea water become polyspermic, indicating that polyspermy prevention depends on an electrically-mediated mechanism. The electrical block is required for about 60 min, since transfer to 51 mM Na+ sea water during this period results in polyspermy. During the first hour following fertilization, the egg is also developing a permanent, nonelectrical block; the degree of polyspermy which results upon transfer to low Na+ sea water decreases progressively with time. The permanent block appears to be at the level of the egg plasma membrane or glycocalyx, since the egg envelope is not a barrier to sperm penetration, nor does its removal induce polyspermy. Electron micrographs show no obvious changes in the morphology of the extracellular layers, plasma membrane or cortex of the egg after fertilization.
AB - We investigated the electrical properties of the egg of the nemertean worm (Cerebratulus, and found evidence that an electrically-mediated polyspermy block operates for a period of about 1 hr after fertilization. At fertilization, in natural or artificial sea water, the membrane potential shifts from its resting level of about -66 mV to a peak of about +43 mV, and in most cases remains greater than 0 mV for more than 1 hr. The average potential during the first 30 min is +22 ± 8 mV (SD, n = 12), When the external Na+ concentration is reduced from 486 to 51 mM (choline substituted) the fertilization potential amplitude is reduced; the average potential during the first 30 min is -27 ± 21 mV (SD, n = 5). Eggs inseminated in 51 mM Na+ sea water become polyspermic, indicating that polyspermy prevention depends on an electrically-mediated mechanism. The electrical block is required for about 60 min, since transfer to 51 mM Na+ sea water during this period results in polyspermy. During the first hour following fertilization, the egg is also developing a permanent, nonelectrical block; the degree of polyspermy which results upon transfer to low Na+ sea water decreases progressively with time. The permanent block appears to be at the level of the egg plasma membrane or glycocalyx, since the egg envelope is not a barrier to sperm penetration, nor does its removal induce polyspermy. Electron micrographs show no obvious changes in the morphology of the extracellular layers, plasma membrane or cortex of the egg after fertilization.
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UR - http://www.scopus.com/inward/citedby.url?scp=0021968680&partnerID=8YFLogxK
M3 - Article
C2 - 4056704
AN - SCOPUS:0021968680
VL - 236
SP - 45
EP - 52
JO - Journal of Experimental Zoology
JF - Journal of Experimental Zoology
SN - 1552-5007
IS - 1
ER -