Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy

K. Suzuki, Y. Tanaka, Y. Nakajima, K. Hirano, H. Itoh, H. Miyata, T. Hayakawa, K. Kinosita

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Four early events of egg fertilization, changes in intracellular calcium concentration and intracellular pH, reorientation of the surface membrane, and the elevation of the fertilization envelope, were imaged in real time and in pairs in single sea urchin eggs. The paired imaging allowed the correlation of the four events spatially and temporally. Three of them propagated as waves starting at the sperm entry site. The earliest was the calcium wave, visualized with fluorescent indicator eyes. After a delay of 10 s there followed a large decrease in the fluorescence polarization of membrane-bound dyes, which we interpret as arising from membrane reorientation as a result of cortical granule exocytosis and microvillar elongation. With a further delay of 15 s the fertilization envelope was seen to rise in transmitted light. All three waves propagated with similar velocities of ~10 μm/s, supporting the view that calcium triggers the latter two events. The fluorescence polarization changed in two steps with a clear pause of 10-20 s in between. The second step, which also propagated as a wave, reflects either further elongation of microvilli or straightening of irregular microvilli. This second step was abolished by cytochalasin B and was coincident with an increase in cytoplasmic pH, suggesting that pH- induced actin reorganization may play a role. The cytoplasmic alkalinization, imaged with a fluorescent probe, was quite different from the other events n that it took place homogeneously throughout the egg and slowly (over 100 s). Apparently, the alkalinization is not on a direct downstream pathway of calcium origin. An opposing possibility, that the alkalinization may in fact be triggered by the traveling calcium wave, is also discussed.

Original languageEnglish
Pages (from-to)739-748
Number of pages10
JournalBiophysical Journal
Volume68
Issue number3
Publication statusPublished - 1995
Externally publishedYes

Fingerprint

Sea Urchins
Fertilization
Eggs
Microscopy
Fluorescence Polarization
Calcium Signaling
Microvilli
Calcium
Ovum
Membranes
Cytochalasin B
Exocytosis
Fluorescent Dyes
Spermatozoa
Actins
Coloring Agents
Light

ASJC Scopus subject areas

  • Biophysics

Cite this

Suzuki, K., Tanaka, Y., Nakajima, Y., Hirano, K., Itoh, H., Miyata, H., ... Kinosita, K. (1995). Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy. Biophysical Journal, 68(3), 739-748.

Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy. / Suzuki, K.; Tanaka, Y.; Nakajima, Y.; Hirano, K.; Itoh, H.; Miyata, H.; Hayakawa, T.; Kinosita, K.

In: Biophysical Journal, Vol. 68, No. 3, 1995, p. 739-748.

Research output: Contribution to journalArticle

Suzuki, K, Tanaka, Y, Nakajima, Y, Hirano, K, Itoh, H, Miyata, H, Hayakawa, T & Kinosita, K 1995, 'Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy', Biophysical Journal, vol. 68, no. 3, pp. 739-748.
Suzuki, K. ; Tanaka, Y. ; Nakajima, Y. ; Hirano, K. ; Itoh, H. ; Miyata, H. ; Hayakawa, T. ; Kinosita, K. / Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy. In: Biophysical Journal. 1995 ; Vol. 68, No. 3. pp. 739-748.
@article{4a65ea471ce0465a8a2b553023adb3de,
title = "Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy",
abstract = "Four early events of egg fertilization, changes in intracellular calcium concentration and intracellular pH, reorientation of the surface membrane, and the elevation of the fertilization envelope, were imaged in real time and in pairs in single sea urchin eggs. The paired imaging allowed the correlation of the four events spatially and temporally. Three of them propagated as waves starting at the sperm entry site. The earliest was the calcium wave, visualized with fluorescent indicator eyes. After a delay of 10 s there followed a large decrease in the fluorescence polarization of membrane-bound dyes, which we interpret as arising from membrane reorientation as a result of cortical granule exocytosis and microvillar elongation. With a further delay of 15 s the fertilization envelope was seen to rise in transmitted light. All three waves propagated with similar velocities of ~10 μm/s, supporting the view that calcium triggers the latter two events. The fluorescence polarization changed in two steps with a clear pause of 10-20 s in between. The second step, which also propagated as a wave, reflects either further elongation of microvilli or straightening of irregular microvilli. This second step was abolished by cytochalasin B and was coincident with an increase in cytoplasmic pH, suggesting that pH- induced actin reorganization may play a role. The cytoplasmic alkalinization, imaged with a fluorescent probe, was quite different from the other events n that it took place homogeneously throughout the egg and slowly (over 100 s). Apparently, the alkalinization is not on a direct downstream pathway of calcium origin. An opposing possibility, that the alkalinization may in fact be triggered by the traveling calcium wave, is also discussed.",
author = "K. Suzuki and Y. Tanaka and Y. Nakajima and K. Hirano and H. Itoh and H. Miyata and T. Hayakawa and K. Kinosita",
year = "1995",
language = "English",
volume = "68",
pages = "739--748",
journal = "Biophysical Journal",
issn = "0006-3495",
publisher = "Biophysical Society",
number = "3",

}

TY - JOUR

T1 - Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy

AU - Suzuki, K.

AU - Tanaka, Y.

AU - Nakajima, Y.

AU - Hirano, K.

AU - Itoh, H.

AU - Miyata, H.

AU - Hayakawa, T.

AU - Kinosita, K.

PY - 1995

Y1 - 1995

N2 - Four early events of egg fertilization, changes in intracellular calcium concentration and intracellular pH, reorientation of the surface membrane, and the elevation of the fertilization envelope, were imaged in real time and in pairs in single sea urchin eggs. The paired imaging allowed the correlation of the four events spatially and temporally. Three of them propagated as waves starting at the sperm entry site. The earliest was the calcium wave, visualized with fluorescent indicator eyes. After a delay of 10 s there followed a large decrease in the fluorescence polarization of membrane-bound dyes, which we interpret as arising from membrane reorientation as a result of cortical granule exocytosis and microvillar elongation. With a further delay of 15 s the fertilization envelope was seen to rise in transmitted light. All three waves propagated with similar velocities of ~10 μm/s, supporting the view that calcium triggers the latter two events. The fluorescence polarization changed in two steps with a clear pause of 10-20 s in between. The second step, which also propagated as a wave, reflects either further elongation of microvilli or straightening of irregular microvilli. This second step was abolished by cytochalasin B and was coincident with an increase in cytoplasmic pH, suggesting that pH- induced actin reorganization may play a role. The cytoplasmic alkalinization, imaged with a fluorescent probe, was quite different from the other events n that it took place homogeneously throughout the egg and slowly (over 100 s). Apparently, the alkalinization is not on a direct downstream pathway of calcium origin. An opposing possibility, that the alkalinization may in fact be triggered by the traveling calcium wave, is also discussed.

AB - Four early events of egg fertilization, changes in intracellular calcium concentration and intracellular pH, reorientation of the surface membrane, and the elevation of the fertilization envelope, were imaged in real time and in pairs in single sea urchin eggs. The paired imaging allowed the correlation of the four events spatially and temporally. Three of them propagated as waves starting at the sperm entry site. The earliest was the calcium wave, visualized with fluorescent indicator eyes. After a delay of 10 s there followed a large decrease in the fluorescence polarization of membrane-bound dyes, which we interpret as arising from membrane reorientation as a result of cortical granule exocytosis and microvillar elongation. With a further delay of 15 s the fertilization envelope was seen to rise in transmitted light. All three waves propagated with similar velocities of ~10 μm/s, supporting the view that calcium triggers the latter two events. The fluorescence polarization changed in two steps with a clear pause of 10-20 s in between. The second step, which also propagated as a wave, reflects either further elongation of microvilli or straightening of irregular microvilli. This second step was abolished by cytochalasin B and was coincident with an increase in cytoplasmic pH, suggesting that pH- induced actin reorganization may play a role. The cytoplasmic alkalinization, imaged with a fluorescent probe, was quite different from the other events n that it took place homogeneously throughout the egg and slowly (over 100 s). Apparently, the alkalinization is not on a direct downstream pathway of calcium origin. An opposing possibility, that the alkalinization may in fact be triggered by the traveling calcium wave, is also discussed.

UR - http://www.scopus.com/inward/record.url?scp=0028913054&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028913054&partnerID=8YFLogxK

M3 - Article

C2 - 7756541

AN - SCOPUS:0028913054

VL - 68

SP - 739

EP - 748

JO - Biophysical Journal

JF - Biophysical Journal

SN - 0006-3495

IS - 3

ER -