Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte.
Knowledge about the mechanism that establishes embryonic polarity is fundamental in understanding mammalian development. In re-addressing several controversial claims, we recently proposed a model in which mouse embryonic polarity is not specified until the blastocyst stage. Before fertilization, th...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2006-05-01
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| Series: | PLoS Biology |
| Online Access: | http://europepmc.org/articles/PMC1440932?pdf=render |
| _version_ | 1818356711005618176 |
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| author | Nami Motosugi Jens-Erik Dietrich Zbigniew Polanski Davor Solter Takashi Hiiragi |
| author_facet | Nami Motosugi Jens-Erik Dietrich Zbigniew Polanski Davor Solter Takashi Hiiragi |
| author_sort | Nami Motosugi |
| collection | DOAJ |
| description | Knowledge about the mechanism that establishes embryonic polarity is fundamental in understanding mammalian development. In re-addressing several controversial claims, we recently proposed a model in which mouse embryonic polarity is not specified until the blastocyst stage. Before fertilization, the fully differentiated oocyte has been characterized as "polarized," and we indeed observed that the sperm preferentially enters the polar body half. Here we show that preferential sperm entry is not due to an intrinsic polarity of the oocyte, since fertilization takes place uniformly when the zona pellucida is removed. We suggest that the term "asymmetry" denotes morphological differences, whereas "polarity" in addition implies developmental consequences. Thus, the mouse oocyte can be considered "asymmetric" but "non-polarized." The penetration through the zona pellucida is also random, and a significant proportion of sperm binds to the oocyte membrane at a point distant from the zona penetration site. Time-lapse recordings confirmed that sperm swim around the perivitelline space before fertilization. Experimental enlargement of the perivitelline space in the non-polar body half increased the regional probability of fertilization. Based on these experiments, we propose a model in which the space asymmetry exerted by the first polar body and the zona pellucida directs sperm entry preferentially to the polar body half, with no need for oocyte polarity. |
| first_indexed | 2024-12-13T20:01:33Z |
| format | Article |
| id | doaj.art-b706637cf1684b64810025aec09a3f7b |
| institution | Directory Open Access Journal |
| issn | 1544-9173 1545-7885 |
| language | English |
| last_indexed | 2024-12-13T20:01:33Z |
| publishDate | 2006-05-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Biology |
| spelling | doaj.art-b706637cf1684b64810025aec09a3f7b2022-12-21T23:33:10ZengPublic Library of Science (PLoS)PLoS Biology1544-91731545-78852006-05-0145e13510.1371/journal.pbio.0040135Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte.Nami MotosugiJens-Erik DietrichZbigniew PolanskiDavor SolterTakashi HiiragiKnowledge about the mechanism that establishes embryonic polarity is fundamental in understanding mammalian development. In re-addressing several controversial claims, we recently proposed a model in which mouse embryonic polarity is not specified until the blastocyst stage. Before fertilization, the fully differentiated oocyte has been characterized as "polarized," and we indeed observed that the sperm preferentially enters the polar body half. Here we show that preferential sperm entry is not due to an intrinsic polarity of the oocyte, since fertilization takes place uniformly when the zona pellucida is removed. We suggest that the term "asymmetry" denotes morphological differences, whereas "polarity" in addition implies developmental consequences. Thus, the mouse oocyte can be considered "asymmetric" but "non-polarized." The penetration through the zona pellucida is also random, and a significant proportion of sperm binds to the oocyte membrane at a point distant from the zona penetration site. Time-lapse recordings confirmed that sperm swim around the perivitelline space before fertilization. Experimental enlargement of the perivitelline space in the non-polar body half increased the regional probability of fertilization. Based on these experiments, we propose a model in which the space asymmetry exerted by the first polar body and the zona pellucida directs sperm entry preferentially to the polar body half, with no need for oocyte polarity.http://europepmc.org/articles/PMC1440932?pdf=render |
| spellingShingle | Nami Motosugi Jens-Erik Dietrich Zbigniew Polanski Davor Solter Takashi Hiiragi Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. PLoS Biology |
| title | Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. |
| title_full | Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. |
| title_fullStr | Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. |
| title_full_unstemmed | Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. |
| title_short | Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. |
| title_sort | space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte |
| url | http://europepmc.org/articles/PMC1440932?pdf=render |
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