Ooplasmic segregation in the zebrafish zygote and early embryo: Pattern of ooplasmic movements and transport pathways

Ricardo Fuentes; Juan Fernández

doi:10.1002/dvdy.22349

Ooplasmic segregation in the zebrafish zygote and early embryo: Pattern of ooplasmic movements and transport pathways

Developmental Dynamics ◽

10.1002/dvdy.22349 ◽

2010 ◽

Vol 239 (8) ◽

pp. 2172-2189 ◽

Cited By ~ 27

Author(s):

Ricardo Fuentes ◽

Juan Fernández

Keyword(s):

Early Embryo ◽

Transport Pathways ◽

Ooplasmic Segregation

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Localization of messenger RNA in the cortex of Chaetopterus eggs and early embryos

Development ◽

10.1242/dev.75.1.225 ◽

1983 ◽

Vol 75 (1) ◽

pp. 225-239

Author(s):

William R. Jeffery ◽

Linda J. Wilson

Keyword(s):

In Situ Hybridization ◽

Messenger Rna ◽

Germinal Vesicle ◽

Early Embryo ◽

Polar Lobe ◽

Early Embryos ◽

Cell Embryo ◽

Ooplasmic Segregation ◽

Actin Mrna

The distribution of mRNA in Chaetopterus pergamentaceus eggs was examined by in situ hybridization with poly(U) and specific cloned DNA probes. Eggs contain three distinct regions; the cortical ectoplasm, endoplasm, and a plasm released from the germinal vesicle (GV) during maturation. The ectoplasm of the mature egg showed a 15-fold enrichment in poly(A) and in histone and actin mRNAs relative to the endoplasm and the GV plasm after in situ hybridization. More than 90% of the total mass of egg poly (A) + RNA and histone and actin messages was estimated to be present in the ectoplasm. The mRNA molecules codistributed with ectoplasmic inclusion granules during ooplasmic segregation. During the extensive cytoplasmic rearrangements which occur at the time of the first cleavage the ectoplasm was divided into animal and vegetal portions. The animal portion was segregated evenly between the AB and CD blastomeres, whereas the vegetal portion entered the polar lobe and was preferentially segregated to the CD blastomere. Histone and actin mRNA entered both the AB and CD blastomeres of the 2-cell embryo. The results demonstrate that mRNA is quantitatively localized in the cortex of the Chaetopterus egg and early embryo.

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Laser scanning confocal microscopic analysis of cytoskeletal and nuclear reorganization in live Drosophila embryos

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146710 ◽

1993 ◽

Vol 51 ◽

pp. 174-175

Author(s):

William Theurkauf

Keyword(s):

Laser Scanning ◽

Microscopic Analysis ◽

Large Cell ◽

Early Embryo ◽

Drosophila Embryo ◽

Cortical Actin ◽

Nuclear Reorganization ◽

Cytoskeletal Elements ◽

Microtubule Structure ◽

Drosophila Embryos

Cell division in eucaryotes depends on coordinated changes in nuclear and cytoskeletal components. In Drosophila melanogaster embryos, the first 13 nuclear divisions occur without cytokinesis. During the final four divisions, nuclei divide in a uniform monolayer at the surface of the embryo. These surface divisions are accompanied by dramatic changes in cortical actin and microtubule structure (Karr and Alberts, 1986), and inhibitor studies indicate that these changes are essential to orderly mitosis (Zalokar and Erk, 1976). Because the early embryo is syncytial, fluorescent probes introduced by microinjection are incorporated in structures associated with all of the nuclei in the blastoderm. In addition, the nuclei divide synchronously every 10 to 20 min. These characteristics make the syncytial blastoderm embryo an excellent system for the analysis of mitotic reorganization of both nuclear and cytoskeletal elements. However, the Drosophila embryo is a large cell, and resolution of cytoskeletal filaments and nuclear structure is hampered by out-of focus signal.

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