Abstract
The process of cleavage during the syncytial blastoderm stage of the Drosophila embryo was studied in fixed whole-mounts using a triple- staining technique. Plasmalemma was stained with Concanavalin A conjugated to tetramethylrhodamine isothiocyanate, the underlying cortical F-actin with a fluorescein derivative of phalloidin, and nuclei with 4',-6 diamidine-2-phenylindole dihydrochloride. The surface caps, which overlie the superficial nuclei at this stage, were found to be rich in F-actin as compared with the rest of the cortex. After the caps formed, they extended over the surface and flattened. Whilst this was occurring the F-actin network within the caps became more diffuse. By the end of the expansion process F-actin had become concentrated at both poles of the caps. The caps then split in two. The cleavage was not accompanied by the formation of any apparent contractile ring of microfilaments across the cap, rather the break region was depleted in F-actin. The cortical actin associated with each half of the old cap then became reorganized around a nucleus to form a new daughter cap, and the cycle began again.
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Selected References
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- Arnold J. M. Cleavage furrow formation in a telolecithal egg (Loligo pealii). I. Filaments in early furrow formation. J Cell Biol. 1969 Jun;41(3):894–904. doi: 10.1083/jcb.41.3.894. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Arnold J. M. Cleavage furrow formation in a telolecithal egg (Loligo pealii). II. Direct evidence for a contraction of the cleavage furrow base. J Exp Zool. 1971 Jan;176(1):73–85. doi: 10.1002/jez.1401760108. [DOI] [PubMed] [Google Scholar]
- Fullilove S. L., Jacobson A. G. Nuclear elongation and cytokinesis in Drosophila montana. Dev Biol. 1971 Dec;26(4):560–577. doi: 10.1016/0012-1606(71)90141-2. [DOI] [PubMed] [Google Scholar]
- Schroeder T. E. Cytokinesis: filaments in the cleavage furrow. Exp Cell Res. 1968 Oct;53(1):272–276. doi: 10.1016/0014-4827(68)90373-x. [DOI] [PubMed] [Google Scholar]
- Schroeder T. E. Dynamics of the contractile ring. Soc Gen Physiol Ser. 1975;30:305–334. [PubMed] [Google Scholar]
- Strauch A. R., LaFountain J. R., Jr Centrifugation shearing exposes filamentous networks in cortical regions of crane-fly spermatocytes. J Cell Biol. 1982 Jun;93(3):670–679. doi: 10.1083/jcb.93.3.670. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Szollosi D. Cortical cytoplasmic filaments of cleaving eggs: a structural element corresponding to the contractile ring. J Cell Biol. 1970 Jan;44(1):192–209. doi: 10.1083/jcb.44.1.192. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Turner F. R., Mahowald A. P. Scanning electron microscopy of Drosophila embryogenesis. 1. The structure of the egg envelopes and the formation of the cellular blastoderm. Dev Biol. 1976 May;50(1):95–108. doi: 10.1016/0012-1606(76)90070-1. [DOI] [PubMed] [Google Scholar]
- Verderame M., Alcorta D., Egnor M., Smith K., Pollack R. Cytoskeletal F-actin patterns quantitated with fluorescein isothiocyanate-phalloidin in normal and transformed cells. Proc Natl Acad Sci U S A. 1980 Nov;77(11):6624–6628. doi: 10.1073/pnas.77.11.6624. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Warn R. M., Bullard B., Magrath R. Changes in the distribution of cortical myosin during the cellularization of the Drosophila embryo. J Embryol Exp Morphol. 1980 Jun;57:167–176. [PubMed] [Google Scholar]
- Warn R. M., Magrath R. F-actin distribution during the cellularization of the Drosophila embryo visualized with FL-phalloidin. Exp Cell Res. 1983 Jan;143(1):103–114. doi: 10.1016/0014-4827(83)90113-1. [DOI] [PubMed] [Google Scholar]
- Warn R. M., Magrath R. Observations by a novel method of surface changes during the syncytial blastoderm stage of the Drosophila embryo. Dev Biol. 1982 Feb;89(2):540–548. doi: 10.1016/0012-1606(82)90344-x. [DOI] [PubMed] [Google Scholar]
- Wieland T., Faulstich H. Amatoxins, phallotoxins, phallolysin, and antamanide: the biologically active components of poisonous Amanita mushrooms. CRC Crit Rev Biochem. 1978 Dec;5(3):185–260. doi: 10.3109/10409237809149870. [DOI] [PubMed] [Google Scholar]
- Wieland T., Miura T., Seeliger A. Analogs of phalloidin. D-Abu2-Lys7-phalloin, an F-actin binding analog, its rhodamine conjugate (RLP) a novel fluorescent F-actin-probe, and D-Ala2-Leu7-phalloin, an inert peptide. Int J Pept Protein Res. 1983 Jan;21(1):3–10. [PubMed] [Google Scholar]
- Wulf E., Deboben A., Bautz F. A., Faulstich H., Wieland T. Fluorescent phallotoxin, a tool for the visualization of cellular actin. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4498–4502. doi: 10.1073/pnas.76.9.4498. [DOI] [PMC free article] [PubMed] [Google Scholar]