Cleavage-stage

Sunderman, F.W., Jr., B.L. Mongillo, M.C. Plowman, and S.M. Brennan. 1990. Uptake and release of 63Ni2+ by Xenopus embryos during early cleavage stages. Biol. Metals 2 214-218. 

During the first few cell divisions of the sea urchin embryo the major histones incorporated into the chromatin are the cleavage stage or CS variants [124]. CS histones are stored in the egg and are translated from stored mRNAs [124-126]. CS H2A, CS H2B, and CS H3 have distinct sequences, while the sequence of the H4... 

Mandl, B., Brandt, W.F., Superti-Furga, G., Gratringer, P.G., Birnstiel, M.L., and Busslinger, M. (1997) The five cleavage-stage (CS) histones of the sea urchin are encoded by a maternally expressed... 

ADP-ribosylation has also been implicated as a proteolytic antagonist during embryonic development [231]. Following fertilization in sea urchin, sperm-specific histones are degraded by the sperm-histone-selective (SpH) protease and subsequently replaced by cleavage stage histone variants. During this process, the maternal replacement histones are protected from proteolysis by ADP-ribosylation. 

In the Xenopus oocyte a large number of ribosomes are made in a short time to handle the rapid demand for cell growth during cleavage stages. How is this large amount of rRNA made in such a short time ... 

The preferred method for delivery of lentiviral vectors is microinjection into the perivitelline space of single cell or cleavage-stage embryos, which is a far less invasive procedure... 

Steeves, C.L. et al., 2003, The glycine neurotransmitter transporter GLYT1 is an organic osmolyte transporter regulating cell volume in cleavage-stage embryos. Proc. Natl. Acad. Sci. TJ.S.A. 100(24) 13982-13987. 

The cleavage stage of the haloform reaction may be regarded as a hydroxide ion displacement reaction at the keto group, although again w e cannot be sure that preliminary addition at the carbonyl group does not take place (p. 90) ... 

Mano, Y. 1970. Cytoplasmic regulation and cyclic variation in protein synthesis in the early cleavage stages of the sea urchin embryo. Dev. Biol. 22 433-60. 

Fig. 2 Two-dimensional PAGE analysis of sperm-associated proteins on condensed chromatin and following chromatin decondensation in egg extract and purified nucleoplasmin. Sperm nuclei were incubated in either (A) buffer, (B) Xenopus egg HSS, or (C) purified egg nucleoplasmin for 10 min. The nuclei were then pelleted, washed, and the chromatin-associated proteins were extracted with acid and analyzed in the first dimension by Triton-acid-urea (TAU)-PACE (left to right) and in the second dimension by SDS-PAGE (top to bottom). The positions of the core histones are indicated as H2A, H2B. H3. and H4 and the sperm-specific basic proteins as X and Y. The arrowheads and arrow indicate the positions of the cleavage-stage linker histone. B4, and Xenopus HMG-2, respectively (Dimitrov et at., 1994). [Reproduced from Philpott and Leno (1992) Copyright Cell Press.]...

Ohsumi, K., and Katagiri, C. (1991a). Occurrence of HI subtypes specific to pronuclei and cleavage-stage cell nuclei of anuran amphibians. Dev. Biol 147, 110-120. 

After washing, pipette vigorously to remove coronal cells and place the eggs in 1% sodium citrate solution for 5 to 10 min at room temperature. For later cleavage stages (e.g., blastocysts), hypotonic treatment may be prolonged to 15 to 20 min. 

The total number of drops necessary is dependent upon the developmental stages of the eggs. For oocytes and early cleavage stages, from one to eight cells, an initial drop followed by two more will suffice. For blastocysts, the total number of fixative drops should be at least five. 

Lane M, Bavister BD. 1999. Regulation of intracellular pH in bovine oocytes and cleavage stage embryos. Mol Reprod Dev 54(4) 396-401. 

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