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A single and rapid calcium wave at egg activation in Drosophila.

York-Andersen AH, Parton RM, Bi CJ, Bromley CL, Davis I, Weil TT - Biol Open (2015)

Bottom Line: Here, we utilise ratiometric imaging of Ca(2+) indicator dyes and genetically encoded Ca(2+) indicator proteins to identify and characterise a single, rapid, transient wave of Ca(2+) in the Drosophila egg at activation.We further show that mechanical pressure alone is not sufficient to initiate a Ca(2+) wave.We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca(2+) transient.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.

No MeSH data available.


Related in: MedlinePlus

P bodies disperse at egg activation.(A–E) Mature oocytes and early embryo expressing Me31B::GFP labelling P bodies. (A) Time series of ex vivo mature oocyte following the addition of activation buffer (t = 0′) show Me31B foci dispersing. (B,C) Higher magnification 63× 1.4 NA lens before (B) and after (C) the addition of activation buffer. Large Me31B particles fall apart following the addition of activation buffer and swelling, consistent with observations of stage 14 oocyte (D) and early embryo (E). Scale bars A,B = 100 µm, C–E = 40 µm. Max projection A = 40 µm, B–E single frame.
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f07: P bodies disperse at egg activation.(A–E) Mature oocytes and early embryo expressing Me31B::GFP labelling P bodies. (A) Time series of ex vivo mature oocyte following the addition of activation buffer (t = 0′) show Me31B foci dispersing. (B,C) Higher magnification 63× 1.4 NA lens before (B) and after (C) the addition of activation buffer. Large Me31B particles fall apart following the addition of activation buffer and swelling, consistent with observations of stage 14 oocyte (D) and early embryo (E). Scale bars A,B = 100 µm, C–E = 40 µm. Max projection A = 40 µm, B–E single frame.

Mentions: Activation in Drosophila heralds a cascade of events, including translational initiation of several mRNA's: bcd, nanos, hunchback, caudal, Toll, torso, smaug, and string (Tadros and Lipshitz, 2005). Previous work has established the presence of cytoplasmic regions in the oocyte termed P bodies, where mRNA translation is not supported and which, therefore, act in repressing the translation of stored mRNA's such as bcd (Weil et al., 2012). Activation has previously been shown to dissipate P bodies at the anterior pole of the oocyte, releasing bcd mRNA for translation (Weil et al., 2012). To test the involvement of the Ca2+ transient in regulation of these P bodies and consequently in regulating translation regulation, we examined the common P body marker, Me31B, at activation (Fig. 7A–C). We show that Me31B particles present in the mature oocyte, disperse following ex vivo activation (n = 11). We observe a similar dispersed pattern of Me31B in the early embryo when compared to the large foci in stage 14 oocyte (Fig. 7D,E).


A single and rapid calcium wave at egg activation in Drosophila.

York-Andersen AH, Parton RM, Bi CJ, Bromley CL, Davis I, Weil TT - Biol Open (2015)

P bodies disperse at egg activation.(A–E) Mature oocytes and early embryo expressing Me31B::GFP labelling P bodies. (A) Time series of ex vivo mature oocyte following the addition of activation buffer (t = 0′) show Me31B foci dispersing. (B,C) Higher magnification 63× 1.4 NA lens before (B) and after (C) the addition of activation buffer. Large Me31B particles fall apart following the addition of activation buffer and swelling, consistent with observations of stage 14 oocyte (D) and early embryo (E). Scale bars A,B = 100 µm, C–E = 40 µm. Max projection A = 40 µm, B–E single frame.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4400597&req=5

f07: P bodies disperse at egg activation.(A–E) Mature oocytes and early embryo expressing Me31B::GFP labelling P bodies. (A) Time series of ex vivo mature oocyte following the addition of activation buffer (t = 0′) show Me31B foci dispersing. (B,C) Higher magnification 63× 1.4 NA lens before (B) and after (C) the addition of activation buffer. Large Me31B particles fall apart following the addition of activation buffer and swelling, consistent with observations of stage 14 oocyte (D) and early embryo (E). Scale bars A,B = 100 µm, C–E = 40 µm. Max projection A = 40 µm, B–E single frame.
Mentions: Activation in Drosophila heralds a cascade of events, including translational initiation of several mRNA's: bcd, nanos, hunchback, caudal, Toll, torso, smaug, and string (Tadros and Lipshitz, 2005). Previous work has established the presence of cytoplasmic regions in the oocyte termed P bodies, where mRNA translation is not supported and which, therefore, act in repressing the translation of stored mRNA's such as bcd (Weil et al., 2012). Activation has previously been shown to dissipate P bodies at the anterior pole of the oocyte, releasing bcd mRNA for translation (Weil et al., 2012). To test the involvement of the Ca2+ transient in regulation of these P bodies and consequently in regulating translation regulation, we examined the common P body marker, Me31B, at activation (Fig. 7A–C). We show that Me31B particles present in the mature oocyte, disperse following ex vivo activation (n = 11). We observe a similar dispersed pattern of Me31B in the early embryo when compared to the large foci in stage 14 oocyte (Fig. 7D,E).

Bottom Line: Here, we utilise ratiometric imaging of Ca(2+) indicator dyes and genetically encoded Ca(2+) indicator proteins to identify and characterise a single, rapid, transient wave of Ca(2+) in the Drosophila egg at activation.We further show that mechanical pressure alone is not sufficient to initiate a Ca(2+) wave.We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca(2+) transient.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.

No MeSH data available.


Related in: MedlinePlus