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| ==Introduction==
| | # REDIRECT [[Morula Development]] |
| [[File:Human embryo day 2.jpg|thumb|300px|Human morula (day 2)<ref name="PMID19924284"><pubmed>19924284</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2773928 PMC2773928] | [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0007844 PLoS One]</ref>]] | |
| (Latin, ''morula'' = mulberry) An early stage in post-fertilization development when cells have rapidly mitotically divided to produce a solid mass of cells (12-15 cells) with a "mulberry" appearance. This stage is followed by formation of a cavity in this cellular mass [[blastocyst]] stage.
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| A key event prior to morula formation is "compaction", where the 8 cell embryo undergoes changes in cell morphology and cell-cell adhesion that initiates the formation of this solid ball of cells.
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| In humans, morula stage of development occurs during the first days of the first week following [[fertilization]]. This developmental stage is followed by formation of a cavity, the blastocoel, which defines formation of the [[blastocyst]].
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| :'''Links:''' [[Fertilization]] | [[Week 1]] | [[Morula]] | [[Blastocyst]]
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| == Some Recent Findings ==
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| [[File:Human_embryo_day_3.jpg|thumb|300px|Human morula (day 3)<ref name="PMID19924284" />]]
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| {|
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| |-bgcolor="F5FAFF"
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| * '''Functional genomics of 5- to 8-cell stage human embryos by blastomere single-cell cDNA analysis'''<ref name="PMID21049019">Galán A, Montaner D, Póo ME, Valbuena D, Ruiz V, Aguilar C, Dopazo J, Simón C. '''Functional genomics of 5- to 8-cell stage human embryos by blastomere single-cell cDNA analysis.''' PLoS One. 2010 Oct 26;5(10):e13615. [http://www.ncbi.nlm.nih.gov/pubmed/21049019 PMID21049019] | [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013615 PLoS One.]</ref> "Forty-nine blastomeres from 5- to 8-cell human embryos have been investigated following an efficient single-cell cDNA amplification protocol to provide a template for high-density microarray analysis. The previously described markers, characteristic of Inner Cell Mass (ICM) (n = 120), stemness (n = 190) and Trophectoderm (TE) (n = 45), were analyzed, and a housekeeping pattern of 46 genes was established. ...In summary, the global single-cell cDNA amplification microarray analysis of the 5- to 8-cell stage human embryos reveals that blastomere fate is not committed to ICM or TE.
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| * '''Non-invasive imaging of human embryos before embryonic genome activation predicts development to the blastocyst stage'''<ref name="PMID20890283"><pubmed>20890283</pubmed>| [http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.1686.html Nat Biotechnol.]</ref> "We report studies of preimplantation human embryo development that correlate time-lapse image analysis and gene expression profiling. By examining a large set of zygotes from in vitro fertilization (IVF), we find that success in progression to the blastocyst stage can be predicted with >93% sensitivity and specificity by measuring three dynamic, noninvasive imaging parameters by day 2 after fertilization, before embryonic genome activation (EGA)."
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| ==Compaction==
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| * E-cadherin mediated adhesion initiates at compaction at the 8-cell stage
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| * regulated post-translationally via protein kinase C and other signalling molecules
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| ==Blastomere Division==
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| [[File:Blastomere mitotic spindle orientation.jpg|thumb|Spindle orientation calculation.<ref name="PMID19997595"><pubmed>19997595</pubmed>| [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0008171 PLoS One.]</ref>]]
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| An in vitro study of human blastocyst development<pubmed>11821286</pubmed> showed that those blastomeres that initially divide quickly are more likely to develop to blastocyst stage.
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| A recent study in mice showed that there was no specific orientation of the mitotic spindle during cell division in the 8 to 16 cell stage transition.<ref name="PMID19997595"><pubmed>19997595</pubmed>| [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0008171 PLoS One.]</ref> This suggests no predetermined cleavage pattern (pre-patterned) at the 8 cell stage and only modulated by the extent of cell rounding up during mitosis. In other species, such as the worm ''C.elegans'' and ascidians, have specific patterns of spindle orientation from the zygote stage.
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| ==Model Human Morula Development==
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| The following figure is from a recent study<ref name="PMID20890283"><pubmed>20890283</pubmed>| [http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.1686.html Nat Biotechnol.]</ref> using video and genetic analysis of ''in vitro'' human development during week 1 following fertilization.
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| [[File:Model human blastocyst development.jpg|800px]]
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| * EGA - embryonic genome activation
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| * ESSP - embryonic stage–specific pattern, four unique embryonic stage–specific patterns (1-4)
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| :'''Links:''' [[:File:Model human blastocyst development.jpg|Figure with legend]]
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| ==Morulas in Other Species==
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| ===Mouse Morula===
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| <gallery>
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| File:Mouse-morula_01.jpg|4 cell morula stage development<ref><pubmed>20405021</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2854157 PMC2854157] | [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010160 PLoS]</ref>
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| File:Mouse_Sox2_expression_01.jpg|Sox2 expression<ref name="PMID21103067"><pubmed>21103067</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2980489 PMC2980489] | [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013952 PLoS One.]</ref>
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| File:Mouse- preimplantation gene expression 02.jpg|Early gene expression<ref name="PMID21103067" />
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| File:Mouse- preimplantation gene expression 03.jpg|Early gene expression<ref name="PMID21103067" />
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| File:Mouse- preimplantation gene expression 04.jpg|Early gene expression<ref name="PMID21103067" />
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| File:Mouse- preimplantation gene expression 05.jpg|Early gene expression<ref name="PMID21103067" />
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| </gallery>
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| :'''Links:''' [[Mouse Development]]
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| ===Sea Urchin Morula===
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| [[File:Sea Urchin- early embryo cleavage pattern.jpg|300px]]
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| '''Sea Urchin''' early embryo cleavage pattern (SDB Gallery Images)
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| :'''Links:''' [[Sea Urchin Development]]
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| ===Bovine Morula===
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| [[File:Bovine_morula_01.jpg|600px]]
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| '''Bovine Morula'''<ref><pubmed>21811561</pubmed>| [http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0022121 PLoS One.]</ref>
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| * Image shows DNA staining (white) and f-actin filaments (orange) at day 4. Scale bars represent 100 µm.
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| * Pale staining round nuclei are at interphase.
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| * Arrow shows single nucleus at prophase.
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| * A single nucleus is seen at metaphase.
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| * Condensed bright nuclei are apoptotic.
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| :'''Links:''' [[Bovine Development]] | [[Cell Division - Mitosis|Mitosis]]
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| ==References==
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| <references/>
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| ===Articles===
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| <pubmed>19289087</pubmed>
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| <pubmed>20157423</pubmed>
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| ===Search PubMed===
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| '''Search Pubmed:''' [http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=search&term=morula%20development morula development] | [http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=search&term=blastomere%20development blastomere development] |
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| {{Template:Glossary}}
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| {{Template:Footer}}
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| [[Category:Human Embryo]] [[Category:Carnegie Stage]] [[Category:Week 1]] [[Category:Morula]]
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