Morula: Difference between revisions
Line 50: | Line 50: | ||
===Mouse Morula=== | ===Mouse Morula=== | ||
<gallery> | <gallery> | ||
File:Mouse-morula_01.jpg|4 cell morula stage development | File:Mouse-morula_01.jpg|4 cell morula stage development | ||
File:Mouse_Sox2_expression_01.jpg|Sox2 expression | File:Mouse_Sox2_expression_01.jpg|Sox2 expression | ||
File:Mouse- preimplantation gene expression 02.jpg|Early gene expression | File:Mouse- preimplantation gene expression 02.jpg|Early gene expression | ||
File:Mouse- preimplantation gene expression 03.jpg|Early gene expression | File:Mouse- preimplantation gene expression 03.jpg|Early gene expression |
Revision as of 09:19, 20 April 2012
Introduction
(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.
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.
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.
- Links: Fertilization | Week 1 | Morula | Blastocyst
Some Recent Findings
|
Compaction
- E-cadherin mediated adhesion initiates at compaction at the 8-cell stage
- regulated post-translationally via protein kinase C and other signalling molecules
Blastomere Division
An in vitro study of human blastocyst development[5] showed that those blastomeres that initially divide quickly are more likely to develop to blastocyst stage.
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.[4] 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.
Model Human Morula Development
The following figure is from a recent study[3] using video and genetic analysis of in vitro human development during week 1 following fertilization.
- EGA - embryonic genome activation
- ESSP - embryonic stage–specific pattern, four unique embryonic stage–specific patterns (1-4)
- Links: Figure with legend
Morulas in Other Species
Mouse Morula
- Links: Mouse Development
Sea Urchin Morula
Sea Urchin early embryo cleavage pattern (SDB Gallery Images)
- Links: Sea Urchin Development
Bovine Morula
Bovine Morula[6]
- Image shows DNA staining (white) and f-actin filaments (orange) at day 4. Scale bars represent 100 µm.
- Pale staining round nuclei are at interphase.
- Arrow shows single nucleus at prophase.
- A single nucleus is seen at metaphase.
- Condensed bright nuclei are apoptotic.
- Links: Bovine Development | Mitosis
References
- ↑ 1.0 1.1 <pubmed>19924284</pubmed>| PMC2773928 | PLoS One
- ↑ 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. PMID21049019 | PLoS One.
- ↑ 3.0 3.1 <pubmed>20890283</pubmed>| Nat Biotechnol.
- ↑ 4.0 4.1 <pubmed>19997595</pubmed>| PLoS One.
- ↑ <pubmed>11821286</pubmed>
- ↑ <pubmed>21811561</pubmed>| PLoS One.
Articles
<pubmed>19289087</pubmed> <pubmed>20157423</pubmed>
Search PubMed
Search Pubmed: morula development | blastomere development |
Glossary Links
- Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link
Cite this page: Hill, M.A. (2024, June 20) Embryology Morula. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Morula
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G