Carnegie stage 2: Difference between revisions
(Created page with '==Introduction== First cell divisions of the zygote forming initially 2 blastomeres and continuing to divide to form the morula. '''Facts:''' Week 1, 2-3 days, size…') |
|||
(40 intermediate revisions by 2 users not shown) | |||
Line 1: | Line 1: | ||
{{header}} | |||
==Introduction== | ==Introduction== | ||
First cell divisions of the zygote forming initially 2 blastomeres | {| | ||
| width=220px|[[File:Stage2.jpg]] | |||
| First cell mitotic divisions of the zygote forming initially 2 blastomeres that continue to divide to form the [[M#morula|morula]], a "berry", a solid mass of cells. | |||
This early mitosis is a unique embryonic cell cycle (M, S, M phases) compared to adult (M, G<sub>1</sub>, S, G<sub>2</sub>, M phase). With virtually no G<sub>1</sub> or G<sub>2</sub> phases this results in a reduction in cytoplasmic volume of each daughter cell with each cell division. | |||
===Summary=== | |||
* Week 1, 2 - 3 days, size 0.1 - 0.2 mm | |||
* [[Morula]], [[Z#zona pellucida|zona pellucida]], [[B#blastomeres|blastomeres]] | |||
{{ | |||
{{ | See also [[#Events|Events]] | ||
{{Carnegie stage 2 links}} | |||
|} | |||
{{Carnegie_stage_table_1}} | |||
{{Carnegie stages}} | |||
<br> | |||
{| border='0px' | |||
|- | |||
| [[File:Hertig1956 fig01.jpg|400px]] | |||
| [[File:Hertig1956 fig02.jpg|400px]] | |||
|- | |||
| Two-cell segmenting egg | |||
| Mid-serial section two-cell | |||
|- | |||
| [[File:Human embryo day 2.jpg|Stage 2 Day 2]] | |||
| [[File:Human embryo day 3.jpg|Stage 2 Day 3]] | |||
|- | |||
| Human Embryo (day 2) | |||
| Human Embryo (day 3) | |||
|- | |||
|} | |||
See also [[:File:Human-oocyte_to_blastocyst.jpg|Human oocyte to blastocyst]] | |||
==Carnegie Collection== | |||
[[File:Stage2_bf01.jpg|500px]] | |||
Two cell blastomere (1-2 days) | |||
{{Carnegie Collection stage 2 table}} | |||
==Events== | |||
* {{mitosis}} | |||
==Some Recent Findings== | |||
{| | |||
|-bgcolor="F5FAFF" | |||
| | |||
* '''{{Mouse}} - Asymmetric expression of maternal mRNA governs first cell-fate decision'''{{#pmid:34694646|PMID34694646}} "The goal of preimplantation development is to establish the fates of the embryonic and extra-embryonic cells. However, when and how cell fates are determined during early mammalian embryonic development remains unclear. We report that the high mobility group (HMG) protein family member HMGA1 was distributed differentially in mouse two-cell {{blastomere}}s. Knockdown of Hmga1 expression in one of the two cells reduced the number of cells contributing to the inner cell mass (ICM), suggesting that differential distribution of HMGA1 in the blastomeres in two-cell {{mouse}} embryos affected the selection of embryonic cell lineages. Mechanistically, HMGA1 promotes the expression of the ICM-specific gene {{Sox}}2. The results of this study show that mouse embryos demonstrate heterogeneity as early as the two-cell stage, and that these differences are related to cell-fate differentiation in early mouse embryos." | |||
|} | |||
===References=== | |||
<references/> | |||
{{Ref-Hertig1956}} | |||
===References=== | |||
<references/> | |||
{{Ref-Hertig1956}} | |||
==Additional Images== | |||
{{Carnegie_stages}} | |||
{{Footer}} | |||
[[Category:Human Embryo]] [[Category:Carnegie Stage]] [[Category:Carnegie Stage 2]] [[Category:Week 1]] | [[Category:Human Embryo]] [[Category:Carnegie Stage]] [[Category:Carnegie Stage 2]] [[Category:Week 1]] |
Latest revision as of 14:12, 1 December 2021
Embryology - 27 Apr 2024 Expand to Translate |
---|
Google Translate - select your language from the list shown below (this will open a new external page) |
العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt These external translations are automated and may not be accurate. (More? About Translations) |
Introduction
First cell mitotic divisions of the zygote forming initially 2 blastomeres that continue to divide to form the morula, a "berry", a solid mass of cells.
This early mitosis is a unique embryonic cell cycle (M, S, M phases) compared to adult (M, G1, S, G2, M phase). With virtually no G1 or G2 phases this results in a reduction in cytoplasmic volume of each daughter cell with each cell division. Summary
|
Week: | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Carnegie stage: | 1 2 3 4 | 5 6 | 7 8 9 | 10 11 12 13 | 14 15 | 16 17 | 18 19 | 20 21 22 23 |
- Carnegie Stages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | About Stages | Timeline
Two-cell segmenting egg | Mid-serial section two-cell |
Human Embryo (day 2) | Human Embryo (day 3) |
See also Human oocyte to blastocyst
Carnegie Collection
Two cell blastomere (1-2 days)
Carnegie Collection - Stage 2 | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
Serial No. | Normality | No. of Blastomeres | Size of Fixed Specimen (µm) | Fixative | Embedding Medium | Thinness (µm) | Stain | Year | Notes | |
8190 | abnormal | 9 | 160x104 | Alc. & Bouin | C-P | 6 | Iron h., or G | 1943 | Hertig et al. (1954) | |
8260 | in vitro | 2 | 50x75 | Bouin | C-P | 8 | (Stain - Haematoxylin Eosin) | 1944 | Menkin and Rock (1948) | |
8450 | abnormal | 8 | 100x96 | Alc. & Bouin | C-P | 6 | (Stain - Haematoxylin Eosin), phlox. | 1947 | Hertig et al. (1954) | |
8452 | abnormal | 12 | 110x93 | Alc. & Bouin | C-P | 6 | (Stain - Haematoxylin Eosin), phlox. | 1946 | Hertig et al. (1954) | |
8500.1 | in vitro | 3 | 50x86 | Bouin | C-P | 8 | (Stain - Haematoxylin Eosin) | 1947 | Menkin and Rock (1948) | |
8630 | abnormal | 5 | 104x94 | Alc. & Bouin | C-P | 6 | (Stain - Haematoxylin Eosin) | 1948 | Hertig et al. (1954) | |
8698 | normal | 2 | 122x88 | Alc. & Bouin | C-P | 6 | (Stain - Haematoxylin Eosin) | 1949 | Hertig et al. (1954) | |
8904 | normal | 12 | 115 | Specimen lost | 1951 | Hertig et al. (1954) | ||||
Abbreviations
| ||||||||||
|
Events
Some Recent Findings
|
References
Hertig AT. Rock J. and Adams EC. A description of 34 human ova within the first 17 days of development. (1956) Amer. J Anat., 98:435-493.
References
Hertig AT. Rock J. and Adams EC. A description of 34 human ova within the first 17 days of development. (1956) Amer. J Anat., 98:435-493.
Additional Images
- Carnegie Stages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | About Stages | Timeline
Cite this page: Hill, M.A. (2024, April 27) Embryology Carnegie stage 2. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_2
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G