Carnegie stage 1: Difference between revisions

Revision as of 06:58, 25 October 2011

Introduction

Human early zygote showing pronuclei

The early human zygote where the male and female pronuclei (centre of image) have not yet combined to form the single zygote nucleus. These pronuclei are the nuclei from the spermatozoa (sperm) and oocyte (egg) and contain all the nuclear genetic material (chromosomes, DNA, genes).

Two of the egg's polar bodies (right, 3 o'clock position of image) are shown at the edge of the egg cytoplasm. These polar bodies contain the excess DNA from the meiotic divisions of the egg.

The zona pellucida (edge of image) forms a specialised thick extracellular matrix layer around both the egg and the developing conceptus for the first week.

Mitochondria in the cytoplasm contain additional genes and in humans these mitochondrial genes are entirely derived from the oocyte.

Facts: Week 1, size 0.1-0.15 mm

Features: zygote, fertilized oocyte, pronuclei, polar bodies, zona pellucida

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Carnegie stage 1

Early zygote labelled
Stage 1 size with ruler
Human zygote two pronuclei^[1]
Human zygote two pronuclei^[1]
Human zygote two pronuclei^[1]
Human zygote two pronuclei (labelled)^[1]
Human oocyte to blastocyst^[2]

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 <pubmed>20579351</pubmed>| Reprod Biol Endocrinol.
↑ <pubmed>19924284</pubmed>

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 16) Embryology Carnegie stage 1. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Carnegie_stage_1

What Links Here?

[PMID20579351-1] 1.0 ^1.1 ^1.2 ^1.3 <pubmed>20579351</pubmed>| Reprod Biol Endocrinol.

[2] <pubmed>19924284</pubmed>

[1]

[2]

@@ Line 4: / Line 4: @@
 Human early zygote showing pronuclei
 |
-The early human zygote where the male and female pronuclei (centre of image) have not yet combined to form the single zygote nucleus. These pronuclei contain all the nuclear DNA (genes) and are the nuclei from the sperm and egg.
+The early human zygote where the male and female pronuclei (centre of image) have not yet combined to form the single zygote nucleus. These pronuclei are the nuclei from the spermatozoa (sperm) and oocyte (egg) and contain all the nuclear genetic material (chromosomes, DNA, genes).
 Two of the egg's polar bodies (right, 3 o'clock position of image) are shown at the edge of the egg cytoplasm. These polar bodies contain the excess DNA from the meiotic divisions of the egg.
 The zona pellucida (edge of image) forms a specialised thick extracellular matrix layer around both the egg and the developing conceptus for the first week.
+Mitochondria in the cytoplasm contain additional genes and in humans these mitochondrial genes are entirely derived from the oocyte.
 '''Facts:''' Week 1, size 0.1-0.15 mm