Key Difference – Blastocyst vsEmbryo
Thekey differencebetween the blastocyst and the embryo is in the developmental stage in which they are formed.The blastocyst is formed at the blastula stage, whereas the embryo is formed when the blastocyst is implanted in the uterine wall.
Embryonic development in organisms takes place via different stages from the initial development of the zygote to the fetal stage. The blastocyst is the blastula stage in mammals that is developed after themorula stage. The embryo is referred to as the stage in which the blastocyst is implanted in the uterine wall.
CONTENTS
1.Overview and Key Difference
2.What is Blastocyst
3.What is Embryo
4.Similarities Between Blastocyst and Embryo
5.Side by Side Comparison – Blastocyst vs Embryo in Tabular Form
6.Summary
What is Blastocyst?
A blastocyst is simply referred to as the blastula stage in mammals. During the embryonic development of mammals, the zygote forms as a result of fertilization, and it undergoes a rapid cell division. Following these rapid divisions, the zygote is cleaved forming the morula. The morula stage then undergoes certain physiological and structural changes to develop into the blastula.
The cells of the morula are termed asblastomeres. When these blastomeres get surrounded by a fluid-filled cavity, it is known as the blastocoel. This stage is thus, referred to as the blastula stage. In mammals, the blastula stage is known as the blastocyst.The above process of developing the blastula from the morula is known as blastulation. During the embryonic development, the blastocyst formation in mammals begins after five days of fertilization.
囊胚是薄壁结构和comprises of two main parts; the inner cell mass and the trophoblast. The inner cell mass eventually develops into the mature embryo. The trophoblast eventually develops into the extraembryonic tissue that includes theplacenta. The structure of the blastocyst can be described by its diameter and the number of cells it contains. The diameter of the blastocyst is about 0.1-0.2 mm, and it is composed of about 200 – 300 cells.
There are important applications of the blastocyst duringIn vitroFertilization (IVF). The blastocyst is used for IVF, and the blastocyst developed underin vitroconditions is implanted in the uterus. The inner cell mass of the blastocyst is also used to isolate embryonic stem cells that widely are used in animal cell culture research and experiments.
What is Embryo?
The Embryo is the developmental stage followed by the development of the blastocyst. The embryo is formed upon implantation of the blastocyst in the uterus. The period from second to the eleventh week after fertilization is referred to as the embryonic stage. During implantation, the inner cell mass of the blastocyst develops into the embryo.
The structure of the embryo contains two main embryonic disks known as the hypoblast and the epiblast. The function of theepiblastlayer is to serve as the primitive endoderm and forms the amniotic cavity. Thehypoblastfunctions in forming the exocoelomic cavity. The embryonic stage also characterizes certain evolutionary patterns in relation to the number of germ layers formed in the embryo.
The organisms that have only two germ layers;ectoderm, endodermare known asdiploblastic, whereas organisms have three germ layers; ectoderm, endoderm, andmesodermare known as triploblastic. Formation of germ layers and the gut during the embryonic stage is known asgastrulation. Gastrulation is then followed byneurulationwhere the neural tissue is developed. Neurulation is then followed byorganogenesis.
The embryo is also observed in flowering plants, where the seed is referred to as the embryo during plant development. The embryo is also used in extracting embryonic cells that are used to develop embryonic cell lines for research and for experimentation.
What are the Similarities Between Blastocyst and Embryo?
- Both Blastocyst and Embryo represent two stages in the embryonic development of an organism.
- Both Blastocyst and Embryo are formed as a result of fertilization between an egg cell and a sperm cell.
- 胚泡和胚胎都是二倍体的结构having 2n chromosomes.
- Both Blastocyst and Embryo are developed inside the female organism.
- Both Blastocyst and Embryo are used in diagnostics and animal cell culture.
What is the Difference Between Blastocyst and Embryo?
Blastocyst vs Embryo |
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Blastocyst is the blastula stage in mammals that is developed after the morula stage. | The embryo is referred to as the stage in that the blastocyst is implanted in the uterine wall. |
Found in, | |
Blastocyst is found only in mammals. | Embryo is found in both animals and plants. |
Development | |
Blastocyst development is followed by the cleavage of the morula stage. | Embryo development occurs during the implantation process. |
Time Period | |
Blastocyst stage runs from five days to two weeks after fertilization. | Embryo stage of mammals runs from 2 weeks to 11 weeks after fertilization. |
Summary –Blastocyst vsEmbryo
The blastocyst and the embryo represent two important stages of the embryonic development in a mammal. The blastocyst represents the blastula stage in mammals. The blastula development takes place following the morula stage. The embryo is termed so forth upon the completion of the implantation process. Both blastocyst and the embryo are used in differentin vitroapplications. This is the difference between blastocyst and embryo.
Reference:
1.Britannica, The Editors of Encyclopaedia. “Blastocyst.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 14 Dec. 2014.Available here
2.Findlay, et al. “Human Embryo: a Biological Definition | Human Reproduction | Oxford Academic.” OUP Academic, Oxford University Press, 18 Dec. 2006.Available here
Image Courtesy:
1.’Blastocyst English’By Seans Potato Business(CC BY-SA 3.0)viaCommons Wikimedia
2.’Human embryo’By Anatomist90 – Own work,(CC BY-SA 3.0)viaCommons Wikimedia
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