Difference Between Archenteron and Blastocoel

The key difference between archenteron and blastocoel is that archenteron is the primary gut formed during gastrulation in the developing zygote, which later develops into the digestive tube, while blastocoel is an inner fluid-filled or yolk-filled cavity of the blastula formed during blastulation.

Fertilization is the event of sexual reproduction that forms a diploid zygote. The zygote eventually turns into an embryo. The embryo undergoes mitotic divisions and cellular differentiation, making a multicellular embryo. Morula is an early stage of the embryo, which contains 16 cells. Morula becomes the blastula at the seventh cleavage. Blastula contains 128 cells. It is a hollow sphere of cells surrounding an inner fluid-filled cavity. And, this fluid-filled cavity of blastula is known as blastocoel. Blastula folds inwards and enlarges to make gastrula, which is a multilayered structure containing primary germ layers. Archenteron is the primary gut located in the gastrula. Archenteron develops into the digestive tube later.

CONTENTS

1. Overview and Key Difference
2. What is Archenteron 
3. What is Blastocoel
4. Similarities Between Archenteron and Blastocoel
5. Side by Side Comparison – Archenteron vs Blastocoel in Tabular Form
6. Summary

 What is Archenteron?

Archenteron is the primary gut formed during gastrulation in the developing zygote. Blastula folds inwards and enlarges to form the gastrula stage. There are three germ layers in gastrula. The middle cavity of the gastrula is the primary gut or archenteron that develops into the digestive tube later.

Since archenteron is the cavity of the gastrula, it is also known as gastrocoel. Archenteron forms from both endoderm and mesoderm. Hence it has an endo-mesodermal origin. Blastopore is the open end of archenteron. Blastopore can be developed into either mouth or anus.

What is Blastocoel?

Blastocoel is an inner fluid-filled cavity which is hollow. Blastocoel can be seen inside the blastula, and it is formed during the blastulation when the early embryo becomes the blastula. It is also called the blastocyst cavity. A spherical cell layer called blastoderm surrounds the blastocoel.

Blastocoel develops as a result of cleavage of the oocyte. In fact, it is the first cavity formed in embryogenesis. The fluid of blastocoels contains many different components, including amino acids, proteins, growth factors, sugars, ions, which are essential for cellular differentiation. Moreover, blastocoel allows blastomeres to move, fold, and enlarge during gastrulation.

What are the Similarities Between Archenteron and Blastocoel?

• Archenteron and blastocoel are two types of cavities appearing during embryonic development.
• Both are important structures necessary for the development of the embryo.
• Archenteron forms after the formation of blastocoels.

What is the Difference Between Archenteron and Blastocoel?

Archenteron is the primary gut or embryonic gut cavity formed during gastrulation, while blastocoel is the fluid-filled cavity of blastula that diminishes during gastrulation and mesoderm formation. So, this is the key difference between archenteron and blastocoel. Furthermore, archenteron develops into the cavity of the digestive tract at the end of gastrulation, while blastocoel becomes obliterated at the end of the blastulation. Thus, this is also an important difference between archenteron and blastocoel.

The below infographic summarizes the difference between archenteron and blastocoel.

Summary – Archenteron vs Blastocoel

Blastocoel and archenteron are two types of cell cavities formed during embryogenesis. Archenteron is the primitive gut formed during gastrulation, while blastocoel is the fluid-filled cavity formed during blastulation. In short, archenteron is the cavity of gastrula, while blastocoel is the cavity of the blastula. Archenteron eventually becomes the cavity of the digestive tract, while blastocoel diminishes in size due to the formation of mesoderm. Blastocoel is the first cavity appearing during embryogenesis, while archenteron develops after the formation of the blastocoel. So, this summarizes the difference between archenteron and blastocoel.

Reference:

“Blastocoel.” Wikipedia, Wikimedia Foundation, 18 Oct. 2019, Available here.
“Archenteron.” Archenteron – an Overview | ScienceDirect Topics, Available here.

Image Courtesy:

1. “Protovsdeuterostomes” By WYassineMrabet✉ – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Blastocyst English” By Seans Potato Business (derivative of the source cited above) – Blastocyst.png (CC BY-SA 3.0) via Commons Wikimedia