What is the Difference Between Diplotene and Diakinesis

The key difference between diplotene and diakinesis is that diplotene is the fourth stage of prophase I of the meiosis I cell division, while diakinesis is the fifth stage of prophase I of the meiosis I cell division.

Meiosis is a special type of cell division of germ cells. It takes place in sexually reproducing organisms. Meiosis occurs when producing gametes such as sperms and egg cells. The mechanism of meiosis was first described by the German biologist Oscar Hertwig in 1876. Meiosis consists of two main stages: meiosis I and meiosis II. Meiosis I is again divided into 4 phases: prophase I, metaphase I, anaphase I, and telophase I. There are five stages in prophase I as leptotene, zygotene, pachytene, diplotene and diakinesis. Moreover, meiosis II has 4 phases: prophase II, metaphase II, anaphase II, and telophase II. Diplotene and diakinesis are two stages of the prophase I of meiosis I cell division.

CONTENTS

1. Overview and Key Difference
2. What is Diplotene
3. What is Diakinesis
4. Similarities –  Diplotene and Diakinesis
5. Diplotene vs Diakinesis in Tabular Form
6. Summary –  Diplotene vs Diakinesis

What is Diplotene (Diplonema)?

Diplotene is the fourth stage of prophase I of the meiosis I cell division. This stage is also known as diplonema. Diplonema is a Greek word meaning “two threads.” In this stage, the synaptonemal complex disassembles, and homologous chromosomes separate from one another. The synaptonemal complex is a protein structure that forms between homologous chromosomes during meiosis. It is thought to mediate synapsis and homologous recombination during the stages of leptotene, zygotene, pachytene of prophase I of meiosis I cell division in eukaryotes.

However, homologous chromosomes of each bivalent remain tightly bound at chiasmata in this stage. Chiasmata are the regions where crossing over occurred previously. Chiasmata remains on the chromosomes until they are broken off at the transition to anaphase I to allow homologous chromosomes to move to opposite poles of the cell.

What is Diakinesis?

Diakinesis is the fifth stage of prophase I of the meiosis I cell division. Diakinesis is a Greek word that means “moving through.” In this stage, chromosomes condense further. Typically, it is the first point in meiosis where the four parts of the tetrads are actually visible. The sites of crossing over also entangle together through effective overlapping. This makes chiasmata clearly visible.

In addition to the above observation, the rest of the diakinesis stage is very similar to the prometaphase of mitosis. In this stage, nucleoli disappear, and the nuclear membrane disintegrates into vesicles. Furthermore, the meiotic spindle also begins to form in the diakinesis stage. Mitotic spindle refers to the cytoskeletal structure of eukaryotic cells that forms during cell division in order to separate chromatids between daughter cells. In mitosis, it is called the mitotic spindle, while in meiosis, it is called the meiotic spindle.

What are the Similarities Between Diplotene and Diakinesis?

• Diplotene and diakinesis are two stages of prophase I.
• Both stages take place in meiotic I cell division.
• These stages take place only in sexually reproducing organisms while producing gametes such as sperms and egg cells.
• The chiasmata are visible clearly in both stages.

What is the Difference Between Diplotene and Diakinesis?

Diplotene is the fourth stage of prophase I of the meiosis I cell division, while diakinesis is the fifth stage of prophase I of the meiosis I cell division. Thus, this is the key difference between diplotene and diakinesis. Furthermore, in the diplotene stage, the nuclear membrane does not disintegrate into vesicles, but in the diakinesis stage, the nuclear membrane disintegrates into vesicles.

The below infographic presents the differences between diplotene and diakinesis in tabular form for side by side comparison.

Summary – Diplotene vs Diakinesis

Diplotene and diakinesis are two stages of the prophase I of meiosis I cell division. Diplotene is the fourth stage of prophase I of the meiosis I cell division, while diakinesis is the fifth stage of prophase I of the meiosis I cell division. So, this summarizes the difference between diplotene and diakinesis.

Reference:

1. Cornell, Brent. “Stages-of-prophase.” BioNinja.
2. “Diakinesis.” Biology Online.

Image Courtesy:

1. “Synaptonemal Complex” By Daniel Wells – “Delineation of meiotic gene expression in male mice” (2020) PhD Thesis (CC BY-SA 4.0) via Commons Wikimedia
2. “Diakinesis” By Vallusruti – Own work (CC BY-SA 4.0) via Commons Wikimedia