What is the Difference Between Diplotene and Diakinesis

The main difference between diplotene and diakinesis is that in the diplotene, synapsis ends with the disappearance of the synaptonemal complex, whereas in diakinesis, chromosomes become fully condensed, and the nuclear membrane disintegrates.

Diplotene and diakinesis are two sub-stages that occur in prophase 1. Prophase 1 occurs in the meiosis.   

Key Areas Covered

1. What is Diakinesis
– Definition, Facts, Features 
2. What is Diplotene
– Definition, Facts, Features
3. Similarities Between Diplotene and Diakinesis
– Outline of Common Features
4. Difference Between Diplotene and Diakinesis
– Comparison of Key Differences

Key Terms  

Diakinesis, Diplotene

What is Diplotene

Diplotene is the fourth phase of prophase 1. It follows the third phase of prophase 1, the pachytene. The pachytene stage begins when the synapsis completes. Also, the chromatin condensation is finished in the pachytene stage, forming chromosomes. These chromosomes are visible under the microscope. Additionally, the synaptonemal complex is formed between homologous chromosomes. It is a protein structure. Also, it is important to mediate synapsis and recombination during meiosis 1. However, it occurs in eukaryotes. On the other hand, it serves as a scaffold that allows the interactions between chromatids to complete crossing-over activities. Further, the bivalent chromosomes contain a structure called recombination nodules. Multiple recombination events can occur between bivalents.

Figure 1: Diplotene

Furthermore, crossing over completes during the diplotene stage. Also, homologous chromosomes retain the complete set of genetic information. Additionally, maternal and paternal homologous chromosomes are mixed. Chiasmata are the visible junctions that hold homologous chromosomes together at locations. The synaptonemal complex dissolves when the recombination occurs. A meiotic arrest occurs in the diplotene stage in many species.   

What is Diakinesis

Diakinesis is the fifth stage of prophase 1 that follows the diplotene stage. Full chromatin condensation occurs in the diakinesis stage. All four sister chromatids are visible in this stage. After the chromatin condensation, the rest of the phase resembles the early stage of mitotic prometaphase. Also, the spindle apparatus begins to form. Further, the nuclear membrane begins to break down. Prophase 2 follows the diakinesis. It is very similar to the prophase of mitosis.

Figure 2: Diakinesis 

Similarities Between Diplotene and Diakinesis

• Diplotene and diakinesis are two sub-stages of prophase 1.
• They occur in meiosis. 

Difference Between Diplotene and Diakinesis

Definition

Diplotene refers to the fourth stage of the prophase of meiosis, following pachytene, during which the paired chromosomes begin to separate into two pairs of chromatids. In contrast, diakinesis refers to the fifth and last stage of the prophase of meiosis, following diplotene, when the separation of homologous chromosomes is complete and crossing over has occurred.

Stage

Diplotene is the fourth stage of the prophase, while diakinesis is the fifth stage of the prophase. 

Follows

Diplotene follows pachytene, while diakinesis follows prophase II.  

Function

Paired chromosomes start to separate into two pairs of chromatids in diplotene, while diakinesis separates homologous chromosomes.

FAQ: How is diplotene different from Diakinesis?

Diakinesis is the fifth stage of prophase 1. The synaptonemal complex degrades the homologous chromosomes. In comparison, chromosomes condense further during the diplotene stage. The four parts of the tetrads are visible in this stage.  

What are diplotene and Diakinesis under the microscope? 

The two homologous chromosomes separate and disintegrate between chromosomal arms in diplotene. In comparison, the condensation of chromosomes stops in the diakinesis stage. Therefore, chiasmata are clearly visible under the electron microscope.    

What is the stage of Diakinesis?

The last stage of prophase 1 of the meiosis is diakinesis. At the end of the diakinesis, the dividing cell enters into metaphase. The key feature of diakinesis is the chiasmata terminalization. Bivalent chromosomes distribute evenly in the nucleus.   

Conclusion

In brief, diplotene and diakinesis are two sub-stages of prophase 1. They occur during meiosis. Diplotene is the fourth stage of prophase 1. Also, it follows pachytene. During diplotene, paired chromosomes begin to separate, forming two pairs of chromatids. In comparison, diakinesis is the fifth stage of prophase 1. Additionally, it follows prophase 2. However, it separates homologous chromosomes. Therefore, the main difference between diplotene and diakinesis is the fate of chromosomes in each stage. 

References:

1. Brent Cornell. (n.d.). Stages of Prophase. BioNinja. 

Image Courtesy:

1. “Meiosis (263 03)” By Doc. RNDr. Josef Reischig, CSc. – Own Work (CC-BY SA 3.0) via Commons Wikimedia
2. “Diakinesis” By Vallusruti – Own Work (CC-BY SA 4.0) via Commons Wikimedia