Transcription in Eukaryotes: Transcription is the process of copying genetic information from one strand of the DNA into RNA. The principle of complementarity governs the process of transcription, except the adenosine now forms base pair with uracil instead of l thymine. In transcription, only a segment of DNA is duplicated and on Iv one of the strands is copied into RNA. Both the strands are not copied.

Transcription in Eukaryotes 

• The structural genes are monocistronic in eukaryotes.
• The process of transcription is similar to prokaryotes.
• It takes place in the nucleus.
• Coding gene sequences called exons form the part of mRNA and non-coding sequence called introns, are removed during RNA splicing and exons are joined in a defined order.

Eukaryotic DNA Polymerase Types and Function

Like prokaryotic cells, eukaryotic cells also have many DNA polymerases, which perform different functions, e.g. mitochondrial DNA replication, nuclear DNA replication, etc. The nuclear DNA replication is mainly done by DNA polymerase 𝝳 and 𝜶. There are at least 15 DNA polymerases identified in human beings.

• DNA polymerase 𝝳 – It is the main enzyme for replication in eukaryotes. It also has 3’→5’ exonuclease activity for proofreading.
• DNA polymerase 𝜶 – The main function of DNA polymerase 𝜶 is to synthesize primers. The smaller subunit has a primase activity. The largest subunit has polymerization activity. It forms a primer for Okazaki fragments, which is then extended by DNA polymerase 𝝳.
• DNA polymerase 𝟄 – The main function is DNA repair. It removes primers for Okazaki fragments from the lagging strand.
• DNA polymerase 𝝲 – It is the main replicative enzyme for mitochondrial DNA.

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By Team Learning Mantras