Due-B Is dispensable for early development and genome duplication in vertebrates

Area of Science:

• Molecular Biology
• Developmental Biology
• Genetics

Background:

• DNA Unwinding Element-Binding protein (DUE-B) is a substrate for Cyclin Dependent Kinase (CDK) and Dbf4-Dependent Kinase (DDK).
• Previous studies suggest DUE-B controls DNA replication initiation and may be a vertebrate-specific factor.
• DUE-B knockdown in cell lines and egg extracts perturbs DNA replication.

Purpose of the Study:

• To investigate if DUE-B is an essential vertebrate gene in vivo.
• To determine the role of DUE-B in embryonic development in zebrafish (Danio rerio).

Main Methods:

• Generated due-b mutant zebrafish using genome-editing TALENs.
• Assessed mRNA and protein expression of DUE-B in mutants.
• Observed zebrafish viability, development, and response to replication inhibitors.
• Performed cell cycle analysis to evaluate DNA replication.

Main Results:

• Mutant zebrafish lacking DUE-B expression are viable and reach adulthood.
• No outward developmental phenotypes were observed in the mutant zebrafish.
• Mutant zebrafish showed normal DNA replication and no increased sensitivity to replication inhibitors.
• DUE-B is not essential for DNA replication initiation in vivo.

Conclusions:

• DUE-B is not a core essential component for vertebrate DNA replication or development.
• DUE-B might be mechanistically redundant or play a specialized role in DNA replication control.