Isolation, characterization, and expression analysis of zebrafish large Mafs

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Large Maf proteins, part of the basic leucine zipper (b-Zip) superfamily, regulate cellular differentiation.
• Previous studies described vertebrate large Maf mRNA expression patterns.

Purpose of the Study:

• To clone and characterize novel zebrafish large Maf proteins, specifically SMaf1 (Somite Maf1).
• To analyze the expression patterns of SMaf1, SMaf2 (Somite Maf2)/Krml2, MafB/Val, and c-Maf during zebrafish embryogenesis.
• To investigate the functional roles of these Maf proteins in somitogenesis and cell lineage determination.

Main Methods:

• Cloning of zebrafish large Maf cDNAs, including SMaf1.
• Analysis of mRNA expression patterns using techniques like in situ hybridization during zebrafish embryogenesis.
• Assessment of the transactivational activity of N-terminus domains of zebrafish large Maf proteins.

Main Results:

• A novel zebrafish large Maf cDNA, SMaf1, was cloned, with its N-terminus showing transactivational activity.
• SMaf1 mRNA expression robustly overlapped with MyoD in somitic cells during somitogenesis.
• SMaf2 and MafB showed overlapping expression in blood-forming regions, while c-Maf and MafB overlapped in lens cells, with distinct temporal patterns.

Conclusions:

• Zebrafish large Maf proteins (SMafs) are implicated in somitogenesis.
• Maf proteins exhibit both overlapping and specific functions in cell lineage determination and differentiation.
• The findings provide insights into the complex roles of Maf proteins in embryonic development.