Comparative genomics on mammalian Fgf3-Fgf4 locus

Area of Science:

• Comparative genomics
• Molecular biology
• Cancer genetics

Background:

• The 11q13.3 locus, containing CCND1-ORAOV1-FGF19-FGF4-FGF3-TMEM16A-FADD-PPFIA1-CTTN (EMS1), is frequently amplified in various cancers.
• FGF4 expression is regulated by transcription factors like Sox2, Pou5f1, MyoD, and GATA in different cell types.

Purpose of the Study:

• To determine the complete coding sequences of rat Fgf3 and Fgf4 using bioinformatics.
• To perform comparative genomics analysis of the Fgf3-Fgf4 locus in human, rat, and mouse genomes.
• To identify conserved regulatory elements and repetitive sequences within the Fgf3-Fgf4 gene cluster.

Main Methods:

• Bioinformatic determination of rat Fgf3 and Fgf4 coding sequences.
• Identification of errors in existing rat Fgf4 RefSeq entries.
• Analysis of gene clustering, promoter regions, and repetitive sequences in human, rat, and mouse genomes.

Main Results:

• Rat Fgf3 and Fgf4 genes are clustered in a tail-to-head manner, approximately 16 kb apart.
• Conserved transcription factor binding sites (CUTL1, NKX2-5, MYOD, MYOG, GATA, SOX2, POU5F1) and TATA boxes were identified in the promoter regions and exon 3 of Fgf3 and Fgf4 orthologs.
• Human FGF3 and FGF4 genes are clustered approximately 35 kb apart, with identified repetitive sequences (FGF34Rep1 and FGF34Rep2).

Conclusions:

• The Fgf3-Fgf4 locus exhibits conserved genomic organization and regulatory elements across mammalian species.
• Repetitive sequences within the human FGF3-FGF4 locus may play a role in genomic instability or regulation.
• This study provides the first comparative genomics analysis of the Fgf3-Fgf4 locus, offering insights into its evolution and potential role in cancer.