Cloning and characterization of the bovine EGR4 gene and evaluation as candidate gene for bovine spinal dysmyelination.
Genes of the early growth response (EGR) family encode transcription factors with a highly conserved DNA binding zinc finger domain, which regulate a variety of genes, e.g. late myelin genes. Here, the cloning, genomic structure and expression of the bovine orthologue of the EGR4 gene are reported. The gene consists of two exons and encodes a 482 amino acid protein with a Cys2His2 zinc finger structure. The predicted protein shares between 80 and 87% identity to mouse, rat and human EGR4 proteins and all four species share almost complete identity in the DNA-binding domain. The bovine transcript is alternatively spliced by retaining intronic sequence, giving rise to two different mRNAs differing in three nucleotides and resulting in an extra alanine residue in the longer variant of the predicted protein. The gene was mapped by radiation hybrid (RH) mapping to markers on bovine chromosome 11. EGR4 transcripts were detected by reverse transcriptase polymerase chain reaction (RT-PCR) in the frontal cortex and cerebellum, and a low expression level was also detected in the liver. The EGR4 gene was evaluated as a candidate gene for bovine spinal dysmyelination (BSD). Sequencing of the gene from a homozygous affected animal and a heterozygous carrier revealed a single base mutation that leads to an amino acid substitution at residue 322 in EGR4. Genotype analysis of this polymorphism in a pedigree segregating for BSD, as well as in a panel of different cattle breeds, and sequence analysis of the entire coding region suggested that the EGR4 is not the gene responsible for BSD. Furthermore, 87 animals of different cattle breeds were screened for single-nucleotide polymorphisms (SNPs) resulting in the identification of two SNPs in EGR4.
Nissen
P H
PH
Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences, DK-8830 Tjele, Denmark. sci08phn@aas.auh.dk
Thomsen
B
B
Offenberg
H
H
Thomsen
P D
PD
Bendixen
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics*; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D003711:Demyelinating Diseases / Q000235:genetics / Q000662:veterinary*; D051765:Early Growth Response Transcription Factors; D006822:Hybrid Cells; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D051765:Early Growth Response Transcription Factors; C486392:Egr4 protein, mouse; D014157:Transcription Factors