Molecular characterization of alternative transcripts of the horse BMAL1 gene.

The research deals with the molecular characterization of different variants of the horse BMAL1 gene, which is central to the circadian rhythm systems in many tissues and cells. Precisely, it was observed that the first exon of the horse-specific BMAL1 gene is produced via an exonization event involving LINE3 (CR1) and SINE (MIR). Various tissue samples also exhibited different transcript variants of the gene as identified through RT-PCR amplification and sequencing techniques.

Molecular Characterization of BMAL1 Gene

• The BMAL1 gene codes for the brain and muscle Arnt-like protein 1. In horses, this protein forms a key part of the mechanism that governs circadian rhythmic systems. These are biological processes that operate on a near-24-hour cycle and can be found in most organs and cells of the horse’s body.
• Through the use of bioinformatics, the researchers found that the first exon of the horse-specific BMAL1 gene is produced by an exonization event. This involves the presence of LINE3 (CR1) and SINE (MIR), both of which are types of repeating elements in the horse’s DNA.

Detection of Transcript Variants

• Further experiments conducted with RT-PCR amplification and sequencing on various horse tissues revealed the creation of alternative gene variants. These transcript variants are created through a process known as cassette exon event, marking the inclusion or omission of certain sections of the gene.
• The researchers identified two main transcript variants of the horse BMAL1 gene – BMAL1a and BMAL1b. These variants contain additional 21 base pairs (bp) and 71 bp sequences respectively when compared to the original, full-length horse BMAL1.

Expression Patterns of Transcript Variants

• Finally, the research team utilized quantitative real-time RT-PCR to gauge the expression patterns of these transcript variants across different horse tissues.
• The results disclosed that the aforementioned splice variants of the BMAL1 gene were not only widely expressed across most tissues, but were especially highly expressed in the tissues of the cerebellum, heart, and kidney.