NTU Undergraduates' research April 2014 - Biosciences | Page 94

Identification of Avian Brian-Derived Neurotrophic Factor (BDNF) Transcripts
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin contributing to many fundamental roles
within the development of the nervous system and subsequently to its physiology and pathology. The
many diverse functions of the BDNF gene are believed to be a result of the existence of many
multiple mRNA transcripts of the gene, all of which translate into the same BDNF protein.
Transcription of the BDNF gene is controlled by many promoters which leads to the production of
these multiple transcripts via alternative splicing of a 3’ coding exon and multiple 5’non-coding
exons. In this study multiple BDNF transcripts were identified within a rat brain tissue sample using
forward primers which are specific to the exon splice sites and a common reverse primer. These rat
specific primers were then used to identify BDNF splice variants within the chicken brain by varying
the annealing temperature of the PCR reaction in increments of 2°C, from 50°C to 58°C. Lower
annealing temperatures were used to produce multiple bands, formed by the occurrence of mismatch
pairing, in the hope that this would produce the BDNF splice variants. The results showed that BDNF
transcripts I-IV were identified in the chicken bran indicating that BDNF gene expression is highly
conserved among mammals and emphasising its crucial function.