Purchase this article with an account.
M. Posner, M. Danko, A. Smith, R. Richards; Tissue specific expression of alpha B crystallin in the amphibian Rana catesbeiana . Invest. Ophthalmol. Vis. Sci. 2004;45(13):3962.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:We previously showed that alpha B crystallin is not expressed at significant levels in zebrafish muscle or nervous tissue. This result is in contrast to the condition found in mammals in which alpha B crystallin is expressed in diverse non–lenticular tissues. In this present study we examined the tissue specific expression of alpha B crystallin from the bullfrog (Rana catesbeiana). We hope to determine whether widespread expression of alpha B crystallin is unique to mammals, or if similar expression is found in other vertebrate taxa. Methods:RT–PCR and RACE were used to clone the complete coding region for bullfrog alpha B crystallin. Primers were based on a previously reported sequence in Genbank. RT–PCR was also used to determine the tissue specific expression of alpha B crystallin from both tadpole and adult life stages. Results:The deduced protein sequence of bullfrog alpha B crystallin contained 173 amino acids and was 72% and 59% identical to the human and zebrafish orthologues, respectively. Our sequence differed from that previously reported in Genbank for bullfrog by 6 nucleotides, resulting in 2 different amino acids. Bullfrog alpha B crystallin expression was highest in lens, but was also found in brain and skeletal muscle of both tadpoles and adults. Lower expression levels were found in some tadpole hearts. Conclusions:Our results indicate that alpha B crystallin is expressed outside of the lens in amphibians. The more restricted expression found previously in the zebrafish does not appear to be a common characteristic of non–mammalian vertebrates, and may be due to unique features of bony fish physiology. The similar expression pattern in tadpoles and adults suggests the lack of a developmental shift in alpha B crystallin function after metamorphosis. This study demonstrates that comparing different vertebrate taxa can provide insights into the evolution of alpha crystallin function, and can help us to understand the role of the alpha crystallins in mammalian physiology.
This PDF is available to Subscribers Only