Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: Molecular phylogenetic analysis of primitive vertebrate ryanodine receptor isoforms
Student Author(s): Polgar, Sara
Faculty Advisor(s): Block, Barbara A.
Pages: 27
Location: Final Papers Biology 175H
Date: June 1995
Abstract: A highly conserved portion of the RyR channel region was amplified, cloned and cycle sequenced from Brachiostoma lanceolatum (amphioxus) and Mustelus californicus (smoothhound dogfish). Two isoforms, Ryr1 and RyR3, are expressed in most vertebrate skeletal muscle, while RyR1 is the sole isoform expressed in mammalian and some reptilian skeltal muscle. The purposed of the study were 1) to investigate how primitive the two isoform condition is, and 2) to determine what clues the sequences of primitive vertebrate RyRs provide about structure and or function in the channel region. In comparisons with published RyR sequences, amphioxus and shark displayed an overall high level of sequence identity with all isoforms in this region. Molecular phylgenetic analyses clustered the amphioxus and shark sequences with the published RyR1 sequences. One region of 50 contiguous amino acids located within a possible transmembrane region did display high variability amony species. However, hydrophilicity profiles of amphioxus, shark, fish RyR1, and frog alpha sequences in this region revealed similar patterns of hydrophobicity. This common characteristic indicates that the amino acid differences mostly likely do not impact on structure or function in this region.