Expression of skeletal myosin light chain 2 in gilthead sea bream (Sparus aurata, L): regulation and correlation to growth markers
In gilthead sea bream (Sparus aurata, L) skeletal muscle two isoforms of myosin light chain 2 (MLC2) are expressed, A and B. MLC2A is encoded by three transcripts produced through alternative polyadenylation signal selection differing in the 3’ untranslated region. cis-acting regulatory elements res...
| Main Authors: | , |
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
University of Thessaly (UTH)
2013
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10442/hedi/29857 https://doi.org/10.12681/eadd/29857 |
| Summary: | In gilthead sea bream (Sparus aurata, L) skeletal muscle two isoforms of myosin light chain 2 (MLC2) are expressed, A and B. MLC2A is encoded by three transcripts produced through alternative polyadenylation signal selection differing in the 3’ untranslated region. cis-acting regulatory elements residing in 3’ UTRs were identified using bioinformatic analysis. Functionality of 3’ UTRs in interaction with the cell protein machinery was investigated in vitro using luciferase reporter constructs. Data indicated that the three transcripts are subject to differential regulation according to 3’ UTR length and regulatory interactions between transcripts were detected.Gene organization of the two isoforms and the syntenic relationships between Sparus aurata, Dicentrarchus labrax, Danio rerio, Gadus morhua, Gasterosteus aculeatus, Oryzias latipes and Tetraodon nigroviridis were studied. MLC2A and MLC2B genes contain 5 and 6 exons respectively in all organisms examined. Exon-intron organization is more similar among evolutionary closer species which is further confirmed by the phylogenetic tree probably indicating different evolutionary trajectories for the two MLC2 isoforms. Divergent expression patterns during myogenesis in primary muscle cell cultures and in developing larvae, and after administration of growth hormone to juveniles, indicated that the two isoforms of MLC2 identified in the gilthead sea bream are duplicated genes (paralogues) and have probably undergone subfunctionalization. White muscle development and growth processes occur through hyperplastic and hypertrophic events driven by several regulatory and hormonal factors. The development of white musculature in gilthead sea bream larvae demonstrated distinct hyperplastic and hypertrophic phases as evident by changes in muscle cellularity (number and size of muscle cells). The expression patterns of MLC2 marked the two phases in an isoform-specific manner; MLC2A marked new fiber formation in the germinal zones, appeared early in development and was ... |
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