Alternative splicing and the steady-state ratios of mRNA isoforms generated by it are under strong stabilizing selection in Caenorhabditis elegans.
Evolutionary studies indicate that a high proportion of alternative splicing (AS) events are species-specific; just 28% of minor-form alternatively spliced exons are conserved between mice and humans. We employed a splicing-sensitive microarray to study the evolution of allele-specific AS in nematodes. We compared splicing levels among five distinct Caenorhabditis elegans lines. Our results indicate that AS is less variable between natural isolates (NIs) from England, Hawaii, and Australia than when compared with mutation accumulation lines (6% vs. 21%, respectively, vary compared with N2). This suggests that strong stabilizing selection shapes the evolution of the ratios of isoforms generated by AS in C. elegans. When we analyzed some of the splicing changes between the NIs, we found examples of changes in both cis and trans that lead to alterations in gene-specific AS. This indicates that both these mechanisms for changing AS are employed along the path toward speciation in nematodes.
Barberan-Soler
Sergio
S
Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California, Santa Cruz, USA.
Zahler
Alan M
AM
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D002107:Caenorhabditis / Q000201:enzymology / Q000235:genetics; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D019143:Evolution, Molecular; D005091:Exons; D006801:Humans; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D020033:Protein Isoforms / Q000235:genetics; D012326:RNA Splicing; D020871:RNA Stability; D018510:RNA, Helminth / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012641:Selection, Genetic; D013045:Species Specificity
D029742:Caenorhabditis elegans Proteins; D020033:Protein Isoforms; D018510:RNA, Helminth; D012333:RNA, Messenger