Expression of Tetrahymena snRNA gene variants including a U1 gene with mutations in the 5′ splice site recognition sequence

The silk moth Bombyx mori U1 and U2 snRNA variants are differentially expressed

“…U1 RNA isoforms have been reported in Tetrahymena (Eugen-Olsen et al, 1997), mice (Lund et al, 1985), Drosophila melanogaster (Lo and Mount, 1990) as well as in wheat and peas (Musci et al, 1992) to name a few examples. The expression of some of these plant and animal U-snRNA variants are developmentally and tissue-specifically regulated (Lund and Dahlberg, 1987;Lo and Mount, 1990;Morales et al, 1997).…”

Variants of U1 small nuclear RNA assemble into spliceosomal complexes

“…Variants of snRNAs have been detected in a multitude of animal and plant species. Some of these U‐snRNA variants are developmentally and tissue‐specifically expressed in several organisms, including Bombyx mori (Forbes et al ., 1984; Adams & Herrera, 1987; Lund et al ., 1987; Adams et al ., 1985; Eugen‐Olsen et al ., 1997; Sierra‐Montes et al ., unpublished data). The multiplicity of these snRNA variants in B. mori and their differential expression during development may be functionally significant by affecting qualitatively and/or quantitatively the pattern of pre‐mRNA splicing, influencing development and tissue differentiation (Forbes et al ., 1984; Laski et al ., 1986; Gorman et al ., 1998).…”