Imprecise excision of the Caenorhabditis elegans transposon Tc1 creates functional 5' splice sites.
Imprecise excision of the Caenorhabditis elegans transposon Tc1 creates functional 5' splice sites.
复制标题
线虫转座子 Tc1 的不精确切除会产生功能性 5 剪接位点。
DOI：
10.1128/mcb.14.5.3426-3433.1994
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发表时间：
1994
影响因子：
5.3
通讯作者：
Anderson,P
中科院分区：
文献类型：
--
作者：
Carr,B;Anderson,P
Imprecise excision of theCaenorhabditis eleganstransposon Tc1 from a specific site of insertion within theunc-54myosin heavy chain gene generates either wild-type or partial phenotypic revertants. Wild-type revertants and one class of partial revertants contain insertions of four nucleotides in theunc-54third exon (Tc1 “footprints”). Such revertants express large amounts of functionalunc-54myosin despite having what would appear to be frameshifting insertions in theunc-54third exon. We demonstrate that these Tc1 footprints act as efficient 5′ splice sites for removal of theunc-54third intron. Splicing of these new 5′ splice sites to the normal third intron splice acceptor removes the Tel footprint from the mature mRNA and restores the normal translational reading frame. Partial revertantunc-54(r661), which contains a single nucleotide substitution relative to the wild-type gene, is spliced similarly, except that the use of its new 5′ splice site creates a frameshift in the mature mRNA rather than removing one. In all of these revertants, two alternative 5′ splice sites are available to remove intron 3. We determined the relative efficiency with which each alternative 5′ splice site is used by stabilizing frameshifted mRNAs withsmg(−)genetic backgrounds. In all cases, the upstream member of the two alternative sites is used preferentially (>75% utilization). This may reflect an inherent preference of the splicing machinery for the upstream member of two closely spaced 5′ splice sites. Creation of new 5′ splice sites may be a general characteristic of Tc1 insertion and excision events.
