Definition: The small RNAs which provide spliced leader sequences, SL1, SL2, SL3, SL4 and SL5 (short sequences which are joined to the 5' ends of pre-mRNAs by TRANS-SPLICING). They are found primarily in primitive eukaryotes (protozoans and nematodes).
do not confuse with LEADER SEQUENCES, MRNA see 5' UNTRANSLATED REGION
See AlsoTrans-Splicing