Cis-acting requirements in flanking DNA for the programmed elimination of mse2.9: a common mechanism for deletion of internal eliminated sequences from the developing macronucleus of Tetrahymena thermophila

• Published in: Nucleic acids research 2001-01, Vol.29 (2), p.488-498
• Main Authors: Fillingham, J S, Bruno, D, Pearlman, R E
• Format: Article
• Language: English
• Subjects: Animals; Cell Nucleus - genetics; Cell Nucleus - metabolism; cis-acting elements; DNA, Protozoan - genetics; DNA, Protozoan - metabolism; DNA, Ribosomal - genetics; DNA, Ribosomal - metabolism; Evolution, Molecular; internal eliminated sequences; Introns - genetics; mse2.9 gene; Physical Chromosome Mapping; Recombination, Genetic; Regulatory Sequences, Nucleic Acid - genetics; Sequence Deletion - genetics; Tetrahymena thermophila; Tetrahymena thermophila - genetics; Tetrahymena thermophila - growth & development; Tetrahymena thermophila - metabolism; Transformation, Genetic; Untranslated Regions - genetics; Untranslated Regions - metabolism
• ISSN: 1362-4962; 0305-1048; 1362-4962
• DOI: 10.1093/nar/29.2.488

During macronuclear development in the ciliated protozoan Tetrahymena thermophila, extensive DNA deletions occur, eliminating thousands of internal eliminated sequences (IESs). Using an rDNA-based transformation assay we have analyzed the role during DNA deletion of DNA flanking mse2.9, an IES within the second intron of a gene encoding an as yet incompletely characterized protein. We establish that a cis-acting sequence for mse2.9 deletion acts at a distance to specify deletion boundaries. A complex sequence element necessary for efficient and accurate mse2.9 deletion is located in the region 47-81 bp from the right side of mse2.9. The ability of a variety of IES flanking sequences to rescue a processing deficient mse2.9 construct indicates that some cis-acting signal is shared among different IESs. In addition, the short intronic sequence that flanks mse2.9 is able to direct efficient and accurate processing. Despite no obvious sequence similarity between mse2.9 and other IESs, we suggest that a common mechanism is used to delete different families of IESs in Tetrahymena.