High frequency intragenic recombination during macronuclear development in Tetrahymena thermophila restores the
1Department of Biology, Cleveland State University, Ohio 44115, USA.
Abstract:
Macronuclear development in ciliates is characterized by extensive rearrangement of genetic material, including sequence elimination, chromosome fragmentation and telomere addition. Intragenic recombination is a relatively rare, but evolutionarily important phenomenon occurring in mitosis and meiosis in a wide variety of organisms. Here, we show that high frequency intragenic recombination, on the order of 30%, occurs in the developing amitotic macronucleus of the ciliate Tetrahymena thermophila. Such recombination, occurring between two nonsense transition mutations separated by 726 nucleotides, reproducibly restores wild-type expression of the SerH1 surface protein gene, thus mimicking complementation in trans heterozygotes. Recombination must be considered a potentially important aspect of macronuclear development, producing gene combinations not present in the germinal micronucleus.
Related Concept Videos
Homologous Recombination
Gene Conversion
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Homologous Recombination
Crossing Over


