72 research outputs found
Regulatory sequences of gene expression in the a- and b-tubulin genes of the hypotrichous ciliate Stylonchia
Regulatory structures of gene expression, DNA replication and DNA rearrangement in macronuclear genes of Stylonychia lemnae, a hypotrichous ciliate
Identification of an amplification promoting DNA sequence from the hypotrichous ciliate Stylonychia lemnae.
The macronucleus of the hypotrichous ciliate Stylonychia lemnae contains a 1218 bp long DNA molecule which becomes highly amplified during vegetative growth due to a continuous overreplication over a long time range. The region which is located upstream the open reading frame of the overamplified 1.2kbp Stylonychia DNA molecule enabled plasmids containing an inefficiently transcribed thymidine kinase gene to persist and amplify upon transfection into mouse L fibroblasts under selective conditions. This region contains long AT-rich stretches. The AT-rich sequences interact with a previously characterized HMG-I like protein from mouse Ehrlich ascites tumour cells. A binding activity for AT-rich stretches could also be identified in macronuclear extracts from Stylonychia lemnae. We suggest a common mechanism for overamplification in Stylonychia macronuclei during vegetative growth and amplification of plasmid DNA in heterologous mouse cells under the influence of a common element
Analysis of the subtelomeric regions of macronuclear gene-sized DNA molecules of the hypotrichous ciliateStylonychia lemnae: Implications for the DNA fragmentation process during macronuclear development?
- …