Telomeres of polytene chromosomes in a ciliated protozoan terminate in duplex DNA loops.
The end of a telomeric DNA sequence isolated from a polytene chromosome of a hypotrichous ciliate folds back and hybridizes with downstream telomeric sequence to form a t loop that is stable in the absence of protein and DNA cross-linking. The single-stranded, telomeric DNA sequence at the end of a macronuclear molecule does not form a t loop but, instead, is complexed with a heterodimeric, telomere-binding protein. Thus, two mechanisms for capping the ends of DNA molecules are used in the same cell.
Murti
K G
KG
Laboratory of Virology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
Prescott
D M
DM
D000818:Animals; D002875:Chromosomes / Q000737:chemistry*; D016054:DNA, Protozoan / Q000737:chemistry*; D016813:Oxytricha / Q000235:genetics*; D016615:Telomere
D016054:DNA, Protozoan