MOTIVATION: RNA Movies is a system for the visualization of RNA secondary structure spaces. Its input is a script consisting of primary and secondary structure information. From this script, the system fully automatically generates animated graphical structure representations. In this way, it creates the impression of an RNA molecule exploring its own two-dimensional structure space. RESULTS: RNA Movies has been used to generate animations of a switching structure in the spliced leader RNA of Leptomonas collosoma and sequential foldings of potato spindle tuber viroid transcripts. AVAILABILITY: Demonstrations of the animations mentioned in this paper can be viewed on our Bioinformatics web server under the following address: http://BiBiServ.TechFak.Uni-Bielefeld. DE/rnamovies/. The RNA Movies software is available upon request from the authors.

MOTIVATION: We present a new probabilistic model of the evolution of RNA-, DNA-, or protein-like sequences and a software tool, Rose, that implements this model. Guided by an evolutionary tree, a family of related sequences is created from a common ancestor sequence by insertion, deletion and substitution of characters. During this artificial evolutionary process, the 'true' history is logged and the 'correct' multiple sequence alignment is created simultaneously. The model also allows for varying rates of mutation within the sequences, making it possible to establish so-called sequence motifs. RESULTS: The data created by Rose are suitable for the evaluation of methods in multiple sequence alignment computation and the prediction of phylogenetic relationships. It can also be useful when teaching courses in or developing models of sequence evolution and in the study of evolutionary processes. AVAILABILITY: Rose is available on the Bielefeld Bioinformatics WebServer under the following URL: http://bibiserv.TechFak.Uni-Bielefeld.DE/rose/ The source code is available upon request. CONTACT: [email protected]