The telomere repeat motif of basal Metazoa.
In most eukaryotes the telomeres consist of short DNA tandem repeats and associated proteins. Telomeric repeats are added to the chromosome ends by telomerase, a specialized reverse transcriptase. We examined telomerase activity and telomere repeat sequences in representatives of basal metazoan groups. Our results show that the 'vertebrate' telomere motif (TTAGGG)( n ) is present in all basal metazoan groups, i.e. sponges, Cnidaria, Ctenophora, and Placozoa, and also in the unicellular metazoan sister group, the Choanozoa. Thus it can be considered the ancestral telomere repeat motif of Metazoa. It has been conserved from the metazoan radiation in most animal phylogenetic lineages, and replaced by other motifs-according to our present knowledge-only in two major lineages, Arthropoda and Nematoda.
Traut
Walther
W
Institut für Biologie, Zentrum für Medizinische Struktur- und Zellbiologie, Universität zu Lübeck, D-23538, Lübeck, Germany. traut@molbio.uni-luebeck.de
Szczepanowski
Monika
M
Vítková
Magda
M
Opitz
Christian
C
Marec
Frantisek
F
Zrzavý
Jan
J
D020816:Amino Acid Motifs; D000818:Animals; D003063:Cnidaria; D017124:Conserved Sequence; D037302:Ctenophora; D007448:Invertebrates / Q000235:genetics*; D018895:Microsatellite Repeats; D010802:Phylogeny; D011161:Porifera; D019098:Telomerase; D016615:Telomere / Q000737:chemistry* / Q000235:genetics
D019098:Telomerase