Avtor/Urednik		Vogler, Alfried P.; Welsh, Alexandra; Hancock, John M.
Naslov		Phylogenetic analysis of slippage-like sequence variation in the V4 rRNA expansion segment in tiger beetles (Cicindelidae)
Tip		članek
Vol. in št.		Letnik 14, št. 1
Leto izdaje		1997
Obseg		str. 6-19
ISSN		0737-4038 - Molecular biology and evolution
Jezik		eng
Abstrakt		Sequence variation in the middle part of the small-subunit rRNA was studied for representatives of the major groups in the family Cicindelidae (Coleoptera). All taxa exhibited a much expanded segment in variable region V4 compared to D. melanogaster. This expanded segment was not found in other groups of beetles, including three taxa in the closely related Carabidae. Secondary structure predictions indicate that the expanded segment folds into a single stem-loop structure in all taxa. Despite its structural conservation, the fragment differs strongly in primary sequence, even between closely related sister taxa. Several features of these sequences are consistent with slippage replication as the mechanism that has generated this sequence variation: the level of internal sequence repetition as measured by the relative simplicity factor (RSF), its variation in length between close relatives, and the strong nucleotide bias compared to the remainder of the gene. With few exceptions, there was also a correlation between sequence length and the level of sequence repetition, frequently interpreted as the result of slippage. Phylogenies inferred from the expansion segment were not consistent with existing hypotheses from other molecular data for the group. This indicates that DNA sequences in this region are not homologous throughout the entire Cicindelidae, but it leaves open the possibility that this expansion segment can be used for phylogeny reconstruction within subgroups. The implications of a phylogenetic approach to the understanding of slippage-like evolution are discussed.
Proste vsebinske oznake		rRNA V4 slippage-like sequence variation phylogenetic analysis rRNA V4 zaporedja drsečih variacij filogenetska analiza