A Secondary Structural Model of the 28S rRNA Expansion Segments D2 and D3 for Chalcidoid Wasps (Hymenoptera: Chalcidoidea)

• Published in: Molecular biology and evolution Vol. 22; no. 7; pp. 1593 - 1608
• Main Authors: Gillespie, Joseph J., Munro, James B., Heraty, John M., Yoder, Matthew J., Owen, Albert K., Carmichael, Andrew E.
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.07.2005
• Subjects: Animals; Base Sequence; DNA, Ribosomal; Evolution, Molecular; Models, Structural; Molecular Sequence Data; Nucleic Acid Conformation; Phylogeny; RNA, Ribosomal, 28S - chemistry; RNA, Ribosomal, 28S - genetics; rRNA 28S; Sequence Alignment; Sequence Homology, Nucleic Acid; Species Specificity; Structural models; Wasps - genetics; secondary structure; chalcidoid; homology; rRNA; multiple sequence alignment; ribosome; 28S; expansion segment
• ISSN: 0737-4038; 1537-1719
• DOI: 10.1093/molbev/msi152

We analyze the secondary structure of two expansion segments (D2, D3) of the 28S ribosomal (rRNA)-encoding gene region from 527 chalcidoid wasp taxa (Hymenoptera: Chalcidoidea) representing 18 of the 19 extant families. The sequences are compared in a multiple sequence alignment, with secondary structure inferred primarily from the evidence of compensatory base changes in conserved helices of the rRNA molecules. This covariation analysis yielded 36 helices that are composed of base pairs exhibiting positional covariation. Several additional regions are also involved in hydrogen bonding, and they form highly variable base-pairing patterns across the alignment. These are identified as regions of expansion and contraction or regions of slipped-strand compensation. Additionally, 31 single-stranded locales are characterized as regions of ambiguous alignment based on the difficulty in assigning positional homology in the presence of multiple adjacent indels. Based on comparative analysis of these sequences, the largest genetic study on any hymenopteran group to date, we report an annotated secondary structural model for the D2, D3 expansion segments that will prove useful in assigning positional nucleotide homology for phylogeny reconstruction in these and closely related apocritan taxa.