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1. 2. 3. New structure-based methods for the phylogenetic analysis of ribosomal RNA sequences using the parsimony optimality criterion. Joseph J. Gillespie Matthew J. Yoder* Anthony I. Cognato. RNA molecules have characteristic higher order structure that is conserved across all life. - PowerPoint PPT Presentation
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New structure-based methods for the phylogeneticanalysis of ribosomal RNA sequences using the
parsimony optimality criterion
Joseph J. GillespieMatthew J. Yoder*
Anthony I. Cognato
1
2
3
1. RAA/RSC/REC coding
2. RNA basepair coding
RNA molecules havecharacteristic higherorder structure that isconserved across all life
Using structure to guidethe assignment of positionalnucleotide homology, weoffer two new approaches toanalyzing rRNA sequences:
CCUGAGA
AAC
CC
GAAA G G
UCG
AAA
GAGGAAAUUCAUUC
GCGUUUCGACUGUCGA
UUG
GAUGU
U
ACGGAUAGCGUU
UCGGCGUCGUCCG
UUAUAUUCUUCGU
GUCGAU
GUC
GAACGCGU
GCACUUUUCCUCUAGU
AG
GACGUCGC
G
AUCCGUUGGGUG
UCUGUCUAAGAC
UCGAGGUGGAGC
CCGCGUAAUUUUU
AAUUAUGCGG
AC
CCUUGGUGUU
C
C
GACAGACUCACUCGACGGUAU
ACUAA
UGGCG
CGGGG C C
GCUA
CUUUA
GU
UAGCG
UUCGG
C
CCGUAGCA
AGCA
CGUUCUG UG
UUUG
ACGGCG
AUCGG
AC
CUG
GUGCCGAU
UCUGUC
C
CAGAACGAC UGUU
GGUUACGGU
GUU C
UCGAACAGACCUCG
UAUGA A A C G C C G
AUC AG C
GA C
GCU C
U A G A UU
GG
G
UAC U
UUCAGG
2
2f
2e
2d
2c
2b
2a
3g
3a
3e
3d
3c
3b
3f
3h
3i
3o
3n
3m
3l
3k
3j
3p
3
1b
1a
AG
5’
U
GC
AUUUGC
UU
3’
RAA/RSC/REC coding*
Methods for characterizing regions of RNA sequencealignments wherein positional nucleotide homologycannot be assigned with confidence
Based on the premise of using information fromsecondary structure (i.e., compensatory base changeevidence) to delimit unalignable positions
*Gillespie (2004) Mol. Phylogenet. Evol. 33: 936-943
RAA/RSC/REC coding
RAA/RSC/REC coding*
Region of ambiguous alignment
Two or more adjacent, non-pairing positions withina sequence wherein positional homology cannot beconfidently assigned due to the high occurrence ofindels in other sequences
RAA
*Gillespie (2004) Mol. Phylogenet. Evol. 33: 936-943
RAA/RSC/REC coding*
Region of slipped-strand compensation
Region involved in base-pairing wherein positionalhomology cannot be defended across a multiplesequence alignment; inconsistency in pairing likelydue to slipped-strand mispairing
RSC
*Gillespie (2004) Mol. Phylogenet. Evol. 33: 936-943
RAA/RSC/REC coding*
Region of expansion and contraction
Variable helical region flanked by conserved basepairsat the 3’ and 5’ ends, and an unpaired terminal bulgeof at least three nucleotides; characteristic of RNAhairpin-stem loops
REC
*Gillespie (2004) Mol. Phylogenet. Evol. 33: 936-943
RAA/RSC/REC coding*
Subdividing large ambiguously aligned regions intosmaller components provides:
why?
1. a means for comparing structurally similar nucleotides in fragment level alignment methods (INAASE, POY)
2. fewer character state transformations between taxa, with less potential to exceed the number of allotted states in a given phylogenetic software
4. improvements to existing global structural models for the various rRNA molecules on public databases
*Gillespie (2004) Mol. Phylogenet. Evol. 33: 936-943
3. the ability to objectively assign different substitution weights to pairing (RSC, REC) and non-pairing (RAA) regions
5. a more explicit set of homologies
RNA basepair coding
A = A AA = C CA = H GA = M UA = T C = R AC = Q CC = I GC = F UC = W G = N AG = E CG = L GG = P UG = Y U = D AU = G CU = K GU = S UU = V
*adopted from Smith et al. (2004) Mol. Biol. Evol. 21: 419-427
non-pairing pairing
code (20 states)*RNA basepair coding
substitution matrix
non-pairing
canonical
non-canonical
(-)
(-)
RNA basepair coding
weighting, i.e.RNA basepair coding
RNA basepair coding scripts
available via the Jrna script package
http://hymenoptera.tamu.edu/rna
This project was funded by NSF-PEET DEB grants 0328922 toRobert Wharton and 0358920 to Anthony Cognato.