#Please insert up references in the next lines (line starts with keyword UP) UP arb.hlp UP glossary.hlp UP pt_server.hlp #Please insert subtopic references (line starts with keyword SUB) SUB next_neighbours.hlp SUB next_neighbours_listed.hlp SUB faligner.hlp # Hypertext links in helptext can be added like this: LINK{ref.hlp|http://add|bla@domain} #************* Title of helpfile !! and start of real helpfile @@@ ******** TITLE Nearest relative search OCCURRENCE ARB_NT/Search/More search/Search Next Relatives of SELECTED Species in PT Server ARB_NT/Search/More search/Search Next Relatives of LISTED Species in PT Server ARB_NT/ARB_EDIT/EDIT/Integrated Aligners SECTION ALGORITHM Splits the sequence(s) into short oligos of a given size. These oligos are 'Probe Matched' against the PT_SERVER database. The more hits within the sequence of another species, the more related the other species is. SECTION PARAMETERS PT-Server Select the PT-Server to search Oligo length Length of oligos used to perform probe match against the PT server. Default is 12. Mismatches Number of mismatches allowed per oligo. Default is 0. Be careful: The search may get incredible slow, when rising the number of mismatches. Search mode Complete: Match all possible oligos Quick: Only match oligos starting with 'A' The 'Quick mode' works well for many sequence types and is approx. 4 times faster than the 'Complete mode'. For some sequence types it completely fails, e.g. if there are repetitive areas containing many 'AAAAA' Match score: absolute: returns the absolute number of hits relative: returns the number of hits relative to maximum possible hits The score depends on several other parameters like number of allowed mismatches, search mode, oligo length and complement settings. The maximum absolute score is (length of relatives sequence) minus (oligo length) Practically this score is rarely reached, because several possible oligos are skipped, namely - all oligos starting with 2 identical nucleotides - all oligos containing IUPAC codes (or N's) If mismatches are used, each oligo may hit at several positions. Thus the maximum relative score may exceed 100% (and the maximum absolute score may exceed its theoretical maximum). If you use 'Quick mode' the mean relative score will be approx. 25% (assuming that 25% of the possible oligos start with an 'A'). That means.. only if you use - 0 mismatches, - 'Complete mode' and - your sequences contain no IUPACs and no repetitions, you will get a score of 100% (or sequenceLength-oligoLength) for the selected species itself and its duplicates. Complement: forward: Match only forward oligos reverse: Match only reverse oligos complement: Match only complement oligos reverse-complement: Match only reverse-complement oligos and all combinations of these. The combinations may affect the score as well! Note: Not available for EDIT4 aligner. NOTES None EXAMPLES None WARNINGS None