Low copy number anonymous nuclear loci were used to search for species
markers in four species of Klamath Basin suckers. We sequenced 28 randomly
chosen loci representing 10,421 bp; 21 loci were similar to sequences in GenBank.
Eight fixed sequence differences were found among Klamath species. Locus 120
contained rare but diagnostic markers for Deltistes luxatus and for Catostomus
rimiculus. Locus 4 also contained three rare but unique sites in Catostomus
rimiculus. No sequence differences were found between Chasmistes brevirostris and
Catostomus snyderi. Loci 4 and 120 exhibited allele frequency differences between
Rogue River C. rimiculus and all Klamath Basin suckers. Genotype BB of locus 4
was a fixed diagnostic marker and genotype BB of locus 120 was a frequency
dependent marker for Rogue C. rimiculus.
Although Klamath suckers represent three genera, very limited variation was
found among 10,431 base pairs. We examined phylogenetic patterns of five loci in
eleven catostomid genera and 25 species to determine if the homogeneity in the
Upper Klamath Basin was due to massive hybridization and introgression or to
retention of ancestral sequences. Two loci with no similarity to GenBank sequences
(non-coding loci) and three loci with substantial similarity to GenBank sequences
(coding loci) gave similar results, providing support for various subfamilies and
tribes, more support for eastern genera and little support for western genera. Each
locus was a mosaic of species or population markers, sometimes providing
discriminatory power for allopatric populations of a species, such as C. macrocheilus,
while not discriminating other species. Upper Klamath Basin species were
noteworthy in their lack of autapomorphies, but had similar numbers of derived
informative sites as other catostomins. Upper Klamath Basin species consistently
shared ancestral or equivocal informative sites either with moxostomatins or a
variable group of western species and shared derived sites with other western species,
especially C. occidentalis. The data suggest that Upper Klamath Basin species have
retained a largely ancestral genome at these loci. Thus, the failure of this technique to
uncover significant variation in Upper Klamath Basin species may be a reflection of
their plesiomorphic genome at these loci and not necessarily hybridization. / Graduation date: 2004
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/30574 |
| Date | 12 November 2003 |
| Creators | Wagman, David Wolfe |
| Contributors | Markle, Douglas F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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