Speciation and evolution in the Gagea reticulata species complex (Tulipeae; Liliaceae)
Zarrei, M. and Wilkin, P. and Ingrouille, Martin J. and Leitch, I.J. and Buerki, S. and Fay, M.F. and Chase, M.W. (2012) Speciation and evolution in the Gagea reticulata species complex (Tulipeae; Liliaceae). Molecular Phylogenetics and Evolution 62 (2), pp. 624-639. ISSN 1055-7903.
For the 12 named taxa in the Gagea reticulata species complex, 609 cloned sequences of the low-copy nuclear gene malate synthase (MS) were used to investigate species relationships, using standard phylogenetic tools and network analyses. Three (homologous) copies of MS locus were present in each individual analyzed, and multiple alleles were present at most of these loci. Duplication of MS occurred after divergence of the G. reticulata complex. After comparisons, 591 sequence types (i.e. haplotypes) were identified, requiring implementation of novel statistical analyses to group haplotypes in a smaller number of groups/lineages to enable further study. Haplotype groups/lineages are not fully congruent with species limits with some widely present among species. MS genotypes at the root of the network are those of G. setifolia from central Iran, with more derived sequences in this species found in the west and northwest. Presence of ancestral genotypes in several other taxa may indicate either the retention of “ancestral” polymorphisms, more recent introgressive hybridization, or both. The relative DNA content of specimens was estimated with flow cytometry (FCM). The FCM analyses revealed two levels of DNA content (putatively “diploid” and “tetraploid”), but no correlation between number of MS gene copies and ploidy was found.
|Keyword(s) / Subject(s):||Ancestral polymorphisms, Gene duplication, Hybridization, Low-copy nuclear genes, Ploidy, Network analysis|
|School:||Birkbeck Schools and Departments > School of Science > Biological Sciences|
|Date Deposited:||18 Nov 2011 09:07|
|Last Modified:||17 Apr 2013 12:21|
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