| one publication added to basket [59469] | A comparison of allozyme and mtDNA phylogenies of some endemic Tanganyikan cichlid fishes (Pisces: Cichlidae)
Rüber, L.; Verheyen, E. (1993). A comparison of allozyme and mtDNA phylogenies of some endemic Tanganyikan cichlid fishes (Pisces: Cichlidae). Belg. J. Zool. 123(Suppl. 1): 63
In: Belgian Journal of Zoology. Koninklijke Belgische Vereniging voor Dierkunde = Société royale zoologique de Belgique: Gent. ISSN 0777-6276; e-ISSN 2295-0451, more
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| Keywords |
Acids > Organic compounds > Organic acids > Nucleic acids > DNA
Biogeny > Phylogeny
Enzymes > Allozymes
Taxa > Species > Endemic species
Cichlidae Bonaparte, 1835 [WoRMS]
Tanzania [Marine Regions]
Fresh water |
| Abstract |
Since more than a century biologists attempt to understand the origin of the endemic flock(s) of cichlid fishes that occur in Lake Tanganyika. In view of the claimed absence of usefull morphological characters for phylogenetic analyses on these fishes, a number of recent studies implement molecular methods to study their phyldgeny. We compared the mtDNA phylogenies of endemic Tanganyikan cichlid fishes based upon published (I) und unpublished mtDNA cytb sequences (2) with a recent phylogeny of these fishes derived from allozyme data (3). Since the author of the latter study used allozyme loci as characters defined only by the most commonly occurring allele we reanalysed these data and followed different alternative assumptions. First we considered all the electrophoretically detected alleles as binary characters with either character states presence or absence, also known as the "independent alleles" model. As this method of ten has limitations in it's use (e.g. unequal weighting of polymorphic loci or problems when no alleles are shared with the outgroup) we also reanalysed these allozyme data under the usually recommended assumption that the locus is the character and that the allelic combinations are its (multistate) character states. Genetic and phenetic distances well as parsimony analysis of allozyme and mtDNA cytb sequence data were used for the construction of phylogenetic trees. Regardless of the choice of characters and the different methods of tree building used, the positions of four taxa (Eretmodus, Cyprichromis, Perissodus and Plecodus) change between the trees obtained using all alleles versus trees obtained with only the most common alleles. (Re)weighting of the data suggests that the observed topological instabilities are the result of highly polymorphic loci: Gpi-2, Idh-2, Mpi and Pgdh. The mtDNA and allozyme based phylogenies differ for the topology of a few taxa including representatives among the "oldest" Tanganyikan lineages like Oreochromis and Bathybates. Interestingly, the same branches (Eretmodus, Cyprichromis, Perissodus and Plecodus) are weakly supported for both DNA and allozyme phylogenics. In view of the observation that the mtDNA and allozyme phylogenies are not identical, future studies will attempt to establish the reliability of these methods (e.g. by studying different "slower" and "faster" mtDNA genes for cichlid taxa separated by different evolutionary distances.(1) C. STURMBAUER and A. MEYER (1993). Mol. Biol. Evol. 10 (4):751-768.(2) C. STURMBAUER, E. VERREYEN and A. MEYER, in press. (3) M. NISHIDA (1991). Experientia 47:974-979. |
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