Estudi de l'associacio entre els polimorfismes cromosomic i enzimatic en poblacions nord-americanes de drosophila subobscura
- Autores: Joan Balañà i Maymó
- Lectura: En la Universitat de Barcelona ( España ) en 1990
- Idioma: español
- Tribunal Calificador de la Tesis: Lluís Serra Camó (presid.), Jordi Ocaña i Rebull (secret.), Montserrat Aguadé Porres (voc.), Rosa Frutos Illan (voc.), Eduard Petitpierre Vall (voc.)
- Materias:
- Texto completo no disponible (Saber más ...)
- Resumen
THE ENZYME POLIMOHPHISM AND ITS ASSOCIATION WITH INVERSION POLYMORPHISM HAVE BEEN STUDIED IN 5 NORTH-AMIRCAN COLONIZING POPULATIONS OF DROSOPHILA SUBOBSCURA. SIX OUT OF THE 15 LOCI ANALYZED, ALL OF THEM POLYMORPHIC IN THE ORIGINAL DISTRIBUTION AREA OF THE SPECIES, TURNED OUT TO BE MONOMORPHIC IN THE COLONIZED AREA; SEVEN LOCI PRESENTED TWO ALLELES AND THE REMAINING 2 PRESENTED 3 ALLELES. POPULATIONS DID NOT DIFFER SIGNIFICANTLY IN THEIR MEAN HETEROZYGOSITY AND PRESENTED VALUES SIMILAR TO THOSE FOUND IN THE PALEARCTIC AREA, WHEREAS THE MEAN NUMBER OF ALLELES PER LOCUS HALVED ITS VALUE IN NORTH-AMRICA. SEVEN LINKAGE DISEQUILIBRIA BETWEEN LOCI AND CHROMOSOMAL INVERSIONS HAVE BEEN DETECTED; THOSE CORRESPONDING TO CHROMOSOME E ARE NOT DETECTED IN THE PALEARCTIC POPULATIONS, WHEREAS THOSE AFFECTING CHROMOSOME O ARE ALREADY PRESENT IN EUROPE, ALTHOUGH THEIR VALUES ARE STRENGTHENED IN THE COLONIZING POPULATIONS.
A LINKAGE DISEQUILIBRUM BETWEEN THE ALLELES OF AMY AND HK-1 LOCI THAT CANNOT BE EXPLAINED BY THEIR ASSOCIATION WITH CHROMOSOMAL INVERSIONS HAS ALSO BEEN DETECTED.
NO SIGNIFICANT 3-LEVEL ASSOCIATION BETWEEN ALLOZUME LOCI AND INVERSIONS HAVE BEEN DETECTED AS REVEALED BY A LOG-LINEAR ANALYSIS. THE DATA OBTAINED SHOW A LACK OF SECONDARY FOUNDER EFFECTS DURING THE EXPANSION OF THE SPECIES THROUGH THE OCCUPIED AREA AND ALSO SUGGEST A COMMON ORIGIN OF THE FOUNDER INDIVIDUALS OF THE NORTH AND SOUTH-AMIRCAN POPULATIONS.
