| dc.contributor.author | Fuller, Kathleen Marguerite. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:44Z | |
| dc.date.available | 1991 | |
| dc.date.issued | 1991 | en_US |
| dc.identifier.other | AAINN64536 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55214 | |
| dc.description | A survey of mitochondrial DNA variation in a sample of 280 individuals from six geographic populations of the scallop species Placopecten magellanicus revealed extensive length polymorphism. Variable regions in the molecule were mapped, and almost all size polymorphism was found to occur at three discrete loci. | en_US |
| dc.description | The mitochondrial genome has a consensus size of 35 kilobase pairs, and varies between 32 and 42 kb. The three major length variable loci exhibit variation both within (heteroplasmy) and among (polymorphism) individuals. Locus I is a tandem array of two to eight copies of a 1.45 kb repeat; locus II and locus III have increments of change of about 250 base pairs and 50 bp, with six and more than ten size classes respectively. Small deletions of about 200 bp in three different restriction fragments between locus II and locus III were also observed. Contiguous fragments totalling over 15 kb located between locus I and locus III showed no variation in length. | en_US |
| dc.description | Two methods were used to measure the diversity of variation. For locus I and locus II, size class diversity was estimated as 64% and 19% respectively. For locus III genotypic rather than allelic diversity was estimated, yielding a conservative value of 91%, and this statistic also gave a restriction morph diversity of 37%. The frequency of heteroplasmy ranged from 3.4% for locus II to 69% for locus III. A number of individuals exhibited simultaneous heteroplasmy for more than one marker. Four cases of restriction site heteroplasmy were observed, and three of them were associated with locus I heteroplasmy. | en_US |
| dc.description | For each of the major length polymorphic loci significant differences in the distribution of variation were found between populations, but there was no consistent pattern of genetic differentiation. It was concluded that the high backward and forward mutation rate among a limited number of size classes that characterizes mtDNA length polymorphism precludes the use of this kind of variation as a population marker. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1991. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Molecular. | en_US |
| dc.title | Polymorphism and heteroplasmy of mitochondrial DNA in the scallop Placopecten magellanicus (Gmelin). | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
