Conservation genetics of the fisher (Martes pennanti) based on mitochondrial DNA sequencing

Translocation of animals to re-establish extirpated populations or to maintain declining ones has often been carried out without genetic information on source or target populations, or adequate consideration of the potential effects of mixing genetic stocks. We consider the conservation status of the fisher (Martes pennanti) and evaluate the potential genetic consequences of past and future translocations on this medium-sized carnivore by examining population variation in mitochondrial control-region sequences. We sampled populations throughout the fisher's range in North America including five populations unaffected by translocations and two western populations that had received long-distance translocations. Twelve haplotypes showed little sequence divergence. Haplotype frequencies differed significantly among subspecies and between populations within subspecies. Analysis of molecular variance (amova) and neighbour-joining analyses of haplotype relationships revealed population subdivision similar to current subspecies designations, but which may reflect an isolation-by-distance pattern. Populations in Oregon and in Montana and Idaho received several translocations and each showed greater similarity to the populations where translocations originated than to adjacent populations. Additional sequences obtained from museum specimens collected prior to any translocations suggest historical gene flow among populations in British Columbia, Washington, Oregon, and California. Anthropogenic impacts in that region have greatly reduced and isolated extant populations in Oregon and California. Future translocations may be necessary to recover populations in Washington and portions of Oregon and California; our results indicate that British Columbia would be the most appropriate source population.

Assessment of DNA fingerprinting for studies of small-mammal populations

We examined the use of DNA fingerprinting for determining degree of genetic relatedness and kin relationships of small mammals. We examined the utility of three DNA probes: a "mouse" probe, a repeat sequence from a Mus musculus genomic library; (CAC)5, a synthesized probe consisting of cytosine–adenine–cytosine repeated five times; and the SNAP probe, a synthesized probe containing a 22 base pair sequence. All three probes provided DNA fingerprints for montane voles (Microtus montanus), although the number of bands per individual varied among probes. We could obtain bands only with the snap probe for deer mice (Peromyscus maniculatus) and pocket mice (Perognathus parvus). Successful modifications of protocols for DNA extraction from small blood samples and for nonradioactive detection of bands suggest that DNA fingerprinting should be useful for in situ studies of natural populations by many research laboratories. To determine genetic similarity we calculated the probability of band sharing between individuals. The average probability varied among probes for the same unrelated M. montanus individuals and among species for the snap probe. For all probes the average probability of band sharing was significantly greater for related than for unrelated individuals of M. montanus. Unrelated individuals usually share an unpredictable number of bands, and the probability of band sharing may reach that of related individuals. Average band sharing for related M. montanus individuals was greater than the expected 0.5 only for (CAC)5. Average probability of band sharing between unrelated and related individuals and the variance of this value must be known before an attempt is made to determine general relationships in field populations. When maternity was known, paternity could be determined with a low probability of misassignment by identifying obligate paternal bands.