An Analysis of the Observed Heterozygosity of Lake Trout Essay

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An analysis of the observed heterozygosity of Lake Trout populations from three lakes: Devil, Eagle, and Loughborough, inferred from microsatellite genotypes.

This study was undertaken in order to compare the heterozygosity of three Lake Trout populations at various loci. Samples of twenty-five Lake Trout were collected from three lakes: Devil, Eagle and Loughborough, all three of which are situated north of Kingston, Ontario. An autoradiograph was used to analyze the genotypes of the individuals at six different loci of microsatellites, which are repeat sequences in the DNA that are neutral and do not code for proteins. This data was used to compare the genetic diversity of the three different trout populations. Numerical
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It may be believed that inbreeding is not good for a population with such opinions being based on having seen the result of inbreeding in humans. Inbreeding as well as outbreeding, however, has both advantages and disadvantages. One advantage of inbreeding is its ability to depress the expression of recessive alleles (Ellstrand and Elam 1993). In a population with a damaging recessive allele, an individual may not seek to mate with anyone who potentially carries or expresses that allele. In this example the population might inbreed to decrease the heterozygosity in an attempt to remove the harmful gene. Mating within the family- when it is apparent that the family does not carry the detrimental allele, is more ideal in an evolutional prospective than putting the survival of that population at risk. In regards to Ellstrand and Elam’s study, this situation could occur in the Lake Trout from Loughborough causing the Lake Trout to have a lower mean heterozygosity. This Lake Trout population could be purging undesired alleles from its gene pool. One can conclude that not only does genetics have an effect on heterozygosity, but humans do as well.
Another factor that may cause a loss of genetic diversity is fishing pressures. Smith et al (1990) suggested that fishing activities which concentrate on spawning populations differentially remove the older and more