An Analysis of the Observed Heterozygosity of Lake Trout

An analysis of the discovered heterozygosity of Lake Trout peoples from ternary lakes crucify, bird of Jove, and Loughborough, inferred from microsatellite ge nonypes. Abstract This eng progress was undertaken in order to comp ar the heterozygosity of iii Lake Trout existences at various loci. Samples of twenty-five Lake Trout were collected from three lakes daimon, eagle and Loughborough, every(prenominal) in completely three of which atomic number 18 situated north of Kingston, Ontario. An autoradiograph was utilise to analyze the genotypes of the individuals at six contrasting loci of microsatellites, which are repeat sequences in the DNA that are neutral and do not code for proteins.This data was used to equality the inherited multifariousness of the three different trout populations. Numerical values for sight heterozygosity (Ho) were then(prenominal) generated using the data and the Doh heterozygosity calculator. The results have indicated that the entail he terozygosity in respect of Devil Lake trout was significantly greater than that of the trout in bird of Jove Lake (p=2. 89E-7) as well as that of Loughborough Lake (p=1. 44E-19). Furthermore, the mean heterozygosity for Eagle Lake trout was significantly greater than that of Loughborough Lake (p=2. 2E-6). This whitethorn be ascribable to the fact that natural selection acts as a force to constitute inbreeding to eliminate harmful genes causing low heterozygosity in a population. In addition, human and natural beliefs occurring in the lakes, for example, sport search and water temperature whitethorn cause differences in heterozygosity. Understanding and using these findings may help with sustaining weight populations. Introduction Heterozygosity is the measure of the transmittable alteration in a population at a particular gene locus.Genetic variation within a population is important in maintaining or increase the fitness of members in the population and ultimately the sur vival of the species. Fitness describes the susceptibility of an individual species of a certain genotype to reproduce, and is usually equal to the property of the individuals genes in all the genes of the next generation. A positive correlation was put up between the heterozygosity at the loci and the fitness (survival and maturation) of the fish, suggesting that heterozygosity is advantageous (Pujolar et al. 005). A heterozygote advantage describes the geek in which the heterozygote genotype has a higher relative fitness than twain the homozygote dominant or homozygote recessive genotype. An individuals fitness is manifested through its phenotype, and the phenotype may be affected by both genes and environmental traces. bingle such characteristic that was observed to possibly have an effect on trains of heterozygosity in a population was the area in which the population lives. In an experiment conducted by Rowe et al. 1999) the heterozygosity of various populations of Na tterjack Toads (Bufo calamita) demonstrate in several areas were compared, ultimately discovering a swallow heterozygosity in a population that is isolated from others. Volckaert and Zouros (1989) conducted a film to measure inheritable diversity levels in scallops (Placopecten magellanicus) and discovered levels of heterozygosity to be highest as age increased. Ferguson (1990) found similar information that affects diversity among rainbow trout (Oncorhynchus mykiss) and concluded that heterozygosity levels were prove to have a direct relationship between the sex, size and age of the fish.There are many reckons that may affect the genetic diversity of a population. In particular, various events and environmental characteristics may affect the genetic diversity of Lake Trout. One factor may include fishing. This activity may cause the population of the fish to return at an unstable rate, thus this study will be undertaken to determine the many factors that may contribute infl uences to the genetic diversity of Lake Trout in three lakes Devil, Eagle and Loughborough Lake.Using six microsatellite loci from 25 Lake Trout from all three lakes, observed heterozygosity values that act as an indicator for genetic diversity, will be obtained and analyzed. This data can be further used by analyzing and providing additional information about the influences of certain characteristics on population genetics. Results Figure 1 illustrates that the lake with the greatest observed heterozygosity is Devil Lake. It was inflexible that the observed heterozygosity of Devil Lake is significantly greater than the observed heterozygosity of Loughborough Lake (p=1. 4E-19). The sample size for all 3 lakes was 25 Lake Trout. Figure 1. The graph illustrates the mean observed heterozygosity of the three lakes. The error bars represent standard deviation. Discussion The conducted experiment involving heterozygosity of Lake Trout from Devil, Eagle and Loughborough Lake shows that th ere are significant differences between the three lakes. Devil Lake had the highest mean heterozygosity within its population, Eagle Lake heterozygosity was found to be in the middle and Loughborough Lake with the lowest.It was determined that the observed heterozygosity of Devil Lake was significantly greater than the observed heterozygosity of Loughborough Lake (p=1. 44E-19). The difference in the data sets outcomes may be explained by a number of factors, such as natural selection, fishing and restocking the lake, and lake temperatures. All these factors may cause diversity in heterozygosity. The goal of an organism is to reproduce and alley their genes on to the next generation allowing the species to survive.The passing on of genetic strong can be achieved through inbreeding or outbreeding. Inbreeding is the breeding amongst family or self outbreeding is the breeding with members of the same species that are not closely related. It may be believed that inbreeding is not good for a population with such opinions being establish 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 train the harmful gene. couple within the family- when it is apparent that the family does not carry the detrimental allele, is more precedent in an evolutional prospective than putting the survival of that population at risk.In regards to Ellstrand and Elams 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 heterozygous individuals from the virgin stock.Previously stated, levels of heterozygosity are higher as age increases (Volckaert and Zouros 1989). Due to fishing, the amount of Lake Trout may decrease and there would be less fish. To fix the amounts of fish in the lakes, humans restock the lakes with hatchery fish (fish that are grown by humans and released into the wild). Evans et al. (1991) found that the human harvested fish tend to have lower genetic variation and actually decrease the fitness and survival of the native species. Loughborough Lake has the biggest population but the lowest heterozygosity.Compared to Eagle Lake and Devil Lake, most people from the Loughborough Lake area receive their income from fishing (Ontario Ministry of innate Resources 1970). Excessive fishing depletes the amount of fish and creates the perceived need to continually restock the lake with fish. The practice of restocking the lake with hatchery fish may result in the great population of Lake Trout which would in turn decrease the heterozygosity of Loughborough Lake. There are other factors that may contribute to increase levels of heterozygosity in fish.One such characteristic that may increase levels of heterozygosity in fish is fluctuations in water temperature. Zimmerman and Richmond (1981) found that highly variable thermal regions demand for greater fitness. The fittest of fish are more heterozygous because they are able to survive in different temperatures. In Zimmerman and Richmonds experiment, the greatest temperature fluctuation was 7C, with the highest heterozygosity level of 49%. This trend may prove that the greater the tempe rature fluctuation, the greater the heterozygosity of a population living within the waters.The temperature fluctuations of the three lakes are Devil Lake at 31F, Eagle Lake at 21F, and Loughborough Lake at 7F (Ontario Ministry of Natural Resources 1970). These numbers correlate with the data by showing that Devil Lake with the highest temperature fluctuation has the greatest heterozygosity, whereas Loughborough Lake with the lowest temperature fluctuation has the lowest heterozygosity. The mean heterozygosity of Lake Trout from Devil Lake was significantly greater than that of trout from Eagle Lake, which was greater than that of Loughborough Lake.Potential reasons for genetic diversity may be caused by natural selection acting as a force to cause inbreeding to eliminate harmful genes, fishing in the lakes which then require the lakes to be restocked with hatchery fish, and thermal fluctuations that cause differences in heterozygosity. Further enquiry and experiments specifically l ooking in depth at effects that causes genetic diversity should provide greater insight into why the heterozygosity in populations varies. literary productions Cited Ellstrand N. , Elam R. 1993.Population genetic consequences of small population size implications of plant conservation. Annual brush up of Ecological Systems. 24 217-242. Evans D. , Casselman J. , Wilcox C. 1991. 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