An Introduction to Detecting Genetic Variation in Populations

This explains the general idea of population genetics and what is used in the field. Only two factors are explained for use to find variation in a population: single nucleotide polymorphisms and microsatellites. This only explains the significance of each
            The field of population genetics focuses genetic variation and gene distribution within a certain population. With today’s ability to perform Sanger Sequencing and next-generation sequencing, population genetics is becoming a quicker and more accurate field of examining how population is impacted by various factors. To detect genetic variation in a population, researchers look at different loci in the populace. A locus (or loci for plural) is a location on a gene which can be a single nucleotide or span several distances of nucleotides. At these nucleotides there can be differences, which are called variation. A particular type of variation is called “single nucleotide polymorphisms” (SNPs) and these are mainly used to study variants in the genetics of human populations. Another common type of loci used to study variation in population genetics is called “microsatellites”. Microsatellites are short repeats of bases ranging from two to six bases long. Variation of microsatellites can be in what bases are repeating and how many times these bases are repeated.

                 Single nucleotide polymorphisms (SNPs) are the most prevalent types of polymorphisms in almost all genomes. There are two types of SNPs, common and rare. Common SNPs are basically SNPs in a population if a less common allele is found at a frequency 5% or more and rare SNPs occur below 5%.  Now SNPs can happen at any part of genes which include introns, exons, and regulatory regions. At the protein coding regions there are three types of classifications: synonymous, non-synonymous, and nonsense. These classifications are essentially naming of mutations of the allele on the genome because mutations are the variations the researchers are looking at for population genetics. Overall these SNPs are useful in population genetics because it is an easy to detecting gene flow in different populations.

                 Now with microsatellites, there are many useful aspects to it that make it useful for population genetics. Microsatellites are abundant, making almost a universal factor to study with any kind of population. Microsatellites are also short (only about 2-4 alleles per locus), which makes it easy to detect and there is high variation because of their short alleles. Genotyping of microsatellite can also allow insight into the structure of a population. If there is a population of a particular type of species and the population is separated by environmental factors, then there are ‘meta-populations’ (populations within populations). Microsatellites that genotyped in this population can be used indicate accurate gene flow in the meta-populations. Overall microsatellites can be very useful for population genetics.

                In the end population genetics is a growing field, especially in the area of conservation genetics. An important application of these techniques is towards conservation of small populations. These small populations can be endangered species in the wild or small populations of captive animals in zoos. By studying and using the resources in population genetics can lead to successful conservation of many species. 


Add a comment

0 answers +0 votes
Post comment Cancel