Molecular Markers. Biological & Biomedical Sciences Essay (Essay Sample)

EXPRESSED SEQUENCE TAGS-SIMPLE SEQUENCE REPEATS (EST-SSR) & START CODON POLYMORPHISM (SCoT) MOLECULAR MARKERS
a REVIEW
OMAR MAGED MOHAMMED | MOLECULAR MARKERS: PRINCIPLES & APPLICATIONS (BT423) | CODE: 140389
Expressed Sequence Tags-Simple Sequence Repeats (EST-SSR) Markers
Molecular markers are currently the most widely used biological markers in genetic diversity studies as they are not affected by environmental conditions and are found along the entire length of a genome (Song et al., 2012). Simple sequence repeats (SSRs), also known as microsatellites, have become in recent years the marker of choice for many genetic analyses studies (Ellis et al., 2007; Pashley et al., 2006). SSRs consist of tandem repeats of a core sequence of 1-6 base pairs along protein-coding and noncoding regions (Weaver, 1999). SSRs are one of the most discriminatively powerful molecular markers because of their co-dominant inheritance, wide genomic distribution, locus specificity, ease of detection, and high reproducibility (Semagn et al., 2006; Song et al., 2012). Despite the vast utility of SSRs, the traditional methods of developing SSR markers are usually time-consuming and labor-intensive (Ponyared et al., 2016; Song et al., 2012). Additionally, the PCR primers necessary for the amplification of SSRs are frequently species-specific making it difficult to make interspecies comparisons (Pashley et al., 2006).