In DNA fingerprinting, specific regions of the human genome are targeted for analysis. The regions most commonly used for DNA fingerprinting are the short tandem repeats (STRs), also known as microsatellites. These regions are found throughout the human genome.
STRs consist of short repeated DNA sequences, typically composed of 2 to 6 base pairs, which are repeated in tandem. The number of repeats at each STR locus varies among individuals, resulting in different alleles. It is the variation in the number of repeats that makes STRs highly informative for DNA profiling.
The selection of specific STR loci for DNA fingerprinting may vary depending on the application, laboratory protocols, or forensic databases. Typically, a panel of several STR loci is analyzed to create an individual's DNA profile. The commonly used STR loci in forensic DNA profiling include D3S1358, TH01, D21S11, D18S51, and FGA, among others.
Other regions of the human genome, such as single nucleotide polymorphisms (SNPs) and insertion/deletion polymorphisms (indels), can also be used in DNA profiling, although they are less commonly employed compared to STRs. SNPs are single-base differences in the DNA sequence among individuals, and indels are insertions or deletions of a small number of base pairs. These regions can provide additional genetic information and may be used in specific cases or as supplementary markers in DNA profiling.
Overall, the targeted regions in the human genome for DNA fingerprinting primarily consist of the highly variable short tandem repeat (STR) loci, which play a crucial role in creating unique DNA profiles for individual identification and forensic analysis.