Overlapping dna fragments meaning5/3/2023 Sequence tagged sites (STSs) were identified in the Asian and the African elephant for the following genes: melatonin receptor 1a (MTNR1A), retinoic acid receptor beta (RARB), and leptin receptor (LEPR) ( Burk et al., 1989). Identification of genes in elephants could provide additional information for evolutionary studies and for evaluating genetic diversity in existing elephant populations. ![]() For example, some STSs can be used in screening by PCR to detect microdeletions in Azoospermia (AZF) genes in infertile men. Sequence-tagged sites are very helpful for detecting microdeletions in some genes. The DNA sequence of an STS may contain repetitive elements, sequences that appear elsewhere in the genome, but as long as the sequences at both ends of the site are unique, unique DNA primers complementary to those ends can be synthesized, the region amplified using PCR, and the specificity of the reaction demonstrated by gel electrophoresis of the amplified product. The uniqueness of the sequence is established by demonstrating that it can be uniquely amplified by the PCR. In both these cases, the sequence was analyzed for the presence of repetitive elements, appropriate PCR primers were synthesized to ‘tag’ the site, and these primers were tested for functionality in the polymerase chain reaction.Īvinash Marwal, Rajarshi Kumar Gaur, in Animal Biotechnology (Second Edition), 2020 Sequence-tagged siteĪ sequence-tagged site (STS) is a short region along the genome (200–300 bases long) whose exact sequence is found nowhereelse in the genome. The end cosmid members of these contigs were subcloned into M13 prior to sequencing. The chromosome 16 cosmid clones were previously fingerprinted and assembled into cosmid contigs covering 60% of the chromosome ( Stallings et al., 1992). The M13 clones from chromosome 5 can be directly sequenced on an automated DNA sequencer. These flow-sorting capabilities were used to construct three chromosome 5 libraries in M13 and a chromosome 16 specific cosmid library. The strategy utilizes flow sorting technology developed at Los Alamos National Laboratory ( Deaven et al., 1986). The process of STS generation depends upon the preparation and sequencing of the sample DNA, the establishment of an effective PCR assay, and the localization of the STS along a chromosome ( Fig. A similar approach involving STSs and YACs is being used to close the gaps in the cosmid contig map of chromosome 16 ( Stallings et al., 1990, 1992). We anticipate that at least 300 STS markers will be needed, given random statistics, to generate this 1 Mb map. These combined approaches are being used to generate a low-resolution map of chromosome 5 with STS markers at intervals of 0.5–1 Mb. This type of map can provide a basis from which YAC contigs can be assembled and ordered. One can now generate a 1 Mb STS framework map directly from two sets of resources, namely a library from flow sorted human chromosomes and a panel of somatic cell hybrids containing varying lengths of a single human chromosome (resulting from chromosomal deletions and translocations, or radiation-induced breakage). ![]() The procedure known as ‘STS content mapping’ ( Green & Olson, 1990), involves the identification of cloned DNA fragments in a library (usually yeast artificial chromosome (YAC) clones) and the establishment of their position along the chromosome through regions of known sequence (STSs). The generation of STSs has become an integral part of strategies designed for mapping of specific chromosomes ( Green & Olson, 1990 Green et al., 1991). Sequence-tagged sites (STSs) ( Olsen et al., 1989) are unique sequence-based landmarks in the genome that are detectable by the polymerase chain reaction (PCR). DEAVEN, in Automated DNA Sequencing and Analysis, 1994 14.1 INTRODUCTION
0 Comments
Leave a Reply. |