Polymorphic (AAT)n trinucleotide repeats derived from a human brain cDNA library
✍ Scribed by Russell L. Margolis; Theresa S. Breschel; Shi-Hua Li; Arif S. Kidwai; Melvin G. McInnis; Christopher A. Ross
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 150 KB
- Volume
- 96
- Category
- Article
- ISSN
- 0340-6717
No coin nor oath required. For personal study only.
✦ Synopsis
Seven cDNA fragments containing polymorphic (AAT)n trinucleotide repeats were isolated from a human brain cDNA library and mapped by linkage to specific loci. These repeats may serve as gene markers or as candidates for diseases caused by expansion mutation.
Source~description. Clones were isolated from a human frontal cortex cDNA library derived from an 85-year-old female using a combination of oligo-dT and random priming, with an average insert length of 1 kb and actin represented in 0.17% of inserts (stratagene). Our previous use of the library indicates a fairly high level of complexity, with over 50 inserts at least partially sequenced and few duplications detected. The library was screened with (AAT)10 and (AAT)20 radiolabeled oligonucleotides to identify trinucleotide repeats (AAT and equivalent) contained within genes expressed in the human brain. Standard techniques were employed as we have previously described (Li et al. 1993; Margolis et al. 1994). Approximately 50,000 plaque forming units (pfu) were screened in total. After plaque purification, clones were fully sequenced on both strands and repeats were tested for length polymorphism by polymerase chain reaction (PCR). Eight clones with at least four consecutive repeats and differing from previously described genes were isolated, suggesting