Genomic localization

The AR gene is located on the long arm of the X chromosome close to the centromere spanning the chromosomal region Xq11.2 to Xq12 and is over 180 kb (http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=367). Prior to the cloning of the AR cDNA and physical mapping, its localization on the X chromosome had already been recognized from genetic studies. In 1975, Meyer et al., who studied the genetics and inheritance of male pseudohermaphroditism, postulated that the dihydrotestosterone receptor gene must be on the X chromosome (Meyer et al. 1975). The same group assigned the gene to a position between Xq11 and Xq13 a few years later, by cell fusion complementation experiments with an androgen binding deficient mouse kidney cell and human cells containing different X -autosomal translocations expressing only segments of the X chromosome (Migeon et al. 1981). This locus was confirmed by a restriction fragment length polymorphism (RFLP) study (Wieacker etal. 1987).

The location on a sex chromosome implies that males possess only one allele whereas females have two. As a result, mutant AR genes are inherited in an X-linked fashion affecting men, whereas women carry and transmit the gene to the next generation without themselves being affected.

The AR cDNA was the last of the steroid receptors to be cloned. Using the high degree of homology of steroid receptor DNA-binding domains to screen cDNA libraries for similar sequences, several groups independently isolated the AR cDNA from different sources anddetermined its sequence at the end of the eighties (Chang etal. 1988a; 1988b; Lubahn etal. 1988a; 1988b; Trapman etal. 1988). Using a cDNA probe Brown et al. (1989) then localized the AR gene to Xq11-q12 by analysis of somatic cell hybrid panels segregating portions of the X chromosome.

Hair Loss Prevention

Hair Loss Prevention

The best start to preventing hair loss is understanding the basics of hair what it is, how it grows, what system malfunctions can cause it to stop growing. And this ebook will cover the bases for you. Note that the contents here are not presented from a medical practitioner, and that any and all dietary and medical planning should be made under the guidance of your own medical and health practitioners. This content only presents overviews of hair loss prevention research for educational purposes and does not replace medical advice from a professional physician.

Get My Free Ebook


Post a comment