Open AccessY chromosome and new concept of azoospermia factor
Author(s) -
KOH EITETSU,
CHOI JIN,
NAMIKI MIKIO
Publication year - 2005
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1111/j.1447-0578.2005.00097.x
Subject(s) - azoospermia factor , genetics , palindrome , biology , y chromosome , sequence tagged site , sequence (biology) , chromosome , gene , locus (genetics) , genome , computational biology , azoospermia , infertility , gene mapping , pregnancy
The completion of a draft sequence of the entire human genome in 2001 was followed by a complete sequencing of the Y chromosome in 2003. It is now possible to refer to a physical map of the Y chromosome. The Y chromosome can be classified into X‐transposed, X‐degenerate and ampliconic sequences depending on the origins of its sequences. In particular, the ampliconic sequences are complexes of massive palindrome structures in which sequences having higher than 99.9% homology are present symmetrically. Interestingly, palindromic repeats may undergo frequent gene conversion associated with intrachromosomal recombination and play an important role in the maintenance of the genetic materials of the Y chromosome. The azoospermia factor (AZF) region of the ampliconic region is the most probable candidate for spermatogenesis, and forms a palindrome structure. Thus, there is a limit in the detection of microdeletion using conventional sequence‐tagged sites based on polymerase chain reaction because of their structure. It is now necessary to update the AZF concept. (Reprod Med Biol 2005; 4 : 123–128)