Abstract |
The Y chromosome plays a determinant rôle in human maleness. Studies on individuals with sex chromosome abnormalities indicate that a testis determining factor (TDF) is located on the short arm of the Y chromosome. A candidate gene, recently cloned, encodes a protein with multiple "finger" domains of a type known to bind DNA and control transcription. The puzzling finding that on the short arm of the X chromosome is located and homolog gene escaping X inactivation raises problems on the functional relationship of the two genes. The whole of the molecular studies using Y-specific probes have shown that XX males result from the transposition of TDF from the short arm of the Y to that of X chromosome; at least some XY females result from the same transposition, that leaves the Y chromosome without its distal short arm, TDF included. In XO males, the TDF is translocated to an autosome; according to the deletion of the latter, different malformation patterns may be present in these patients. If the presence or the absence of a critical segment of the Y chromosome do explain many instances of sex several, an outstanding problem is still represented by XX hermaphrodites since no Y-specific sequences have been found in their genome. Thus although the Y-chromosome testis- determining factor seems to play a pivotal rôle in sex determination, testicular tissue can be formed in the absence of it.
|
Authors | O Zuffardi, A Caiulo |
Journal | La Pediatria medica e chirurgica : Medical and surgical pediatrics
(Pediatr Med Chir)
1989 Sep-Oct
Vol. 11
Issue 5
Pg. 481-4
ISSN: 0391-5387 [Print] Italy |
Vernacular Title | Attualità in tema di differenziazione gonadica. |
PMID | 2517143
(Publication Type: English Abstract, Journal Article, Review)
|
Chemical References |
- DNA-Binding Proteins
- Kruppel-Like Transcription Factors
- Metalloproteins
- Transcription Factors
- ZFY protein, human
|
Topics |
- Animals
- DNA-Binding Proteins
(physiology)
- Female
- Humans
- Kruppel-Like Transcription Factors
- Male
- Metalloproteins
(physiology)
- Mice
- Sex Differentiation
(physiology)
- Testis
(embryology)
- Transcription Factors
- X Chromosome
(physiology)
- Y Chromosome
(physiology)
|