X-monosomy effects on visuospatial attention in mice: a candidate gene and implications for Turner syndrome and attention deficit hyperactivity disorder.
BACKGROUND
The loss of all, or part of an X chromosome, in Turner syndrome (TS, 45,XO) results in deficits in attentional functioning.


METHODS
Using a 39,XO mouse model, we tested the hypothesis that X-monosomy and/or parental origin of the single X chromosome may influence visuospatial attentional functioning in a 5-choice serial reaction time task (5-CSRTT).


RESULTS
Under attentionally demanding conditions 39,XO mice displayed impaired discriminative response accuracy and slowed correct reaction times relative to 40,XX mice; these deficits were alleviated in a version of the task with reduced attentional demands. Parental origin of the X did not affect performance of the 5-CSRTT. In contrast, the attentional phenotype was rescued in 40,XY*X mice possessing a single maternally inherited X chromosome and a small Y*X chromosome that comprises a complete pseudoautosomal region (PAR), and a small X-specific segment.


CONCLUSIONS
Our findings are consistent with an X-monosomy effect on attention and suggest the existence of X-linked gene(s) that escape X-inactivation, are present on the small Y*X chromosome and impact on attentional functioning; the strongest candidate gene is Sts, encoding steroid sulfatase. The data inform the TS literature and indicate novel genetic mechanisms that may be of general significance to the neurobiology of attention.
Davies
William
W
Laboratories of Cognitive and Behavioral Neuroscience and Developmental Genetics and Imprinting, The Babraham Institute, Babraham Research Campus, Babraham, United Kingdom.
Humby
Trevor
T
Isles
Anthony R
AR
Burgoyne
Paul S
PS
Wilkinson
Lawrence S
LS
D000818:Animals; D001288:Attention / Q000502:physiology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D001522:Behavior, Animal; D001853:Bone Marrow / Q000502:physiology; D002755:Choice Behavior / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D020690:GTPase-Activating Proteins / Q000235:genetics; D007621:Karyotyping; D007858:Learning / Q000502:physiology; D051379:Mice; D009006:Monosomy / Q000235:genetics*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011597:Psychomotor Performance; D011930:Reaction Time; D013028:Space Perception / Q000502:physiology*; D016615:Telomere / Q000235:genetics; D014424:Turner Syndrome / Q000235:genetics*; D014796:Visual Perception / Q000502:physiology*; D014960:X Chromosome / Q000235:genetics*; D014998:Y Chromosome / Q000235:genetics
C484667:Arhgap6 protein, mouse; D017931:DNA Primers; D020690:GTPase-Activating Proteins