Impaired spatial learning strategies and novel object recognition in mice haploinsufficient for the dual specificity tyrosine-regulated kinase-1A (Dyrk1A).

[monosomy 21]

Pathogenic aneuploidies involve the concept of dosage-sensitive genes leading to over- and underexpression phenotypes . Monosomy 21 in human leads to mental retardation and skeletal , immune and respiratory function disturbances . Most of the human condition corresponds to partial monosomies suggesting that critical haploinsufficient genes may be responsible for the phenotypes . The DYRK 1 A gene is localized on the human chromosome 21 q 22 .2 region , and has been proposed to participate in monosomy 21 phenotypes . It encodes a dual-specificity kinase involved in neuronal development and in adult brain physiology , but its possible role as critical haploinsufficient gene in cognitive function has not been explored .We used mice heterozygous for a Dyrk 1 A targeted mutation (Dyrk 1 A +/-) to investigate the implication of this gene in the cognitive phenotypes of monosomy 21 . Performance of Dyrk 1 A +/- mice was assayed 1 / in a navigational task using the standard hippocampally related version of the Morris water maze , 2 / in a swimming test designed to reveal potential kinesthetic and stress-related behavioral differences between control and heterozygous mice under two levels of aversiveness (25 degrees C and 17 degrees C ) and 3 / in a long -term novel object recognition task , sensitive to hippocampal damage . Dyrk 1 A +/- mice showed impairment in the development of spatial learning strategies in a hippocampally-dependent memory task , they were impaired in their novel object recognition ability and were more sensitive to aversive conditions in the swimming test than euploid control animals .The present results are clear examples where removal of a single gene has a profound effect on phenotype and indicate that haploinsufficiency of DYRK 1 A might contribute to an impairment of cognitive functions and stress coping behavior in human monosomy 21 .

Diseases
Validation

Diseases presenting "mental retardation" symptom

achondroplasia

alexander disease

alpha-thalassemia

aniridia

aromatase deficiency

canavan disease

classical phenylketonuria

coats disease

cohen syndrome

cowden syndrome

cystinuria

dentin dysplasia

familial hypocalciuric hypercalcemia

homocystinuria without methylmalonic aciduria

hydrocephalus with stenosis of the aqueduct of sylvius

kabuki syndrome

kallmann syndrome

lamellar ichthyosis

lymphangioleiomyomatosis

monosomy 21

phenylketonuria

primary hyperoxaluria type 1

proteus syndrome

pyruvate dehydrogenase deficiency

sneddon syndrome

triple a syndrome

wolf-hirschhorn syndrome

zellweger syndrome

This symptom has already been validated