Biomedical subjects

M Arbonés

Publications and source records attributed to M Arbonés.

4 recordsLinked to original sources

PubMed2004

Haploinsufficiency of Dyrk1A in mice leads to specific alterations in the development and regulation of motor activity.

DYRK1A is a protein kinase proposed to be involved in neurogenesis. Gene-targeting disruption of Dyrk1A in mice leads to decreased body and brain size, with no severe disturbance of behavior. In this study, the authors focused on the motor profile of Dyrk1A(+/-) mice. These mice presented impairment of neuromotor development with decreased activity, suggesting a physiological role of Dyrk1A in the maturation of the neuromotor system. In the adult, a marked hypoactivity and alteration of specific motor parameters were detected. These results are in agreement with the significant expression of Dyrk1A in structures related to motor function and support a role of Dyrk1A in the control of motor function.

Age Factors↗

PubMed2002

Neurobehavioral development of two mouse lines commonly used in transgenic studies.

The present study was aimed at establishing the differences in the neurodevelopmental profile between two F2 lines derived from two F1 hybrid mouse strains (129 x C57BL/6 and C57BL/6 x SJL). The choice of the given strains was based on the frequent use of these mice in transgenic research. For the neurodevelopment phenotyping, we employed a test battery consisting of 23 somatometric, sensorial and motor tests. Significant variations between the strains were established in different functional domains. Some specific delays in the appearance of developmental landmarks were observed in F2 mice derived from crosses of F1 C57BL/6 x 129, whereas they acquired early developmental functions, such as the righting reflex, sooner than C57BL/6 x SJL-derived mice. C57BL/6 x 129 F2 offspring were spontaneously hypoactive, and their poorer motor performance was confirmed by low performance in the negative geotaxis test. However, there were no differences in the general psychomotor development as shown by the good performance in the homing test in both F2 lines. Both strains were susceptible to the handling procedures used, presenting a similar alteration in the response observed in the homing test as compared to nonhandled control mice. In conclusion, our work highlights the importance of the genetic background for transgenesis experiments and also the need for well-established testing protocols to obtain sufficient information at the first stage of behavioral screening of genetically modified mice.

Animals↗

PubMed2001

Murine models for Down syndrome.

The availability of the recently published DNA sequence of human chromosome 21 (HSA21) is a landmark contribution that will have an immediate impact on the study of the role of specific genes to Down syndrome (DS). Trisomy 21 or DS is the only autosomal aneuploidy that is not lethal in the fetal or early postnatal period. DS phenotypes show variable penetrance, affecting many different organs, including brain (mental retardation, early onset of Alzheimer's disease, AD), muscle (hypotonia), skeleton, and blood. DS phenotypes may stem directly from the cumulative effect of overexpression of specific HSA21 gene products or indirectly through the interaction of these gene products with the whole genome, transcriptome, or proteome. Mouse genetic models have played an important role in the elucidation of the contribution of specific genes to the DS phenotype. To date, the strategies used for modeling DS in mice have been three: (1) to assess single-gene contributions to DS phenotype, using transgenic techniques to create models overexpressing single or combinations of genes, (2) to assess the effects of overexpressing large foreign DNA pieces, introduced on yeast artificial chromosomes (YACs) or bacterial artificial chromosomes (BACs) into transgenic mice, and (3) mouse trisomies that carry all or part of MMU16, which has regions of conserved homology with HSA21. Here we review the existing murine models and the relevance of their contribution to DS research.

Animals↗

PubMed2001

Dscr1, a novel endogenous inhibitor of calcineurin signaling, is expressed in the primitive ventricle of the heart and during neurogenesis.

We have demonstrated that DSCR1 acts as a negative regulator of calcineurin-mediated signaling and that its transcript is overexpressed in the Down syndrome (DS) fetal brain. To evaluate the possible involvement of DSCR1 in DS, we have cloned the mouse gene and analyzed its expression pattern in the central nervous system (CNS). Early expression of Dscr1 is detected mainly in the heart tube and in the CNS in rhombomere 4 and the pretectum. From embryonic day 14.5 onwards, Dscr1 is widely distributed in the CNS but becomes more restricted as the brain matures. We confirmed its neuronal expression pattern in the adult, preferentially in Purkinje and pyramidal cells, by double labeling with glial fibrillary acidic protein. We also show that although Dscr1 is present in trisomy in the Ts65Dn mouse, the adult brain expression pattern is not significantly altered. This expression pattern indicated that Dscr1 is a developmentally regulated gene involved in neurogenesis and cardiogenesis and suggests that it may contribute to the alterations observed in these organ systems in DS patients.

Animals↗