title: Functional analysis of genes implicated in Down syndrome: 2. Laterality and corpus callosum size in mice transpolygenic for Down syndrome chromosomal region -1 (DCR-1).
abstract: The association between atypical laterality and mental retardation has been reported several times, particularly in Down syndrome (DS). We investigated common genetic correlates of these components of the syndrome, examining direction (number of right paw entries in the Collins test) and degree (absolute difference between the number of right paw entries and the number of left paw entries) in mice that had incorporated extra-contiguous HSA21 fragments covering DCR-1 (Down Chromosomal Region-1). As corpus callosum size is substantially reduced in DS, and as the structure has been suspected of playing a role in atypical laterality, we also measured the corpus callosum in these mice. Extra copies of two regions (F7 and E6) have been associated with an atypical degree of laterality (strongly reduced degree). Extra copies of E8, G6 and E6 are also linked to the reduced size of the corpus callosum, indicating that the abnormal number of fibers linking the two hemispheres is not associated with atypical laterality in DS. Together, these results indicate that some of the genes involved in atypical laterality and in the reduced size of the corpus callosum in DS are present on DCR-1. An extra copy of F7 and, to a lesser extent, an extra copy of E6, are also associated with cognitive impairment. These results support the hypothesis of common genetic correlates in atypical laterality and mental retardation in DS.
authors.affiliation: Génétique, Neurogénétique, Comportement, CNRS, France. rouber@dpm.cnrs-mrs.fr
authors.forename: Pierre L
authors.initials: PL
authors.lastname: Roubertoux
authors.forename: Zoë
authors.initials: Z
authors.lastname: Bichler
authors.forename: Walter
authors.initials: W
authors.lastname: Pinoteau
authors.forename: Zohra
authors.initials: Z
authors.lastname: Seregaza
authors.forename: Sylvia
authors.initials: S
authors.lastname: Fortes
authors.forename: Marc
authors.initials: M
authors.lastname: Jamon
authors.forename: Desmond J
authors.initials: DJ
authors.lastname: Smith
authors.forename: Edward
authors.initials: E
authors.lastname: Rubin
authors.forename: Danièle
authors.initials: D
authors.lastname: Migliore-Samour
authors.forename: Michèle
authors.initials: M
authors.lastname: Carlier
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D003337:Corpus Callosum / Q000033:anatomy & histology* / Q000473:pathology; D004195:Disease Models, Animal; D004314:Down Syndrome / Q000235:genetics*; D007839:Functional Laterality; D005819:Genetic Markers; D008297:Male; D051379:Mice
chemical_list: D005819:Genetic Markers