Expression of regulatory genes during differentiation of thalamic nuclei in mouse and monkey

Abstract

Expression patterns of genes implicated in development of the thalamus were examined in mice and monkeys, using in situ hybridization with RNA probes complementary to Cad6, Dlx1, Dlx2, Dlx5, Gbx2, Id2, and Lef1 cDNAs. Expression patterns were related to the evolving cytoarchitecture in mice at birth (P0) and in adulthood, and in fetal monkeys early and late in the period of gestation when thalamic nuclei are becoming histologically differentiated out of a series of pronuclear masses. At the earlier developmental stage, each gene was expressed in a pattern that appeared to be pronucleus-specific and maintained a nucleus-specific pattern into adulthood, with the possible exception of Gbx2. Each gene displayed a unique expression pattern in the dorsal thalamus, ventral thalamus, and epithalamus, and no gene was expressed throughout all three divisions or in every nucleus of a division. With the exception of Dlx2, whose expression disappeared at the later time point, all continued to be expressed into adulthood at higher levels and with identical patterns. Despite late appearance of gamma-aminobutyric acid (GABA)ergic cells in the dorsal lateral geniculate nucleus of mice, no Dlx genes, which promote formation of a GABAergic phenotype elsewhere, were detected in dorsal thalamus. Each thalamic nucleus was distinguished by expression of a combination of genes, and homologous nuclei in mouse and monkey exhibited the same combination. The presence of a centre médian nucleus and four pulvinar nuclei in monkeys was marked by patterns of expression not found in mice. The centre médian nucleus was marked by high expression of Id2, which was expressed only weakly in very few nuclei of mice.

LEF1/β-Catenin Complex Regulates Transcription of the Cav3.1 Calcium Channel Gene (Cacna1g) in Thalamic Neurons of the Adult Brain

“…Our observation that LEF1 and ␤-catenin are present in cell nuclei in the thalamus essentially confirms previous reports (Lucas et al, 1999;Jones and Rubenstein, 2004;Shimogori et al, 2004). However, the present study further identifies the positive cells as neurons.…”

“…After birth, Lef1 mRNA levels dramatically decrease in the brain (Coyle-Rink et al, 2002) and can be detected only in the thalamus (Jones and Rubenstein, 2004;Shimogori et al, 2004). The role of LEF1 in the thalamus of the adult brain, however, is unknown.…”

Comparative Anatomy of Marmoset and Mouse Cortex from Genomic Expression

“…Comparative gene expression studies in embryonic mouse and monkey brains showed small differences in expression related to area identities (Donoghue and Rakic, 1999;Yun et al, 2003;Jones and Rubenstein, 2004). Another comparative gene expression analysis in adult mouse and marmoset brain using microarray analysis did not report major differences (Datson et al, 2009).…”

An Essential Role for Frizzled5 in Neuronal Survival in the Parafascicular Nucleus of the Thalamus

“…Thus far, the utility of these approaches has been limited by the availability of characterized promoters or genes that are, respectively, expressed in or required for the development of single anatomically or functionally defined CNS structures. For example, in the thalamus, transcription factor genes are typically expressed in overlapping patterns, with the expression domain of each gene generally encompassing multiple thalamic nuclei (Nakagawa and O'Leary, 2001;Jones and Rubenstein, 2004). However, improved regional and/or cell-type specificity, as well as temporal control, should be possible either by the combinatorial manipulation of gene expression with the CreER/4HT or reverse Tet transactivator (rtTA)/tetracycline systems (Feil et al, 1996;Backman et al, 2004), or by pharmacologically or optically activating or inactivating genetically targeted neurons (Lechner et al, 2002(Lechner et al, , 2007Zhang et al, 2007).…”