Pallial and subpallial derivatives in the embryonic chick and mouse telencephalon, traced by the expression of the genes Dlx-2, Emx-1, Nkx-2.1, Pax-6, and Tbr-1.
Pallial and subpallial morphological subdivisions of the developing chicken telencephalon were examined by means of gene markers, compared with their expression pattern in the mouse. Nested expression domains of the genes Dlx-2 and Nkx-2.1, plus Pax-6-expressing migrated cells, are characteristic for the mouse subpallium. The genes Pax-6, Tbr-1, and Emx-1 are expressed in the pallium. The pallio-subpallial boundary lies at the interface between the Tbr-1 and Dlx-2 expression domains. Differences in the expression topography of Tbr-1 and Emx-1 suggest the existence of a novel "ventral pallium" subdivision, which is an Emx-1-negative pallial territory intercalated between the striatum and the lateral pallium. Its derivatives in the mouse belong to the claustroamygdaloid complex. Chicken genes homologous to these mouse genes are expressed in topologically comparable patterns during development. The avian subpallium, called "paleostriatum," shows nested Dlx-2 and Nkx-2.1 domains and migrated Pax-6-positive neurons; the avian pallium expresses Pax-6, Tbr-1, and Emx-1 and also contains a distinct Emx-1-negative ventral pallium, formed by the massive domain confusingly called "neostriatum." These expression patterns extend into the septum and the archistriatum, as they do into the mouse septum and amygdala, suggesting that the concepts of pallium and subpallium can be extended to these areas. The similarity of such molecular profiles in the mouse and chicken pallium and subpallium points to common sets of causal determinants. These may underlie similar histogenetic specification processes and field homologies, including some comparable connectivity patterns.
Puelles
L
L
Department of Morphological Sciences, Medical School, University of Murcia, E30100 Murcia, Spain. puelles@fcu.um.es
Kuwana
E
E
Puelles
E
E
Bulfone
A
A
Shimamura
K
K
Keleher
J
J
Smiga
S
S
Rubenstein
J L
JL
D000367:Age Factors; D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002642:Chick Embryo / Q000166:cytology / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins / Q000235:genetics*; D004622:Embryo, Mammalian; D005136:Eye Proteins; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice / Q000033:anatomy & histology / Q000196:embryology* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D020825:T-Box Domain Proteins; D013687:Telencephalon / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics*; D000099260:Empty Spiracles Homeobox Proteins
D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D020825:T-Box Domain Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D000099260:Empty Spiracles Homeobox Proteins; C088334:Distal-less homeobox proteins; C000614414:Nkx2-1 protein, mouse; C000605732:Pax6 protein, mouse; C492271:Tbr1 protein, mouse; C093661:Tes protein, mouse