Development of the cerebellar body in sharks: spatiotemporal relations of Pax6 expression, cell proliferation and differentiation.
We have studied the patterns of cell proliferation, regional organization and differentiation in the cerebellar body of embryos and juveniles of two shark species by immunohistochemistry with antibodies against proliferating cell nuclear antigen (PCNA), Pax6, reelin (RELN), GABA, glutamic acid decarboxylase (GAD) and calretinin (CR). The organization of Pax6-expressing cells was also studied by in situ hybridization. Our results reveal that a transient secondary matrix zone, the external germinal layer, is formed in sharks at early stages of cerebellar development and is the source of the earliest Pax6-expressing (granule) cells. Later in development, new granule Pax6-expressing cells arise from medial proliferation zones and accumulate medially in the granular eminences. The GABAergic components appear very early, and show clear regional differences. The medial proliferation zones remain active even in adults. Taken together, the proliferation and differentiation markers used in the present study highlight striking similarities during development between the cerebellar body of elasmobranchs and the cerebella of tetrapods. These results show the importance of elasmobranch models to reconstruct the evolutionary developmental history of the vertebrate cerebellum.
Rodríguez-Moldes
Isabel
I
Department of Cell Biology and Ecology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain. bfmoldes@usc.es
Ferreiro-Galve
Susana
S
Carrera
Iván
I
Sueiro
Catalina
C
Candal
Eva
E
Mazan
Sylvie
S
Anadón
Ramón
R
D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning / Q000502:physiology; D064032:Calbindin 2; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002531:Cerebellum / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D000091042:Reelin Protein; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D012754:Sharks / Q000196:embryology* / Q000378:metabolism*; D013045:Species Specificity; D013997:Time Factors; D014714:Vertebrates / Q000196:embryology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D064032:Calbindin 2; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D000091042:Reelin Protein; D012097:Repressor Proteins; D064030:S100 Calcium Binding Protein G; D005680:gamma-Aminobutyric Acid; D012697:Serine Endopeptidases; D005968:Glutamate Decarboxylase