Cell death in the CNS of the Wnt-1 mutant mouse.
Using the benzothiazolium-4-quinolium dye, TO-PRO-1, to detect cell death in live embryos, we labeled a developmental series of Wnt-1 null mutant and wild type embryos to determine if cell death contributed to the absence of the midbrain and rostral metencephalon observed in Wnt-1 mutant embryos. We found that there is no detectable cell death at early somite stages in Wnt-1 mutant embryos. However, we detected a significant, but transient, population of dying cells within the anterior dorsal metencephalon in 20-29 somite stage embryos. These cells located in the anterior dorsal metencephalon also stain positive using the TUNEL technique that utilizes terminal transferase to label DNA fragments that are typical in the nuclei of apoptotic cells. Thus, programmed cell death plays a role in the loss of the metencephalon, but apparently does not contribute to the earliest aspect of the mutant phenotype, namely the loss of the midbrain.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA. serbedzija@wru.mgh.harvard.edu
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D000818:Animals; D016923:Cell Death; D002531:Cerebellum / Q000002:abnormalities* / Q000473:pathology; D005326:Fetal Proteins / Q000235:genetics*; D005838:Genotype; D018398:Homeodomain Proteins / Q000235:genetics; D008636:Mesencephalon / Q000002:abnormalities* / Q000473:pathology; D051379:Mice; D008817:Mice, Mutant Strains; D009419:Nerve Tissue Proteins / Q000235:genetics; D010641:Phenotype; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D019170:Somites / Q000473:pathology; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D000099266:Engrailed 2 Protein
D005326:Fetal Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D000099266:Engrailed 2 Protein; C080330:En1 protein, mouse; C495246:Wnt1 protein, mouse