biostudies-literature001500Chen WVNINDS NIH HHS402-9https://www.ebi.ac.uk/biostudies/studies/S-EPMC3426296biostudies-literatureUnknown75(3)The mammalian Protocadherin (Pcdh) alpha, beta, and gamma gene clusters encode a large family of cadherin-like transmembrane proteins that are differentially expressed in individual neurons. The 22 isoforms of the Pcdhg gene cluster are diversified into A-, B-, and C-types, and the C-type isoforms differ from all other clustered Pcdhs in sequence and expression. Here, we show that mice lacking the three C-type isoforms are phenotypically indistinguishable from the Pcdhg null mutants, displaying virtually identical cellular and synaptic alterations resulting from neuronal apoptosis. By contrast, mice lacking three A-type isoforms exhibit no detectable phenotypes. Remarkably, however, genetically blocking apoptosis rescues the neonatal lethality of the C-type isoform knockouts, but not that of the Pcdhg null mutants. We conclude that the role of the Pcdhg gene cluster in neuronal survival is primarily, if not specifically, mediated by its C-type isoforms, whereas a separate role essential for postnatal development, likely in neuronal wiring, requires isoform diversity.NeuronFunctional significance of isoform diversification in the protocadherin gamma gene cluster.PMC3426296R01 NS047357R01NS029169R01 NS043915R01 NS029169NS047357R01NS043915R56 NS047357Nwakeze CFriedman BSmith CTasic BGeiman EAlvarez FJChen WVThu CATapia JCSanes JRLefebvre JLManiatis T150falseFunctional significance of isoform diversification in the protocadherin gamma gene cluster.The mammalian Protocadherin (Pcdh) alpha, beta, and gamma gene clusters encode a large family of cadherin-like transmembrane proteins that are differentially expressed in individual neurons. The 22 isoforms of the Pcdhg gene cluster are diversified into A-, B-, and C-types, and the C-type isoforms differ from all other clustered Pcdhs in sequence and expression. Here, we show that mice lacking the three C-type isoforms are phenotypically indistinguishable from the Pcdhg null mutants, displaying virtually identical cellular and synaptic alterations resulting from neuronal apoptosis. By contrast, mice lacking three A-type isoforms exhibit no detectable phenotypes. Remarkably, however, genetically blocking apoptosis rescues the neonatal lethality of the C-type isoform knockouts, but not that of the Pcdhg null mutants. We conclude that the role of the Pcdhg gene cluster in neuronal survival is primarily, if not specifically, mediated by its C-type isoforms, whereas a separate role essential for postnatal development, likely in neuronal wiring, requires isoform diversity.2012-01-01T00:00:00Z2012 Aug2024-11-06T06:49:52.717Z2019-03-27T00:57:07ZS-EPMC34262962288432410.1016/j.neuron.2012.06.039