title: Independent genomic control of neuronal number across retinal cell types.
abstract: The sizes of different neuronal populations within the CNS are precisely controlled, but whether neuronal number is coordinated between cell types is unknown. We examined the covariance structure of 12 different retinal cell types across 30 genetically distinct lines of mice, finding minimal covariation when comparing synaptically connected or developmentally related cell types. Variation mapped to one or more genomic loci for each cell type, but rarely were these shared, indicating minimal genetic coregulation of final number. Multiple genes, therefore, participate in the specification of the size of every population of retinal neuron, yet genetic variants work largely independent of one another during development to modulate those numbers, yielding substantial variability in the convergence ratios between pre- and postsynaptic populations. Density-dependent cellular interactions in the outer plexiform layer overcome this variability to ensure the formation of neuronal circuits that maintain constant retinal coverage and complete afferent sampling.
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Patrick W
authors: PW
authors: Keeley
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Irene E
authors: IE
authors: Whitney
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Nils R
authors: NR
authors: Madsen
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Ace J
authors: AJ
authors: St John
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Sarra
authors: S
authors: Borhanian
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Stephanie A
authors: SA
authors: Leong
authors: Center of Genomics and Bioinformatics, University of Tennessee Health Science Center, Memphis, TN 38120, USA; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38120, USA.
authors: Robert W
authors: RW
authors: Williams
authors: Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. Electronic address: breese@psych.ucsb.edu.
authors: Benjamin E
authors: BE
authors: Reese
mesh_terms: D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D023281:Genomics; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D040641:Quantitative Trait Loci; D012160:Retina / Q000166:cytology* / Q000378:metabolism; D013569:Synapses / Q000502:physiology*