Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research
GABA type-A (GABA-A) receptors containing the α2 subunit (GABRA2) are expressed in most brain regions and are critical in modulating inhibitory synaptic function. Genetic variation at the GABRA2 locus has been implicated in epilepsy, affective and psychiatric disorders, alcoholism and drug abuse. Ga...
| Main Authors: | , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-03-01
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| Series: | Frontiers in Genetics |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fgene.2019.00188/full |
| _version_ | 1828421257714991104 |
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| author | Megan K. Mulligan Timothy Abreo Sarah M. Neuner Sarah M. Neuner Cory Parks Christine E. Watkins M. Trevor Houseal Thomas M. Shapaker Michael Hook Haiyan Tan Xusheng Wang Jesse Ingels Junmin Peng Lu Lu Catherine C. Kaczorowski Camron D. Bryant Gregg E. Homanics Robert W. Williams |
| author_facet | Megan K. Mulligan Timothy Abreo Sarah M. Neuner Sarah M. Neuner Cory Parks Christine E. Watkins M. Trevor Houseal Thomas M. Shapaker Michael Hook Haiyan Tan Xusheng Wang Jesse Ingels Junmin Peng Lu Lu Catherine C. Kaczorowski Camron D. Bryant Gregg E. Homanics Robert W. Williams |
| author_sort | Megan K. Mulligan |
| collection | DOAJ |
| description | GABA type-A (GABA-A) receptors containing the α2 subunit (GABRA2) are expressed in most brain regions and are critical in modulating inhibitory synaptic function. Genetic variation at the GABRA2 locus has been implicated in epilepsy, affective and psychiatric disorders, alcoholism and drug abuse. Gabra2 expression varies as a function of genotype and is modulated by sequence variants in several brain structures and populations, including F2 crosses originating from C57BL/6J (B6J) and the BXD recombinant inbred family derived from B6J and DBA/2J. Here we demonstrate a global reduction of GABRA2 brain protein and mRNA in the B6J strain relative to other inbred strains, and identify and validate the causal mutation in B6J. The mutation is a single base pair deletion located in an intron adjacent to a splice acceptor site that only occurs in the B6J reference genome. The deletion became fixed in B6J between 1976 and 1991 and is now pervasive in many engineered lines, BXD strains generated after 1991, the Collaborative Cross, and the majority of consomic lines. Repair of the deletion using CRISPR-Cas9-mediated gene editing on a B6J genetic background completely restored brain levels of GABRA2 protein and mRNA. Comparison of transcript expression in hippocampus, cortex, and striatum between B6J and repaired genotypes revealed alterations in GABA-A receptor subunit expression, especially in striatum. These results suggest that naturally occurring variation in GABRA2 levels between B6J and other substrains or inbred strains may also explain strain differences in anxiety-like or alcohol and drug response traits related to striatal function. Characterization of the B6J private mutation in the Gabra2 gene is of critical importance to molecular genetic studies in neurobiological research because this strain is widely used to generate genetically engineered mice and murine genetic populations, and is the most widely utilized strain for evaluation of anxiety-like, depression-like, pain, epilepsy, and drug response traits that may be partly modulated by GABRA2 function. |
| first_indexed | 2024-12-10T15:26:41Z |
| format | Article |
| id | doaj.art-6a8d1268bcf34cf8a5aabfe4fc41124e |
| institution | Directory Open Access Journal |
| issn | 1664-8021 |
| language | English |
| last_indexed | 2024-12-10T15:26:41Z |
| publishDate | 2019-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Genetics |
| spelling | doaj.art-6a8d1268bcf34cf8a5aabfe4fc41124e2022-12-22T01:43:31ZengFrontiers Media S.A.Frontiers in Genetics1664-80212019-03-011010.3389/fgene.2019.00188449946Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience ResearchMegan K. Mulligan0Timothy Abreo1Sarah M. Neuner2Sarah M. Neuner3Cory Parks4Christine E. Watkins5M. Trevor Houseal6Thomas M. Shapaker7Michael Hook8Haiyan Tan9Xusheng Wang10Jesse Ingels11Junmin Peng12Lu Lu13Catherine C. Kaczorowski14Camron D. Bryant15Gregg E. Homanics16Robert W. Williams17Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartment of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United StatesThe Jackson Laboratory, Bar Harbor, ME, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, Memphis, TN, United StatesDepartments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesDepartments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, Memphis, TN, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesThe Jackson Laboratory, Bar Harbor, ME, United StatesLaboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry, Boston University School of Medicine, Boston, MA, United StatesDepartments of Anesthesiology and Perioperative Medicine, Neurobiology, and Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, United StatesDepartment of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United StatesGABA type-A (GABA-A) receptors containing the α2 subunit (GABRA2) are expressed in most brain regions and are critical in modulating inhibitory synaptic function. Genetic variation at the GABRA2 locus has been implicated in epilepsy, affective and psychiatric disorders, alcoholism and drug abuse. Gabra2 expression varies as a function of genotype and is modulated by sequence variants in several brain structures and populations, including F2 crosses originating from C57BL/6J (B6J) and the BXD recombinant inbred family derived from B6J and DBA/2J. Here we demonstrate a global reduction of GABRA2 brain protein and mRNA in the B6J strain relative to other inbred strains, and identify and validate the causal mutation in B6J. The mutation is a single base pair deletion located in an intron adjacent to a splice acceptor site that only occurs in the B6J reference genome. The deletion became fixed in B6J between 1976 and 1991 and is now pervasive in many engineered lines, BXD strains generated after 1991, the Collaborative Cross, and the majority of consomic lines. Repair of the deletion using CRISPR-Cas9-mediated gene editing on a B6J genetic background completely restored brain levels of GABRA2 protein and mRNA. Comparison of transcript expression in hippocampus, cortex, and striatum between B6J and repaired genotypes revealed alterations in GABA-A receptor subunit expression, especially in striatum. These results suggest that naturally occurring variation in GABRA2 levels between B6J and other substrains or inbred strains may also explain strain differences in anxiety-like or alcohol and drug response traits related to striatal function. Characterization of the B6J private mutation in the Gabra2 gene is of critical importance to molecular genetic studies in neurobiological research because this strain is widely used to generate genetically engineered mice and murine genetic populations, and is the most widely utilized strain for evaluation of anxiety-like, depression-like, pain, epilepsy, and drug response traits that may be partly modulated by GABRA2 function.https://www.frontiersin.org/article/10.3389/fgene.2019.00188/fullGABRA2C57BL/6JGABA-A receptorneurosciencegeneticsCRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 |
| spellingShingle | Megan K. Mulligan Timothy Abreo Sarah M. Neuner Sarah M. Neuner Cory Parks Christine E. Watkins M. Trevor Houseal Thomas M. Shapaker Michael Hook Haiyan Tan Xusheng Wang Jesse Ingels Junmin Peng Lu Lu Catherine C. Kaczorowski Camron D. Bryant Gregg E. Homanics Robert W. Williams Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research Frontiers in Genetics GABRA2 C57BL/6J GABA-A receptor neuroscience genetics CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 |
| title | Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research |
| title_full | Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research |
| title_fullStr | Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research |
| title_full_unstemmed | Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research |
| title_short | Identification of a Functional Non-coding Variant in the GABAA Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research |
| title_sort | identification of a functional non coding variant in the gabaa receptor α2 subunit of the c57bl 6j mouse reference genome major implications for neuroscience research |
| topic | GABRA2 C57BL/6J GABA-A receptor neuroscience genetics CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 |
| url | https://www.frontiersin.org/article/10.3389/fgene.2019.00188/full |
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