Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants.
The primary cilium is a signaling center critical for proper embryonic development. Previous studies have demonstrated that mice lacking Ttc21b have impaired retrograde trafficking within the cilium and multiple organogenesis phenotypes, including microcephaly. Interestingly, the severity of the mic...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2019-11-01
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| Series: | PLoS Genetics |
| Online Access: | https://doi.org/10.1371/journal.pgen.1008467 |
| _version_ | 1819020608434864128 |
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| author | John Snedeker William J Gibbons David F Paulding Zakia Abdelhamed Daniel R Prows Rolf W Stottmann |
| author_facet | John Snedeker William J Gibbons David F Paulding Zakia Abdelhamed Daniel R Prows Rolf W Stottmann |
| author_sort | John Snedeker |
| collection | DOAJ |
| description | The primary cilium is a signaling center critical for proper embryonic development. Previous studies have demonstrated that mice lacking Ttc21b have impaired retrograde trafficking within the cilium and multiple organogenesis phenotypes, including microcephaly. Interestingly, the severity of the microcephaly in Ttc21baln/aln homozygous null mutants is considerably affected by the genetic background and mutants on an FVB/NJ (FVB) background develop a forebrain significantly smaller than mutants on a C57BL/6J (B6) background. We performed a Quantitative Trait Locus (QTL) analysis to identify potential genetic modifiers and identified two regions linked to differential forebrain size: modifier of alien QTL1 (Moaq1) on chromosome 4 at 27.8 Mb and Moaq2 on chromosome 6 at 93.6 Mb. These QTLs were validated by constructing congenic strains. Further analysis of Moaq1 identified an orphan G-protein coupled receptor (GPCR), Gpr63, as a candidate gene. We identified a SNP that is polymorphic between the FVB and B6 strains in Gpr63 and creates a missense mutation predicted to be deleterious in the FVB protein. We used CRISPR-Cas9 genome editing to create two lines of FVB congenic mice: one with the B6 sequence of Gpr63 and the other with a deletion allele leading to a truncation of the GPR63 C-terminal tail. We then demonstrated that Gpr63 can localize to the cilium in vitro. These alleles affect ciliary localization of GPR63 in vitro and genetically interact with Ttc21baln/aln as Gpr63;Ttc21b double mutants show unique phenotypes including spina bifida aperta and earlier embryonic lethality. This validated Gpr63 as a modifier of multiple Ttc21b neural phenotypes and strongly supports Gpr63 as a causal gene (i.e., a quantitative trait gene, QTG) within the Moaq1 QTL. |
| first_indexed | 2024-12-21T03:53:55Z |
| format | Article |
| id | doaj.art-516befcb73b34af68e91e757e6b55bdb |
| institution | Directory Open Access Journal |
| issn | 1553-7390 1553-7404 |
| language | English |
| last_indexed | 2024-12-21T03:53:55Z |
| publishDate | 2019-11-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS Genetics |
| spelling | doaj.art-516befcb73b34af68e91e757e6b55bdb2022-12-21T19:16:54ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042019-11-011511e100846710.1371/journal.pgen.1008467Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants.John SnedekerWilliam J GibbonsDavid F PauldingZakia AbdelhamedDaniel R ProwsRolf W StottmannThe primary cilium is a signaling center critical for proper embryonic development. Previous studies have demonstrated that mice lacking Ttc21b have impaired retrograde trafficking within the cilium and multiple organogenesis phenotypes, including microcephaly. Interestingly, the severity of the microcephaly in Ttc21baln/aln homozygous null mutants is considerably affected by the genetic background and mutants on an FVB/NJ (FVB) background develop a forebrain significantly smaller than mutants on a C57BL/6J (B6) background. We performed a Quantitative Trait Locus (QTL) analysis to identify potential genetic modifiers and identified two regions linked to differential forebrain size: modifier of alien QTL1 (Moaq1) on chromosome 4 at 27.8 Mb and Moaq2 on chromosome 6 at 93.6 Mb. These QTLs were validated by constructing congenic strains. Further analysis of Moaq1 identified an orphan G-protein coupled receptor (GPCR), Gpr63, as a candidate gene. We identified a SNP that is polymorphic between the FVB and B6 strains in Gpr63 and creates a missense mutation predicted to be deleterious in the FVB protein. We used CRISPR-Cas9 genome editing to create two lines of FVB congenic mice: one with the B6 sequence of Gpr63 and the other with a deletion allele leading to a truncation of the GPR63 C-terminal tail. We then demonstrated that Gpr63 can localize to the cilium in vitro. These alleles affect ciliary localization of GPR63 in vitro and genetically interact with Ttc21baln/aln as Gpr63;Ttc21b double mutants show unique phenotypes including spina bifida aperta and earlier embryonic lethality. This validated Gpr63 as a modifier of multiple Ttc21b neural phenotypes and strongly supports Gpr63 as a causal gene (i.e., a quantitative trait gene, QTG) within the Moaq1 QTL.https://doi.org/10.1371/journal.pgen.1008467 |
| spellingShingle | John Snedeker William J Gibbons David F Paulding Zakia Abdelhamed Daniel R Prows Rolf W Stottmann Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. PLoS Genetics |
| title | Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. |
| title_full | Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. |
| title_fullStr | Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. |
| title_full_unstemmed | Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. |
| title_short | Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. |
| title_sort | gpr63 is a modifier of microcephaly in ttc21b mouse mutants |
| url | https://doi.org/10.1371/journal.pgen.1008467 |
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