1997 Fiscal Year Final Research Report Summary
Examination of phosducin gene
| Project/Area Number |
08672004
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | Tohoku University |
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Principal Investigator |
ABE Toshiaki Tohoku Univ.Ophthalmol.Lecturer, 医学部附属病院, 講師 (90191858)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIGURO Sei-ichi Tohoku Univ.Ophthalmol.Lecturer, 医学部, 講師 (20111271)
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| Project Period (FY) |
1996 – 1997
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| Keywords | phosducin / gene family / transgenic mice / adaptation / retina / photoreceptor |
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| Research Abstract |
Phosducin inhibit phototransduction signal by interacting with transducin betagamma-subunit (1) by cAMP-dependent protein kinase A,but phosducin does not inhibit the initial onset of phototransduction signal (2) (3). The gene was suspected to have gene family from the Southern blotting analysis (4) and was located close to the disease locus of usher syndrome type II (5), (6). We screened the bovine cDNA library using the probe, which was generated the rat retina cDNA by polymerase chain reaction. We cloned a gene, which was considered bovine phosducin like protein as that of rat phosducin like protein reported by Miles and coworkers (7). The gene produced isoforms by alternative splicing and interestingly, one of the form was extensively expressed in the rat retina.
We constracted transgenic mice harvaring mutant phosducin gene, which had isoleucin instead of serin at amino acid 73. The transgenic mice showed 50% recovery of the b-wave of electroretinogram after light stimulation as that of normal control mice under light adaptation. The transgenic mice also showed 50% recovery under dark adaptation. We speculated that phosducin may play an important role for the photoreceptor adaptation.
Microscopic and electronmicroscopic examination revealed that photoreceptor cells show normal appearance at the early post natal days, but gradually decreased the length of the outer segment and outer nuclear layr.
Immunohistochemical study revealed that immunostaining was also observed at habenula commissura amygdala or superiorcolliculus.
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