TY - JOUR
T1 - R9AP overexpression alters phototransduction kinetics in iCre75 mice
AU - Sundermeier, Thomas R.
AU - Vinberg, Frans
AU - Mustafi, Debarshi
AU - Bai, Xiaodong
AU - Kefalov, Vladimir J.
AU - Palczewski, Krzysztof
PY - 2014/2/13
Y1 - 2014/2/13
N2 - Purpose. Determine the impact of rod photoreceptor-specific expression of Cre recombinase on the kinetics of phototransduction in the mouse eye and identify changes in gene expression that underlie any observed phenotypic differences. Methods. Transretinal ERG and single-cell suction electrode recordings were used to measure the kinetics of phototransduction in a mouse line exhibiting rod photoreceptor-specific Cre recombinase expression, and the results were compared with those from control non-Creexpressing littermates. Gene expression changes were evaluated using RNA sequencing transcriptome analysis. The pattern of expression of Rgs9bp was determined by mapping sequencing reads to the mouse genome and performing 3'-rapid amplification of cDNA ends (3'-RACE). Results. Expression of the rod-specific iCre75 transgene was accompanied by accelerated phototransduction inactivation, likely due to overexpression of the Rgs9bp gene, which encodes the Rgs9 anchor protein (R9AP). R9AP upregulation stabilized the RGS9 GAP complex, altering phototransduction kinetics. 3'-Race identified an abundant, unexpected Rgs9bp-Prm1 fusion mRNA in Cre-expressing mouse retinas, which was determined to be derived from a second transgene present in the iCre75 line. Conclusions. Here we report the presence of a second, R9AP-expressing transgene in the iCre75 mouse line, leading to altered kinetics of phototransduction. These results highlight an important caveat that must be considered when utilizing this mouse line for rod photoreceptor-specific gene loss of function studies.
AB - Purpose. Determine the impact of rod photoreceptor-specific expression of Cre recombinase on the kinetics of phototransduction in the mouse eye and identify changes in gene expression that underlie any observed phenotypic differences. Methods. Transretinal ERG and single-cell suction electrode recordings were used to measure the kinetics of phototransduction in a mouse line exhibiting rod photoreceptor-specific Cre recombinase expression, and the results were compared with those from control non-Creexpressing littermates. Gene expression changes were evaluated using RNA sequencing transcriptome analysis. The pattern of expression of Rgs9bp was determined by mapping sequencing reads to the mouse genome and performing 3'-rapid amplification of cDNA ends (3'-RACE). Results. Expression of the rod-specific iCre75 transgene was accompanied by accelerated phototransduction inactivation, likely due to overexpression of the Rgs9bp gene, which encodes the Rgs9 anchor protein (R9AP). R9AP upregulation stabilized the RGS9 GAP complex, altering phototransduction kinetics. 3'-Race identified an abundant, unexpected Rgs9bp-Prm1 fusion mRNA in Cre-expressing mouse retinas, which was determined to be derived from a second transgene present in the iCre75 line. Conclusions. Here we report the presence of a second, R9AP-expressing transgene in the iCre75 mouse line, leading to altered kinetics of phototransduction. These results highlight an important caveat that must be considered when utilizing this mouse line for rod photoreceptor-specific gene loss of function studies.
KW - Cre recombinase
KW - Mouse
KW - Phototransduction
KW - R9AP
KW - Retina
KW - Rod photoreceptors
UR - http://www.scopus.com/inward/record.url?scp=84895879945&partnerID=8YFLogxK
U2 - 10.1167/iovs.13-13564
DO - 10.1167/iovs.13-13564
M3 - Article
C2 - 24526444
AN - SCOPUS:84895879945
SN - 0146-0404
VL - 55
SP - 1339
EP - 1347
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 3
ER -