| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 From the Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Florida; 2 Gray Matter Research, Miami, Florida; and the 3 Departments of Ophthalmology and Molecular and Medical Genetics, The Oregon Health Sciences University, Portland.
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
METHODS. HRG4 was screened for mutations in patients with various retinopathies, and a transgenic mouse model was constructed and analyzed based on a mutation found.
RESULTS. A heterozygous premature termination codon mutation was found in a 57-year-old woman with late-onset cone–rod dystrophy. In some transgenic mice carrying the identical mutation, age-dependent fundus lesions developed accompanied by electroretinographic changes consistent with defects in photoreceptor synaptic transmission (depressed b-wave, normal c-wave), and retinal degeneration occurred with marked synaptic and possible transsynaptic degeneration.
CONCLUSIONS. HRG4, the only synaptic protein known to be highly enriched in photoreceptor ribbon synapses, is now shown to be pathogenic when mutated.
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
While the initial report of HRG4 was in press, a novel Caenorhabditis elegans gene, unc-119, was reported, which had been isolated on the basis of a mutation causing abnormal coordination and feeding due to defective chemosensation.11 Comparison of the two sequences revealed that HRG4 showed a 57% homology with unc-119. Subsequent immunofluorescence microscopy and immunocytochemistry localized HRG4 in the rod and cone photoreceptor synapses, establishing it as the first synaptic protein enriched in the photoreceptors.12 The HRG4 gene has been mapped to chromosome 17q11.2 and shown to consist of five exons and a promoter containing GC boxes.13
To investigate the function and pathogenic potential of HRG4, we screened the HRG4 gene for mutations in patients with various retinal degenerations, constructed a transgenic mouse model that expresses a discovered mutation, and studied its phenotype. A heterozygous premature termination codon mutation in HRG4 was uncovered in a patient with late-onset cone–rod dystrophy, and transgenic mice carrying the same mutation showed a spectrum of electroretinographic abnormality of b-wave depression and evidence of retinal degeneration, demonstrating the pathogenic potential of HRG4 and providing evidence of its involvement in neurotransmission.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Construction of the Transgene
A hybrid mouse–rat HRG4 gene with a nonsense codon
mutation was designed as the transgene. Because of the unavailability
of a full-length mouse cDNA clone, the hybrid gene was constructed to
maintain the size of the expressed message. The mouse HRG4
gene (MRG4) was cloned from a Lambda Fix II mouse genomic
library, and an exon 1 region just upstream of the translational
initiation codon to codon 57 was PCR-amplified with a termination codon
mutation inserted at codon 57 and PstI sites at the ends.
This fragment was combined with PstI-digested rat HRG4
cDNA10
to obtain a hybrid cDNA. The ability of the hybrid
HRG4 cDNA to express the truncated 56-amino-acid MRG4 protein was
tested by cloning into the pGEX
glutathione-S-transferase (GST)–coupled vector
(Pharmacia Biotech, Uppsala, Sweden), expression in bacteria, and
analysis of the product. The hybrid cDNA was then inserted into plasmid
gBR200-lacF (generous gift of Donald Zack), which contains the 2.2-kbp
bovine rhodopsin promoter,18
to construct the transgene.
Production of Transgenic Mice
Production of transgenic mice was performed at the Transgenic
Facility of the University of Miami School of Medicine. All procedures
using mice were conducted in accordance with the ARVO Statement for the
Use of Animals in Ophthalmic and Vision Research. The transgene was
injected into approximately 100 fertilized eggs (C57Bl6J/SJL) each time
(5–10 ng/egg, four injections). Seven transgenic founders were
obtained. Two of the founders (numbers 456 and 919) were sterile. To
establish independent transgenic lines and to breed out the
rd retinal degeneration genotype carried by the SJL strain,
each of the founders was mated with a normal mouse (C57Bl6J), and their
progenies were mated with either normal mice or each other. The
presence of the rd genotype was monitored by PCR
amplification of the mutated region of the cyclic guanosine
monophosphate (cGMP)-phosphodiesterase ß-subunit gene from the
mouse’s DNA, restriction digestion, and gel analysis, as
described.19
Either the heterozygous state, which does not
produce a phenotype, or a complete elimination of the rd
genotype was achieved in all the transgenic animals.
Detection of Transgene Integration
PCR Amplification.
Two PCR primers were made, one (BRP-2,
5'-aggcccatcagctgagatgc-3') in the bovine rhodopsin promoter and
another (10R-13, 5'-gagcacaggtagtcgccggt-3') in the RRG4 cDNA region of
the transgene, which can amplify a transgene-specific fragment. Genomic
DNA obtained from tail biopsies of mice was subjected to PCR
amplification with these primers, and a 551-bp product was detected in
the transgenic animals.
Genomic Southern Blot Analysis.
Ten micrograms of mouse genomic DNA from the tail biopsies was digested
with EcoRl or BamHI, electrophoresed, and
blotted. The blot was hybridized with a
32P-labeled EcoRI fragment of the
transgene as the probe, washed, and autoradiographed.
Detection and Quantitation of Transgene Expression
Northern Blot Analysis.
Retinas were dissected from the transgenic and nontransgenic mice and
used for RNA extraction by the guanidium thiocyanate
method.20
Five micrograms of RNA was electrophoresed in a
formaldehyde gel and blotted.21
The blots were hybridized
with a transgene-specific probe (PCR product of primers
5'-ACGAGTCGTCCAGCCGGAGC-3' at the transcription start site of the
bovine opsin gene and 5'-GCGGCGCGAACCCGGGGATG-3' at the ligation site
of the bovine opsin promoter to the mutated mouse MRG4
sequence—i.e., sequence expressed only from the transgene) and
endogenous MRG4-specific probe (PCR product of primers
5'-CCCCTTCCCCTGGCTCCAGC-3' at the transcriptional start site of
MRG4 and 5'-CTCGCGGGGCCGCAGATCCTC-3' at the end of the 5'
untranslated region not contained in the transgene—i.e., sequence
expressed only from the endogenous MRG4 gene). The blots
were also hybridized with actin to determine the quantity and quality
of RNA present in each lane. The hybridized signals were quantitated by
densitometry.
Quantitative RT-PCR Analysis.
To determine the regional expression of the transgene in the mouse
retina, primers were produced to detect the transgene transcript by
reverse transcription–polymerase chain reaction (RT-PCR): TGRT-2
(5'-ctcagaagcatccccgggtt-3') in the bovine rhodopsin promoter region
after the transcriptional start site and 10R-13 in the RRG4 cDNA as
described earlier, yielding a product of 239 bp. Two primers were also
produced to detect the endogenous MRG4 expression by RT-PCR:
MRG4F-1 (5'-gaaggtgaagaaaggcggcg-3') starting at the translational
initiation codon and MRG4B-1 (5'-aggggagcacaggtagtcac-3') in the coding
sequence of the MRG4 transcript corresponding to a region
that straddles exons 1 and 2, yielding a 234-bp product. The transgene
plasmid was used as a positive control template for the 239-bp product.
One microgram of RNA from the four retinal quadrants of transgenic mice
was subjected to RT, and the product was divided into 12 to 18 equal
portions. The samples were PCR-amplified for a varying number of cycles
(26, 28, 30, 32, 34 and 36 cycles) with primers to detect both the
transgene and the endogenous MRG4 transcript in the
transgenic mouse retina. ß-Actin was also PCR amplified and examined
to confirm the quality and quantity of the RNA used for the analysis.
Densitometric analysis of the RT-PCR products was performed, the result was plotted, and the linear phase of the PCR-amplification was identified and used to compare the levels of the transgene and the endogenous MRG4 transcripts. The linear phase of the reaction was used because, with excess substrates and primers, the extent of the reaction in this phase depends solely on the amount of reverse transcribed mRNA present.
Western Blot Analysis.
Protein was extracted from the transgenic and nontransgenic retinas
(whole and quadrants) and analyzed (100 µg) by Western blot analysis
with the RRG4 antibody.12
Approximate quantitation was
performed by densitometry of the chemiluminescent bands.
Fundus Examination
Animals were anesthetized with a mixture of ketamine, xylazine and
urethane; the pupils were dilated with phenylephrine and atropine; and
fundus photographs were taken (model RC2 camera; Kowa, Tokyo, Japan).
Electroretinography
Methods for recording ERGs from mice have been reported
earlier.22
In brief, mice were anesthetized and the pupils
were dilated as for the fundus examination. The ERGs were recorded
between a wick Ag-AgCl electrode placed on the cornea and a reference
electrode (a 30-gauge hypodermic needle) placed subcutaneously on the
head. The animal was grounded by an electrode placed subcutaneously in
the neck region. The responses were fed to a preamplifier (A39;
Tektronix, Beaverton, OR) with the half-amplitude bandpass set at DC to
10 kHz (DC recordings) or at 0.1 Hz to 10 kHz (AC recordings). The
output of the preamplifier was displayed on an oscilloscope and fed to
a signal averaging program (M100; Biopac; Goleta, CA). The light for
the stimulus was obtained from a quartz halogen bulb. The lamp filament
was brought into focus in the plane of a shutter (Uniblitz; Vincent,
Rochester, NY), and another lens focused the filament onto the tip of a
fiber optic bundle. The other end of the fiber optic bundle was brought
into the Faraday cage, and the tip was placed 1 to 2 mm from the
cornea.
The stimulus intensity was measured with a photometer (UDT Instruments, Orlando, FL) with the detector placed at the position of the cornea. The maximum stimulus luminance was 1.59 x 103 candelas [cd]/m2, and neutral density (ND) filters were used to attenuate the full-intensity stimulus. The stimulus intensity was increased in 0.5 log unit steps, and two responses were averaged at the lower stimulus intensities (ND = 6.0–3.5). Only one response was recorded at the higher stimulus intensities (ND = 3.0–0). The implicit time of the b-waves was measured in 10 transgenic mice from line 452 and in 10 control animals. The measurements were made on the electroretinograms (ERGs) elicited by the full-intensity stimulus.
Light and Electron Microscopy
Age-matched transgenic and nontransgenic control mice were
examined at ages 9 to 30 months. Mice were killed and eyes were
enucleated and immersed in fixative containing 2.0% paraformaldehyde
and 2.5% glutaraldehyde in 0.1 M phosphate buffer, pH 7.4. For light
microscopy, eyes were embedded in paraffin and examined in histologic
sections stained with hematoxylin and eosin. For electron microscopy,
blocks of tissue, fixed as described, were prepared from affected
retinal regions of transgenic mice and comparable regions in control
animals, then postfixed in buffered 1% OsO4,
dehydrated through a graded series of alcohols, and embedded in epoxy
resin, by using standard procedures. Ultrathin sections stained with
uranyl acetate and lead citrate were examined in an electron microscope
(JEOL, Peabody, MA).
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
|
The transgene construct was injected into fertilized mouse eggs at four different times, 100 eggs each. The four injections yielded 20, 26, 32, and 17 pups. The transgenic animals were identified by tail biopsies and DNA analysis. The DNA analysis consisted of both a PCR amplification assay to identify products unique to the transgenic animals (Fig. 2A ) and a genomic Southern blot analysis of the mouse DNA to identify fragments also unique to the transgenic animals (Fig. 2B) . From the four groups of pups, seven transgenic founders were identified. To produce independent lines of transgenic animals and to breed out the rd gene that was present in the mice used for the injection, the transgenic founders were initially mated with a normal strain (C57B6J), and their transgenic offspring were mated with each other. The presence of the rd allele was detected by PCR amplification of the mutated portion of the cyclic guanosine monophosphate-phosphodiesterase ß-subunit gene and restriction digestion assay as described.19 Achievement of rd heterozygosity or complete elimination of the rd genotype was confirmed in the transgenic animals. Two of the original seven founders were sterile and could not be propagated. The remaining five lines were subjected to further analysis.
|
|
|
|
Histopathology
Light Microscopy.
A spectrum of pathologic changes was observed in the line 452
transgenic retinas, depending on the age of the animal and the severity
of the observed funduscopic and ERG abnormalities. In the younger
transgenic mice with mild b-wave reduction and a few fundus lesions,
the outer nuclear layer appeared more disorganized and loose than that
of age-matched nontransgenic animals, with numerous photoreceptor
nuclei appearing to migrate into the inner segment and outer plexiform
layers (Figs. 6A
6B
). In older transgenic mice with multiple flecks or degenerative
changes in the fundus and significant reduction in the b-wave, the
retina showed evidence of outright degeneration, with thinning of the
outer nuclear layer down to four to five rows of nuclei, compared with
approximately 10 rows seen in age-matched nontransgenic mice (Fig. 6C)
.
There was also extensive vacuolation and pyknosis in the inner nuclear
layer and an overall reduction in the number of nuclei present in this
layer (Figs. 6C 6E)
. Within the outer plexiform layer, the site of
localization of HRG4,12
extensive vacuolation was apparent
by light microscopy, confirmed by electron microscopy (Figs. 6D
6E)
.
The degenerative changes in the retina were present in the same region
as the fundus lesions, typically in the superior temporal quadrant,
which showed the highest expression of the transgene. No significant
histologic abnormality was present in the retinas of the other four
lines that expressed lower levels of the transgene.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
The striking disease observed in the photoreceptor ribbon synapse in the transgenic mouse, which correlated with the level of expression of the transgene, was consistent with the site of expression of the mutated MRG4. The synaptic degeneration was observed in the rod photoreceptor spherules, consistent with the expression of the transgene from the rhodopsin promoter. The presence of the disease mostly in the superior temporal quadrant also correlated with the highest expression of the transgene in this region of the retina. The observed pathologic changes in the synapse, including vacuolation, swollen, watery dendritic processes containing flocculent material, and accumulation of osmiophilic granules or 10- to 15-nm neurofilaments matched those previously described in other examples of neuronal degeneration. The same types of changes were seen in the nerve terminals in the lateral geniculate nucleus after enucleation in rhesus monkeys and in the olfactory bulb of rabbit and rat after removal of the olfactory mucosa.25 26 These changes led to an electron-dense transformation of the neuron called "dark degeneration" that was clearly evident in some of the HRG4 transgenic photoreceptor ribbon terminals, which became filled with osmiophilic material.
Of interest in the transgenic retina was the suggestion of transsynaptic degeneration, which presumably occurred as a result of the photoreceptor synaptic degeneration. Evidence of vacuolation was present in the outer plexiform and the inner nuclear layers with significant reduction in the number of inner retinal nuclei and many surviving inner nuclear layer cells, showing evidence of apoptosis with pyknotic nuclei at the ultrastructural level. Transsynaptic degeneration is a well-known phenomenon, both antero- and retrograde, as seen in the deep cerebellar nuclei of Purkinje cell degeneration (pcd) mutant mice,27 in the lateral geniculate nucleus of enucleated rhesus monkey,25 and in the olfactory bulb of rabbit and rat after the removal of olfactory mucosa.26 Loss of the ganglion cell layer has been reported in diseases of the outer retinal layer, such as cone–rod dystrophy and rod–cone dystrophy, presumably by transsynaptic degeneration.28 The disease observed in the transgenic retina may be consistent with this. One of the postulated mechanisms for this phenomenon, which can be studied in the transgenic model, is the release of neuroactive material from the degenerating terminals that affects the postsynaptic neurons.
The retinal disease in the human patient and the transgenic model based on the same mutation show multiple features in common. The observed age dependence of the disease in the human was evident in the transgenic model when the ERG abnormality of transgenic mice 1 year of age or more was compared with that of transgenic mice less than a year of age, with the older transgenic mice showing a significant reduction in the b-wave. The histopathologic changes also showed a clear-cut age-dependent progression, with overt retinal degeneration not occurring before the mice were at least middle aged (i.e., 1 year of age or more). We have shown that HRG4 is expressed in both rod and cone photoreceptor synapses.10 12 Thus it could be predicted that disease with both rod-predominant (retinitis pigmentosa) and cone-predominant (macular pattern dystrophy) characteristics would be produced, as in the case of rds/peripherin, which is also expressed in both rod and cone photoreceptors.29 30 31 32 Indeed, the phenotype of the human disease cone–rod dystrophy, at least in the one patient found to date, is certainly consistent with the expression of HRG4 in both rod and cone photoreceptors. The transgenic model, however, is theoretically not suitable for comparison in this respect, because the transgene is driven by a rhodopsin promoter and is expressed only in rod photoreceptors, resulting in rod photoreceptor degeneration. It is interesting, however, that the absence of a b-wave gain in the ERG of the line 452 transgenic mice at the higher stimulus intensities seemed to suggest the possibility of a cone system defect in addition to rod dysfunction. This may actually reflect a leakiness of the rhodopsin promoter, resulting in expression of the transgene in both rods and cones or a secondary effect of the rod degeneration on cone function. Regardless, a significant reduction in the ERG b-wave, consistent with a defect in photoreceptor synaptic neurotransmission, was seen in both the human patient and the transgenic model. Given all the above similarities to the human disease, the transgenic mouse model may be useful for analysis of the pathophysiological mechanism of the disease and approaches to treatment for this form of retinal degeneration. Screening of this gene in additional retinopathies is ongoing.
Our transgenic model was designed to achieve a dominant negative effect of a mutant MRG4, as observed in a patient with cone–rod dystrophy who had the heterozygous mutation, by the expression of a truncated MRG4 protein containing only the proximal proline-rich domain. Similar transgenic models based on the expression of a truncated gene product to achieve a dominant negative effect have been described.33 34 Because we have shown that the MRG4 transgene construct is capable of expressing the truncated N-terminal protein and that this protein is expressed in the line 452 transgenic mouse retina, the pathogenic mechanism must involve an interference of the function of the normal MRG4 gene product by the truncated protein—i.e., a dominant negative effect. Such interference may be by competition for the putative target protein, as we had predicted from the likely protein-interacting function of the proline-rich N-terminal region,12 or by a direct inhibition of normal MRG4 by the truncated protein.
The pathogenic mechanism is unlikely to involve haploinsufficiency, because the full complement of the normal MRG4 gene is expressed in the transgenic mouse, yet the degeneration occurs. An overexpression of the transgene in the retina was also ruled out as the cause of the retinal degeneration. Although the transgene message level was 172% of the endogenous MRG4 message, the level of the transgene protein was quite low at 8% of the total MRG4 protein. The low level of the abnormal truncated protein may explain the slow progress of the disease. It is possible that most of the expressed abnormal protein is being degraded in the photoreceptors. The transgenic model should be useful for testing hypotheses regarding the pathophysiological mechanism involving the mutant MRG4 and for studying the mechanism of the subsequent retinal degeneration.
The precise function of HRG4 is not known yet. Its importance in synaptic neurotransmission and its capacity for pathogenicity, however, have been amply supported by the presence of an HRG4 mutation in a patient with cone–rod dystrophy and by the phenotype produced in our transgenic model expressing the identical mutation. Its precise function will begin to be elucidated by the identification of its target protein by such strategies as the yeast two-hybrid system.35 36 HRG4 represents the first example of a synaptic protein that is highly enriched in, if not specific to, the photoreceptor ribbon synapse and which is pathogenic when mutated.
|
Footnotes |
|---|
Submitted for publication March 15, 2000; revised May 30, 2000; accepted June 20, 2000.
Commercial relationships policy: N.
Corresponding author: George Inana, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, 1638 NW 10th Avenue, Miami, FL 33136. ginana{at}bpei.med.miami.edu
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
-transducin FEBS Lett 234,39-43[Medline][Order article via Infotrieve]
This article has been cited by other articles:
|
|
 |
|
  L. C. Keller, S. Geimer, E. Romijn, J. Yates III, I. Zamora, and W. F. Marshall Molecular Architecture of the Centriole Proteome: The Conserved WD40 Domain Protein POC1 Is Required for Centriole Duplication and Length Control Mol. Biol. Cell, February 1, 2009; 20(4): 1150 - 1166. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Haeseleer Interaction and Colocalization of CaBP4 and Unc119 (MRG4) in Photoreceptors Invest. Ophthalmol. Vis. Sci., June 1, 2008; 49(6): 2366 - 2375. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Vepachedu, M. M. Gorska, N. Singhania, G. P. Cosgrove, K. K. Brown, and R. Alam Unc119 Regulates Myofibroblast Differentiation through the Activation of Fyn and the p38 MAPK Pathway J. Immunol., July 1, 2007; 179(1): 682 - 690. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. P. Kocaoglu, S. R. Uhlhorn, E. Hernandez, R. A. Juarez, R. Will, J.-M. Parel, and F. Manns Simultaneous Fundus Imaging and Optical Coherence Tomography of the Mouse Retina Invest. Ophthalmol. Vis. Sci., March 1, 2007; 48(3): 1283 - 1289. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Suzuki, M. Yagi, and K. Suzuki Duplicated insertion mutation in the microtubule-associated protein Spag5 (astrin/MAP126) and defective proliferation of immature Sertoli cells in rat hypogonadic (hgn/hgn) testes Reproduction, July 1, 2006; 132(1): 79 - 93. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Mori, Y. Ishiba, S. Kubota, A. Kobayashi, T. Higashide, M. J. McLaren, and G. Inana Truncation Mutation in HRG4 (UNC119) Leads to Mitochondrial ANT-1-Mediated Photoreceptor Synaptic and Retinal Degeneration by Apoptosis. Invest. Ophthalmol. Vis. Sci., April 1, 2006; 47(4): 1281 - 1292. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Castori, E. M. Valente, M. Clementi, A. P. Tormene, F. Brancati, V. Caputo, and B. Dallapiccola A Novel Locus for Autosomal Dominant Cone and Cone-Rod Dystrophies Maps to the 6p Gene Cluster of Retinal Dystrophies Invest. Ophthalmol. Vis. Sci., October 1, 2005; 46(10): 3539 - 3544. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Sokal, W. J. Dupps, M. A. Grassi, J. Brown Jr, L. M. Affatigato, N. Roychowdhury, L. Yang, S. Filipek, K. Palczewski, E. M. Stone, et al. A Novel GCAP1 Missense Mutation (L151F) in a Large Family with Autosomal Dominant Cone-Rod Dystrophy (adCORD) Invest. Ophthalmol. Vis. Sci., April 1, 2005; 46(4): 1124 - 1132. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M Michaelides, G E Holder, D M Hunt, F W Fitzke, A C Bird, and A T Moore A detailed study of the phenotype of an autosomal dominant cone-rod dystrophy (CORD7) associated with mutation in the gene for RIM1 Br. J. Ophthalmol., February 1, 2005; 89(2): 198 - 206. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Norose, F. Aosai, A. Mizota, S. Yamamoto, H.-S. Mun, and A. Yano Deterioration of Visual Function as Examined by Electroretinograms in Toxoplasma gondii-Infected IFN-{gamma}-Knockout Mice Invest. Ophthalmol. Vis. Sci., January 1, 2005; 46(1): 317 - 321. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Ito, M. Nakamura, Y. Nuno, Y. Ohnishi, T. Nishida, and Y. Miyake Novel Complex GUCY2D Mutation in Japanese Family with Cone-Rod Dystrophy Invest. Ophthalmol. Vis. Sci., May 1, 2004; 45(5): 1480 - 1485. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. M. Gorska, S. J. Stafford, O. Cen, S. Sur, and R. Alam Unc119, a Novel Activator of Lck/Fyn, Is Essential for T Cell Activation J. Exp. Med., February 2, 2004; 199(3): 369 - 379. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. Cen, M. M. Gorska, S. J. Stafford, S. Sur, and R. Alam Identification of UNC119 as a Novel Activator of SRC-type Tyrosine Kinases J. Biol. Chem., February 28, 2003; 278(10): 8837 - 8845. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Mizota and E. Adachi-Usami Effect of Body Temperature on Electroretinogram of Mice Invest. Ophthalmol. Vis. Sci., December 1, 2002; 43(12): 3754 - 3757. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. Klevering, A. Blankenagel, A. Maugeri, F. P. M. Cremers, C. B. Hoyng, and K. Rohrschneider Phenotypic Spectrum of Autosomal Recessive Cone-Rod Dystrophies Caused by Mutations in the ABCA4 (ABCR) Gene Invest. Ophthalmol. Vis. Sci., June 1, 2002; 43(6): 1980 - 1985. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Thaung, K. West, B. J. Clark, L. McKie, J. E. Morgan, K. Arnold, P. M. Nolan, J. Peters, A. J. Hunter, S. D. M. Brown, et al. Novel ENU-induced eye mutations in the mouse: models for human eye disease Hum. Mol. Genet., April 1, 2002; 11(7): 755 - 767. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Kubota, A. Kobayashi, N. Mori, T. Higashide, M. J. McLaren, and G. Inana Changes in Retinal Synaptic Proteins in the Transgenic Model Expressing a Mutant HRG4 (UNC119) Invest. Ophthalmol. Vis. Sci., February 1, 2002; 43(2): 308 - 313. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
