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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Úloha TGFß a studium prognostických faktorů u pacientů s MDS a AML / The role of TGFß and study of prognostic factors of patients with MDS and AML

Provazníková, Dana January 2011 (has links)
We did not find mutation in coding areas of genes for components of TGFbeta1 signaling pathway but we detected decreased or undetectable expression of these analysed genes.The decreased expression is probably caused by epigenetic changes, so by hypermethylation and deacetylation of promoter regionsof these genes.Antiproliferative and apoptotic effect of TGF1 was analysed in AML cell lines (ML1, ML2, CTV1 and Kasumi1). ML2 cells rezistence to inhibition of DNA synthesis by TGFβ1 is not caused by mutations of genes for components of TGFβ1 signaling pathway. We found that increased SnoN (Ski-like novel gene) expression on the level of coresponding mRNA and protein is probably accountable for this rezistence. Kasumi1 and M2 cells were sensitive to induction of apoptózis caused by TGFβ1 treatment but in less extent than by proteazome inhibitor bortezomib. The difference of AML cells of different lines answers shows a great heterogeneity AML in AML patients. Prognostic factors analysis in AML with normal karyotype confirmed that CEBPA (CCAAT/enhancer binding protein alpha) mutations predict favourable prognosis but the elevated EVI1 ("Ecotropic Virus Integration Site 1") and ERG ("ETS-related gene") expression are connected with unfavourable prognosis. EVI1 is a negative marker for MDS as well. We did not confirm...
12

Incremental and decremental L- and M-cone driven ERG responses: II. Sawtooth stimulation.

Kremers, Jan, Pangeni, G., Tsaousis, K.T., McKeefry, Declan J., Murray, I.J., Parry, Neil R.A. 04 1900 (has links)
No / L- and M-cone driven on- and off- ERG responses and their interactions were examined using full field stimuli with sawtooth temporal profiles. The effects of temporal frequency and contrast were studied. ERG recordings were obtained from 21 trichromatic, 1 protanopic, and 1 deuteranopic subjects. ERGs to L-cone increments and decrements resembled those to M-cone decrements and increments, respectively (i.e., of the opposite polarity). Temporal frequency and contrast had little effect on the implicit times. All response components varied linearly with contrast. When stimulated simultaneously, the responsivities of most components were larger for counterphase than for inphase modulation. The retinal processing leading to an ERG response is reversed for L- and M-cone driven responses.
13

Investigação dos mRNAs de Fusão do Gene TMPRSS2/ERG em Pacientes com Câncer de Próstata. / Investigation of mRNAs of the Fusion Gene TMPRSS2/ERG in Patients with Prostate Cancer in Brazil.

Souza, Bruna Ferreira de 26 April 2013 (has links)
O interesse científico em rearranjos gênicos relacionados com a etiogênese e progressão do câncer relaciona-se, principalmente, à descoberta da fusão BCR/ABL na Leucemia Mieloide Crônica, sendo que desde então, houve uma evolução no manejo dessa doença, instigando uma série de estudos correlatos em outras neoplasias. Essas pesquisas culminaram no encontro do primeiro rearranjo gênico em tumores sólidos, o gene de fusão TMPRSS2/ERG, envolvendo a região promotora do gene da serina protease, o TMPRSS2, e o gene da família de fatores de transcrição ETS, o ERG. Ele é específico de adenocarcinoma da próstata, o que o torna forte candidato a biomarcador e já demonstra exercer papel de destaque no manejo clínico do câncer de próstata (CaP), tal qual o exercido pela fusão BCR/ABL. Sua frequência têm se mostrado associada a diversos fatores, sobretudo à etnia de origem. Indivíduos portadores de CaP oriundos de diversos países já foram estudados quanto à frequência dessa fusão e o resultado é bastante diversificado. No Brasil, entretanto, ainda não há dados a respeito desse rearranjo, e este trabalho visa contribuir para a identificação da frequência da mesma e sua contribuição para o diagnóstico e o tratamento do CaP no país. Para tal, utilizamos mRNA de 20 indivíduos com CaP provenientes do serviço de atendimento do HCFMRP/USP, e por meio da técnica de RT-PCR, obtivemos o cDNA dos mesmos que foram investigados quanto à presença da fusão TMPRSS2/ERG, e as amostras positivas sequenciadas para determinação do tipo de isoforma envolvida. Identificamos que 35% das amostras continham o rearranjo e que todas correspondiam à isoforma do tipo III, cuja literatura a relaciona com um fenótipo agressivo do CaP, porém não metástico, e é também a mais comumente identificada. Ao confrontarmos essa evidência com os dados clínicos e histopatológicos, constatamos que havia correlação entre eles, sugerindo assim, como em outros trabalhos, o potencial desse rearranjo como marcador de agressividade do CaP. No entanto, não verificamos relação entre a presença da fusão e dados de progressão da doença. Em vista desses resultados, destacamos a necessidade da promoção de outros trabalhos de mesmo caráter, abrangendo outras regiões, a fim de se delinear um perfil mais representativo desse rearranjo no Brasil, uma vez que seu potencial como biomarcador diagnóstico e clínico é enorme e pode influenciar sobremaneira no manejo do CaP. / Scientific interest in gene rearrangements associated with cancer progression and etiogenesis relates mainly to the discovery of BCR/ABL fusion in chronic myelogenous leukemia, and since then there has been an evolution in the management of this disease, prompting a series of related studies in other malignancies. These researches resulted in the meeting of the first gene rearrangement in solid tumors, the fusion gene TMPRSS2/ERG involving the promoter region of the gene of serine protease, TMPRSS2, and the gene family of transcription factors ETS, the ERG. It is specific for adenocarcinoma of the prostate, which makes it a strong candidate biomarker and shows already exert a prominent role in the clinical management of prostate cancer (PCa), as is exercised by the BCR/ABL. Its frequency has been shown to be associated with several factors, especially the ethnic origin. Individuals with CaP from different countries have been studied in the frequency of this merger and the result is quite diverse. In Brazil, however, there is no data about this rearrangement, and this paper aims to contribute to the identification of the same frequency and its contribution to the diagnosis and treatment of PCa in the country. Therefore, we used mRNA from 20 individuals with CaP from the answering service HCFMRP/USP, and by RT-PCR, cDNA obtained from the same people who were investigated for the presence of fusion TMPRSS2/ERG, and positive samples sequenced to determine the type of isoform involved. We found that 35% of the samples contained the rearrangement and that all corresponded to the type III isoform, whose literature relates to an aggressive phenotype of PCa, but not metastatic, and is also the most commonly identified. When we compared this evidence with clinical and histopathological data, we found that there was a correlation between them, suggesting, as in other studies, the potential of this rearrangement as a agressivity marker of PCa. However, no significant association between the presence of data fusion and disease progression. In view of these results, we highlight the need to promote other works of the same character, covering other regions, in order to delineate a more representative profile of this rearrangement in Brazil, since its potential as a biomarker and clinical diagnosis is huge and can influence greatly in the management of PCa.
14

Electroretinography and exploration of visual and auditory function in mutant mice with synaptic defects / Elektroretinographie und Untersuchung der visuellen und auditorischen Funktion von Mausmutanten mit synaptischen Defekten

Bauer, Gabriele Cornelia Maria 20 November 2012 (has links)
No description available.
15

Investigação dos mRNAs de Fusão do Gene TMPRSS2/ERG em Pacientes com Câncer de Próstata. / Investigation of mRNAs of the Fusion Gene TMPRSS2/ERG in Patients with Prostate Cancer in Brazil.

Bruna Ferreira de Souza 26 April 2013 (has links)
O interesse científico em rearranjos gênicos relacionados com a etiogênese e progressão do câncer relaciona-se, principalmente, à descoberta da fusão BCR/ABL na Leucemia Mieloide Crônica, sendo que desde então, houve uma evolução no manejo dessa doença, instigando uma série de estudos correlatos em outras neoplasias. Essas pesquisas culminaram no encontro do primeiro rearranjo gênico em tumores sólidos, o gene de fusão TMPRSS2/ERG, envolvendo a região promotora do gene da serina protease, o TMPRSS2, e o gene da família de fatores de transcrição ETS, o ERG. Ele é específico de adenocarcinoma da próstata, o que o torna forte candidato a biomarcador e já demonstra exercer papel de destaque no manejo clínico do câncer de próstata (CaP), tal qual o exercido pela fusão BCR/ABL. Sua frequência têm se mostrado associada a diversos fatores, sobretudo à etnia de origem. Indivíduos portadores de CaP oriundos de diversos países já foram estudados quanto à frequência dessa fusão e o resultado é bastante diversificado. No Brasil, entretanto, ainda não há dados a respeito desse rearranjo, e este trabalho visa contribuir para a identificação da frequência da mesma e sua contribuição para o diagnóstico e o tratamento do CaP no país. Para tal, utilizamos mRNA de 20 indivíduos com CaP provenientes do serviço de atendimento do HCFMRP/USP, e por meio da técnica de RT-PCR, obtivemos o cDNA dos mesmos que foram investigados quanto à presença da fusão TMPRSS2/ERG, e as amostras positivas sequenciadas para determinação do tipo de isoforma envolvida. Identificamos que 35% das amostras continham o rearranjo e que todas correspondiam à isoforma do tipo III, cuja literatura a relaciona com um fenótipo agressivo do CaP, porém não metástico, e é também a mais comumente identificada. Ao confrontarmos essa evidência com os dados clínicos e histopatológicos, constatamos que havia correlação entre eles, sugerindo assim, como em outros trabalhos, o potencial desse rearranjo como marcador de agressividade do CaP. No entanto, não verificamos relação entre a presença da fusão e dados de progressão da doença. Em vista desses resultados, destacamos a necessidade da promoção de outros trabalhos de mesmo caráter, abrangendo outras regiões, a fim de se delinear um perfil mais representativo desse rearranjo no Brasil, uma vez que seu potencial como biomarcador diagnóstico e clínico é enorme e pode influenciar sobremaneira no manejo do CaP. / Scientific interest in gene rearrangements associated with cancer progression and etiogenesis relates mainly to the discovery of BCR/ABL fusion in chronic myelogenous leukemia, and since then there has been an evolution in the management of this disease, prompting a series of related studies in other malignancies. These researches resulted in the meeting of the first gene rearrangement in solid tumors, the fusion gene TMPRSS2/ERG involving the promoter region of the gene of serine protease, TMPRSS2, and the gene family of transcription factors ETS, the ERG. It is specific for adenocarcinoma of the prostate, which makes it a strong candidate biomarker and shows already exert a prominent role in the clinical management of prostate cancer (PCa), as is exercised by the BCR/ABL. Its frequency has been shown to be associated with several factors, especially the ethnic origin. Individuals with CaP from different countries have been studied in the frequency of this merger and the result is quite diverse. In Brazil, however, there is no data about this rearrangement, and this paper aims to contribute to the identification of the same frequency and its contribution to the diagnosis and treatment of PCa in the country. Therefore, we used mRNA from 20 individuals with CaP from the answering service HCFMRP/USP, and by RT-PCR, cDNA obtained from the same people who were investigated for the presence of fusion TMPRSS2/ERG, and positive samples sequenced to determine the type of isoform involved. We found that 35% of the samples contained the rearrangement and that all corresponded to the type III isoform, whose literature relates to an aggressive phenotype of PCa, but not metastatic, and is also the most commonly identified. When we compared this evidence with clinical and histopathological data, we found that there was a correlation between them, suggesting, as in other studies, the potential of this rearrangement as a agressivity marker of PCa. However, no significant association between the presence of data fusion and disease progression. In view of these results, we highlight the need to promote other works of the same character, covering other regions, in order to delineate a more representative profile of this rearrangement in Brazil, since its potential as a biomarker and clinical diagnosis is huge and can influence greatly in the management of PCa.
16

Etude des mécanismes de résistance des cancers de prostate aux inhibiteurs de topoisomérases I de la famille des camptothécines / Study of the resistance mecanisms of prostate cancer to topoisomerase I inhibitors from the camptothecin familly

Roche, Emmanuel 17 December 2014 (has links)
Les ADN-Topoisomérases (Topo) de type I et II sont des enzymes essentielles à la suppression des surenroulements de engendrés par la plupart des transactions de l’ADN. Elles sont des cibles de médicaments anticancéreux très utilisés en clinique. Parmi eux, les inhibiteurs de Topo1 de la famille des camptothécines (CPT) exercent leur cytotoxicité en produisant des cassures double-brin de l’ADN provenant de la collision des fourches de réplications avec les complexes ADN-Topo1 stabilisés par ces inhibiteurs. Les dérivés de CPT sont approuvés pour le traitement des cancers coliques, de l’ovaire et du poumon, mais il existe de multiples mécanismes de résistance à ces agents qui sont à l’origine de l’échec du traitement. Les cancers de la prostate sont réfractaires aux CPT, mais très peu d’études ont été réalisées pour expliquer cette résistance « intrinsèque ». Ce travail de thèse visait à identifier les mécanismes de cette résistance en nous appuyant (1) sur des résultats antérieurs de l’équipe montrant que l’interaction entre la DNA-PKcs, une kinase impliquée dans la réparation de l’ADN par recombinaison non-homologue, et la Topo1 pouvait réguler la sensibilité aux CPT de manière indépendante de la réparation de l’ADN et (2) sur une étude ayant mis en évidence une interaction entre DNA-PKcs et le facteur de transcription ERG dont le gène est remanié dans plus de 50% des tumeurs de prostate. Nos résultats montrent pour la première fois que ERG est effectivement impliqué dans la régulation de la réponse aux CPT dans la lignée VCaP présentant un gène de fusion TMPRSS2-ERG. La répression de ERG dans la lignée VCaP induit une sensibilisation à la CPT mais pas à l’étoposide (un inhibiteur de Topo2) et est accompagnée d’une augmentation du nombre de complexes ADN/Topo1. Ce mécanisme peut-être soit lié à un effet de ERG sur l’interaction DNA-PKcs/Topo1 ou à une régulation transcriptionnelle de gènes impliqués dans la réponse aux CPT incluant la Topo1 elle-même. Nous avons confirmé cette deuxième hypothèse, en démontrant que ERG régule la transcription du micro ARN miR-24 et que l’expression de Topo1 est également sous contrôle de miR-24 dans la lignée VCaP. Des résultats similaires ont été obtenus dans la lignée LNCaP (présentant le gène de fusion TMPRSS2-ETV1) dans laquelle la répression de ETV1 confère aussi une sensibilisation à la CPT. Au cours de notre travail nous avons également recherché des inhibiteurs de l’interaction entre la DNA-PKcs et Topo1 afin de pouvoir utiliser ces composés comme agents de potentialisation des dérivés de CPT en clinique. Les résultats du criblage d’une banque de 320 composés naturels réalisé par la technologie AlphaScreen n’ont malheureusement pu identifier que des inhibiteurs catalytiques de Topo1. Nous avons néanmoins pu montrer que l’un d’entre eux, la mahanimbine, présentait une forte activité cytotoxique vis-à-vis de lignées résistantes aux dérivés de CPT et vis-à-vis de la lignée VCaP ce qui permet d’envisager le développement de nouvelles classes d’inhibiteurs catalytiques Topo1 pouvant contourner la résistance des dérivés de CPT en clinique. / Type I and II DNA Topoisomerases (Top) are essential enzymes involved in the removal of DNA torsional constraints induced by most DNA transactions. They are the targets of various anticancer agents used in the clinic. Among them, Top1 inhibitors from the camptothecins (CPT) family exert their cytotoxicity by producing DNA double-strand breaks that are generated by the collision of advancing replication forks with DNA-Top1 complexes that are stabilized by these inhibitors. CPT derivatives are approved for the treatment of colon, ovary and lung cancers but resistance mechanisms are developed and lead to treatment failure. Prostate cancers are refractory to CPT, but few studies have addressed the mechanisms of such “intrinsic” resistance. This work was aimed at identifying such mechanisms based on (1) previous results from the laboratory showing that interaction of Top1 with DNA-PKcs, a kinase that is essential for non-homologous end-joining, could regulate cell sensitivity to CPT independently of DNA repair and (2) a study that showed an interaction of DNA-PKcs with ERG, a transcription factor from the ETS family which is rearranged in more than 50% of prostate tumors. Our results show for the first time that ERG is indeed involved in the regulation of prostate cancer cell response to CPT as its repression sensitized VCaP cells displaying the TMPRSS2-ERG gene fusion to CPT but not to the Top2 inhibitor etoposide. This effect is accompanied with an increase in Top1-DNA complexes. This could be due to either an effect of ERG on DNA-PKcs/Top1 interaction, or to the transcriptional regulation of genes involved in cell response to CPT, including Top1 itself. We confirmed the latter hypothesis by showing that ERG can regulate the transcription levels of the microRNA miR-24 and that Top1 expression relies, at least in part, on miR24 levels in VCaP cells. We obtained similar results in LNCaP cells (characterized by a TMPRSS2-ETV1 gene fusion), in which ETV1 repression also sensitizes cells to CPT. In parallel, we also searched for inhibitors of DNA-PKcs/Top1 interaction in order to use these compounds to potentiate CPT derivatives in the clinic. We screened a chemical library of 320 natural compounds using the AlphaScreen technology. The results were disappointing as we only identified compounds that are catalytic inhibitors of Top1. Nevertheless, we could show that among them, mahanimbine displayed a potent cytotoxic activity towards CPT-resistant colon cancer cell lines and could efficiently inhibit the growth of VCaP cells that are highly resistant to CPT. This opens new avenues for the development of new classes of Top1 catalytic inhibitors that could be used to circumvent the clinical resistance to CPT derivatives.
17

Snabba cash : Attityder, självuppfyllelse, och motivationer till snabbmat som yrke / Easy money : Attitudes, self-fulfillment, and motivations towards the fast-food occupation.

Lönnquist, Jonathan, Öhgren, Alexander January 2023 (has links)
No description available.
18

Electrodiagnóstico: protocolo clínico y estandarización de Electrorretinografía (ERG)y Potenciales Evocados Visuales (PEV)en el perro beagle

Torres Soriano, Desireé 02 December 2010 (has links)
La presente tesis se ha basado en conseguir dos objetivos fundamentales: diseñar un protocolo clínico de electrodiagnóstico para obtener el electrorretinograma (ERG) y los potenciales evocados visuales (PEV) en el perro beagle, y elaborar un estándar de los resultados para esta raza.Hemos establecido un protocolo clínico de electrodiagnóstico adaptado a nuestro equipo de diagnóstico, a las características de nuestros pacientes y, en general, a los recursos materiales que teníamos a nuestra disposición. De este modo, hemos conseguido realizar un protocolo de corta duración que nos permite evaluar la funcionalidad de las vías visuales del perro y detectar posibles anomalías.Concluimos que el protocolo que hemos establecido nos permite registrar adecuadamente el ERG y los PEV para el perro beagle, así como obtener resultados fiables y reproducibles que podemos considerar como estándar para esta raza canina y este equipo de electrodiagnóstico. / The aims of this thesis were firstly to design a clinical protocol for Electro, electroretinography (ERG) and visual evoked potential (VEP) in the Beagle dog and, secondly, to develop a performance standard for this breed. A clinical electrodiagnostic protocol adapted to our diagnostic equipment was established. This protocol considered the characteristics of the patients as well as the material resources at our Institution. This protocol allowed us to evaluate the functionality of the visual pathways in order to detect any anomalies. It can be concluded that the protocol established in this Thesis allows to record accurately the ERG and the VEP of Beagle dogs. Moreover, the results are reliable and reproducible and it could be considered as a good standard for this breed when these electrodiagnosis tools are employed.
19

電子化服務傳遞之協同式定價模式研究 / iPrice: A Collaborative Pricing Model for e-Service Bundle Delivery

張瑋倫, Chang,Wei-Lun Unknown Date (has links)
Information goods pricing is an essential and emerging topic in the era of information economy. Myriad researchers have devoted considerable attention to developing and testing methods of information goods pricing. Nevertheless, in addition; there are still certain shortcomings as the challenges to be overcome. This study encompasses several unexplored concepts that have attracted research attention in other disciplines lately, such as collaborative prototyping, prospect theory, ERG theory, and maintenance from design, economic, psychological, and software engineering respectively. This study proposes a novel conceptual framework for information goods pricing and investigates the impact of three advantages: (1) provides collaborative process that could generate several prototypes via trial and error in pricing process, (2) deliberates the belief of consumer and producer by maximizing utility and profit, and (3) offers an appropriate service bundle by interacting with consumer and discovering the actual needs. Due to the unique cost structure and product characteristics of information goods, conventional pricing strategies are unfeasible, and a differential pricing strategy is crucial. Nevertheless, few models exist for pricing information goods in the e-service industry. This study proposes a novel collaborative pricing model in which customers are active participants in determining product prices and adopt prices and services that meet their changing needs. This study also shows that the collaborative pricing model generates an optimal bundle price at equilibrium with optimal profit and utility. Theoretical proofs and practical implications justify this pricing model, which is essential for future information goods pricing in information economy. Moreover, we apply iCare e-service delivery as an exemplar and scenario for our system. The objective of iCare is to provide quality e-services to the elderly people anywhere and anytime. The new pricing method will go beyond the current iCare e-service delivery process which furnishes personalized and collaborative bundles. iPrice system for pricing information goods fills the gap among previous literatures which only considers consumers or providers. Different from existing works, iPrice system is novel in integrating distinctively important concepts yielding more benefits to consumers and profits to more providers. Thus, iPrice also guides and provides a roadmap for information goods pricing for future research. / Information goods pricing is an essential and emerging topic in the era of information economy. Myriad researchers have devoted considerable attention to developing and testing methods of information goods pricing. Nevertheless, in addition; there are still certain shortcomings as the challenges to be overcome. This study encompasses several unexplored concepts that have attracted research attention in other disciplines lately, such as collaborative prototyping, prospect theory, ERG theory, and maintenance from design, economic, psychological, and software engineering respectively. This study proposes a novel conceptual framework for information goods pricing and investigates the impact of three advantages: (1) provides collaborative process that could generate several prototypes via trial and error in pricing process, (2) deliberates the belief of consumer and producer by maximizing utility and profit, and (3) offers an appropriate service bundle by interacting with consumer and discovering the actual needs. Due to the unique cost structure and product characteristics of information goods, conventional pricing strategies are unfeasible, and a differential pricing strategy is crucial. Nevertheless, few models exist for pricing information goods in the e-service industry. This study proposes a novel collaborative pricing model in which customers are active participants in determining product prices and adopt prices and services that meet their changing needs. This study also shows that the collaborative pricing model generates an optimal bundle price at equilibrium with optimal profit and utility. Theoretical proofs and practical implications justify this pricing model, which is essential for future information goods pricing in information economy. Moreover, we apply iCare e-service delivery as an exemplar and scenario for our system. The objective of iCare is to provide quality e-services to the elderly people anywhere and anytime. The new pricing method will go beyond the current iCare e-service delivery process which furnishes personalized and collaborative bundles. iPrice system for pricing information goods fills the gap among previous literatures which only considers consumers or providers. Different from existing works, iPrice system is novel in integrating distinctively important concepts yielding more benefits to consumers and profits to more providers. Thus, iPrice also guides and provides a roadmap for information goods pricing for future research.
20

THE ROLE OF R7 REGULATORS OF G PROTEIN SIGNALING IN THE RETINA

Shim, Hoon 01 January 2012 (has links)
The R7 regulators of G protein signaling (R7 RGS), namely RGS6, RGS7, RGS9 and RGS11, are expressed in the retina along with its binding partner Gβ5. The RGS9-1 isoform is expressed only in retinal photoreceptors and rate-limits the recovery of rod phototransduction by acting as a member of the transducin GAP complex (RGS9-1/Gβ5L/R9AP). The Gβ5L isoform is also only expressed in retinal photoreceptors and acts by stabilizing the GAP complex. The Gβ5S isoform differs from Gβ5L by the absence of exon 1 due to alternative splicing and is expressed in many other retinal cells. Gβ5L is barely detectable in RGS9-/- mice suggesting that Gβ5L has a protein degradation signal conferring instability in the absence of RGS9. To study the role of exon 1 of Gβ5L, we replaced Gβ5L with Gβ5S in rods by expressing transgenic Gβ5S under the control of the rhodopsin promoter within a Gβ5-/- mouse and determined that exon 1 of Gβ5L has two previously unidentified functions: (1) to increase the capacity of Gβ5L to bind to RGS9-1 and (2) to serve as a signal for rapid degradation of Gβ5L in RGS9-/- photoreceptors. Several groups have reported that RGS7 and RGS11 with Gβ5S reside in the dendritic tips of depolarizing bipolar cells (DBCs) and that they are involved in the mGluR6/Gαo/TRPM1 pathway, which mediates DBC light responses. The exact role of RGS7 in DBCs has not been unequivocally determined. We have contributed by making a true RGS7 null mouse line and found the RGS7-/- mice are viable and fertile, but have a small body size. Electroretinogram (ERG) b-wave implicit time in young RGS7-/- mice is prolonged at eye opening, but the phenotype disappears by 2 months of age. Expression levels of RGS6 and RGS11 are unchanged in RGS7-/- retina, but the Gβ5S level is significantly reduced. We further generated a RGS7 and RGS11 double knockout (711dKO) mouse line and found that Gβ5S expression in the retinal outer plexiform layer is eliminated, as well as the ERG b-wave. Ultrastructural defects similar to those of Gβ5-/- mice are present in 711dKO. Furthermore, in retinas of mice lacking RGS6, RGS7, and RGS11, Gβ5S becomes undetectable, while the photoreceptor-specific Gβ5L remains unaffected. Whereas RGS6 alone sustains a significant amount of Gβ5S expression in the retina, the DBC-related defects found in Gβ5-/- mice appear to be caused solely by a combined loss of RGS7 and RGS11. The notion that the role of Gβ5 in the retina, and likely in the entire nervous system, is mediated exclusively by R7 RGS proteins is firmly established in this work. The availability of all four R7 RGS single knockout mouse lines enables future studies to further elucidate the roles of R7 RGS proteins in vision.

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