Brain and behavioural disorders represent a leading cause of morbidity and suffering worldwide. The 'fierce' mouse has a spontaneous deletion of Nr2e1 that results in a complex phenotype that includes cortical hypoplasia and socially abnormal behaviours. Notably, functional protein and regulatory equivalency of mouse and human NR2E1 has been established. Furthermore, human studies implicate the genomic region containing NR2E1 in mental illness, although a role for NR2E1 in humans is currently unknown. Here, I integrate mouse models and human molecular genetics to understand the involvement of NR2E1 in human brain-behaviour development. First, we test the hypothesis that the spontaneous 'fierce' deletion involves onlyNr2el. It was demonstrated that the 'fierce' mutation results in the loss of all Nr2e1 exons without affecting neighbouring genes. Next, the hypothesis that some humans with cortical malformations will harbour NR2E1 mutations was tested by sequencing the coding, untranslated, splice-site, proximal promoter, and evolutionarily conserved regions of this gene in 60 subjects with microcephaly. Four candidate regulatory mutations were identified. To help interpret these findings, the genomic architecture and molecular evolution of NR2E1 were characterized in 94ethnically-diverse humans and 13 non-human primates, which indicated strong functional constraint. Finally, the hypothesis that some humans with behavioural and psychiatric disorders will harbour mutations in NR2E1 was tested by sequencing the regions outlined above in 126humans with impulsive-aggressive disorders, bipolar disorder, or schizophrenia. Eleven candidate regulatory mutations were identified. Taken together, the findings presented in this thesis are consistent with the proposal that non-coding regulatory mutations may be important to the pathogenesis of brain-behavioural disorders in some humans.

Brain and behavioural disorders represent a leading cause of morbidity and suffering worldwide. The 'fierce' mouse has a spontaneous deletion of Nr2e1 that results in a complex phenotype that includes cortical hypoplasia and socially abnormal behaviours. Notably, functional protein and regulatory equivalency of mouse and human NR2E1 has been established. Furthermore, human studies implicate the genomic region containing NR2E1 in mental illness, although a role for NR2E1 in humans is currently unknown. Here, I integrate mouse models and human molecular genetics to understand the involvement of NR2E1 in human brain-behaviour development. First, we test the hypothesis that the spontaneous 'fierce' deletion involves onlyNr2el. It was demonstrated that the 'fierce' mutation results in the loss of all Nr2e1 exons without affecting neighbouring genes. Next, the hypothesis that some humans with cortical malformations will harbour NR2E1 mutations was tested by sequencing the coding, untranslated, splice-site, proximal promoter, and evolutionarily conserved regions of this gene in 60 subjects with microcephaly. Four candidate regulatory mutations were identified. To help interpret these findings, the genomic architecture and molecular evolution of NR2E1 were characterized in 94ethnically-diverse humans and 13 non-human primates, which indicated strong functional constraint. Finally, the hypothesis that some humans with behavioural and psychiatric disorders will harbour mutations in NR2E1 was tested by sequencing the regions outlined above in 126humans with impulsive-aggressive disorders, bipolar disorder, or schizophrenia. Eleven candidate regulatory mutations were identified. Taken together, the findings presented in this thesis are consistent with the proposal that non-coding regulatory mutations may be important to the pathogenesis of brain-behavioural disorders in some humans.

Brain and behavioural disorders represent a leading cause of morbidity and suffering worldwide. The 'fierce' mouse has a spontaneous deletion of Nr2e1 that results in a complex phenotype that includes cortical hypoplasia and socially abnormal behaviours. Notably, functional protein and regulatory equivalency of mouse and human NR2E1 has been established. Furthermore, human studies implicate the genomic region containing NR2E1 in mental illness, although a role for NR2E1 in humans is currently unknown. Here, I integrate mouse models and human molecular genetics to understand the involvement of NR2E1 in human brain-behaviour development. First, we test the hypothesis that the spontaneous 'fierce' deletion involves onlyNr2el. It was demonstrated that the 'fierce' mutation results in the loss of all Nr2e1 exons without affecting neighbouring genes. Next, the hypothesis that some humans with cortical malformations will harbour NR2E1 mutations was tested by sequencing the coding, untranslated, splice-site, proximal promoter, and evolutionarily conserved regions of this gene in 60 subjects with microcephaly. Four candidate regulatory mutations were identified. To help interpret these findings, the genomic architecture and molecular evolution of NR2E1 were characterized in 94ethnically-diverse humans and 13 non-human primates, which indicated strong functional constraint. Finally, the hypothesis that some humans with behavioural and psychiatric disorders will harbour mutations in NR2E1 was tested by sequencing the regions outlined above in 126humans with impulsive-aggressive disorders, bipolar disorder, or schizophrenia. Eleven candidate regulatory mutations were identified. Taken together, the findings presented in this thesis are consistent with the proposal that non-coding regulatory mutations may be important to the pathogenesis of brain-behavioural disorders in some humans. / Medicine, Faculty of / Medical Genetics, Department of / Graduate

Nuclear receptors constitute a large family of transcription factors that are powerful regulators of animal tissue metabolism, homeostasis, tissue maintenance and development. They are particularly attractive for their ability to respond to the binding of hormones, metabolites, xenobiotics and artificially prepared molecules and transmit the interaction with these small lipophylic molecules to specific regulatory potential. In search for nuclear receptors that are likely to be critical for neural tissues in invertebrates and conserved during the evolution of animals, we have identified a close homologue of vertebrate TLX in a planarian Schmidtea mediterranea. Planaria represent very promising biological model systems for studies on tissue maintenance and regeneration. Planaria are able to resorb their tissues and use them as sources of energy during fasting and they re-build their bodies from neoblasts when food is plentiful. Our search in Schmidtea mediterranea's publicly accessible genome sequencing data indicated that planarian genome contains at least one gene with a high degree of similarity to vertebrate TLX. We cloned full length CDS (coding DNA sequence of cDNA) and characterized the gene functionally. This showed that the planarian and vertebrate NR2E1 are highly similar...

Nuclear receptors constitute a large family of transcription factors that are powerful regulators of animal tissue metabolism, homeostasis, tissue maintenance and development. They are particularly attractive for their ability to respond to the binding of hormones, metabolites, xenobiotics and artificially prepared molecules and transmit the interaction with these small lipophylic molecules to specific regulatory potential. In search for nuclear receptors that are likely to be critical for neural tissues in invertebrates and conserved during the evolution of animals, we have identified a close homologue of vertebrate TLX in a planarian Schmidtea mediterranea. Planaria represent very promising biological model systems for studies on tissue maintenance and regeneration. Planaria are able to resorb their tissues and use them as sources of energy during fasting and they re-build their bodies from neoblasts when food is plentiful. Our search in Schmidtea mediterranea's publicly accessible genome sequencing data indicated that planarian genome contains at least one gene with a high degree of similarity to vertebrate TLX. We cloned full length CDS (coding DNA sequence of cDNA) and characterized the gene functionally. This showed that the planarian and vertebrate NR2E1 are highly similar...