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Transcriptional regulation of two immune genes: teleost activation-induced cytidine deaminase and duck major histocompatibility complex class I
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- Author / Creator
- Chan, Wing Fuk
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Differential gene expression allows organisms to develop specialized cell types and promptly respond to foreign pathogens. I) Activation-induced cytidine deaminase (AID/Aicda) is expressed in B-cells to diversify the secondary repertoire and effector functions of antibodies during the processes of somatic hypermutation and class switch recombination, respectively. Transcriptional regulation of Aicda involves a complex interplay between cis-regulatory elements. Previous studies have shown that two repressive elements (intron 1 and upstream 1) cooperatively enhance Aicda expression in fish. This thesis demonstrates the existence of further repressor elements and provides some insights of how DNA methylation could regulate the transcription of Aicda. II) Major histocompatibility complex class I (MHC class I) proteins play a role in combating viral infections as they present endogenously derived peptides to cytotoxic T-lymphocytes. MHC class I transcription in ducks is stimulated by RIG-I and interferon signaling elicited during influenza infection. In mammals, polygeny, polymorphism and codominant expression of MHC class I genes increase the pool of antigens that can be presented, yet in ducks there is only one predominantly expressed MHC class I gene (UAA) despite the presence of four additional MHC class I genes (UBA-UEA) in the genome. The present work suggests that UBA and UEA are inactivated through the mutations at promoter region. Conversely UDA is expressed but its’ transcripts can be degraded by let-7 microRNAs, suggesting a function for UDA that is limited in time or space.
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- Subjects / Keywords
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- Graduation date
- Fall 2015
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.