The immunoglobulin (Ig) genes provide a paradigm to study many interesting biologically relevant problems, which include: DNA sequence organization and evolution, tissue-specific transcriptional regulation, site-specific recombination, somatic hypermutation, regulation of replication timing, modulation of DNA methylation patterns, developmental control of many of these events, allelic exclusion and the relationships between chromatin structure and function. This proposal focuses on the mousse kappa immunoglobulin (Ig) gene locus. Our goals during the proposed project period are to elucidate features of the genomic organization, chromatin structure, and relationship between chromatin structure and function within this locus. Our experimental approach is designed to uncover new cis-acting regulatory elements.
These specific aims are described more fully below: 1. To isolate the entire mouse kappa Ig locus from a genomic library contained within yeast artificial chromosomes (YACs). We will establish contigs, a physical linkage map between selected V gene families, and a low resolution restriction endonuclease map. 2. To locate new putative cis-acting regulatory sequences within the kappa Ig gene locus. We will selectively map endogenous topoisomerase II and exogenous DNase I cleavage sites within the chromatin of various cell lines of B- and non-B-lymphocyte lineages. Special attention will be placed on distal upstream and downstream regions. 3. To functionally elucidate cis-acting regulatory sequences within the kappa Ig gene locus. We will create deletions within YACs containing the mouse kappa Ig locus of selected known and putative new cis-acting regulatory sequences (identified in specific aim 2). These YACs containing engineered kappa Ig sequences will be introduced into endogenous-kappa- gene-deficient pre-B cells for germ-line transcription and recombination assays, and into the germline of endogenous-kappa-gene-deficient mice for a variety of functional assays. In summary, these studies have the potential of identifying novel regulatory elements, which may include locus control region(s) (LCRs), domain boundary sequences, and components yet to be understood that may further regulate the efficiency of the immune response.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM029935-17
Application #
2654935
Study Section
Allergy and Immunology Study Section (ALY)
Project Start
1982-02-01
Project End
1999-03-31
Budget Start
1998-02-01
Budget End
1999-03-31
Support Year
17
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Texas Sw Medical Center Dallas
Department
Biochemistry
Type
Schools of Medicine
DUNS #
City
Dallas
State
TX
Country
United States
Zip Code
75390
Xiang, Yougui; Park, Sung-Kyun; Garrard, William T (2014) A major deletion in the V?-J? intervening region results in hyperelevated transcription of proximal V? genes and a severely restricted repertoire. J Immunol 193:3746-54
Park, Sung-Kyun; Xiang, Yougui; Feng, Xin et al. (2014) Pronounced cohabitation of active immunoglobulin genes from three different chromosomes in transcription factories during maximal antibody synthesis. Genes Dev 28:1159-64
Zhou, Xiaorong; Xiang, Yougui; Ding, Xiaoling et al. (2013) Loss of an Igýý gene enhancer in mature B cells results in rapid gene silencing and partial reversible dedifferentiation. Mol Cell Biol 33:2091-101
Xiang, Yougui; Park, Sung-Kyun; Garrard, William T (2013) Výý gene repertoire and locus contraction are specified by critical DNase I hypersensitive sites within the Výý-Jýý intervening region. J Immunol 190:1819-26
Zhou, Xiaorong; Xiang, Yougui; Ding, Xiaoling et al. (2012) A new hypersensitive site, HS10, and the enhancers, E3' and Ed, differentially regulate Ig? gene expression. J Immunol 188:2722-32
Xiang, Yougui; Zhou, Xiaorong; Hewitt, Susannah L et al. (2011) A multifunctional element in the mouse Ig? locus that specifies repertoire and Ig loci subnuclear location. J Immunol 186:5356-66
Zhou, Xiaorong; Xiang, Yougui; Garrard, William T (2010) The Ig? gene enhancers, E3' and Ed, are essential for triggering transcription. J Immunol 185:7544-52
Liu, Zhe; Ma, Zhenyi; Terada, Lance S et al. (2009) Divergent roles of RelA and c-Rel in establishing chromosomal loops upon activation of the Igkappa gene. J Immunol 183:3819-30
Xiang, Yougui; Garrard, William T (2008) The Downstream Transcriptional Enhancer, Ed, positively regulates mouse Ig kappa gene expression and somatic hypermutation. J Immunol 180:6725-32
Xiao, Fei; Widlak, Piotr; Garrard, William T (2007) Engineered apoptotic nucleases for chromatin research. Nucleic Acids Res 35:e93

Showing the most recent 10 out of 53 publications