title: Effects of sequence and structure on the hypermutability of immunoglobulin genes.
abstract: Somatic hypermutation (SHM) is investigated in related immunoglobulin transgenes that differ in a short artificial sequence designed to vary the content of hotspot motifs and the potential to form RNA or DNA secondary structures. Mutability depends on hotspots, not secondary structure. Hotspot motifs predict about 50% of the mutations; the rest are in neutral and coldspots. Clusters of mutations and the sequential addition of mutations found in cell pedigrees suggest epigenetic attributes of SHM. Sometime in SHM, an essential factor seems to become limiting. Particular error-prone DNA polymerases appear to create mutations in hotspots on the top and bottom DNA strands throughout the target and the SHM process. One transgene is superhypermutable in all regions, suggesting the presence of a cis-element that enhances SHM.
authors.affiliation: Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Michael
authors.forename: Terence E
authors.initials: TE
authors.lastname: Martin
authors.forename: Dan
authors.initials: D
authors.lastname: Nicolae
authors.forename: Nayun
authors.initials: N
authors.lastname: Kim
authors.forename: Kris
authors.initials: K
authors.lastname: Padjen
authors.forename: Ping
authors.initials: P
authors.lastname: Zhan
authors.forename: Hanh
authors.initials: H
authors.lastname: Nguyen
authors.forename: Carl
authors.initials: C
authors.lastname: Pinkert
authors.forename: Ursula
authors.initials: U
authors.lastname: Storb
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry; D005803:Genes, Immunoglobulin; D051379:Mice; D008822:Mice, Transgenic; D005810:Multigene Family; D027041:Somatic Hypermutation, Immunoglobulin; D019076:Transgenes
chemical_list: D004247:DNA