# Investigating the landscape and genetic architecture of germline mutagenesis

> **NIH NIH R35** · UNIVERSITY OF WASHINGTON · 2022 · $32,272

## Abstract

PROJECT SUMMARY
 The rate at which DNA mutates ultimately determines how many people are born with serious genetic dis-
eases, as well as how long a person is likely to live before getting cancer. It is also crucial to understand how
mutations generate genetic variation in order to accurately infer evolutionary history from genomic data. Despite
this fundamental importance for human health and disease, we know little about how the mutation rate varies
from person to person and what genetic factors might cause the mutation rate to vary. My previous research has
shown that mutations from different populations are biased to occur in different sequence contexts; for example,
Europeans contain more mutations in the motif “TCC” than Africans or East Asians do. This implies that each
population is affected by a distinctive combination of sequence-biased mutational processes. Unless these dif-
ferences are all induced by environmental mutagens, some of them must be the signatures of “mutator alleles,”
genetic variants that subtly affect the likelihood of DNA damage or the efﬁcacy of DNA repair. This proposal
describes a multi-pronged strategy for interrogating the causes and consequences of variation in DNA replication
ﬁdelity. The ﬁrst step will be to look beyond short, three-letter motifs to identify longer DNA sequences that differ in
mutability between populations. To achieve this, we will adapt statistical techniques that have recently been used
to identify the motifs that drive hypermutation in immune cells. Once we identify such motifs, we will scan them for
concordance with the rich libraries of motifs that are known to regulate protein binding and gene expression. We
aim to improve our understanding of the pace of mutation rate evolution, interrogating the role of global migration
events in spreading mutator alleles, as well as the contribution of non-genetic factors such as the parental age
effect. In humans, it is known that the ages of mothers and fathers at the time children are conceived impacts both
the rate and spectrum of mutagenesis, and we propose to investigate this effect in greater generality by sequenc-
ing young and old parents together with their offspring in a several species of killiﬁsh, a model vertebrate that
is famous for maturing and aging extremely rapidly. We plan to exploit the utility of model organisms in another
way as well: in natural populations, is difﬁcult to map the genomic locations of mutator alleles because they are
predicted to quickly recombine away from mutations they create, but in lab-reared populations, inbreeding can be
used to force mutations to stay linked to the genetic backgrounds on which they arise. We will develop methods
to map mutator alleles in two different inbred model systems: the BXD recombinant inbred mouse strains and
the Drosophila Genome Reference Panel, looking for regions of the genome where speciﬁc genetic variants are
associated with mutability in speciﬁc sequence contexts. Togethe...

## Key facts

- **NIH application ID:** 10542240
- **Project number:** 3R35GM133428-03S1
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Kelley Harris
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $32,272
- **Award type:** 3
- **Project period:** 2019-08-01 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10542240

## Citation

> US National Institutes of Health, RePORTER application 10542240, Investigating the landscape and genetic architecture of germline mutagenesis (3R35GM133428-03S1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10542240. Licensed CC0.

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