# Methods and Tools to Analyze Genetic Complexity

> **NIH NIH R01** · JACKSON LABORATORY · 2020 · $358,750

## Abstract

PROJECT SUMMARY/ABSTRACT
Formulating biological models from genetic studies with multidimensional phenotype data requires new
analytical methods that capture the complexity of genetic systems while also providing verifiable hypotheses of
variant activity. This challenge has become increasingly acute with the advent of genome-scale data resources
designed to determine how genetic variation affects biological processes at molecular resolution.
This proposal addresses this need by leveraging two complementary aspects of genetic complexity: pleiotropy,
in which one variant affects multiple phenotypes; and epistasis, in which multiple variants interact to affect one
phenotype. Although widely observed in model organisms and increasingly in human data, these phenomena
are rarely distilled into concise models. Our method, called Combined Analysis of Pleiotropy and Epistasis
(CAPE), integrates these aspects to mathematically constrain possible genetic models and determine a
genetic network that best describes the multiple phenotypes. This is achieved through multivariate linear
regression followed by a formal reparametrization that translates interaction coefficients into directed edges
between variants, each representing genetic suppression or enhancement. CAPE has proven successful in
model systems and we now aim to extend the approach to complex genetic systems that include greater allelic
diversity, sex, and dietary differences. To this end, we will use the Diversity Outbred (DO) mouse population,
the Genotype-Tissue Expression (GTEx), and the ENCODE and Roadmap projects to developing models of
complex gene regulation. We will model regulatory interactions between genetic variants and epigenetic states
to interpret genetic networks and uncover rules that govern gene expression. To facilitate collaborations and
community use, we will develop open-source software tools. These tools will include an R-based software
library to perform CAPE analysis in human and model populations, and a suite of visualization tools to facilitate
researcher exploration and interpretation of results. Our overall goal is to derive new methods to discover
complex and novel genetic mechanisms of gene regulation and disease risk and, in the course of this work,
release analytical and visualization tools for use in complex trait research.
This project is divided into three specific aims. Aim 1 is to develop methods to infer networks of genetic
variants that influence high-dimensional quantitative traits and create analytic and visualization software for
community use. Aim 2 is to apply our methods to model gene expression in DO mice and human tissues. Aim
3 is to integrate epigenetic and genetic data to model how genetic variation and chromatin modifications
interactively affect gene expression.

## Key facts

- **NIH application ID:** 9995501
- **Project number:** 5R01GM115518-05
- **Recipient organization:** JACKSON LABORATORY
- **Principal Investigator:** Gregory W Carter
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $358,750
- **Award type:** 5
- **Project period:** 2016-09-01 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9995501

## Citation

> US National Institutes of Health, RePORTER application 9995501, Methods and Tools to Analyze Genetic Complexity (5R01GM115518-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9995501. Licensed CC0.

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