An evaluation of machine-learning for predicting phenotype: studies in yeast, rice, and wheat
Journal article, 2020

In phenotype prediction the physical characteristics of an organism are predicted from knowledge of its genotype and environment. Such studies, often called genome-wide association studies, are of the highest societal importance, as they are of central importance to medicine, crop-breeding, etc. We investigated three phenotype prediction problems: one simple and clean (yeast), and the other two complex and real-world (rice and wheat). We compared standard machine learning methods; elastic net, ridge regression, lasso regression, random forest, gradient boosting machines (GBM), and support vector machines (SVM), with two state-of-the-art classical statistical genetics methods; genomic BLUP and a two-step sequential method based on linear regression. Additionally, using the clean yeast data, we investigated how performance varied with the complexity of the biological mechanism, the amount of observational noise, the number of examples, the amount of missing data, and the use of different data representations. We found that for almost all the phenotypes considered, standard machine learning methods outperformed the methods from classical statistical genetics. On the yeast problem, the most successful method was GBM, followed by lasso regression, and the two statistical genetics methods; with greater mechanistic complexity GBM was best, while in simpler cases lasso was superior. In the wheat and rice studies the best two methods were SVM and BLUP. The most robust method in the presence of noise, missing data, etc. was random forests. The classical statistical genetics method of genomic BLUP was found to perform well on problems where there was population structure. This suggests that standard machine learning methods need to be refined to include population structure information when this is present. We conclude that the application of machine learning methods to phenotype prediction problems holds great promise, but that determining which methods is likely to perform well on any given problem is elusive and non-trivial.

Random forest

Support vector machines

Statistical genetics

BLUP

GWAS

Plant biology

Ridge regression

Gradient boosting machines

Lasso regression

Author

Nastasiya F. Grinberg

University of Cambridge

University of Manchester

Oghenejokpeme I. Orhobor

University of Manchester

Ross King

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Machine Learning

0885-6125 (ISSN) 1573-0565 (eISSN)

Vol. 109 2 251-277

Subject Categories

Language Technology (Computational Linguistics)

Bioinformatics (Computational Biology)

Bioinformatics and Systems Biology

DOI

10.1007/s10994-019-05848-5

More information

Latest update

3/9/2021 7