David W. Loehlin

Research Interests

 My interest is in identifying basic rules of how genes work. This could benefit society by simplifying our understanding of genetics, evolution, and human health. My research expertise is in molecular, evolutionary, and developmental genetics – all focused on finding the genetic basis of quantitative phenotypes. My lab at Williams is focused on understanding how tandem gene duplication impacts gene expression.

Do two tandem genes behave independently — and thus the gene expression levels add together — or is there interaction between the two gene copies?  Results from our lab using Drosophila flies suggest interaction, with an excess production of RNA and protein over the combined single-copy levels. Study of tandem duplicate genes is a relatively new area, with many open questions. How does excess expression occur — from what aspect of the duplicated structure?  Are tandem gene interactions universal or dependent on specific sequences or structures? Do interactions persist over evolutionary time?

MoClo Drosophila toolkit: My lab is developing a toolkit for assembly of multi-gene constructs in Drosophila from standardized parts using MoClo (Modular Cloning). MoClo combines the flexible Golden Gate assembly procedure with a growing library of interchangeable DNA parts.  My inspiration and design source is the MoClo Yeast Toolkit (Lee et al. 2015, ACS Synthetic Biology). Please contact me if you are a researcher interested in this toolkit.

Selected Publications

A complete list of publications is available at my Google Scholar page.

Williams undergraduate student coauthors are underlined.

Loehlin DW, McClain GL, Xu M, Kedia R, Root E. 2023. Demonstration of in vivo engineered tandem duplications of varying sizes using CRISPR and recombinases in Drosophila melanogaster. G3: Genes, Genomes, Genetics https://doi.org/10.1093/g3journal/jkad155

Loehlin DW. 2022. Drosophila genomic DNA isolation using NEB Monarch kit. Protocols.io dx.doi.org/10.17504/protocols.io.bp2l694qklqe/v1

Loehlin DW, Kim JY, Paster CO. 2022. A tandem duplication in Drosophila melanogaster shows enhanced expression beyond the gene copy number. Genetics iyab231 https://doi.org/10.1093/genetics/iyab231

Dean DM, Deitcher DL, Paster CO, Xu M, Loehlin DW. 2022. “A fly appeared”: sable, a classic Drosophila mutation, maps to Yippee, a gene affecting body color, wings, and bristles. G3 Genes| Genomes| Genetics. https://doi.org/10.1093/g3journal/jkac058

Loehlin DL, JR Ames, K Vaccaro, SB Carroll. 2019 A major role for noncoding regulatory mutations in the evolution of enzyme activity. Proceedings of the National Academy of Sciences https://doi.org/10.1073/pnas.1904071116

Siddiq MA, Loehlin DW, Montooth KL, Thornton JW. 2017 Experimental test and refutation of a classic hypothesis of molecular adaptation. Nature Ecology and Evolution 1(0025). https://doi.org/10.1038/s41559-016-0025

Loehlin D.W. and S.B. Carroll. 2016 Expression of tandem gene duplicates is often greater than twofold. PNAS 113(21):5988–5992. https://doi.org/10.1073/pnas.1605886113