Why haploinsufficiency persists

Haploinsufficiency describes the decrease in organismal fitness observed when a single copy of a gene is deleted in diploids. We investigated the origin of haploinsufficiency by creating a comprehensive dosage sensitivity data set for genes under their native promoters. We demonstrate that the expre...

Full description

Bibliographic Details
Main Authors: Morrill, Summer A., Amon, Angelika B
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:English
Published: National Academy of Sciences 2020
Online Access:https://hdl.handle.net/1721.1/126033
_version_ 1811079122707808256
author Morrill, Summer A.
Amon, Angelika B
author2 Massachusetts Institute of Technology. Department of Biology
author_facet Massachusetts Institute of Technology. Department of Biology
Morrill, Summer A.
Amon, Angelika B
author_sort Morrill, Summer A.
collection MIT
description Haploinsufficiency describes the decrease in organismal fitness observed when a single copy of a gene is deleted in diploids. We investigated the origin of haploinsufficiency by creating a comprehensive dosage sensitivity data set for genes under their native promoters. We demonstrate that the expression of haploinsufficient genes is limited by the toxicity of their overexpression. We further show that the fitness penalty associated with excess gene copy number is not the only determinant of haploinsufficiency. Haploinsufficient genes represent a unique subset of genes sensitive to copy number increases, as they are also limiting for important cellular processes when present in one copy instead of two. The selective pressure to decrease gene expression due to the toxicity of overexpression, combined with the pressure to increase expression due to their fitness-limiting nature, has made haploinsufficient genes extremely sensitive to changes in gene expression. As a consequence, haploinsufficient genes are dosage stabilized, showing much more narrow ranges in cell-to-cell variability of expression compared with other genes in the genome. We propose a dosage-stabilizing hypothesis of haploinsufficiency to explain its persistence over evolutionary time.
first_indexed 2024-09-23T11:10:24Z
format Article
id mit-1721.1/126033
institution Massachusetts Institute of Technology
language English
last_indexed 2024-09-23T11:10:24Z
publishDate 2020
publisher National Academy of Sciences
record_format dspace
spelling mit-1721.1/1260332022-09-27T17:37:05Z Why haploinsufficiency persists Morrill, Summer A. Amon, Angelika B Massachusetts Institute of Technology. Department of Biology Paul F. Glenn Center for Biology of Aging Research (Massachusetts Institute of Technology) Koch Institute for Integrative Cancer Research at MIT Haploinsufficiency describes the decrease in organismal fitness observed when a single copy of a gene is deleted in diploids. We investigated the origin of haploinsufficiency by creating a comprehensive dosage sensitivity data set for genes under their native promoters. We demonstrate that the expression of haploinsufficient genes is limited by the toxicity of their overexpression. We further show that the fitness penalty associated with excess gene copy number is not the only determinant of haploinsufficiency. Haploinsufficient genes represent a unique subset of genes sensitive to copy number increases, as they are also limiting for important cellular processes when present in one copy instead of two. The selective pressure to decrease gene expression due to the toxicity of overexpression, combined with the pressure to increase expression due to their fitness-limiting nature, has made haploinsufficient genes extremely sensitive to changes in gene expression. As a consequence, haploinsufficient genes are dosage stabilized, showing much more narrow ranges in cell-to-cell variability of expression compared with other genes in the genome. We propose a dosage-stabilizing hypothesis of haploinsufficiency to explain its persistence over evolutionary time. 2020-06-30T21:46:15Z 2020-06-30T21:46:15Z 2019-05 2019-06 2019-11-26T15:42:30Z Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 https://hdl.handle.net/1721.1/126033 Morrill, Summer A. and Angelika Amon. "Why haploinsufficiency persists." Proceedings of the National Academy of Sciences 116, 24 (May 2019): 11866-11871 © 2019 National Academy of Sciences en http://dx.doi.org/10.1073/pnas.1900437116 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences PNAS
spellingShingle Morrill, Summer A.
Amon, Angelika B
Why haploinsufficiency persists
title Why haploinsufficiency persists
title_full Why haploinsufficiency persists
title_fullStr Why haploinsufficiency persists
title_full_unstemmed Why haploinsufficiency persists
title_short Why haploinsufficiency persists
title_sort why haploinsufficiency persists
url https://hdl.handle.net/1721.1/126033
work_keys_str_mv AT morrillsummera whyhaploinsufficiencypersists
AT amonangelikab whyhaploinsufficiencypersists