1
|
Chen J, Landback P, Arsala D, Guzzetta A, Xia S, Atlas J, Sosa D, Zhang YE, Cheng J, Shen B, Long M. Evolutionarily new genes in humans with disease phenotypes reveal functional enrichment patterns shaped by adaptive innovation and sexual selection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.14.567139. [PMID: 38045239 PMCID: PMC10690195 DOI: 10.1101/2023.11.14.567139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
New genes (or young genes) are genetic novelties pivotal in mammalian evolution. Their phenotypic impacts and evolutionary pattern over time, however, remain elusive in humans due to the technical and ethical complexities in functional studies. By combining human gene age dating and Mendelian disease phenotyping, our research reveals a gradual increase in disease gene proportions with gene age. Logistic regression modeling indicates that this increase could be related to longer protein lengths and higher burdens of deleterious de novo germline variants (DNVs) for older genes. We also find a steady integration of new genes with biomedical phenotypes into the human genome over macroevolutionary timescales (~0.07% per million years). Despite this stable pace, we observe distinct patterns in phenotypic enrichment, pleiotropy, and selective pressures across gene ages. Notably, young genes show significant enrichment in diseases related to the male reproductive system, indicating strong sexual selection. Young genes also exhibit disease-related functions in tissues and systems potentially linked to human phenotypic innovations, such as increased brain size, musculoskeletal phenotypes, and color vision. We further reveal a logistic growth pattern of pleiotropy over evolutionary time, indicating a diminishing marginal growth of new functions for older genes due to intensifying selective constraints over time. We propose a "pleiotropy-barrier" model that delineates higher potentials of phenotypic innovation for young genes than for older genes, a process subject to natural selection. Our study demonstrates that evolutionary new genes are critical in influencing human reproductive evolution and adaptive phenotypic innovations driven by sexual and natural selection, with low pleiotropy as a selective advantage.
Collapse
Affiliation(s)
- Jianhai Chen
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
- Institutes for Systems Genetics, West China University Hospital, Chengdu 610041, China
| | - Patrick Landback
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| | - Deanna Arsala
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| | - Alexander Guzzetta
- Department of Pathology, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| | - Shengqian Xia
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| | - Jared Atlas
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| | - Dylan Sosa
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| | - Yong E. Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jingqiu Cheng
- Institutes for Systems Genetics, West China University Hospital, Chengdu 610041, China
| | - Bairong Shen
- Institutes for Systems Genetics, West China University Hospital, Chengdu 610041, China
| | - Manyuan Long
- Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street, Chicago, IL 60637
| |
Collapse
|
2
|
Macionis V. Fetal head-down posture may explain the rapid brain evolution in humans and other primates: An interpretative review. Brain Res 2023; 1820:148558. [PMID: 37634686 DOI: 10.1016/j.brainres.2023.148558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 08/29/2023]
Abstract
Evolutionary cerebrovascular consequences of upside-down postural verticality of the anthropoid fetus have been largely overlooked in the literature. This working hypothesis-based report provides a literature interpretation from an aspect that the rapid evolution of the human brain has been promoted by fetal head-down position due to maternal upright and semi-upright posture. Habitual vertical torso posture is a feature not only of humans, but also of monkeys and non-human apes that spend considerable time in a sitting position. Consequently, the head-down position of the fetus may have caused physiological craniovascular hypertension that stimulated expansion of the intracranial vessels and acted as an epigenetic physiological stress, which enhanced neurogenesis and eventually, along with other selective pressures, led to the progressive growth of the anthropoid brain and its organization. This article collaterally opens a new insight into the conundrum of high cephalopelvic proportions (i.e., the tight fit between the pelvic birth canal and fetal head) in phylogenetically distant lineages of monkeys, lesser apes, and humans. Low cephalopelvic proportions in non-human great apes could be accounted for by their energetically efficient horizontal nest-sleeping and consequently by their larger body mass compared to monkeys and lesser apes that sleep upright. One can further hypothesize that brain size varies in anthropoids according to the degree of exposure of the fetus to postural verticality. The supporting evidence for this postulation includes a finding that in fossil hominins cerebral blood flow rate increased faster than brain volume. This testable hypothesis opens a perspective for research on fetal postural cerebral hemodynamics.
Collapse
|
3
|
Chen J. Evolutionarily new genes in humans with disease phenotypes reveal functional enrichment patterns shaped by adaptive innovation and sexual selection. RESEARCH SQUARE 2023:rs.3.rs-3632644. [PMID: 38045389 PMCID: PMC10690325 DOI: 10.21203/rs.3.rs-3632644/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
New genes (or young genes) are structural novelties pivotal in mammalian evolution. Their phenotypic impact on humans, however, remains elusive due to the technical and ethical complexities in functional studies. Through combining gene age dating with Mendelian disease phenotyping, our research reveals that new genes associated with disease phenotypes steadily integrate into the human genome at a rate of ~ 0.07% every million years over macroevolutionary timescales. Despite this stable pace, we observe distinct patterns in phenotypic enrichment, pleiotropy, and selective pressures between young and old genes. Notably, young genes show significant enrichment in the male reproductive system, indicating strong sexual selection. Young genes also exhibit functions in tissues and systems potentially linked to human phenotypic innovations, such as increased brain size, bipedal locomotion, and color vision. Our findings further reveal increasing levels of pleiotropy over evolutionary time, which accompanies stronger selective constraints. We propose a "pleiotropy-barrier" model that delineates different potentials for phenotypic innovation between young and older genes subject to natural selection. Our study demonstrates that evolutionary new genes are critical in influencing human reproductive evolution and adaptive phenotypic innovations driven by sexual and natural selection, with low pleiotropy as a selective advantage.
Collapse
|