A reanalysis of genes tied to life span in mice reveals only a select few affect aging.

Like it or not, you are always getting older. The mechanisms responsible for this fact of life, non-negotiable as it is, remain poorly understood. To identify genes that drive the aging process, researchers typically look for those that affect lifespan. On the surface, interpreting such studies might seem simple: if animals with a mutation live longer or shorter than their wild-type counterparts, the mutation must have some effect on aging, right? Not necessarily; many mutations change the rate at which animals die, not the rate at which they age. In a report in GENETICS, de Magalhães et al. demonstrate the importance of this distinction by reanalyzing a set of genes previously connected to aging in mice. Their results have broad implications for interpreting studies of longevity.

To reevaluate these genes, the authors calculated the “demographic” rate of aging in the corresponding mutants, which reflects age-dependent mortality. The Gompertz-Makeham law of mortality states that the effective human death rate is made up of both age-dependent factors (e.g. heart disease) and age independent-factors (e.g. lightning strikes). When the age-independent factors leading to death are rare (like with laboratory mice), the law can be simplified into just the Gompertz equation. This equation describes the exponential increase in mortality rate with age, and by applying it to data from previous mouse studies, the authors were able to determine which genes affect the demographic rate of aging.

Most of the genes the authors analyzed turned out to affect mouse longevity in an age-independent manner. Only two out of 30 genes that increased lifespan did so by decreasing the demographic rate of aging. Similarly, only five out of 24 genes that shorten mouse lives increased the demographic rate of aging. While all of these genes are undeniably important for lifespan, the select few identified to influence the aging process are better candidates for studying the details of how organisms change as they age.

The authors also offered some insight into how studies of aging and longevity in mice are conducted, noting significant variation in the life span of control animals from study to study. This variation suggests that differences in how animals were housed and cared for, as well as other random factors, could be influencing the results of aging studies. Such variation must be taken into consideration as future studies attempt to unravel the biological complexities behind getting old.

CITATION:

A Reassessment of Genes Modulating Aging in Mice Using Demographic Measurements of the Rate of Aging

João Pedro de Magalhães, Louise Thompson, Izabella de Lima, Dale Gaskill, Xiaoyu Li, Daniel Thornton, Chenhao Yang, Daniel Palmer

GENETICS April 2018; 208: 1617-1630. DOI: 10.1534/genetics.118.300821

http://www.genetics.org/content/208/4/1617

 

 

, ,

Science Writing and Communications Intern, Genetics Society of America.

View all posts by Marisa Wexler »

Read more in

  • Ed Grell at his dissecting microscope using ether to anesthetize his flies.

    In Memoriam: Ellsworth Herman Grell (1932–2023), a pioneer of Drosophila genome engineering and annotation

    Ellsworth (Ed) Grell blessed the Drosophila community through three enduring legacies: as a pioneer of chromosome mechanics, as a primary organizer and synthesizer of genetic knowledge in Drosophila, and as a graceful mentor to those fortunate to have known him personally. Ed grew up in rural Nebraska, completed his undergraduate studies at Iowa State, and…

  • Congratulations to the #Fungal24 Poster Award winners!

    We are pleased to announce the recipients of the GSA Poster Awards for posters presented at the 32nd Fungal Genetics Conference! Undergraduate and graduate student members of GSA were eligible for the awards, and a hard-working team of judges made the determinations. Congratulations to all! Felicia Ebot Ojong, The University of Georgia My research is focused…

  • Poster presentation tips for TAGC 2024

    You’ve been selected to present a poster at The Allied Genetics Conference 2024 in March—you’ve celebrated, made plans to attend, now what? This is an exciting opportunity to showcase your research and engage with fellow members of the genetics community, so you want to make sure you’re prepared. We wanted to offer you some tips…

  • Maximize your TAGC 2024 experience 

    A guide to all that National Harbor & DC have to offer Are you joining us for The Allied Genetics Conference 2024 in March? Make the most of your #TAGC24 experience in National Harbor! We know the science will keep you busy, but you deserve to unwind and have some fun, so we’ve curated a…

  • Early Career Leadership Spotlight: Sarah Petrosky

    We’re taking time to get to know the members of the GSA’s Early Career Scientist Committees. Join us to learn more about our early career scientist advocates. Sarah PetroskyMultimedia SubcommitteeUniversity of Pittsburgh Research Interest I am interested in understanding adaptation that has been happening recently in populations by dissecting the ways that genes underlying an adaptation…

  • TAGC 2024 Early Career Award Winners

    GSA is pleased to announce the winners of the early career awards presented at The Allied Genetics Conference 2024. These awards are specific to particular TAGC communities and recognize early career scientists’ outstanding work on their respective research organisms. The awardees will present their talks in keynote sessions at TAGC 2024.  Don’t miss the opportunity…

  • Preeminent geneticists recognized with revamped GSA Awards

    In 2022, GSA’s Board of Directors launched an audit to review the five major awards conferred by the Society. Today, we are thrilled to announce the recipients of the reimagined GSA Awards, including the new Genetics Society of America Early Career Medal. The scientists honored this year are recognized by their peers for their outstanding…

  • Fly Board funds outreach programs to spread the word about Drosophila research

    In 2020, the Fly Board voted to use part of its reserve fund to support efforts to increase trainee participation as well as equity and diversity in the Drosophila community. An awards committee decides how the money will be spent each year, and from 2020–2022, the committee posted a very broad call for applications from…

  • New members of the GSA Board of Directors: 2024–2026

    We are pleased to announce the election of four new leaders to the GSA Board of Directors: 2024 Vice President/2025 President Brenda Andrews Professor, University of Toronto It’s an honor to continue my association with the Society by serving as Vice President of the Board of Directors. I have broad knowledge of the ongoing activities…

  • A rose-ringed parakeet, one of three parrot species used in the study.

    Parrot plumage study aids breeders and endangered natural populations

    Yellow coloration is maladaptive in the wild but prized by breeders. People have long been fascinated with birds, which exhibit one of the widest ranges of coloration among vertebrates. Parrots, in particular, have captivated humans by their ability to mimic human speech and spectacular plumage. Brightly colored feathers are used primarily to attract mates, intimidate…

  • Early Career Leadership Spotlight: Sarah Gilmour

    We’re taking time to get to know the members of the GSA’s Early Career Scientist Committees. Join us to learn more about our early career scientist advocates. Sarah GilmourMultimedia SubcommitteeStowers Institute for Medical Research Research Interest Questions of evolution have always fascinated me. I am extremely fortunate to be starting out my research career in a…