Elaborate genome rearrangements take nesting to the extreme.
Oxytricha trifallax is a single-celled virtuoso of genome rearrangement. Oxytricha is a ciliate, and like all ciliates, it has two nuclei: a tiny, germline micronucleus and a large, somatic macronucleus. Mating brings together two micronuclei, and the daughter cell creates a new macronucleus out of the zygotic micronucleus in an intricate process of cutting and splicing. Though all ciliates reproduce this way, Oxytricha takes the genome shuffling to an even more massive scale, deleting 90% of the non-coding genomic information and rearranging the remaining sequences into millions of short chromosomes—each large enough to contain only one or a handful of genes.
In G3: Genes|Genomes|Genetics, Braun et al. describe a peculiar feature of these already strange genomes. They explore cases where some parts of the genes retained in the macronucleus are located in the eliminated sequences of other genes. The authors compare these genes to matryoshka, or Russian nesting dolls, since they are nestled into each other.
These arrangements are not always as straightforward as one gene contained within another. Some genes are interwoven across multiple levels of nesting, with as many as four different genes’ coding sequences contained within the eliminated regions of another gene. Often, these sequences are scrambled together with individual genes out of order, suggesting that complex regulatory processes must be needed to properly rearrange them to achieve their final macronuclear form. To analyze these tangled patterns, the authors developed new methods for mathematically describing the nesting and scrambling of genes.
Their observations raise many questions about these convoluted genomic architectures. Future investigations could explore whether nesting affects any properties of the gene, or look for clues to the evolutionary pressures that drive the genome to such extraordinary complexity.
CITATION:
Russian Doll Genes and Complex Chromosome Rearrangements in Oxytricha trifallax
Intrigued by ciliates? The Ciliate Molecular Biology Conference will be held July 17 – July 22, 2018 in Washington, DC. Abstracts are due this week, April 4!
Science Writing and Communications Intern, Genetics Society of America.
View all posts by Marisa Wexler »Read more in
-
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…
-
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…