Nav: Home

Biologists find the long and short of it when it comes to chromosomes

February 27, 2019

A team of biologists has uncovered a mechanism that determines faithful inheritance of short chromosomes during the reproductive process. The discovery, reported in the journal Nature Communications, elucidates a key aspect of inheritance--deviation from which can lead to infertility, miscarriages, or birth defects such as Down syndrome.

The research centers on how short chromosomes can secure a genetic exchange. Genetic exchanges are critical for chromosome inheritance, but are in limited supply.

How short chromosomes ensure a genetic exchange is of great interest to scientists given the vulnerability of short chromosomes.

"Short chromosomes are at a higher risk for errors that can lead to genetic afflictions because of their innate short lengths and therefore have less material for genetic exchange," explains Viji Subramanian, a post-doctoral researcher at New York University and the paper's lead author. "However, these chromosomes acquire extra help to create a high density of genetic exchanges--but it hadn't been understood as to how short chromosomes received this assistance."

To explore this question, the researchers, who also included Andreas Hochwagen, an associate professor in NYU's Department of Biology, studied this process in yeast--a model organism that shares many fundamental processes of chromosome inheritance with humans.

Overall, they found that vast regions near the ends of both short and long chromosomes are inherently primed for a high density of genetic exchanges--the scientists labeled these end-adjacent regions (EARs). Of particular note, a high density of genetic exchanges in EARs is conserved in several organisms, including birds and humans.

Significantly, the researchers noted that EARs are of similar size on all chromosomes. This means that EARs only occupy a limited fraction of long chromosomes but almost the entirety of short chromosomes. This difference drives up the density of genetic exchanges, specifically on short chromosomes, and does so without cells having to directly measure chromosome lengths.
-end-
The paper's other authors included Tovah Markowitz, an NYU doctoral student at the time of the research, and Luis Vale-Silva, an NYU post-doctoral researcher at the time of the study, as well as Xuan Zhu and Scott Keeney of Memorial Sloan Kettering Cancer Center, Nancy Hollingsworth of Stony Brook University, and Pedro San-Segundo of the University of Salamanca.

This research was supported by grants from the National Institutes of Health (R01 GM111715, R35 GM118092, R01 GM050717, and P30 CA008748)

New York University

Related Chromosomes Articles:

Andalusian experts indicate new elements responsible for instability in chromosomes
The researchers state that RNA joins with DNA by chance or because of a disease, the structure of the chromatin, the protein envelope of the chromosomes is altered, causing breaks in the DNA.
Reconstruction of ancient chromosomes offers insight into mammalian evolution
Researchers have gone back in time, at least virtually, computationally recreating the chromosomes of the first eutherian mammal, the long-extinct, shrewlike ancestor of all placental mammals.
Newly discovered DNA sequences can protect chromosomes in rotifers
Rotifers are tough, microscopic organisms highly resistant to radiation and repeated cycles of dehydration and rehydration.
For keeping X chromosomes active, chromosome 19 marks the spot
After nearly 40 years of searching, Johns Hopkins researchers report they have identified a part of the human genome that appears to block an RNA responsible for keeping only a single X chromosome active when new female embryos are formed, effectively allowing for the generally lethal activation of more than one X chromosome during development.
Researchers assemble five new synthetic chromosomes
A global research team has built five new synthetic yeast chromosomes, meaning that 30 percent of a key organism's genetic material has now been swapped out for engineered replacements.
More Chromosomes News and Chromosomes Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...