Wrong Number

Whether it’s children on a school bus, money in the bank, or DNA in a cell, careful counting is critical. At the very earliest stage of development, the wrong number of chromosomes [bundled strings of DNA], called aneuploidy, can cause various serious conditions. Most research into this problem has focussed on errors during meiosis [cell division that produces sperm or eggs cells], but errors during chromosome segregation (when paired chromosomes separate and spread out) are equally likely to cause problems. A new study investigated the molecular mechanisms underpinning aneuploidy during cell division in early development, and found some embryos containing micronuclei – enclosed chromosomes that failed to properly segregate (examination of cattle embryos pictured, with an indicator of micronuclei contents highlighted red). Unpicking the process behind aneuploidy in cattle embryos could help better understand the process in humans, and lead to new approaches to keep chromosome numbers straight.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Kelsey E. Brooks and colleagues, originally published in BioRXiv, Aug 2020, Oregon National Primate Research Center
• Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Beaverton, OR, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Research published in Development, April 2022