Definition of "micronucleus" [micronucleus]

• The smaller of two nuclei in ciliate protozoans that contains genetic material and functions in reproduction. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Each ciliate has something called a micronucleus; this contains two complete versions of its genome."
• "Small RNAs produced by an RNAi-related mechanism are involved in DNA elimination during development of the somatic macronucleus from the germline micronucleus in Tetrahymena."
• "On the other hand, when the mutagenic activity of the irradiated diet was tested by observing occurrence of micronucleus in erythrocytes, no significant increase was recognized."