Definition of "macronucleus" []

• The larger of two nuclei present in ciliate protozoans, which controls nonreproductive functions of the cell, such as metabolism. (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.

• "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."
• "The macronucleus is a long-beaded structure, or it may be in several parts connected by strands (Gruber)."
• "It's this other DNA that gets removed from the macronucleus: the macronucleus is a genes-only sort of place."