nucleolus

noun

nu·​cle·​o·​lus nü-ˈklē-ə-ləs 

nyü-

plural nucleoli nü-ˈklē-ə-ˌlī 

nyü-

: a spherical body of the nucleus of most eukaryotes that becomes enlarged during protein synthesis, is associated with a nucleolus organizer, and contains the DNA templates for ribosomal RNA see cell illustration

nucleolar

nü-ˈklē-ə-lər 

nyü-

adjective

Examples of nucleolus in a Sentence

Recent Examples on the Web

In 2019 in Non-Coding RNA, Weber and a co-author weighed the support for phase separation in the cell nucleus and concluded that solid data back its role in forming three structures, including the nucleolus, but not two other structures commonly attributed to the process. —Mitch Leslie, Science | AAAS, 21 Jan. 2021

In 2012, Brangwynne and colleagues saw similar fluid features in the nucleolus, a dense mix of proteins, RNA, and DNA that manufactures ribosomes, the cell’s protein factories. —Mitch Leslie, Science | AAAS, 21 Jan. 2021

More membraneless structures continued to be found, such as the nucleolus, a dense structure in the cell nucleus. —Quanta Magazine, 26 Nov. 2018

But there’s more to the nucleolus than just making ribosomes. —Joanna Klein, New York Times, 20 May 2018

Word History

Etymology

New Latin, from Latin, diminutive of nucleus

First Known Use

1839, in the meaning defined above

Phrases Containing nucleolus

• nucleolus organizer

• nucleolus organizer

Kids Definition

nucleolus

noun

nu·​cle·​o·​lus n(y)ü-ˈklē-ə-ləs 

plural nucleoli -ˌlī 

: a sphere-shaped body in the cell nucleus that is associated with a particular part of a chromosome, and is rich in ribosomal RNA

Medical Definition

nucleolus

noun

nu·​cle·​o·​lus n(y)ü-ˈklē-ə-ləs 

plural nucleoli -ˌlī 

: a spherical body of the nucleus of most eukaryotes that becomes enlarged during protein synthesis, is associated with a nucleolus organizer, and contains the DNA templates for ribosomal RNA

called also plasmosome