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 (mĕz′ə-mîr′, mĕs′-)
1. A blastomere of intermediate size, larger than a micromere but smaller than a macromere.
2. The middle zone of the mesoderm of a chordate vertebrate embryo, from which excretory tissue develops.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Physiology) a blastomere of medium size that is formed by certain types of cleavage
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈmɛz əˌmɪər, ˈmɛs-, ˈmi zə-, -sə-)

1. a blastomere of intermediate size between a micromere and a macromere.
2. the intermediate zone of the mesoderm.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
10a-b): Short and broad; basal apodeme comparatively broader, with thick and darkly pigmented struts, anteriorly less sclerotized; basal plate laterally concave; endome and mesomere structure (fig.
rosaceus follows the typical pattern for echinoids with planktotrophic larvae, beginning with three equal cleavages followed by the formation of mesomeres, macromeres, and micromeres at the 16-cell stage (Fig.
Furthermore, only a presumptive ectodermal region derived from eight mesomeres (animal cap) isolated from 16-cell staged embryos formed wrinkles (data not shown).