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A large, thick-walled, nitrogen-fixing cell that occurs at intervals along the filaments of certain cyanobacteria.
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.


(Biology) biology a special cell type found in cyanobacteria and responsible for fixing nitrogen
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈhɛt ər əˌsɪst)

one of the enlarged nitrogen-fixing cells along the filaments in some blue-green algae.
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 ?
They did not undergo gastric operation or endoscopic treatment previously and were confirmed having disorder of epithelium structure or heterocyst, including dysplasia and carcinoma in situ, by gastroscopy or postoperative histopathological examination.
To study the morphology of cyanobacteria, cell shape, width, color, motility and presence/absence of hormogonial cell, sheath and heterocyst were recorded.
The result showed psammoma bodies and some heterocyst. We considered it as micropapillary carcinomas.
Several studies depicted that B is involved in increasing the absorption of N through fixation in heterocyst cells.
Heterocystscylindric, intercalary, 5-7 [micro]m in diameter and 7-20 [micro]m long, akinetes elongate, cylindric, solitary formed near the middle of the trichome but not adjacent to the heterocyst, 6-8 [micro]m in diameter and 20-60 [micro]m long (Fig.
Ohmori, "NrrA, a nitrogen-responsive response regulator facilitates heterocyst development in the cyanobacterium Anabaena sp.
Cyanobacterial heterocyst glycolipids in cultures and environmental samples: Diversity and biomarker potential.
Cyanobacteria are morphologically diverse and they consist of unicellular, colonial, pseudofilamentous, pseudoparenchymatous uniseriate, filamentous forms unbranched, undifferentiated, differentiated with specialized cells called heterocyst and akinetes and heterotrichous branched forms [2].
Most of the cyanobionts appear to be heterocystous which is as close to a multicellular organisation as is possible in these bacteria in which hexose, produced by photosynthesis, moves from the vegetative cells to the heterocyst (Meeks & Elhai, 2002).
In cultures of the two-membered assemblage, 10 to 50 epibiotic cells were attached to each heterocyst (Fig.
However, the heterocystous cyanobacteria have an 11 kb insertion element present within the coding region of nifD, which is excised by site specific recombination during heterocyst differentiation.