nucleoid

[noo´kle-oid]

1. resembling a nucleus.

2. a nucleus-like body sometimes seen in the center of an erythrocyte.

3. the central region of a bacterium, consisting of a dense irregularly shaped region containing DNA material without a surrounding nuclear membrane.

4. the genetic material (nucleic acid) of a virus, situated in the center of the virion.

nu·cle·oid

(nū'klē-oyd),

1. Synonym(s): nucleiform

2. A nuclear inclusion body.

3. Synonym(s): nucleus (2)

[nucleo- + G. eidos, resemblance]

Farlex Partner Medical Dictionary © Farlex 2012

nucleoid

(no͞o′klē-oid′, nyo͞o′-)

The undefined region of genetic material inside a prokaryotic cell, consisting of aggregated DNA.

nucleoid

A condensed body within a bacterium that contains the prokaryote’s genome.

nu·cle·oid

(nū'klē-oyd)

1. Synonym(s): nucleiform.

2. A nuclear inclusion body.

3. Synonym(s): nucleus (2) .

[nucleo- + G. eidos, resemblance]

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

nucleoid

the chromosomal region of a BACTERIUM. In ESCHERICHIA COLI it comprises mainly DNA with some PROTEINS (analagous to, but not HISTONES) and RNA. The structure is very compact and the DNA is folded into a series of loops, that are supercoiled (see SUPERCOILED DNA).
the DNA mass in the CHLOROPLAST or MITOCHONDRION.
the core of ribonucleic acid and protein in the virion of a RETROVIRUS.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

nu·cle·oid

(nū'klē-oyd)

1. A nuclear inclusion body.

2. Synonym(s): nucleus (2) .

[nucleo- + G. eidos, resemblance]

Medical Dictionary for the Dental Professions © Farlex 2012

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References in periodicals archive

Caption: FIGURE 3: Flow cytometric analysis of nucleoid size.

Overexpression of PCNA Attenuates Oxidative Stress-Caused Delay of Gap-Filling during Repair of UV-Induced DNA Damage

The nucleoid displaying fine DNA fibrils occupied the central zone of the cells.

Effects of betaine on the ultrastructure of salt-treated escherichia coli

(38, 39) Male and female gametes contained about ten mitochondria with rod-shaped mitochondrial nuclei (nucleoids).

Mechanisms of organelle division and inheritance and their implications regarding the origin of eukaryotic cells

Of the six genes identified, northern hybridization analysis demonstrated that four (callose synthase, HSP90, serine decarboxylase, and the biotin carboxylase subunit of acetyl-coenzyme A carboxylase) increased in expression, while the other two genes (the HAP5 subunit of the heme-activated protein (HAP) transcription factor and the chloroplast nucleoid DNA-binding protein CND41) decreased in expression.

Aquatic Plant Genomics: Advances, Applications, and Prospects

The A type 'immature' particles about 87nm in diameter consisted of a ring-shaped nucleoid surrounded by a membrane and a submembranous electron-dense layer or shell.

Effects of hyperthermia on the ultrastructure of spontaneous mouse mammary tumors with reference to viral dysmorphogenesis

On the contrary, histone-like nucleoid structuring protein (H-NS) encoded by the hns gene, a global prokaryotic gene regulator, has been shown to repress the transcription of several virulence genes including toxT, ctx and tcpA (38).

Inhibition of virulence potential of Vibrio cholerae by natural compounds

The prokaryotic nucleoid, site of the bacterial DNA, as well as the gram-negative cell wall of the adhering spirochete, and the lack of kinetosome make the structure in Figures 4 and 5 easily distinguished from bona fide undulipodia.

Spirochete attachment ultrastructure: implications for the origin and evolution of cilia

usually have a single, circular chromosome located in the nucleoid region of the cell.

Chapter 3 Bacterial zoonoses

EBV shares the classic structural features of the other herpes viruses: it is enveloped, contains a nucleoid and capsid, and has a linear double-stranded DNA genome, which is contained within the nucleoid structure.

Laboratory-based investigations of IM and Epstein-Barr virus

2:15 EFFECT OF SULFUR METABOLITES ON THE EXPRESSION OF THE PLASTID NUCLEOID PROTEIN FERREDOXIN:SULFITE REDUCTASE IN CULTURED SOYBEAN CELLS

Cellular, Molecular and Developmental Biology

SlmA is a DNA-associated division inhibitor that is directly involved in preventing Z ring assembly on portions of the membrane surrounding the nucleoid [28].

Exception to the Rule: Genomic Characterization of Naturally Occurring Unusual Vibrio cholerae Strains with a Single Chromosome