WordNet

used to express refusal or denial or disagreement etc or especially to emphasize a negative statement; "no, you are wrong"
a negative; "his no was loud and clear"
referring to the degree to which a certain quality is present; "he was no heavier than a child" (同)no more
not in any degree or manner; not at all; "he is no better today"
quantifier; used with either mass nouns or plural count nouns for indicating a complete or almost complete lack or zero quantity of; "we have no bananas"; "no eggs left and no money to buy any"; "have you no decency?"; "did it with no help"; "Ill get you there in no time"
state of being disconnected (同)disjuncture, disconnection, disconnectedness
the fifth of the seven canonical hours; about 3 p.m.

PrepTutorEJDIC

《名詞の前に置いて》『一つも』(『一人も,少しも』)・・・『ない』 / 《補語につけて》『決して・・・でない』 / 《省略文で》・・・なし;・・・お断り / 《話》少ししか(あまり)・・・ない / (肯定の問いに対して)『いいえ』;(否定の問いに対して)はい,ええ / 《not, norの前に挿入して》『いや』,否 / 《形容詞の前に置その形容詞を否定して》…どころではない / 《比較級の前に置いて》ちっとも…でない,…と全く同じ / 《… or no の形で》…であってもなくても / 《驚き・困惑・不信などを表して》とんでもない / 《単数形で》『拒否』,「『いいえ』」という返事 / 《複数形で》反対[投]票

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/11/07 19:21:00」(JST)

wiki en

Non-disjunction ("not coming apart") is the failure of chromosome pairs to separate properly during meiosis stage 1 or stage 2, specifically in the anaphase. This could arise from a failure of homologous chromosomes to separate in meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. The result of this error is a cell with an imbalance of chromosomes. Such a cell is said to be aneuploid. Loss of a single chromosome (2n-1), in which the daughter cell(s) with the defect will have one chromosome missing from one of its pairs, is referred to as a monosomy. Gaining a single chromosome, in which the daughter cell(s) with the defect will have one chromosome in addition to its pairs is referred to as a trisomy.

In the event that an aneuploidic gamete is fertilized, a number of syndromes might result. The only known survivable monosomy is Turner syndrome, where the individual is monosomic for the X chromosome. Examples of trisomies include Down syndrome (trisomy of chromosome 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13).

The following diagram shows the two possible types of nondisjunction in meiosis:

2n / \ n+1 n-1 / \ / \ n+1 n+1 n-1 n-1	2n / \ n n / \ / \ n n n+1 n-1
Schematic of nondisjunction in meiosis I. Duplicated chromosomes in diploid cell (2n). All gametes are affected by nondisjunction in meiosis I. Two gametes have a single extra chromosome; two gametes are missing a single chromosome.	Schematic of nondisjunction in meiosis II. Duplicated chromosomes in diploid cell (2n). Half of the gametes are affected by nondisjunction in meiosis II. One gamete has a single extra chromosome; one gamete is missing a single chromosome.

"n" denotes a cell with a single copy of each chromosome (haploid cell); 2n denotes a cell with two copies of each chromosome (diploid cell)

Though a person of any age can have nondisjunction occur during meiosis, the chances tend to increase with age.^{[citation needed]}

References

Snustad, D.P., Simmons, M.J.(2006). Principles of Genetics (4th ed.). Hoboken: John Wiley & Sons, Inc.

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UpToDate Contents

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English Journal

[Association of MTHFR and MTRR genes polymorphisms with non-disjunctions of chromosomes 18 and 21].

Guo Q1, Wang H, Yang K, Zhang B, Li T, Liao S.
Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics.Zhonghua Yi Xue Yi Chuan Xue Za Zhi.2015 Jun 10;32(3):395-9. doi: 10.3760/cma.j.issn.1003-9406.2015.03.021.
OBJECTIVE: To explore the effect of MTHFR and MTRR genes polymorphisms on chromosomes 18 and 21 non-disjunction through investigation of Henan Han Chinese young females with a gestational history of trisomy 21 (Down syndrome, DS) or trisomy 18 (Edwards syndrome, ES).METHODS: Polymorphisms of MTHFR 6
PMID 26037359

Altered segregation pattern and numerical chromosome abnormalities interrelate in spermatozoa from Robertsonian translocation carriers.

Godo A1, Blanco J1, Vidal F1, Sandalinas M2, Garcia-Guixé E2, Anton E3.
Reproductive biomedicine online.Reprod Biomed Online.2015 Apr 16. pii: S1472-6483(15)00158-3. doi: 10.1016/j.rbmo.2015.04.003. [Epub ahead of print]
The aim of this study was to assess whether there is a relationship between numerical chromosome abnormalities and certain segregation modes in spermatozoa from Robertsonian translocation carriers. A sequential fluorescence in-situ hybridization protocol based on two successive hybridization rounds
PMID 25985997

Analysis of genotoxic activity of ketamine and rocuronium bromide using the somatic mutation and recombination test in Drosophila melanogaster.

Koksal PM1, Gürbüzel M2.
Environmental toxicology and pharmacology.Environ Toxicol Pharmacol.2015 Mar;39(2):628-34. doi: 10.1016/j.etap.2014.12.010. Epub 2014 Dec 27.
The present study evaluated the mutagenic and recombinogenic effects of two commonly used anesthetic agents, ketamine and rocuronium bromide, in medicine using the wing somatic mutation and recombination test (SMART) in Drosophila. The standard (ST) cross and the high-bioactivation (HB) cross with h
PMID 25682000

Japanese Journal

Effect of a rye B chromosome and its segments on homoeologous pairing in hybrids between common wheat and Aegilops variabilis

RyotaKousaka,TakashiR.Endo
Genes & genetic systems 87(1), 1-7, 2012-02-25
… Rye B chromosomes, which are supernumerary chromosomes dispensable for the host but increase in number by non-disjunction after meiosis, have been reported to affect meiotic homoeologous pairing in wheat-rye hybrids. …
NAID 10030616055

高齢出産は, 第1減数分裂不分離後のトリソミーレスキューを介したupd(15)matの発症リスクである

緒方勤,松原圭子,永田絵子,佐野伸一郎,村上信行,永井敏郎
Journal of mammalian ova research = 日本哺乳動物卵子学会誌 28(3), 96-102, 2011-10-01
NAID 10029898301

Advanced Maternal Age and the Development of Prader-Willi Syndrome Resulting from Upd(15)mat through Non-disjunction at Meiosis 1 (Mini-Symposium : Ageing and Epigenetics)

Ogata Tsutomu,Matsubara Keiko,Nagata Eiko [他]
Journal of mammalian ova research 28(3), 96-102, 2011-10
NAID 40019058210

Related Pictures

Nondisjunction of sister chromatids during Nondisjunction can also occur in meiosis Mistakes in Meiosis. Nondisjunction The Nondisjunction. Causes, symptoms Meiotic nondisjunction. Causes, symptoms them nondisjunction events nondisjunction.html 15_12Nondisjunction_L Non-Disjunction IIIR.jpg 04-Sep-2006 13:16