ヌル対立遺伝子

WordNet

(genetics) either of a pair (or series) of alternative forms of a gene that can occupy the same locus on a particular chromosome and that control the same character; "some alleles are dominant over others" (同)allelomorph
lacking any legal or binding force; "null and void" (同)void
the 13th letter of the Greek alphabet

PrepTutorEJDIC

対立遺伝子(通例突然変異によって生じる)
(法律上)無効の,効力のない / ゼロの,無価値の / (数学で集合が)空(から)の
ニュー(ギリシア語アルファベットの第13字Ν,ν;英語のN,nに相当)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/12/20 22:42:14」(JST)

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A null allele is a mutant copy of a gene that completely lacks that gene's normal function. This can be the result of the complete absence of the gene product (protein, RNA) at the molecular level, or the expression of a non-functional gene product. At the phenotypic level, a null allele is indistinguishable from a deletion of the entire locus.

A mutant allele that produces no protein is called a protein null (shown by western analysis), and one that produces no RNA is called an RNA null (shown by Northern analysis or by DNA sequencing of a deletion allele). A genetic null or amorphic allele has the same phenotype when homozygous as when heterozygous with a deficiency that disrupts the locus in question. A genetic null allele can be a protein and RNA null, but can also express normal levels of a gene product that is non-functional due to mutation.

Another definition of null allele concerning molecular markers, refers to such a marker in the case it can no longer be detected because of a mutation. For example, microsatellites (i.e. a repetitive sequence of DNA, in which the repeat is rather short) are used as molecular markers amplifying them through PCR. To do so, a primer or oligonucleotide aligns with either of ends of the locus. If a mutation occurs in the annealing site, then the marker can no longer be used and the allele is turned into a null allele.

One example of a null allele is the 'O' blood type allele in the human A, B and O blood type system. The alleles for the A-antigen and B-antigen are co-dominant, thus they are both phenotypically expressed if both are present. The allele for O blood type, however, is a mutated version of the allele for the A-antigen, with a single base pair change due to genetic mutation. The protein coded for by the O allele is enzymatically inactive and therefore the O allele is expressed phenotypically in homozygous OO individuals as the lack of any blood antigen. Thus we may consider the allele for the O blood type as a null allele.

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English Journal

Polymorphisms of glutathione-S-transferases M1, T1, P1 and susceptibility to colorectal cancer in a sample of the Tunisian population.

Kassab A, Msolly A, Lakhdar R, Gharbi O, Miled A.SourceBiochemistry Laboratory, Farhat Hached University Hospital, Sousse, Tunisia.
Medical oncology (Northwood, London, England).Med Oncol.2014 Jan;31(1):760. doi: 10.1007/s12032-013-0760-z. Epub 2013 Nov 20.
In this study, we investigated the associations of polymorphisms in glutathione-S-transferases (GSTs) genes that are GSTM1, GSTT1, and GSTP1, with sporadic colorectal cancer (CRC). Hundred and fifty patients with CRC and 128 healthy controls were genotyped. DNA was isolated from blood samples. Polym
PMID 24254297

A conditional mouse line for lineage tracing of Sox9 loss-of-function cells using enhanced green fluorescent protein.

Chatterjee S, Kraus P, Sivakamasundari V, Xing X, Yap SP, Jie S, Lufkin T.SourceStem Cell and Developmental Biology Department, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672, Singapore, chatterjees@gis.a-star.edu.sg.
Biotechnology letters.Biotechnol Lett.2013 Dec;35(12):1991-6. doi: 10.1007/s10529-013-1303-6. Epub 2013 Aug 2.
Traditionally, conditional knockout studies in mouse have utilized the Cre or Flpe technology to activate the expression of reporter genes such as lacZ or PLAP. Employing these reporter genes, however, requires tissue fixation. To make way for downstream in vivo or in vitro applications, we have ins
PMID 23907671

Estimating relatedness and inbreeding using molecular markers and pedigrees: the effect of demographic history.

Robinson SP, Simmons LW, Kennington WJ.SourceCentre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, WA, 6009, Australia.
Molecular ecology.Mol Ecol.2013 Dec;22(23):5779-92. doi: 10.1111/mec.12529. Epub 2013 Nov 5.
Estimates of inbreeding and relatedness are commonly calculated using molecular markers, although the accuracy of such estimates has been questioned. As a further complication, in many situations, such estimates are required in populations with reduced genetic diversity, which is likely to affect th
PMID 24102888

Japanese Journal

Bmp7 maintains undifferentiated kidney progenitor population and determines nephron numbers at birth.

Tomita Mayumi,Asada Misako,Asada Nariaki,Nakamura Jin,Oguchi Akiko,Higashi Atsuko Y,Endo Shuichiro,Robertson Elizabeth,Kimura Takeshi,Kita Toru,Economides Aris N,Kreidberg Jordan,Yanagita Motoko
PloS one 8(8), 2013-08-26
… In this study, utilization of conditional null allele of Bmp7 in combination with systemic inducible Cre deleter mice enabled us to analyze Bmp7 function at desired time points during kidney development, and to discover the novel function of Bmp7 to inhibit the precocious differentiation of the progenitor cells to nephron. …
NAID 120005324904

The involvement of CD36 in monocyte activation by antiphospholipid antibodies

Kato M.,Atsumi T.,Oku K.,Amengual O.,Nakagawa H.,Fujieda Y.,Otomo K.,Horita T.,Yasuda S.,Koike T.
Lupus 22(8), 761-771, 2013-07
… Then, the involvement of CD36 in antiphospholipid antibody (aPL)-induced tissue factor (TF) expression was examined using CD36-null mice or anti-CD36. … Results Minor allele carrier of rs3765187 was less frequent in patients with APS (3.8% p=0.032), but not in patients with SLE in the absence of APS (7.9% p=0.32), compared with healthy subjects (10.2%). …
NAID 120005372328

Compound Heterozygosity of the Functionally Null Cdh23v-ngt and Hypomorphic Cdh23ahl Alleles Leads to Early-onset Progressive Hearing Loss in Mice

MIYASAKA Yuki,SUZUKI Sari,OHSHIBA Yasuhiro [他],Watanabe Kei,Sagara Yoshihiko,Yasuda Shumpei P.,Matsuoka Kunie,Shitara Hiroshi,Yonekawa Hiromichi,Kominami Ryo,Kikkawa Yoshiaki
Experimental Animals 62(4), 333-346, 2013
… In mice, functionally null Cdh23 mutations affect stereociliary morphogenesis and the polarity of both cochlear and vestibular hair cells. … In contrast, the murine Cdh23ahl allele, which harbors a hypomorphic mutation, causes an increase in susceptibility to age-related hearing loss in many inbred strains. …
NAID 130003382717