WordNet

the means of connection between things linked in series (同)nexus
a unit of length equal to 1/100 of a chain
an interconnecting circuit between two or more locations for the purpose of transmitting and receiving data (同)data link
a fastener that serves to join or connect; "the walls are held together with metal links placed in the wet mortar during construction" (同)linkup, tie, tie-in
(computing) an instruction that connects one part of a program or an element on a list to another program or list
tell the sex (of young chickens)
the properties that distinguish organisms on the basis of their reproductive roles; "she didnt want to know the sex of the foetus" (同)gender, sexuality
all of the feelings resulting from the urge to gratify sexual impulses; "he wanted a better sex life"; "the film contained no sex or violence" (同)sexual urge
either of the two categories (male or female) into which most organisms are divided; "the war between the sexes"
that which is inherited; a title or property or estate that passes by law to the heir on the death of the owner (同)heritage
(genetics) attributes acquired via biological heredity from the parents (同)hereditary pattern
any attribute or immaterial possession that is inherited from ancestors; "my only inheritance was my mothers blessing"; "the worlds heritage of knowledge" (同)heritage
hereditary succession to a title or an office or property (同)heritage
having sexual differentiation
characterized by sexuality; "highly sexed"

PrepTutorEJDIC

(鎖の)『輪』,環 / 鎖のようにつながったソーセージの一節 / (…と)つなぐ物(人),(…との)きずな,つながり《+『with』(『to』)+『名』》 / 《複数形で》=cuff links / …‘を'『つなぎ合わせる』,連結する;(…と)…‘を'つなぐ《+『名』+『with』(『to』)+『名』》 / (…と)結合する,つながる《+[『up』(『together』)]『with』+『名』》
たいまつ
〈U〉〈C〉『性』,性別 / 《the~》《形容詞を伴い集合的に》『男性』,『女性』 / 〈U〉(男女(雌雄)間の)相違[の意識] / 〈U〉性に関する事柄(情報) / 〈U〉性交 / 〈ひよこなど〉‘の'性別を見分ける
〈U〉『相続』,継承 / 〈C〉『遺産』,相続財産 / 〈C〉(両親・前任者・前代などから)受け継いだもの

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/08/11 18:35:59」(JST)

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Experimental cross performed by Morgan, illustrating the X-linked inheritance of white eyed mutation in fruit flies.^[1]

Sex linkage is the phenotypic expression of an allele related to the chromosomal sex of the individual. This mode of inheritance is in contrast to the inheritance of traits on autosomal chromosomes, where both sexes have the same probability of inheritance. Since humans have many more genes on the X than the Y, there are many more X-linked traits than Y-linked traits.

In mammals, the female is the homogametic sex, with two X chromosomes (XX), while the male is heterogametic, with one X and one Y chromosome (XY). Genes on the X or Y chromosome are called sex-linked.

In birds, the opposite is true: the male is the homogametic sex, having two Z chromosomes (ZZ), and the female (hen) is heterogametic, having one Z and one W chromosome (ZW).

X-linked recessive traits are expressed in all heterogametics, but are only expressed in those homogametics that are homozygous for the recessive allele. For example, an X-linked recessive allele in humans causes haemophilia. Haemophilia is much more common in males than females because males are hemizygous - they only have one copy of the gene in question - and therefore express the trait when they inherit one mutant allele. In contrast, a female must inherit two mutant alleles, a less frequent event since the mutant allele is rare in the population. Tsarevich Alexei of Russia was the most famous sufferer of X-linked haemophilia.

The incidence of recessive X-linked phenotypes in females is the square of that in males (squaring a proportion less than one gives an outcome closer to 0 than the original). If 1 in 20 males in a human population are red-green color blind, then 1 in 400 females in the population are expected to be color-blind (¹/₂₀)*(¹/₂₀). (The term 'color-blind' is not completely accurate. There are degrees of weakness in color vision and it is now called 'color vision deficiency'.)

X-linked traits are maternally inherited from carrier mothers or from an affected father. Each son born to a carrier mother has a 50% probability of inheriting the X-chromosome carrying the mutant allele. There are a few Y-linked traits; these are inherited from father.

In classical genetics, a reciprocal cross is performed to test if a trait is sex-linked.

(A)

(B)

(C)

Illustration of some X-linked heredity outcomes (A) the affected father has one X-linked dominant allele, the mother is homozygous for the recessive allele: only daughters (all) will be affected. (B) the affected mother is heterozygous with one copy of the X-linked dominant allele: both daughters and sons will have 50% probability to be affected. (C) the heterozygous mother is called "carrier" because she has one copy of the recessive allele: sons will have 50% probability to be affected, 50% of unaffected daughters will become carriers like their mother.^[2]

X-linked dominant inheritance

An example pedigree chart of the inheritance of a sex linked disorder.

Each child of a mother affected with an X-linked dominant trait has a 50% chance of inheriting the mutation and thus being affected with the disorder. If only the father is affected, 100% of the daughters will be affected, since they inherit their father's X-chromosome, and 0% of the sons will be affected, since they inherit their father's Y-chromosome.

Examples

Alport's syndrome
Aarskog-Scott syndrome
Coffin-Lowry syndrome (CLS)
idiopathic hypoparathyroidism
incontinentia pigmenti
Ornithine carbamoyltransferase deficiency
Rett syndrome (RS)
vitamin D resistant rickets
fragile X syndrome

X-linked recessive inheritance

Females possessing one X-linked recessive mutation are considered carriers and will generally not manifest clinical symptoms of the disorder. All males possessing an X-linked recessive mutation will be affected, since males have only a single X-chromosome and therefore have only one copy of X-linked genes. All offspring of a carrier female have a 50% chance of inheriting the mutation if the father does not carry the recessive allele. All female children of an affected father will be carriers (assuming the mother is not affected or a carrier), as daughters possess their father's X-chromosome. No male children of an affected father will be affected, as males only inherit their father's Y-chromosome.

Examples

ALD
Duchenne muscular dystrophy
Hunter syndrome
Menkes disease (kinky hair syndrome)
Glucose-6-phosphate dehydrogenase deficiency
Haemophilia A and B
Fabry's disease
Wiskott-Aldrich syndrome
Bruton's agammaglobulinemia
Color blindness
Complete androgen insensitivity syndrome
Congenital aqueductal stenosis (hydrocephalus)
Inherited nephrogenic diabetes insipidus

Y-linked

Various failures in the SRY genes

Sex-linked traits in other animals

Fur color in domestic cats: the gene that causes orange pigment is on the X chromosome; thus a Calico or tortoiseshell cat, with both black (or gray) and orange pigment, is nearly always female.
White eyes in Drosophila melanogaster flies— the first sex-linked gene discovered in Drosophila.^[3]
The first sex-linked gene ever discovered was the "lacticolor" X-linked recessive gene in the moth Abraxas grossulariata by Leonard Doncaster.^[4]

Related terms

It is important to distinguish between sex-linked characters, which are controlled by genes on sex chromosomes, and two other categories.^[5]

Sex-influenced traits

Sex-influenced or sex-conditioned traits are phenotypes affected by whether they appear in a male or female body.^[6] Even in a homozygous dominant or recessive female the condition may not be expressed fully. Example: baldness in humans.

Sex-limited traits

These are characters only expressed in one sex. They may be caused by genes on either autosomal or sex chromosomes.^[6] Examples: female sterility in Drosophila; and many polymorphic characters in insects, especially in relation to mimicry. Closely linked genes on autosomes called "supergenes" are often responsible for the latter.^[7]^[8]^[9]

References

^ Morgan, Thomas Hunt 1919. The physical basis of heredity. Philadelphia: J.B. Lippincott Company.
^ Genetics home reference (2006), genetic conditions illustrations, National Library of Medicine.
^ Morgan T.H. 1910. Sex-limited inheritance in Drosophila. Science 32: 120-122
^ Doncaster L. & Raynor G.H. 1906. Breeding experiments with Lepidoptera. Proceedings of the Zoological Society of London. 1: 125-133
^ Zirkle, Conrad 1946. The discovery of sex-influenced, sex limited and sex-linked heredity. In Ashley Montagu M.F. (ed) Studies in the history of science and learning offered in homage to George Sarton on the occasion of his sixtieth birthday. New York: Schuman, p167–194.
^ ^a ^b King R.C; Stansfield W.D. & Mulligan P.K. 2006. A dictionary of genetics. 7th ed, Oxford University Press. ISBN 0-19-530761-5
^ Mallet J. & Joron M. (1999). "The evolution of diversity in warning color and mimicry: polymorphisms, shifting balance, and speciation". Annual Review of Ecology and Systematics 30: 201–33. doi:10.1146/annurev.ecolsys.30.1.201.
^ Ford E.B. 1965. Genetic polymorphism. p17-25. MIT Press 1965.
^ Joron M, Papa R, Beltrán M et al. (2006). "A conserved supergene locus controls colour pattern diversity in Heliconius butterflies". PLoS Biol. 4 (10): e303. doi:10.1371/journal.pbio.0040303. PMC 1570757. PMID 17002517.

UpToDate Contents

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1. メンデル遺伝の概要 overview of mendelian inheritance
2. 単一遺伝子性疾患の非メンデル遺伝のパターン non mendelian inheritance patterns of monogenic diseases
3. 遺伝性疾患の基本原則 basic principles of genetic disease
4. 着床前の男女生み分け技術 techniques for preimplantation sex selection
5. 先天異常の遺伝学的および環境的原因 genetic and environmental causes of birth defects

English Journal

Early replication dynamics of sex-linked mitochondrial DNAs in the doubly uniparental inheritance species Ruditapes philippinarum (Bivalvia Veneridae).

Guerra D1, Ghiselli F1, Milani L1, Breton S2, Passamonti M1.
Heredity.Heredity (Edinb).2015 Dec 2. doi: 10.1038/hdy.2015.105. [Epub ahead of print]
Mitochondrial homoplasmy, which is maintained by strictly maternal inheritance and a series of bottlenecks, is thought to be an adaptive condition for metazoans. Doubly uniparental inheritance (DUI) is a unique mode of mitochondrial transmission found in bivalve species, in which two distinct mitoch
PMID 26626575

Inheritance and heritability of deltamethrin resistance under laboratory conditions of Triatoma infestans from Bolivia.

Gomez MB1, Pessoa GD2, Rosa AC3, Echeverria JE4, Diotaiuti LG5.
Parasites & vectors.Parasit Vectors.2015 Nov 16;8:595. doi: 10.1186/s13071-015-1211-9.
BACKGROUND: Over the last few decades, pyrethroid-resistant in Triatoma infestans populations have been reported, mainly on the border between Argentina and Bolivia. Understanding the genetic basis of inheritance mode and heritability of resistance to insecticides under laboratory conditions is cruc
PMID 26572249

Dominant Inheritance of Field-Evolved Resistance to Fipronil in Plutella xylostella (Lepidoptera: Plutellidae).

Wang X1, Wu S1, Gao W1, Wu Y2.
Journal of economic entomology.J Econ Entomol.2015 Oct 28. pii: tov317. [Epub ahead of print]
A field-collected strain (HF) of Plutella xylostella (L.) showed 420-fold resistance to fipronil compared with a susceptible laboratory strain (Roth). The HF-R strain, derived from the HF strain by 25 generations of successive selection with fipronil in the laboratory, developed 2,200-fold resistanc
PMID 26511983

Japanese Journal

<i>EDA</i>遺伝子に変異を認めた無汗型外胚葉異形成症の1例

山口聖士,町田純一郎,木村将士,柴田章夫,嘉悦淳男,下郷和雄
日本口腔外科学会雑誌 59(4), 270-274, 2013
… In addition, a misssense mutation leading to an amino acid substitution from arginine to histidine in position 156 of the ectodysplasin A gene, responsible for sex-linked inheritance, was identified. …
NAID 130004707958

Estimation of the mode of inheritance of thermal tolerance in the guppy Poecilia reticulata

NAKAJIMA Masamichi,FUJISAWA Kimitada,TANIGUCHI Nobuhiko
Fisheries science : FS 75(3), 683-687, 2009-05-01
NAID 10024971114

ウズラの育種ならびに飼料,栄養

佐藤勝紀
岡山大学農学部学術報告 98, 47-57, 2009-02
岡山大学農学部家畜育種学教室では1973年からウズラの育種ならびに飼料、栄養に関する研究に取組んできた。本研究で取り上げたウズラ（Coturnix coturnix japonica）は鶏の実験動物として利用され、また卵・肉を目的とした産業・経済動物として飼育されている。本研究では、はじめに育種学上、重要な課題である近交退化と雑種強勢の解析を試み、つぎに選抜の指標となる遺伝的パラメータを推定すると …
NAID 120002308084