The Frizzle is a

breed A breed is a specific group of breedable domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist seve ...

chicken The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...

with characteristic curled or

frizzled Frizzled is a family of atypical G protein-coupled receptor, G protein-coupled receptors that serve as receptors in the Wnt signaling pathway and other signaling pathways. When activated, Frizzled leads to activation of Dishevelled in the cytosol ...

plumage. While the frizzle gene can be seen in many breeds, such as the Pekin and

Polish Polish may refer to: * Anything from or related to Poland, a country in Europe * Polish language * Polish people, people from Poland or of Polish descent * Polish chicken * Polish brothers (Mark Polish and Michael Polish, born 1970), American twin ...

, the Frizzle is recognised as a distinct breed in a number of European countries and Australia. In the United States, frizzled chickens are not considered a breed, and at shows are judged by the standards of the breed they belong to.

History

The origin of the Frizzle is unknown. The frizzle gene is thought to have originated in

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

; frizzled chickens have been reported from the

Far East The Far East is the geographical region that encompasses the easternmost portion of the Asian continent, including North Asia, North, East Asia, East and Southeast Asia. South Asia is sometimes also included in the definition of the term. In mod ...

since the eighteenth century. The Frizzle breed is the result of

selective breeding Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant m ...

for exhibition. It is recognised in nine European countries: Belgium, Czech Republic, France, Germany, Ireland, Italy, Poland, Slovakia and the United Kingdom.

Characteristics

The gene for the curling of the feathers is incompletely dominant over normal plumage; not all members of the breed have frizzled feathers. Frizzled birds are

heterozygous Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mos ...

for the

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

; when two are bred, the offspring inherit the gene in the usual

Mendelian Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularized ...

1:2:1 ratio: 50% are heterozygous and frizzled like the parents, 25% have normal feathering, and 25% are "over-frizzled", with brittle feathers resembling pipe-cleaners. The Frizzle has a single

comb A comb is a tool consisting of a shaft that holds a row of teeth for pulling through the hair to clean, untangle, or style it. Combs have been used since prehistoric times, having been discovered in very refined forms from settlements dating ba ...

and is clean-legged – without feathers on the shanks. It is a good forager and is hardy. Four colours are recognised in the

Entente Européenne Entente, meaning a diplomatic "understanding", may refer to a number of agreements: History * Entente (alliance), a type of treaty or military alliance where the signatories promise to consult each other or to cooperate with each other in case o ...

standard: black, blue, cuckoo and white. The

Poultry Club of Great Britain The Poultry Club of Great Britain is a registered charity founded in 1877. Its stated purpose is to "safeguard the interests of all pure and traditional breeds of poultry including chickens, bantams, ducks, geese and turkeys". The club main ...

recognises nineteen colours for both standard and bantam sizes; not all of them are currently bred. The

Australian Poultry Standards The ''Australian Poultry Standards'' is the official breed standard for poultry fancy in Australia. It is the standard of perfection from which all poultry in Australia is supposed to be judged when exhibited at poultry shows. It is published ...

recognise black, blue, buff, white, Columbian, red and "any recognised colour".

Genetics

Research suggests that the frizzled phenotype comes from a mutation within the keratin gene ''

KRT75 KRT75 is a keratin gene involved in hair shaft structure in mice. In chickens, mutations in ''KRT75'' cause animals to have frizzled Frizzled is a family of atypical G protein-coupled receptor, G protein-coupled receptors that serve as receptor ...

''. A deletion that removed part of

exon An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence ...

5 and

intron An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word ''intron'' is derived from the term ''intragenic region'', i.e., a region inside a gene."The notion of the cistron .e., gen ...

5 ameliorated the

splice site RNA splicing is a process in molecular biology where a newly-made precursor messenger RNA (pre-mRNA) transcript is transformed into a mature messenger RNA (mRNA). It works by removing all the introns (non-coding regions of RNA) and ''splicing'' ...

. This caused a 69

base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

deletion of the ''KRT75'' gene.

Use

The Frizzle is reared exclusively for

exhibition An exhibition, in the most general sense, is an organized presentation and display of a selection of items. In practice, exhibitions usually occur within a cultural or educational setting such as a museum, art gallery, park, library, exhibiti ...

. It is a good layer of white or tinted eggs, and frequently gets broody.

References

{{reflist, 45em, refs= APA Recognized Breeds and Varieties: As of January 1, 2012
American Poultry Association. Archived 4 November 2017. {{cite book, title=Australian Poultry Standards, date=2011, publisher=Victorian Poultry Fanciers Association (trading as Poultry Stud Breeders and Exhibitors Victoria), isbn=9781921488238, page=79 & 80, edition=2nd Frances Bassom (2009). ''Chicken Breeds & Care: A Color Directory of the Most Popular Breeds and Their Care''. Buffalo, NY: Firefly Books. {{ISBN, 9781554074730. Liste des races et variétés homologuée dans les pays EE (28.04.2013)
Entente Européenne d’Aviculture et de Cuniculture. Archived 16 June 2013. Carol Ekarius (2007)
''Storey's Illustrated Guide to Poultry Breeds''
North Adams, Massachusetts: Storey Publishing. {{isbn, 9781580176675. Chris Graham (2006). ''Choosing and Keeping Chickens''. London: Hamlyn. {{ISBN, 9780600614388. Breed Classification
Poultry Club of Great Britain. Archived 12 June 2018. Victoria Roberts (2008)
''British poultry standards: complete specifications and judging points of all standardized breeds and varieties of poultry as compiled by the specialist breed clubs and recognised by the Poultry Club of Great Britain''
Oxford: Blackwell. {{ISBN, 9781405156424. Welcome
The Frizzle Society of Great Britain. Archived 30 September 2012. Frizzle Breed Standards
The Frizzle Society of Great Britain. Archived 16 October 2012. __NOTOC__ Chicken breeds