Dairy Cattle Name for Fertile Male Beef Cattle Name for Fertile Male

Infertile cow with XX/XY chromosomes

A plate showing a "Complimentary Martin" from the collected works of John Hunter.

A freemartin or free-martin (sometimes martin heifer) is an infertile female cattle with masculinized behavior and not-functioning ovaries.^[i] Phenotypically, the animal appears female person, only various aspects of female reproductive development are altered due to conquering of anti-Müllerian hormone from the male twin.^[two] Genetically the animal is chimeric: karyotypy of a sample of cells shows Xx/XY chromosomes. The brute originates as a female (XX), simply acquires the male (XY) component in utero by exchange of some cellular material from a male twin, via vascular connections between placentas: an instance of microchimerism.^[three] The chimerism is mainly nowadays in the hematopoietic stem cells.^[4]

History [edit]

Freemartins are known to have been described by the Roman author Varro, who called them "taura" .^[5]

The 18th-century physician John Hunter discovered that a freemartin always has a male twin.^[half-dozen]

It was hypothesized early in the 20th century that masculinizing factors travel from the male twin to the female twin through the vascular connections of the placenta because of the vascular fusion and affect the internal anatomy of the female.^[7]

Several researchers made the discovery that a freemartin results when a female fetus has its chorion fuse in the uterus with that of a male twin. The upshot was published in 1916 past Tandler and Keller.^[8] The discovery was fabricated independently by American biologist Frank R. Lillie, who published information technology in Science in 1916.^[ix] Both teams are at present credited with the discovery.^[10]

In rural areas folklore often claimed this condition was not just peculiar to cattle, but extended too to human twins; this belief perpetuated for generations, equally was mentioned in the writings of Cuthbert Bede.^[xi]

Etymology [edit]

The etymology of the term "freemartin" is uncertain: speculations include that "free" may indicate "willing" (referring to the freemartin'southward willingness to work) or "exempt from reproduction" (referring to its sterility, or to a farmer'due south decision to not bother trying to brood a freemartin, or both), or that it may be derived from a Flemish word for a cow which gives no milk and/or has ceased to exist capable of bearing offspring;^[five] "martin" is generally held to derive from an Irish or Gaelic word for "cow" or "heifer", although connections to Martinmas take besides been posited.^[5]

Mechanism [edit]

In most cattle twins, the blood vessels in the chorions become interconnected, creating a shared circulation for both twins. If both fetuses are the same sexual practice this is of no significance, but if they are unlike, male hormones pass from the male twin to the female twin. The male hormones (testosterone and anti-Müllerian hormone) then masculinize the female person twin, and the result is a freemartin.^[12] The degree of masculinization is greater if the fusion occurs earlier in the pregnancy – in about ten percent of cases no fusion takes identify and the female person remains fertile.

The male twin is largely unaffected by the fusion, although the size of the testicles may exist slightly reduced. Testicle size is associated with fertility, so there may be some reduction in bull fertility.

Freemartins behave and grow in a similar style to castrated male person cattle (steers).

Diagnosis [edit]

If suspected, a test can exist done to observe the presence of the male Y-chromosomes in some circulating white blood cells of the subject. Genetic testing for the Y-chromosome can be performed within days of nativity and can aid in the early on identification of a sterile female person bovine.

Concrete test of the calf may also reveal differences: a subjective cess is that frequently in that location is a lengthened tuft of hair at the ventral tip of the vulva in a freemartin heifer atypical in fertile heifer calves. Also, oftentimes many (just not all) freemartins will have a shortened length of vagina compared with that of a fertile heifer. Commercial probes are available to cheque heifers for obvious freemartinism in lieu of doing a blood test ^[13]

Other animals [edit]

A freemartin is the normal result of mixed twins in all cattle species which take been studied. Information technology does non ordinarily occur in near other mammals, though it has been recorded in sheep,^[14] goats,^[15] and pigs.^[16]

Uses [edit]

Freemartins are occasionally used in stem jail cell and immunology research.^[17] During fetal development cells are exchanged betwixt the fused circulations of the bovine twins. Up to 95% of the freemartin's claret cells can be derived from those of her twin blood brother. Male-derived cells and their progeny can be easily visualised in the freemartin tissues, equally only they contain the male Y chromosome. Thus, by analysing these tissues, one can investigate the capacity of hematopoietic stalk cells or other circulating cells to produce other tissues in improver to blood. The freemartin model allows one to analyse perfectly healthy and unmanipulated animals, without resorting to transplantation oft used in stem cell research.

Fictional apply [edit]

• In the Aldous Huxley novel Brave New World, a "freemartin" (mentioned in capacity i, 3, 11 and 17) is a woman who has been deliberately fabricated sterile by exposure to hormones during fetal development; in the book, government policy requires freemartins to constitute lxx% of the female population. A side result of this is some freemartin women having developed beards.
• The Robert A. Heinlein novel Beyond This Horizon lists "the clever and repulsively beautiful pseudo-feminine freemartins" as one of the genetically-engineered specialist types of humans that were created in the "Empire of the Smashing Khans" (chapter 2).
• In the Robert Heinlein novel Farnham's Freehold, the protagonist, Hugh Farnham, is given a companion ("bedwarmer") that is described as a "natural freemartin".
• In the Avram Davidson story "The House the Blakeneys Congenital", the cattle are freemartins.
• In the fantasy book series Bazil Broketail by Christopher Rowley, "freemartin" is the proper name for a breed of sterile female dragons.
• In Footfall by Larry Niven and Jerry Pournelle, a lithely-congenital human woman uses the term "freemartin" to depict herself, while doubting her sexuality.
• In Nicola Griffith'due south novel Hild, the title character is sometimes referred to past others as a freemartin, in reference to her not-feminine character and social part.
• In Lauren Groff's novel Matrix (New York: Riverhead Books, 2021), 12th-century English peasants utilize freemartins to pull wagons.

References [edit]

1. ^ Freemartinism at the US National Library of Medicine Medical Subject field Headings (MeSH)
2. ^ Rota A, Ballarin C, Vigier B, Cozzi B, Rey R (October 2002). "Age dependent changes in plasma anti-Müllerian hormone concentrations in the bovine male, female, and freemartin from birth to puberty: relationship betwixt testosterone production and influence on sex activity differentiation". Full general and Comparative Endocrinology. 129 (one): 39–44. doi:10.1016/S0016-6480(02)00514-2. PMID 12409094. {{cite periodical}}: CS1 maint: multiple names: authors listing (link)
3. ^ In utero prison cell transfer between porcine littermates, in Reproduction, Fertility, and Evolution (2011; 23(ii): 297–302. - doi: 10.1071/RD10165)
4. ^ Veterinary reproduction and obstetrics. David E. Noakes, Timothy J. Parkinson, Gary C. W. England (Tenth ed.). [Edinburgh, Scotland]. 2019. ISBN978-0-7020-7238-3. OCLC 1077474208. {{cite book}}: CS1 maint: others (link)
5. ^ ^{a b c} EARLY RECOGNITION OF THE FREEMARTIN CONDITION IN HEIFERS TWINBORN WITH BULLS, by W.West. Swett, C.A. Matthews, and R. R. Graves, in the Journal of Agricultural Enquiry, vol. 61, no. viii (October 15, 1940)
6. ^ Hunter, John (1779). "Account of the Costless Martin. By Mr. John Hunter, F. R. Due south." Philosophical Transactions of the Royal Society of London. 69: 279–93. Bibcode:1779RSPT...69..279H. doi:x.1098/rstl.1779.0020. JSTOR 106420.
7. ^ (Nelson, Randy. An introduction to behavioral endocrinology. Sinauer Associates: Massachusetts. 2005: pg 145)
8. ^ Keller, One thousand. and Tandler, J.: Wiener Tieraztl. Wochensch., iii, 513-526 (1916).^{[ verification needed ]}
9. ^ Lillie FR (April 1916). "The Theory of the Free-Martin". Science. 43 (1113): 611–3. Bibcode:1916Sci....43..611L. doi:ten.1126/scientific discipline.43.1113.611. JSTOR 1641047. PMID 17756274.
10. ^ Freeman Thou (March 2007). "Explaining the freemartin: Tandler and Keller vs. Lillie and the question of priority". Journal of Experimental Zoology B. 308 (2): 105–12. doi:10.1002/jez.b.21151. PMID 17219370.
11. ^ Cuthbert Bede (1859–1860). "The folk-lore of a country parish". Once a Calendar week. 1. Vol. 2. Bradbury & Evans. If twins are born in our state parish, information technology is believed that of the little bipeds—similar the quadrupedal martin-heifers and free-martins—only i volition prove the father (or mother) of a family. {{cite magazine}}: CS1 maint: engagement format (link)
12. ^ Padula AM (June 2005). "The freemartin syndrome: an update". Creature Reproduction Scientific discipline. 87 (1–ii): 93–109. doi:ten.1016/j.anireprosci.2004.09.008. PMID 15885443.
13. ^ Eldridge FE, Blazak WF (March 1977). "Chromosomal assay of fertile female heterosexual twins in cattle". Periodical of Dairy Science. 60 (three): 458–63. doi:10.3168/jds.S0022-0302(77)83888-5. PMID 845292.
14. ^ Wilkes PR, Munro IB, Wijeratne WV (Feb 1978). "Studies on a sheep freemartin". The Veterinary Tape. 102 (vii): 140–ii. doi:10.1136/vr.102.seven.140. PMID 565559. S2CID 43776725. {{cite journal}}: CS1 maint: multiple names: authors list (link)
15. ^ Ilbery PL, Williams D (1967). "Evidence of the freemartin status in the goat". Cytogenetics. six (three): 276–85. doi:x.1159/000129948. PMID 6035567.
16. ^ Bruere AN, Fielden ED, Hutchings H (March 1968). "XX-XY mosaicism in lymphocyte cultures from a pig with freemartin characteristics". New Zealand Veterinarian Journal. xvi (3): 31–8. doi:10.1080/00480169.1968.33743. PMID 5241942. {{cite journal}}: CS1 maint: multiple names: authors list (link)
17. ^ Niku M, Ilmonen L, Pessa-Morikawa T, Iivanainen A (2004). "Express contribution of circulating cells to the development and maintenance of nonhematopoietic bovine tissues". Stem Cells. 22 (1): 12–20. doi:10.1634/stemcells.22-1-12. PMID 14688387. S2CID 13556114. {{cite periodical}}: CS1 maint: multiple names: authors list (link)

External links [edit]

• Mosaicism and Chimerism at colostate.edu
• Moving picture at agric.gov.ab.ca

bakeroweept99.blogspot.com

Source: https://en.wikipedia.org/wiki/Freemartin

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