Freemartin

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

A freemartin or free-martin (sometimes martin heifer) is an infertile cow with masculinized behavior and non-functioning ovaries.[1] Phenotypically, the animal appears female, but various aspects of female reproductive development are altered due to acquisition of anti-Müllerian hormone from the male twin.[2] Genetically, the animal is chimeric: karyotypy of a sample of cells shows XX/XY chromosomes. The animal originates as a female (XX), but acquires the male (XY) component in utero by exchange of some cellular material from a male twin, via vascular connections between placentas: an example of microchimerism.[3] The chimerism is mainly present in the hematopoietic stem cells.[4]

  1. ^ Freemartinism at the U.S. National Library of Medicine Medical Subject 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 between testosterone production and influence on sex differentiation". General and Comparative Endocrinology. 129 (1): 39–44. doi:10.1016/S0016-6480(02)00514-2. PMID 12409094.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ In utero cell transfer between porcine littermates, in Reproduction, Fertility, and Development (2011; 23(2): 297–302. - doi: 10.1071/RD10165)
  4. ^ "9 - Abnormalities of Development and Pregnancy". Veterinary reproduction and obstetrics. David E. Noakes, Timothy J. Parkinson, Gary C. W. England (Tenth ed.). [Edinburgh, Scotland]. 2019. pp. 168–194. doi:10.1016/B978-0-7020-7233-8.00009-4. ISBN 978-0-7020-7238-3. OCLC 1077474208. S2CID 81828645.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)