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* Ovaries are usually small, cord-like thickenings in the ovarian ligament are semniferous tubules.
* Ovaries are usually small, cord-like thickenings in the ovarian ligament are semniferous tubules.
====FREEMARTIN SYNDROME (i.e. Chimeras)====
*A freemartin is a masculinised female born co-twin with a normal male.
*11/12 female calves born co-twin to a male will be freemartins.
*Mainly recognised in cattle, but occurs in sheep, goats and pigs.
[[Category:Reproductive Disorders]]
*During foetal development placental anastomosis allows blood to be shared by the twins (anastamosis occurs in 90% of bovine twins, <2% in other species).
*Each twin acquires genetically distinct population of blood cells from the other twin - CHIMERISM.
*Blood tests can be used to demonstrate different chromosome complement in nucleated WBC and presence of two blood groups in each twin.
'''Aetiology:'''
Testes develop earlier in embryonic life than ovaries and impair normal female development by the production of TDF, MIS and testosterone which enters the female twins circulation via the placental anastomosis.
'''Consequences:'''
#Paramesonephric (Mullerian) ducts do not form or atrophy.
#Mesonephric (Wolffian) ducts persist in the female twin and may form rudimentary male tubular genitalia.
'''Morphological features:'''
#External genitalia may appear relatively normal - condition only detected at puberty or
#Enlarged clitoris, long tufts of hair round vulva, skin fold from groin to umbilicus.
#Vulva and vestibule patent but vestibule or vagina is blind-ended - can be checked using speculum or probe.
#Vagina never communicates with uterus. Uterus variably under developed - fibrous cords or non-patent tubes.
#Ovaries are usually small, cord-like thickenings in the ovarian ligament seminiferous tubules.
[[Category:Reproductive Disorders]][[Category:Reproductive System - Developmental Pathology]][[Category:Reproductive Diseases - Cattle]]