----start 11.20.96-----embryo----

lecture from Dr Pat Sertich on clinical aspects of urogenital 
development.
works mostly on horse.

she remarks that she does have high expectations of us.

see handout.
she's talking about how embryology is useful. not saying anything about 
the subject at hand. <ho hum>

ah. ok. so the gametes arise as primordial germ cells in the hindgut 
region, and then migrate up into the genital ridge region, with the 
mesonephros/developing kidney. the genital ridge eventually becomes an 
ovary or testis. 

the undifferentiated embryo has both mesonephric and paramesonephric 
duct, and depending on if it will be male or female it will keep one or 
the other.

paramesonephric duct will form uterus, uterin tubes, cervix, and cranial 
vagina in female.

"intersex" - individual with congenital anatomical variation making 
diagnosis of sex of the animal confusing. this is a general term.

INTERSEX: classifications

-genetic sex: XX or XY
-gonadal sex: ovaries vs testicles
-phenotypic sex: external appearance 
-behavioral sex

HERMAPHRODITE: is a type of intersex individual. has both male and female 
qualities.

TRUE hermaphrodite: has both ovarian and testicular tissue. sometimes a 
full gonad of each type, other times gonads of mixed type "ovotestes". 
may have to do histological exam to diagnose ovotestes. these are rare, 
don't see many true hermaphrodites.

[slide- excised repro tract of cow. has preputial opening in ventral 
abdominal position and a bit of a penis, 4 teats, uterus, straight 
"ductus deferens-like" fallopian tubes, and gonads in ovary position that 
on exam were ovotestes. has vesicular gland, poorly developed cervix, 
some pelvic urethra. a true hermaphrodite!]

PSEUDO hermaphrodite:  these are also rare but you will see them. most 
are genetically female, XX. most often seen in goats, swine. unusual in 
horse, cow.
has gonads of only one sex.

MALE pseudohermaphrodite: looks female but has testicular tissue.

[slide: cervix and uterine horns with gonads in appropriat place except 
they're testes. down in the urethra was an opening for ampulla but that 
wasn't really there... male pseudo]

[slide: cow, standing. vulva with either large clitoris or small penis. 
this animal looks like a female, but had testicular tissue. male pseudo]

[slide of horse standing. this horse presented as good jumper, field 
hunter, mare. was brought in for amputation because the woman who bought 
her said sometimes this thing would come out from under her tail and she 
wanted it cut off. so she was brought into the breeding stall, and she 
had flehmen response to teaser mare in heat. she had a protuberance 
coming out from under her tail at the time. this mare had gonads that 
LOOKED grossly ovarian, and another one looked testicular. turned out to 
be testicle. had opening to ampulla,had pelvic urethra, had epidymis near 
the gonad. this horse was a male pseudohermaphrodite. this horse was 
NAMED gender gap! the owner wasn't that bright i guess.]

[slide: "stallion" with penis and teats. human males and bulls and rams 
have teats. boars have teats. stallions do not have teats. this horse had 
subcutaneously located testicles in the thigh region. looks very male 
like, had no scrotum, has teats. intersex]

[slide: breeding stallion, not that fertile, but able to fertilize some 
females. he had teats too.]

FEMALE pseudohermaphrodite: looks phenotypically male, has ovarian 
tissue. very very rare. intersexes with ovarian tissue and male genitalia 
may be produced by exposure to androgens in embryonic life.
regumate: synthetic progestin given to horses - alters sexual behavior. 
sometimes given to horses to make them run or jump or behave better or 
stay out of heat. if yougive too much - eg 3x dose - can cause 
masculinization of genital tract. will see enlarged clitoris.

CAPRINE pseudohermaphrodite: relatively common.

genetic sex usually XX
these animals smell male :)
has testes
phenotypically female
enlarged clitoris
male pseudohermaphrodite
projecting vulva
hypoplastic vagina
simple sexlinked recessive character to this phenomenon.
associated w/polled condition. (polled=no horns)

HYPOSPADIA: urethral canal abnormality, large outpouching of of urethra .


[slide: small uterus type thing, no well developed cervix, large gonads 
with epididymis type thing.]

it's important to understand this problem to make recommendations about 
herd management. it's sexlinked, recessive, related to polled 
characteristic. so you might never breed two polled animals to make this 
gene not show up.

FREEMARTIN: female that develops in the same uterus with a male twin and 
had anastomosis of blood supply. technically, could occur in any twinning 
species, practically, really only occurs in cows.

you can have twins in the same uterus without anastomosis and they will 
not have this problem. that's likely why we don't see this in other 
species. time frame for sex differentiation is different in other 
species, and diff kinds of placentation as well.

these animals have tiny ovaries, female external genitalia, 
underdeveloped oviduct, uterus, vagina, and seminal vesicles. these 
animals are thought to be XX/XY chimeras.  (i wonder if this is like what 
happens in marmosets?)

recall that cattle have cotyledon type of placenta with intercotyledonary 
areas.

[slide: broad ligament surrounding very small, very minimal uterus and 
also very small ovaries. a minimal cervix, and a reasonable vulva.]
[slide: other freemartin example. better looking uterus, obvious seminal 
vesicles.]
[slide: another one. bigg uterus, reasonable cervix, tiny ovaries, 
obvious seminal vesicles. ]

very poorly developed vaginas in these animals, usually no opening into 
the cervix from the vagina. clinically you can diagnose this condition at 
birth - when there is a set of male/female twins, the farmer will want to 
know right now if she'll be fertile. you do the "test tube test" (could 
do karyotype but that's likely expensive), take 10 mL vacutainer, insert 
it into the vulva. a normal heifer can accomodate the whole thing. a 
freemartin won't. it will get to the opening of the urethra, and there 
will be a blind pouch.

[slide: normal horse fetus 50 days- vulvar lips present. this fetus was 
female. these changes occur very quickly in the fetus.]

63 XO: 
turner's syndrome. small stature, no estrus cycle, small flaccid uterus, 
"streak ovaries". streak ovaries are small, have ovarian stroma, but are 
not populated with germ cells. mare ovaries normally 3-5 cm, these streak 
ovaries are about 2 cm.

sometimes you see a mare with small ovaries...in winter anestrus, the 
ovaries should be small, and this might be ok. you would want to recheck 
in april or may. or you could do a karyotype.

MALE TORTOISESHELL CAT: color gene is carried on x chromosome - need 2 x 
chromosomes to have yellow and black. These animals are XXY. they have 
small testicles. this is like klinefelter's syndrome in men. many xxy 
humans end up in jail. undeveloped seminiferous tubules. why do men end 
up in jail? more aggressive? or in bad moods due to small testicular 
size.  Dr. Sertitch collects photos of these cats.

SEGMENTAL APLASIA: failure of a portion of the genital tract to develop.

-hydrosalpinx: common in swine. if a portion of oviduct is missing, this 
could develop. fluid accumulates in the uterine tube.

-hydrometra: accumulation of fluid in uterus due to abnormality of 
cervix/uterus. uterus produces normal secretions but they can't get out, 
they acumulate within the uterus.

[slide- sow with poorly developed repro tract. missing one uterine horn. 
has both ovaries. no normal cervix. could have been fertile on one side.]


[slide: segmental aplasia at base of uterine horn. can be diagnosed in 
cow by palpation per rectum. ]

UTERUS UNICORNIS: only one horn forms. problem with this is:
PERSISTENT CORPUS LUTEUM: this occurs if ovulation takes place on the 
side that a uterine horn is absent. now, in cows, when stuff is released 
from uterus and goes into vein, diffuses into nearby artery and has local 
effects. prostoglandins (PGF2a) kill the corpus luteum, allowing animal 
to come into heat. if the cow doesn't have a uterus on that side, but she 
ovulates on that side, she may form a corpus luteum but not have a uterus 
to stimulate that ovary, and she'll stay out of heat for a long time. so 
these animals fail to cycle and come in as anestrus females, and you can 
treat this by taking out the ovary on that side, but it's recommended to 
cull these animals as this may be genetic problem.

FAILURE OF WOLFIAN DUCT to develop - lack of epididymis. these animals 
can make sperm but can't house them while they mature, so are infertile. 


[slide: bizarre looking bovine penis...looks like possum penis! two 
parts]

REMNANTS OF DUCT SYSTEM: uterus masculinus is normal. appendix testis is 
normal (both in males)

cysts of gartner's duct are remnants of wolffian ducts in floor of 
vagina. cause no problems in most cases. 

parovarian cysts present in females, don't cause physiological problem 
but might confuse you. you might think it is a folllicle.

epoophoron cyst: remnant of wolffian duct- hard to diagnose the first few 
times. sometimes you find a mare who ALWAYS has a follicle in the same 
place, turns out to be this. these won't ovulate, won't lutenize. simply 
note their location.

FIMBRIA cyst...on fimbria of oviduct. cause no problems. remnant of 
wolffian duct.

DOUBLE CERVIX: paramesonephric ducts fuse during development. if this 
fails you may get double cervix and/or double vagina. may both be patent 
or not. one may be blind end. if both open, can be bad during 
parturition...can cause dystocia. also if doing AI might accidentally 
breed into blind pouch.


----end----