Repro Path Flashcards
compare chromosomal versus gonadal sex determination STAR
gonadal:
-everyone bipotential gonads during development/no default state
-ovaries and testes are gene-directed processes!
chromosomal:
female: XX; no SRY gene
male: XY; SRY gene, encodes for testis determining factor that makes mullerian inhibitory substance, which urges primordial gonad to become a testis
describe phenotypical sex determination STAR
hormonal secretion causes development of secondary sexual characteristics
-internal and external genitalia
what can go wrong with sex determination?
- chromosomal abnormalities
-abnormal number and/or mixture of sex chromosomes - gonadal abnormalities
-failure of effective signal to primitive and undifferentiated gonads - phenotypic abnormalities:
-message did not get through to ensure development of mesonephric vs paramesonephric duct
describe Turner syndrome
- a chromosome is missing!
-need 2 X’s to make all mediators in females, so can’t do that - common in mares
-ovaries are hypoplastic, tract is rudimentary
describe mosaic’s versus chimeras STAR
- mosaicism: occurs when there are 2 or more genetically different cell lines present originating from a single zygote
- chimerism: occurs when there are 2 or more genetically different cells lines present originating from 2 or more zygotes (freemartin)
describe klinefelter’s syndrome STAR
- polysomy: more than one X chromosome isn present
-XXY karyotype or more complex - occurs in stallions, bulls, boars, dogs
- cats: males with tricolor, tortoiseshell, or calico coat types
- also leads to testicular hypoplasia
- MALE CALICO CATS ARE USUALLY MOSAICS AND INFERTILE
describe intersex
- associated with gonadal dysgenesis and a female phenotype
- true hermaphrodite has to have both gonads (ovotestis) = RARE
- male pseudohermaphrodites COMMON
-clitoral hyperplasia
-androgen sensitivity syndrome: inability of tissue to respond to androgens
-5alpha-reductase deficiency: converts testosterone into DHT; feminized or ambiguous ext genitals with a functional testis
-SRY-positive but downstream gene dysregulation: mutation in genes downstream to SRY signaling; testes may form but fail to produce significant testosterone; external genitalia is female
-persistent mullerian duct syndrome: results from AMH mutations or its receptor, leads to persistence of mullerian duct structures (uterus and oviducts) alongside male gonads
describe developmental ovary conditions
- agenesis: RARE
-can be uni or bilateral - hypoplasia:
-XXX and X_ in mares and XXX in cows
-swedish highland cattle: autosomal recessive trait - ovarian remnant syndrome:
-2 different ovaries on each side by splitting during development or complete new ovary formation
-classic history of spayed female in heat or stump pyometra
describe developmental uterus, vagina, vulva conditions
- segmental aplasia: can happen at any portion of repro tubular organs
- imperforate hymen: blocks the flow of secretions and can lead to fluid accumulations or infections
-failure of fusion of caudal part of tube, causing double cervix
where can cysts occur?
not just ovaries!
intraovarian, periovarian, uterine, vaginal, vestibular
describe peri (para) ovarian cysts STAR
EQUINE!!
- an embryonic (wolffian duct) remnant becomes cystic, blocks egg from reaching oviduct
-oocyte released by ovulation but cyst may block ovulation fossa and the ovum pick up by uterine tube
describe ovarian tumors
- epithelium: adenoma/adenocarcinoma
-most common in dogs - carcinomatosis
describe ovarian sex cord tumors
- granulosa cell tumors, thecomas, luetomas, and sustentacular tumors
-granulosa cell tumors: common in cows and horses, usually benign but can be malignant in cats and dogs; on histopath will see follicle-like structures with granulosa cells surrounding eosinophilic material (Carl-Exner bodies); MAY produce testosterone and can get really big in horses
- frequently produce hormones
- generally unilateral and benign
describe teratomas
- germ cell derived neoplasm
- often have bits of bone or liver or other tissue all mixed in together
describe uterine adenocarcinomas STAR
- particularly common in older rabbits
- malignant and metastasize often!!
-come from epithelial cells