sex differentiation Flashcards
What are the three key parts of reproductive development?
- sexual determination (sex genetically decided)
- Sexual differentiation (first physiological differences)
- Sexual maturation (puberty)
What cells are responsible for forming the gonadal ridge formation?
Somatic Gonadal Precursor Cells (SGPCs)
…. germ cells (PGCs) migrate to site of …. development during embryogenesis
Primordial germ cells
gonad
PGCs are formed prior to … in zebrafish and migrate toward … cells
gastrulation
somatic gonad
PGCs divide mitotically then differentiate into … or …
oogonia
spermatogonia
What initiates PGCs migration to germinal ridge?
chemokine signaling
List three stock manipulations that improve farming efficiency
- Compensate for environmental factors
- induce sterility (e.g. escapee fish)
- select for preferential sex (monosex culture)
What are some reasons to select for a preferential sex?
maximise growth
maximise growth phase
avoid reproductive precocity
even size distribution (reduce cannibalism, easier grading)
avoid reduction
isolate females for kavier production
name three advantages for monosex female production in salmon
grow faster
mature later
produce eggs (caviar)
name two strategies to maintain a monosex culture
-manual sorting, by hand or mechanical grading
-hormonal sex reversal
(ideally, you would manipulate sex of broodstock so that all progeny are the desired sex)
Describe how hormonal sex reversal works
We want all-females(e.g. Salmon)
Create neo males (XX) by treating regular females with androgens (egMT)
What are two issues in the administration of sex hormones to developing fish during their critical period of sensitivity
-Requires precise knowledge of sex differentiation
–Highly species-specific (every fish is different)
Name three ways hormones can be delivered
- ingestion
- injection
- immersion
Name three hormones used for sex reversal to induce masculinisation (2) and feminisation (1)
