Sex determination, etc. Flashcards
Sexual dimorphism
development of sexes occurs at different times in opp. sexes
(male gametogenesis = diff. start time than female gametogenesis)
Acrosomal vesicles
Part of head of sperm,
contains hydrolytic enzymes to help get through outer coat of egg (ovum)
Protamines
Special molecs in sperm that give structure to DNA
Instead of regular histones
Sertoli cells
Support cells in seminiferous tubules in male,
help with spermatogenesis;
Secrete:
1. anti-mullerian hormone (AMH) –> push development
2. activins and inhibins (after puberty) –> regulate FSH secretion
Leydig cells
In interstitium around seminiferous tubules,
Secrete testosterone
(Respond to LH)
Capacitation
Process of sperm maturation that occurs in Fallopian tubes (right before fertilization),
Many changes in sperm that increase ability to break through ovum
* requires at least albumin, Ca2+, and HCO3-
Changes in sperm during capacitation
- Cholesterol efflux
- Polarize membrane
- Increase cytosol pH
- Unmask surface receptors
Ovum
Mature oocyte
Kisspeptin
Key regulator of puberty,
Binds to GPR54 (a GPCR),
Signals to pituitary gland
Effect of cAMP on meiosis
High cAMP induces meiosis arrest
(via Wee1/MYT1 phosphorylation of cdk1/CYB –> “pre-MPF”)
– low cAMP => meiotic resumption
(Cdc25b activates MPF)
Mos
Serine/threonine kinase,
Activates (+P) MEK, *for meiosis arrest
Acrosomal reaction
Event where contents of acrosome are exocytosed, just before fertilization;
Ca2+ mediated rxn
Primordial germ cells (“PGCs”)
Give rise to gametes,
Specification of gamete cells
Sex differentiation
Specification of gonads (into male or female);
Determined by chromosomes, esp the Y (presence or absence)
SRY (Sex-determining Region of Y chromosome)
short arm of Y chromosome.
* needed for male characteristics,
THE major gene for testis determination
*also activates Sox9 TF (inhibited for female discrimination)
