1. GAMETOGENESIS
DR. JOSÉ LUIS ESPINOZA V.

2. The first phase in this process involves the developing gonad by primordial germ cells
from which the germ cells develop. The subsequent process, by which the maternal and
paternal gametes are produced from the primordial germ cells, is referred to as
gametogenesis.
The primordial germ cells are the predecessors of the female and male gametes.

4. • During and after their migration, the primordial
germ cells proliferate by mitoses.
• The female (XX) and male (XY) primordial germ cells
become engaged in sex-specific differentiation of
the gonads and become surrounded by somatic cells
• They are now referred to as oogonia and
spermatogonia, respectively.
• These cells undergo further proliferation before they
enter gametogenesis and, thus, meiosis.

5. 1
2

6. GAMETOGENESIS
• Proceso de
transformación a través
del cual estas células se
convierten en unidades
altamente especializadas:
– Células sexuales
• Óvulos
• Espermatozoides

7. • Gametogenesis includes meiosis, to allow
for recombination of genetic material and
for reduction of the number of
chromosomes from the diploid to the
haploid complement, and
cytodifferentiation, to achieve the cellular
structure characteristic of the female or
male gamete.

8. CONSECUENCIAS DE LA MEIOSIS

10. ÓVULO VS ESPERMATOZOIDE

20. ESPERMATOGENESIS
• Divisiones celulares en
túbulo seminífero
(espermatocitogénesis)
• Cambios morfológicos
(espermiogénesis)
• De la periferia al centro

35. • En esta fase se elimina
el citoplasma por
desplazamiento del
mismo hacia la pieza
terminal de la cola
originando la llamada
gota citoplasmática.

40. • El espermatozoide
adquiere la capacidad
de mover el flagelo en
su tránsito por el
epidídimo, pero el
movimiento empieza
después de la
eyaculación.
• Este proceso es
conocido como la
activación del
esperma.

42. CICLO DEL EPITELIO SEMINIFERO (ciclo
espermatogénico)
• En la pared del túbulo
seminífero hay
asociaciones de
células

52. SEMEN
• Suspensión celular liquida o
semigelatinosa que contiene
los espermatozoides y las
secreciones de las glándulas
accesorias

53. PLASMA SEMINAL (J Reprod Immunol. 2002 Jan;53)
• Fracción liquida del semen
• Las vesículas seminales del bovino secretan una familia de proteínas
(proteínas del plasma seminal; PPS)
• Con la eyaculación las PPS se unen a la superficie del espermatozoide
• Interactúan con factores de capacitación bovina (heparina y HDL)
• Las PPS estimulan la pérdida de colesterol y fosfolípidos de la
membrana espermática
– Paso importante en el proceso de capacitación

54. • Killian et al. (1993) reported the presence of four “fertility-
associated proteins” in the Holstein seminal plasma, one of
them later identified as osteopontin (OPN).
• The same protein, detected in accessory sex gland fluid, was
associated with fertility indexes of dairy bulls.
• This protein is expressed in the ampullae, seminal vesicles
and possibly the epididymis, as well as in the oviduct.
• In the seminiferous tubules, where it is synthesized by Sertoli
and germ cells, OPN is potentially involved in cell adhesion
and migration.

55. • The potential influence of seminal proteins
on male reproduction came to attention
because of the studies showing that their
expression is associated with breeding
scores of dairy bulls, beef bulls and horses.
– Prostaglandin D synthase
– Oseopontin