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PUBERTY

PUBERTY. Gonadal maturation with acquisition of secondary sexual characteristics and associated growth spurt FERTILITY AND FINAL HEIGHT. Sex Determination. Genetic Sex. XY. XX. Ovary-determining genes. Testis-determining genes. Gonadal Sex. Gonadal steroids (E 2 , P 4 ).

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PUBERTY

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  1. PUBERTY Gonadal maturation with acquisition of secondary sexual characteristics and associated growth spurt FERTILITY AND FINAL HEIGHT

  2. Sex Determination Genetic Sex XY XX Ovary-determining genes Testis-determining genes Gonadal Sex Gonadal steroids (E2, P4) Gonadal steroids & peptides (T, DHT, MIS) Phenotypic Sex

  3. Genetic Pathway for Testis Development Bipotential Gonad Testis Development Testis Function Leydig -Testosterone ↓ Dax1 Wnt4 ↓ Sf1 Wt1 Sf1 Dmrt1 M33 Emx2 Lim1 Lhx9 Atrx Dhh Pdgf Sox9 Sox8 Sertoli -AMH -ABP -Inhibin B Insulin/IGF Gata4/Fog2 Wt1 Sf1 Sry Fgf9 Fgfr2 Sf1 Dax1 Germ cells -Spermatogenesis • Vascularization • Germ cell migration/proliferation • Inhibition of PGC meiosis • Sertoli proliferation/differentiation • Leydig cell migration/differentiation • PTM cell migration/proliferation • Testis cord formation

  4. Morphologic Steps in Testis Development XY XX Proliferation Sertoli Differentiation Migration Testis cords Vascularization Leydig cells Brennan J, Capel B: Nat Rev Genet 5: 509, 2004

  5. Hypothalamus GnRH pulses GnRH LH pulses Pituitary LH FSH Gonads Inhibin T E2 P

  6. PUBERTY Gonadal maturation with acquisition of secondary sexual characteristics and associated growth spurt FERTILITY AND FINAL HEIGHT

  7. PUBERTY Average age of onset: • 11.4 years in girls • 12.0 years in boys First signs of pubertal maturation: • breast budding in girls • increase in testicular volume in boys

  8. TANNER’S STAGING OF PUBERTY IN BOYS

  9. Testosterone produced by Leyding cells induces/ maintains secondary sexual characteristics and sustain germ cell production • Virilization of external genitalia • Phallus growth • Pubic, axillary, facial hair • Libido • Erections/ejaculate • Voice change • Body composition • Bone mineralization

  10. CONCERNS RAISED BY DELAYED PUBERTY • Possibly sinister underlying cause • Fear that puberty will never occur • Emotional and psychosocial upset of immaturity, specially when associated with short stature • Long term sequelae: ? Reduced bone mineralization

  11. DELAYED PUBERTY • Absence of a clear pattern of pulsatile gonadotrophin secretion • Pre-pubertal LH and FSH levels • Development of secondary sexual characteristics • Normal "Consonance" • Bone age delay • Final height is not impaired except if severe degree of delay

  12. Male Homosexuality: Nature or Culture? • 1500 species • Data mostly in males: more common more studied more confronted by religion • Genetic • Autoimmune • Neurohormonal Jannini 2010

  13. Nature - BIOLOGY Inherited from the mother Cause or result

  14. Brain Anatomy Swaab 2004

  15. Nature – Culture Biology • Older brother – more biological brothers ++ more immunity? • Fertility Advantage of carrying the HM gene (Camperio-Ciani 2008) • Ratio of 2D:4D (lower-male, higher-female) • Nature does not deny Nurture • Culture denies Nature!

  16. Older brothers and hand preference

  17. “Half Woman”??? Testosterone - higher (Brodie 1974, Jannini 2009) Testicular feminization example CAH Fetal Brain epigenetics Sexual activity - higher

  18. Penis - Longer (Ghanem 2007) (Bogaret 1999)

  19. Nature • recent genetic study 2005 • a full genome scan • 456 individuals from 146 families with two or more homosexual brothers 3 locuses and X chromosome 28q

  20. A genome-wide scan of male sexual orientation Journal of Human Genetics (2010) 55 Sreeram V Ramagopalan, Journal of Human Genetics (2010)

  21. Culture • low paternal presence, high maternal cures • Oedipus Diagnostic and Statistical Manual of Psychological Disorders (DSM-IV-TR) - “homosexuality” absent

  22. Culture • early childhood traumas • propose a reparative therapy • based on psychoanalysis, group therapy, and spiritual help

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