2009 BGD-B Lecture Sexual Differentiation
From Embryology
Introduction
This lecture is still available online with links to powerpoint slides as PDF for printing online lecture.
This current page is only in the early developmental stage and not complete.
BGD Genital 2009 Lecture Slides
The links below to PDF versions of lecture slides.
- 1 slide/page (52 pages 1.25 Mb)
- 4 slides/page (13 pages, 803 Kb)
- 6 slides/page (18 pages, 776 Kb)
- Lecture Handout (5 pages 172 Kb)
Lecture Overview
- Gonad
- Internal Genitalia
- Reproductive Tract
- External Genitalia
- Development
- Function
- Abnormalities
Background Reading
UNSW Embryology
NIH Bookshelf
- Developmental Biology (Gilbert) Chapter 17
- Endocrinology (Nussey and Whitehead) The Gonad
Textbook References
- Human Embryology (3rd ed.) Larson Chapter 10 pp266-313
- The Developing Human (6th ed.) Moore & Persaud Chapter 13 p303-346
- Before We Are Born (5th ed.) Moore & Persaud Chapter 14 p289-326
- Essentials of Human Embryology, Larson Chapter 10 p173-205
- Human Embryology, Fitzgerald and Fitzgerald Chapter 21-22 p134-152
Genital System Development
3 stages
- Differentiation of gonad (sex determination)
- Differentiation of internal genital organs
- Differentiation of external genital organs
2nd and 3rd stages dependent on endocrine gonad
- Long Maturation Time-course
- Begins in embryo
- Continues through fetal
- Finishes in puberty
Sex Chromosomes
X Chromosome
- 1400+ genes
- 150 million base pairs
- 95% determined
Y Chromosome
- 200+ genes
- 50 million base pairs
- 50% determined
Sex Determination
- Humans (week 5-6)
- Germ cells migrate into gonadal ridge
- Gonads (male/female) identical at this stage (Indifferent)
Gonad development dependent on sex chromosome
- Y present testes
- No Y ovary
DNA with SRY Protein SRY protein binds DNA
Testes determining factor (TDF)
- Transcription factor
- Bends DNA 70–80 degrees
Genital Abnormalities
- Chromosomal
- Hermaphroditism
- Gonadal Dysfunction
- Tract Abnormalities
- External Genitalia
- Gonadal Descent
