TOX 4000 Study Guide - Final Guide: Endocrine Disruptor, Testicular Cancer, Alkylphenol

• School: University of Guelph
• Department: Toxicology
• Course: TOX 4000
• Professor: Craig Bailey

Document Summary

Stages of reproduction and development: (i) (ii) (iii) During early human development, there is a short period immediately prior to sexual differentiation when the gonad is sexually indifferent and it is not until the seventh week of gestation that male and female morphological characteristics begin to develop. In rodents, the embryo remains sexually indifferent and possesses both male and female reproductive tract primordia until embryonic day 13. 5 regardless of its genetic sex. Gonadal differentiation is dependent on signals from the y chromosome, which contains the genes necessary to induce testicular morphogenesis. One of these signals is the sry gene, which is the sex-determining region on the short arm of the y chromosome, and acts as a (cid:498)switch(cid:499) to initiate transcription of other genes, which contribute to testicular organogenesis. In the absence of the sry protein, the gonad remains indifferent for a short period of time before differentiating into an ovary.