Uhlenhaut developed a strain of genetically engineered mice, whose copies of FOXL2 could be deleted with the drug tamoxifen.
The change was a thorough one; the altered organs were testes right down to the structure of their cells and their portfolio of active genes. They developed testosterone-secreting Leydig cells, which pumped out as much of the hormone as their counterparts in XY mice. They only fell short of actually producing sperm. The two genes are at opposite ends of a tug-of-war, with sex as the prize. Without its repressive hand, Sox9 switches on and sets about its gender-bending antics.
FOXL2 also has a partner-in-repression — the oestrogen receptor, a docking molecule for the hormone oestrogen. The two proteins interact with one another and they cooperate to block Sox9. In these animals, oestrogens often cause males to change sex into females, and falling levels of oestrogen can trigger the reverse transformation. FOXL2 may also be involved. The fact that oestrogen helps to maintain the gender of mice is surprising. Unlike other back-boned animals, mammals are thought to be largely insensitive to levels of sex hormones outside of development.
There have been hints from many species that FOXL2 plays an important role in determining sex. People who inherit faulty copies of the gene can develop a rare disease called BPES that often leads to infertility because of failing ovaries. Females that lack the gene altogether fail to develop proper ovaries at all. Understanding how gender is set and maintained is vital, for it is such a basic and pervasive element of our lives.
It could also help to treat disorders of sexual development. It could also change how gender reassignment therapies are done, paving the way for gene therapies rather than multiple painful surgeries. Make sure to wear laboratory gloves. Use forceps and other instruments while handling the organs. Make sure the focus of the microscopic lens is adjusted well enough.
Once the experiment is over, store the slides carefully and clean the microscopic lens. All of the experiments mentioned above are performed by using the transverse section of the testis and transverse section of an ovary of mice and grasshoppers. The anatomy of the two organs remains the same for all mammals. Solved Examples. Difference Between Testis and Ovary. It is the male gonad. It is the female gonad. It produces Spermatozoa. It produces Ova.
Hormone production. Oestrogen and Progesterone. Outside the body. Inside the body. Functions of Testis and Ovary. A small amount is also produced by the adrenal cortex.
Production of testosterone begins during fetal development, continues for a short time after birth, nearly ceases during childhood, and then resumes at puberty. This steroid hormone is responsible for:. Testosterone secretion is regulated by a negative feedback system that involves releasing hormones from the hypothalamus and gonadotropins from the anterior pituitary.
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