Question

Q6: 2 parts

A) Would it be possible for a person to be born with ovaries, a labia, clitoris, organs derived from the Wolffian ducts, and organs derived from the Mullerian ducts?

B) Explain why or why not with reference to how hormones control the development of each set of structures.

When answering these questions, consider only the effects of hormones on the sexual differentiation of the reproductive system and assume that there are no unusual patterns of receptor expression.

Answer 1

1. Yes, it is possible for a person to be born with ovaries, a labia, clitoris, organs derived from wolffian ducts like epididymis, vas deferens, seminal vesicles and ejaculatory ducts and organs developed from mullerian ducts like fallopian tubes and uterus. This rare condition is called true hermaphroditism. Both male and female sex differentiation occur with the development of combined female and male external and internal genitalia. The karyotype pattern is 46 XX-XY.

2. The differentiation of genital duct and external genitalia requires hormones. The basic rule of this differentiation is under the direct positive hormonal influence, the male gonadal system develops and in the absence of any hormonal influence, female gonadal system develops.

In males, the wolffian or mesonephric ducts which gives rise to epididymis, vas deferens, seminal vesicles and ejaculatory ducts. This differentiation occurs only due to the appearance of leydig cells in the testis and that secretes testosterone. This testosterone stimulates growth and differentiation of wolffian duct into male genital system.

Mullerian ducts regress by the time of appearance of sertoli cells in testis. As these cells produce a hormone called anti-mullerian hormone or mullerian inhibiting substance or mullerian regression factor. This causes degeneration of mullerian duct by facilitating its apoptosis. The SRY gene in males also promotes the synthesis of mullerian inhibiting substance (MIS).

In females, wolffian duct degenerate as ovaries doesn't secrete testosterone. From wolffian ducts on each side mullerian or paramesonephric ducts arise which develops into fallopian tubes uterus cervix and vagina. There lack mullerian inhibiting substance and so this differentiation of mullerian duct into female genital system occurs.