Increased adipose tissue in male and female estrogen receptor-alpha knockout mice. At six weeks, the gonad switches on the developmental pathway to become an ovary or a testis. Until recently, the X chromosome was thought not to participate significantly in the process of sexual differentiation.
Open in a separate window. Inactivation of one X chromosome in each non-germline XX cell greatly reduces the sex difference in level of expression of X genes that is predicted based on the number of copies of X genes . Although gonadal hormones are a key determinant of sexual dimorphism in body fat and metabolism, it is notable that even prior to the differentiation of the gonads, human and mouse male embryos are larger than female embryos, suggesting that non-gonadal factors also contribute .
Genetics— Moreover, differences between XX and XY mice are found after the gonads are removed in adulthood making their adult gonadal hormone levels zero, and equivalent across groups. If the gonad becomes an ovary, it makes oestrogen, and the lack of testosterone causes the male plumbing to wither.
Obesity represents a risk factor for many types of metabolic disease, including diabetes, coronary heart disease, osteoarthritis, and even cancer.
Biochim Biophys Acta. Umar S 1. When tested for preference for a novel versus familiar mouse, mice with two X chromosomes had greater preference for the unfamiliar mouse. The Ancel Keys Lecture. Kdm6a is required for proper embryonic development of the heart.
Wajchenberg BL. The homogenate was centrifuged at g for 3 min; the supernatant was filtered through cheesecloth and centrifuged at 10 g for 10 min. Studies of DSDs have shown that sex is no simple dichotomy.
Mice were gonadectomized at 75 days of age, continued on a chow diet for 4 weeks, and then fed the high fat diet for 16 weeks.