In Mice Engineered to Overexpress the Syndecan-1 Gene in the Hypothalamic Region

Multiple Choice

 In mice engineered to overexpress the syndecan-1 gene in the hypothalamic region of the brain and other tissues,normal control of feeding by antisatiety peptides is disrupted,and the animals overeat and become obese.Other studies have shown that syndecan-3 may also be involved in the regulation of feeding behavior.Given the following information,which of these outcomes might you expect in experimentally manipulated mice?
Hypothalmic expression of syndecan-3 is increased by fasting.
Syndecan-3 knockout mice are resistant to diet-induced obesity.
Heparinase can cleave syndecan-3 to release heparin sulfate GAG chains that may suppress the activity of antisatiety peptides and feeding behavior.

A) Overexpression of heparinase in mice with normal levels of syndecan-3 would result in resistance to diet-induced obesity.
B)  In mice with normal levels of syndecan-3,fasting followed by free access to a high-fat diet would lead to resistance to diet-induced obesity.
C) Lack of heparinase in mice with normal levels of syndecan-3 would result in animals that overeat and become obese.
D) Overexpression of heparinase in syndecan-3 knockout mice would reverse the resistance to diet-induced obesity.
E) There are two plausible hypotheses: 1) Overexpression of heparinase in mice with normal levels of syndecan-3 would result in resistance to diet-induced obesity;and 2) lack of heparinase in mice with normal levels of syndecan-3 would result in animals that overeat and become obese.