The complex imprinted Gnas locus encodes several gene products including G s α, the
ubiquitously expressed G protein α-subunit required for receptor-stimulated cAMP
generation, and the neuroendocrine-specific G s α isoform XLαs. XLαs is only expressed
from the paternal allele, whereas G s α is biallelically expressed in most tissues. XLαs knock-
out mice (Gnasxl m+/p–) have poor suckling and perinatal lethality, implicating XLαs as
critical for postnatal feeding. We have now examined the metabolic phenotype of adult …