The Booroola (FecB) mutation is associated with smaller adrenal glands in young adult ewes.
The Booroola (FecB) phenotype is associated with a mutation in the bone morphogenetic protein (BMP) receptor 1B. The BMP action is important during development; surprisingly the only differences so far observed in adult animals are restricted to the ovaries where precocious development of the antral follicles and increased ovulation rate of mutant ewes is observed. The internal organs of 17 ewes homozygous for the mutation (BB) and 18 wild-type ewes (++) were macroscopically examined and weighed. No macroscopic differences were found, and the weight of the heart, liver, lungs, kidneys, and spleen were similar for both genotypes (P > 0.05). In contrast, the adrenals of BB ewes were lighter than those of ++ ewes (P < 0.05). The effect of the mutation on the adrenal function of cortisol secretion was measured at basal level and after an adrenocorticotrophic hormone challenge, before and after dexamethasone suppression. The Booroola mutation had no effect (P > 0.05) in any of these conditions. These findings indicate that the Booroola mutation also affects the size of the adrenal glands and suggest that the mutated gene could be important in the development of other organs in addition to the ovary. However, in the mutant ewes the function of the adrenal glands is not compromised or it is compensated.
Souza
C J H
CJ
EMBRAPA Genetic Resource and Biotechnology, Parque Estação Biológica s/n, Final W5 norte, CEP 70770-900, Brasilia, Brazil. csouza@cenargen.embrapa.br
Baird
D T
DT
D000311:Adrenal Glands / Q000473:pathology*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D052005:Bone Morphogenetic Protein Receptors, Type I; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D005838:Genotype; D005938:Glucocorticoids / Q000494:pharmacology; D006720:Homozygote; D006854:Hydrocortisone / Q000097:blood; D009154:Mutation; D009994:Osmolar Concentration; D010641:Phenotype; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D017978:Receptors, Growth Factor / Q000235:genetics*; D012756:Sheep
D005938:Glucocorticoids; D017978:Receptors, Growth Factor; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D017346:Protein Serine-Threonine Kinases; D052005:Bone Morphogenetic Protein Receptors, Type I; D006854:Hydrocortisone