Analysis Tools
homeostasis/metabolism
|
• in the presence of this cre deleter, which expresses in tissues posterior to the umbilicus but not anterior to it, floxed homozygotes have reduced serum levels of myostatin, with females having 26 +/- 2 ng/ml and males 42.7 +/- 2.6 nm/ml, compared with wild-type values of 62.2 and 82.9 ng/ml respectively, and this results from ablated expression from posterior muscles but relatively normal expression from anterior muscles. The levels found in females, but not males, is lower than the levels found in haploinsufficient females heterozygous for a null allele.
|
muscle
|
• two posteriorly located muscles, quadriceps and gastrocnemius, have dramatically higher weights than those of control mice at 10 weeks of age, while the anteriorly located muscles, pectoralis and triceps, have a slight increase, likely due to the decreased levels of serum myostatin. The increase in quadriceps size in both males and females is statistically larger in mice homozygous for a null allele than in these compartmentally null mice indicating that serum myostatin generated from anterior muscles has an impact, albeit a minority impact, on posterior muscles
|
 |
• the gastrocnemius, assessed from females, has an increase in the total number of muscle fibers from an average of 8,802 in the absence of cre to 13,079 in the presence of cre
|
|
|
• the gastrocnemius, assessed from females, has an increase in the fiber diameter of muscle fibers averaging 16.5% larger than the muscle fibers in the absence of cre
|
