Truett G E, Tempelman R J, Walker J A
Pennington Biomedical Research Center, Baton Rouge 70808.
Am J Physiol. 1995 Jan;268(1 Pt 1):E15-20. doi: 10.1152/ajpendo.1995.268.1.E15.
Expression of a single copy of the rat obesity fatty (fa) gene may affect energy balance. To test this hypothesis, the effects of zero, one, and two copies of fa on early growth were evaluated, using a molecular genetic method for counting fa alleles inherited by 7- and 14-day-old F2 offspring of a BN/Crl x Crl:ZUC-fa F1 intercross. Litter and sex effects were controlled by multiple-regression analysis, allowing genotype effects on the weights of body, inguinal adipose pads, interscapular brown adipose tissue, and liver to be isolated. At 7 days of age, the fa copy number had linear effects on body and inguinal adipose pads weight. At 14 days of age, the fa copy number had linear effects on body, inguinal adipose pads, and interscapular brown adipose tissue weights and an additional quadratic effect on inguinal adipose pads weight. Thus fa has codominant effects on growth during the first week of life. The recessive effects of fa on growth appear during the second week of life.
大鼠肥胖脂肪（fa）基因单拷贝的表达可能会影响能量平衡。为验证这一假设，利用分子遗传学方法对7日龄和14日龄的BN/Crl×Crl:ZUC-fa F1杂交后代F2中继承的fa等位基因进行计数，评估了fa基因零拷贝、单拷贝和双拷贝对早期生长的影响。通过多元回归分析控制窝效应和性别效应，从而分离出基因型对体重、腹股沟脂肪垫、肩胛间棕色脂肪组织和肝脏重量的影响。7日龄时，fa拷贝数对体重和腹股沟脂肪垫重量有线性影响。14日龄时，fa拷贝数对体重、腹股沟脂肪垫和肩胛间棕色脂肪组织重量有线性影响，对腹股沟脂肪垫重量还有额外的二次效应。因此，fa在出生后第一周对生长有共显性效应。fa对生长的隐性效应在出生后第二周出现。
