Ka S, Lindberg J, Strömstedt L, Fitzsimmons C, Lindqvist N, Lundeberg J, Siegel P B, Andersson L, Hallböök F
Department of Neuroscience, Uppsala University, Uppsala, Sweden.
J Neuroendocrinol. 2009 Mar;21(3):208-16. doi: 10.1111/j.1365-2826.2009.01819.x. Epub 2009 Jan 15.
Long-term selection (> 45 generations) for low or high body weight from the same founder population has generated two extremely divergent lines of chickens, the low (LWS) and high weight (HWS) lines, which at the age of selection (56 days) differs by more than nine-fold in body weight. The HWS line chickens are compulsive feeders, whereas, in the LWS line, some individuals are anorexic and others have very low appetites. The involvement of the central nervous system in these behavioural differences has been experimentally supported. We compared a brain region at 0 and 56 days of age containing the major metabolic regulatory regions, including the hypothalamus and brainstem, using a global cDNA array expression analysis. The results obtained show that the long-term selection has produced minor but multiple expression differences. Genes that regulate neuronal plasticity, such as actin filament polymerisation and brain-derived neurotrophic factor, were identified as being differentially expressed. Genes involved in lipid metabolism were over-represented among differentially expressed genes. The expression data confirm that neural systems regulating feeding behaviours in these lines are different. The results suggest that the lines are set in separate developmental trajectories equipped with slightly different nervous systems. We suggest that the lines adapt behaviourally different to changing situations post hatch, such as the transition from dependence on yolk to feeding, in order to obtain energy. The present study has identified and exemplifies the kind of changes that may underlie the extreme differences in such behaviours.
从同一创始群体中对低体重或高体重进行长期选择（>45代），已培育出两个截然不同的鸡品系，即低体重（LWS）品系和高体重（HWS）品系，在选择年龄（56日龄）时，它们的体重差异超过9倍。HWS品系的鸡是强迫性进食者，而在LWS品系中，一些个体厌食，另一些个体食欲极低。中枢神经系统参与这些行为差异已得到实验支持。我们使用全局cDNA阵列表达分析，比较了0日龄和56日龄时包含主要代谢调节区域（包括下丘脑和脑干）的一个脑区。所得结果表明，长期选择产生了微小但多样的表达差异。调节神经元可塑性的基因，如肌动蛋白丝聚合和脑源性神经营养因子，被鉴定为差异表达。参与脂质代谢的基因在差异表达基因中过度富集。表达数据证实，这些品系中调节摄食行为的神经系统不同。结果表明，这些品系处于配备略有不同神经系统的不同发育轨迹中。我们认为，这些品系在孵化后对不断变化的情况（如从依赖卵黄到进食的转变）在行为上有不同的适应，以获取能量。本研究已经识别并举例说明了可能是此类行为极端差异基础的那种变化。
