Blankenship Kaley, Gilley Alex, Piekarski Alissa, Orlowski Sara, Greene Elizabeth, Bottje Walter, Anthony Nicholas, Dridi Sami
Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, United States.
Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, United States.
Neuropeptides. 2016 Aug;58:31-40. doi: 10.1016/j.npep.2015.12.007. Epub 2015 Dec 11.
Livestock and poultry sectors are facing a combination of challenges, including a substantial increase in global demand for high quality animal protein, general droughts and steady rise in animal feed cost. Thus feed efficiency (FE), which defines the animal's ability to convert feed into body weight, is a vital economic and agricultural trait. Genetic selection for FE has been largely used in chickens and has been applied without knowledge of the underlying molecular mechanisms. Although it has made tremendous progress (breast yield, growth rate, egg production), there have been a number of undesirable changes such as metabolic disorders. In the present study we divergently selected male and female quail for high and low FE and we aimed to characterize the molecular basis of these differences at the central level, with the long-term goal of maximizing FE and avoiding the unfavorable consequences. The FE phenotype in first generation quails seemed to be achieved by reduced feed intake in female and increased body weight gain in males. At the molecular level, we found that the expression of feeding-related hypothalamic genes is gender- and line-dependent. Indeed, the expression of NPY, POMC, CART, CRH, melanocortin system (MC1R, MC2R, MC4R, MC5R), ORX, mTOR and ACCα was significantly decreased, however ORXR1/2, AMPKα1, S6K1 and STAT1, 5 and 6 were increased in high compared to low FE males (P<0.05). These genes did not differ between the two female lines. ADPN gene expression was higher and its receptor Adip-R1 was lower in LFE compared to HFE females (P<0.05). In male however, although there was no difference in ADPN gene expression between the genotypes, Adip-R1 and Adip-R2 mRNA abundances were higher in the LFE compared to HFE line (P<0.05). This study identified several key central feeding-related genes that are differentially expressed between low and high FE male and female quails which might explain the differences in feed intake/body weight gain observed between the two lines. Of particular interest, we provided novel insights into central AMPK-mTOR-ACC transcriptional differences between low and high FE quail which may open new research avenues on their roles in the regulation of energy balance and FE in poultry and livestock species.
畜禽养殖部门面临着一系列挑战，包括全球对优质动物蛋白的需求大幅增加、普遍干旱以及动物饲料成本稳步上升。因此，饲料效率（FE），即动物将饲料转化为体重的能力，是一项至关重要的经济和农业性状。对FE的遗传选择已在鸡中广泛应用，但在应用时并不了解其潜在的分子机制。尽管已经取得了巨大进展（胸肉产量、生长速度、产蛋量），但也出现了一些不良变化，如代谢紊乱。在本研究中，我们对雄性和雌性鹌鹑进行了高FE和低FE的差异选择，旨在从核心层面表征这些差异的分子基础，长期目标是最大化FE并避免不良后果。第一代鹌鹑的FE表型似乎是通过雌性采食量减少和雄性体重增加来实现的。在分子水平上，我们发现与进食相关的下丘脑基因的表达具有性别和品系依赖性。事实上，与低FE雄性相比，高FE雄性中NPY、POMC、CART、CRH、黑皮质素系统（MC1R、MC2R、MC4R、MC5R）、ORX、mTOR和ACCα的表达显著降低，然而ORXR1/2、AMPKα1、S6K1以及STAT1、5和6的表达增加（P<0.05）。这两个雌性品系之间这些基因没有差异。与高FE雌性相比，低FE雌性中ADPN基因表达更高，其受体Adip-R1更低（P<0.05）。然而在雄性中，尽管不同基因型之间ADPN基因表达没有差异，但与高FE品系相比，低FE品系中Adip-R1和Adip-R2的mRNA丰度更高（P<0.05）。本研究确定了几个与核心进食相关的关键基因，它们在低FE和高FE的雄性和雌性鹌鹑之间差异表达，这可能解释了两个品系之间观察到的采食量/体重增加差异。特别值得关注的是，我们对低FE和高FE鹌鹑之间核心的AMPK-mTOR-ACC转录差异提供了新的见解，这可能为它们在调节家禽和家畜能量平衡及FE中的作用开辟新的研究途径。
