Lu Yuan, Klimovich Charlotte M, Robeson Kalen Z, Boswell William, Ríos-Cardenas Oscar, Walter Ronald B, Morris Molly R
Molecular Bioscience Research Group, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA.
Department of Biological Sciences, Ohio University, Athens, OH, USA.
PeerJ. 2017 May 2;5:e3275. doi: 10.7717/peerj.3275. eCollection 2017.
Nutritional programming takes place in early development. Variation in the quality and/or quantity of nutrients in early development can influence long-term health and viability. However, little is known about the mechanisms of nutritional programming. The live-bearing fish has the potential to be a new model for understanding these mechanisms, given prior evidence of nutritional programming influencing behavior and juvenile growth rate. We tested the hypotheses that nutritional programming would influence behaviors involved in energy homeostasis as well gene expression in
We first examined the influence of both juvenile environment (varied in nutrition and density) and adult environment (varied in nutrition) on behaviors involved in energy acquisition and energy expenditure in adult male . We also compared the behavioral responses across the genetically influenced size classes of males. Males stop growing at sexual maturity, and the size classes of can be identified based on phenotypes (adult size and pigment patterns). To study the molecular signatures of nutritional programming, we assembled a transcriptome for using RNA from brain, liver, skin, testis and gonad tissues, and used RNA-Seq to profile gene expression in the brains of males reared in low quality (reduced food, increased density) and high quality (increased food, decreased density) juvenile environments.
We found that both the juvenile and adult environments influenced the energy intake behavior, while only the adult environment influenced energy expenditure. In addition, there were significant interactions between the genetically influenced size classes and the environments that influenced energy intake and energy expenditure, with males from one of the four size classes (Y-II) responding in the opposite direction as compared to the other males examined. When we compared the brains of males of the Y-II size class reared in a low quality juvenile environment to males from the same size class reared in high quality juvenile environment, 131 genes were differentially expressed, including metabolism and appetite master regulator gene.
Our study provides evidence for nutritional programming in , with variation across size classes of males in how juvenile environment and adult diet influences behaviors involved in energy homeostasis. In addition, we provide the first transcriptome of , and identify a group of candidate genes involved in nutritional programming.
营养编程发生在早期发育阶段。早期发育过程中营养物质质量和/或数量的变化会影响长期健康和生存能力。然而，关于营养编程的机制知之甚少。鉴于先前有营养编程影响行为和幼鱼生长速率的证据，胎生鱼类有潜力成为理解这些机制的新模型。我们检验了以下假设：营养编程会影响能量稳态相关行为以及基因表达。
我们首先研究了幼鱼环境（营养和密度不同）和成年环境（营养不同）对成年雄性鱼能量获取和能量消耗相关行为的影响。我们还比较了不同遗传影响大小类别的雄性鱼的行为反应。雄性鱼在性成熟时停止生长，可根据表型（成年大小和色素模式）确定其大小类别。为了研究营养编程的分子特征，我们使用来自脑、肝、皮肤、睾丸和性腺组织的RNA为某鱼类组装了转录组，并使用RNA测序来分析在低质量（食物减少、密度增加）和高质量（食物增加、密度降低）幼鱼环境中饲养的雄性鱼大脑中的基因表达情况。
我们发现幼鱼环境和成年环境都会影响能量摄入行为，而只有成年环境会影响能量消耗。此外，在遗传影响的大小类别与影响能量摄入和能量消耗的环境之间存在显著相互作用，四个大小类别之一（Y-II）的雄性鱼与其他被研究的雄性鱼反应方向相反。当我们将在低质量幼鱼环境中饲养的Y-II大小类别的雄性鱼大脑与在高质量幼鱼环境中饲养的相同大小类别的雄性鱼大脑进行比较时，有131个基因差异表达，包括代谢和食欲主调节基因。
我们的研究为某鱼类的营养编程提供了证据，不同大小类别的雄性鱼在幼鱼环境和成年饮食如何影响能量稳态相关行为方面存在差异。此外，我们提供了某鱼类的首个转录组，并鉴定出一组参与营养编程的候选基因。
