A fisherman's new tale: Nutrient-mediated mechanisms of brachial plasticity in rainbow trout.

磷在中间代谢中起着重要的生理作用，是DNA/RNA、磷脂和骨骼组织的重要组成部分。尽管有这些关键作用，但人们对缺磷的生理影响知之甚少。已有多项研究表明，饲料对磷在鱼体内的转运和体内磷吸收的调控具有重要意义。在虹鱼中，饲料磷限制增加了肠道对磷的摄取，这是由于一些调节磷运输的分子机制。研究表明，限制饮食磷可上调两种基因的表达，并增加组织对磷的摄取。钠-Napi是肾脏中发现的一种磷转运体，并受饮食磷限制而上调，尽管最近的研究表明，肾脏Napi mRNA对饮食P的变化相对不敏感，这是因为肾脏P调节的主要机制是通过Napi蛋白的运输而介导的，而Napi蛋白的运输不依赖于基因转录。我的实验室最近的研究表明，缺乏磷的虹鲑鱼能够从非饲料来源的磷中摄取磷。实验一直表明，缺磷的鱼来自周围的水。我们提出了多种方法来验证缺磷鱼类对水中磷的吸收。我们将确认P的吸收，这一现象将被描述，并使用免疫组织学定位和下一代测序技术/qPCR来定位，以确定受影响的允许P吸收的关键途径。将研究拟议现象的动态以及鱼的大小、磷状况的影响。这项工作将对理解营养缺乏发育过程中营养吸收的影响，特别是淡水鱼从根本上改变目前被认为微不足道的生理过程的适应反应产生重要影响。

Phosphorus (P) plays a vital physiological role in intermediary metabolism, and is a key component of DNA/RNA, phospholipids, and skeletal tissues. Despite these key roles, little is known about the physiological effects of P deficiency. There have been a number of studies demonstrating dietary regulation of Pi transport in fish and the regulation of Pi absorption in vivo. In rainbow trout, dietary P restriction increases intestinal Pi uptake due to a number of molecular mechanisms regulating Pi transport. Dietary P restriction has been shown to upregulate both mRNA species as well as to increase Pi uptake by the tissue. Sodium-NaPi is a Pi transporter found in kidney, and is upregulated by dietary P restriction, although recent work has suggested that renal NaPi mRNA is relatively insensitive to changes in dietary P due to the fact that he primary mechanism of renal P regulation is mediated by the trafficking of NaPi protein that is independent of gene transcription. Recent work from my laboratory demonstrates that P-deficient rainbow trout are able to take up P from non feed-derived P. Experiments have consistently revealed that P-deficient fish from surrounding water. We propose a variety of approaches to verify uptake of P from the water by P-deficient fish. We will confirm the uptake of P, and this phenomenon will be characterized, localised using immuno-histological localisation and next generation sequencing techniques/qPCR employed to determine the key pathways that are affected to permit P uptake. The dynamics of the proposed phenomenon and the impact of fish size, P status will be studied. This work will have an important impact on the understanding of the effect of nutrient absorption during nutrient deficiency development, and in particular the adaptive response of freshwater trout to fundamentally alter physiological processes that are currently thought to be insignificant.