Nutrigenomics: a case study in the measurement of insect response to nutritional quality

Recent developments in the area of nutrigenomics hold the promise of providing valuable information about the impact of nutrition on a wide range of biochemical parameters by investigating how nutrition alters global gene expression patterns. Our goal is to use a nutrigenomics approach to identify insect molecular markers that could be used as early indicators of insect responses to different nutritional sources. Such molecular markers could be chosen for degree of expression and evaluated for suitability as nutritional biomarkers by examining developmental and generational expression. Ideal markers would be highly expressed, manifested in the first generation within one developmental stage, and consistent over many generations. Our objective for the current study was to illustrate the potential discovery of molecular markers using Perillus bioculatus (F.) (Heteroptera: Pentatomidae), when reared on an optimal vs. suboptimal diet, and analyze the presence of differentially expressed genes resulting from those treatments. In this paper we present preliminary results of microarray and subtractive hybridization experiments that represent the feasibility of using nutrigenomics to assist in analyzing insect responses to nutritional changes and dietary quality with the intent of stimulating further studies in this area.     

Fertility estimation: a review of past experience and future prospects

Fertility has many components and stages which require that males and females be functionally capable of carrying out all critical stages if each generational reproductive cycle is to be completed. To accomplish this, the male must produce and ejaculate normal fertile sperm. The female must produce, store and ovulate normal fertilizable oocytes. Furthermore, the female must provide a reproductive system compatible with sperm transport, capacitation, and fertilization of the oocytes, embryo and fetal development, and finally birth of healthy young. Reproductive success or failure at several of these points can be estimated quantitatively on a population basis, and in a few situations on an individual basis. It is important that fertility estimates be determined accurately and with precision to be most useful to researchers and managers of animal enterprises. Many studies have underestimated the biological relationship of fertility to other traits because the estimates lacked precision. Many in vitro manipulations of sperm in artificial insemination, of gametes in various assisted reproductive technologies, and of embryos in embryo transfer are utilized in animal breeding programs. Accurate estimation of reproductive efficiency of these in vitro procedures also is important. Conditions surrounding different sets of fertility estimates almost certainly will be different. These conditions should be described as precisely as possible, and appropriate controls included in all experiments. When possible, experiments should be replicated over time and place to determine the repeatability of the various criteria used to estimate fertility and reproductive efficiency. Advances in genomic information and molecular biology should facilitate characterizing more fully inherent potential fertility of animals at birth. In vitro tests will improve, and automated techniques will facilitate making multiple determinations possible on a large scale. Reliability of fertility estimates will increase, with the potential for enhanced animal reproductive performance through more accurate selection, genetic engineering, and enlightened animal care. Simultaneously, it is important to recognize that prediction of future fertility is more hazardous than estimating fertility, as a completely new set of circumstances may occur which are not predictable. Because fertility estimation may be applied under a myriad of conditions, principles and factors affecting fertility will be emphasized in this review as being more useful than a compilation of numerical examples.     

营养基因组学的研究进展

营养学是一门古老的学科, 为人们的健康保护和疾病预防提供了重要的理论指导。随着分子生物学技术的发展, 它已成为21世纪生命科学研究最为主要的技术之一。分子生物学与营养学的结合, 产生了分子营养学。而基因组学与营养学的结合, 则形成了营养基因组学。营养基因组学涵盖了一个广泛的领域, 它研究营养素和基因表达的相互影响, 预测其对营养素的反应。基因组学技术可以帮助确认一些与疾病发生有关的基因, 人们可以根据各自的基因图谱制定一份个性化的饮食方案, 以此防病治病, 使人们的健康状况通过调整饮食来达到最佳。文中重点介绍了营养基因组学的主要研究方法及其应用。     

Understanding the nutrigenomic definitions and concepts at the food-genome junction

The marked differences in individual response to dietary factors have led to major controversies in nutrition and puzzled nutrition scientists over the last century. The emerging field of nutrigenomics helps us to understand the basis for some of these differences and also promises us the ability to tailor diet based on individual genetic makeup. Great advances in Human Genome Project, documentation of single nucleotide polymorphisms (SNPs) in candidate genes and their association with metabolic imbalances have gradually added new tests to the nutrigenomic panel. Studies based on ethnopharmacology and phytotherapy concepts showed that nutrients and botanicals can interact with the genome causing marked changes in gene expression. This has led to the commercial development of nutraceuticals and functional foods that can modify negative health effects of individual genetic profile bringing the field to the "food/genome" junction. Despite the promise of nutrigenomics to personalize diet, there is skepticism whether it can truly bring about meaningful modification of the risk factors connected to chronic diseases, due to the lack of large scale nutrition intervention studies. Several intervention studies currently underway in the United States and abroad (Israel, Spain, and France) will further help validate nutrigenomic concepts. France has already introduced a National Nutrition and Health Program to assess nutritional status and risk of major metabolic diseases. As the field(s) related to nutritional genomics advance in their scope, it is essential that: (a) strict guidelines be followed in the nomenclature and definition of the subdisciplines; and (b) the state/federal regulatory guidelines be updated for diagnostic laboratories, especially for those offering tests directly to the public (without a physician's request) to help protect the consumer.     

Evolutionary conservation of metabolism explains howDrosophila nutrigenomics can help us understand human nutrigenomics

While large populations in the third world are enduring famine, much of the developed world is undergoing an obesity epidemic. In addition to reflecting an unbalanced distribution of food, the "epidemic of overabundance" is ironically leading to a decrease in the health and longevity of the obese and improperly nourished in the first world. International consortia, such as the European Nutrigenomics Organization (NuGO), are increasing our knowledge of nutrientgene interactions and the effects of diet and obesity on human health. In this review, we summarize both previous and ongoing nutrigenomics studies in Drosophila and we explain how these studies can be used to provide insights into molecular mechanisms underlying nutrigenomics in humans. We will discuss how quantitative trait locus (QTL) experiments have identified genes that affect triglyceride levels in Drosophila, and how microarray analyses show that hundreds of genes have altered gene expression under different dietary conditions. Finally, we will discuss ongoing combined microarray-QTL studies, termed "genetical genomics," that promise to identify "master modulatory loci" that regulate global responses of potentially hundreds of genes under different dietary conditions. When "master modulatory loci" are identified in Drosophila, then experiments in mammalian models can be used to determine the relevance of these genes to human nutrition and health.     

The challenges for molecular nutrition research 3: comparative nutrigenomics research as a basis for entering the systems level

Human nutrition and metabolism may serve as the paradigm for the complex interplay of the genome with its environment. The concept of nutrigenomics now enables science with new tools and comprehensive analytical techniques to investigate this interaction at all levels of the complexity of the organism. Moreover, nutrigenomics seeks to better define the homeostatic control mechanisms, identify the de-regulation in the early phases of diet-related diseases, and attempts to assess to what extent an individual's sensitizing genotype contributes to the overall health or disease state. In a comparative approach nutrigenomics uses biological systems of increasing complexity from yeast to mammalian models to define the general rules of metabolic and genetic mechanisms in adaptations to the nutritional environment. Powerful information technology, bioinformatics and knowledge management tools as well as new mathematical and computational approaches now make it possible to study these molecular mechanisms at the cellular, organ and whole organism level and take it on to modeling the processes in a "systems biology" approach. This review summarizes some of the concepts of a comparative approach to nutrigenomics research, identifies current lacks and proposes a concerted scientific effort to create the basis for nutritional systems biology.     

Proteomics of boar seminal plasma - current studies and possibility of their application in biotechnology of animal reproduction

Proteomics is critical to identify the properties and functions of proteins involved in the mechanism regulating the male reproductive tract function. This approach is important in male fertility assessment and clinical diagnosis of the physiological state of individual reproductive organs. Proteomics also provides a tool to understand the interactions of seminal plasma proteins with spermatozoa, which could provide a useful model for studying ligand-cell interaction occurring at the sperm cell surface. This review covers a selection of advances in the realm of functional proteomics of boar seminal plasma proteins and is focused on some fundamental proteomic technologies. Also, this review explores key themes in proteomics and their application in animal reproductive techniques.