CELL BIOLOGY SYMPOSIUM Research Articles

CELL BIOLOGY SYMPOSIUM: METABOLIC RESPONSES TO STRESS: FROM ANIMAL TO CELL: Poor maternal nutrition during gestation: effects on offspring whole-body and tissue-specific metabolism in livestock species1,2.

Poor maternal nutrition, both restricted-feeding and overfeeding, during gestation can negatively affect offspring growth, body composition, and metabolism. The effects are observed as early as the prenatal period and often persist through postnatal growth and adulthood. There is evidence of multigenerational effects demonstrating the long-term negative impacts on livestock production. We and others have demonstrated that poor maternal nutrition impairs muscle growth, increases adipose tissue, and negatively affects liver function. In addition to altered growth, changes in key metabolic factors, increased glucose concentrations, insulin insensitivity, and hyperleptinemia are observed during the postnatal period. Furthermore, there is recent evidence of altered metabolism in specific tissues (e.g., muscle, adipose, and liver) and stem cells. The systemic and local changes in metabolism demonstrate the importance of determining the mechanism(s) by which maternal diet programs offspring growth and metabolism in an effort to develop novel management practices to improve the efficiency of growth and health in these offspring.

CELL BIOLOGY SYMPOSIUM: Membrane trafficking and signal transduction1

CELL BIOLOGY SYMPOSIUM: Membrane trafficking and signal transduction1

CELL BIOLOGY SYMPOSIUM: Practical application of the basic aspects of GLUT4 membrane trafficking and insulin signaling on issues related to animal agriculture.

Because of the relatively short lifespans of beef cattle, membrane trafficking in relation to inflammation is not considered important unless it overtly affects productivity. However, glucose uptake and utilization is important for adipose tissue development in beef cattle, and increasing glucose utilization in intramuscular adipose tissue can increase carcass quality. Research from the 1980s demonstrated a lack of insulin sensitivity in isolated bovine adipocytes and adipose tissue explants incubated in vitro. Insulin did not stimulate glucose or acetate incorporation into fatty acids, nor did it increase concentrations of glycolytic intermediates in bovine adipose tissue incubated with exogenous glucose. Specific binding of [I] iodoinsulin and insulin degradation in bovine isolated adipocytes was low to non-detectable. These early studies indicated that insulin-dependent receptor-mediated signaling was less important in bovine adipose tissue than in adipose tissues of humans, swine, or laboratory species. More recent research demonstrated that glucose transporter protein 4 (GLUT4) expression in muscle and adipose tissue declines markedly after birth in calves, indicating the development of insulin resistance as cattle transition from suckling to functional ruminants. Insulin resistance is important in dairy cattle, causing ketosis and fatty liver. Consistent with this, subcutaneous adipose tissue expression decreases 50% following parturition in dairy cattle, although expression of genes associated with insulin responsiveness (, , and ) is up-regulated by 21 d postpartum. Understanding the underlying mechanisms of insulin resistance in beef and dairy cattle would increase animal health and thereby improve productivity.

CELL BIOLOGY SYMPOSIUM: Membrane trafficking and signal transduction

CELL BIOLOGY SYMPOSIUM: Membrane trafficking and signal transduction

CELL BIOLOGY SYMPOSIUM: Practical application of the basic aspects of GLUT4 membrane trafficking and insulin signaling on issues related to animal agriculture

CELL BIOLOGY SYMPOSIUM: Practical application of the basic aspects of GLUT4 membrane trafficking and insulin signaling on issues related to animal agriculture

A Symposium-Based Self-Directed Learning Approach to Teaching Medical Cell Biology to Medical Students

The Commonwealth Medical College has used a variety of self-directed learning pedagogies to promote the student’s performance and knowledge retention since its inception in 2009. Based on this goal, a Cell Biology Symposium was designed to allow students to present medical cell biology concepts to their peers. It was believed that by utilizing a team-based learning strategy, this would enhance the students’ learning. This is a study that describes how well medical students mastered medical cell biology concepts in a classroom lecture-based format versus a peer-teaching format arranged as a Medical Cell Biology Symposium. We analyzed the list of cell biology concepts that medical students were required to understand according to guidelines published by the 2009 US Medical Licensing Examination (USMLE) Step 1 Content Description and General Information (2008) and chose eight appropriate subjects and associated diseases that would cover these concepts. The 65 students in the 2009 class were assigned to teams and given faculty selected papers. Their goal was a PowerPoint presentation to their fellow students, designed on updating the class on the changes in medical knowledge since their assigned paper was published, including associated learning objectives and an annotated bibliography. We analyzed a student-derived, take-home test and a multiple-choice test given to the subsequent class of 2010, also composed of 65 students. As expected, scores for the open-book take-home test were much higher than the scores in a closed-book, multiple-choice examination given in the subsequent year. Our data indicate that satisfaction with an activity does not necessarily correlate with knowledge of this subject area in test performance and that this type of self-directed learning activity is an excellent way to deliver cell biology content to medical students. The real value of the Cell Biology Symposium may lie more in improving student skills in communication, problem solving, leadership, and working together as a team. These skills will be at least as important to the future success of our medical students as their mastery of the basic science, in this case cell biology, associated with the practice of medicine.

CELL BIOLOGY SYMPOSIUM: The Immune System in Pregnancy

CELL BIOLOGY SYMPOSIUM: The Immune System in Pregnancy

CELL BIOLOGY SYMPOSIUM: the immune system in pregnancy.

CELL BIOLOGY SYMPOSIUM: the immune system in pregnancy.

CELL BIOLOGY SYMPOSIUM: Perspectives: Possible roles of polymorphonuclear neutrophils in angiogenesis and lymphangiogenesis in the corpus luteum during development and early pregnancy in ruminants1

The establishment of pregnancy requires well-balanced regulation of the endocrine and immune systems and involves interactions among the conceptus, oviduct-uterus, and corpus luteum (CL). In particular, a rapid increase in plasma progesterone during the first week after ovulation is critical for the growth of the conceptus and successful pregnancy in cattle. Events involved in maternal recognition of pregnancy (MRP) may commence within 1 wk from AI, when interferon-stimulated gene expression in circulating polymorphonuclear neutrophils (PMN) increases in pregnant cows. To regulate optimal endocrine conditions within this time, the CL must develop rapidly, with active angiogenesis and lymphangiogenesis. The major angiogenic factors, vascular endothelial growth factor and fibroblast growth factor 2, contribute to the development of the CL but may also act as chemoattractants for PMN. Indeed, the number of PMN is greatest in the new CL, where PMN together with IL-8 induce active angiogenesis and lymphangiogenesis. During MRP, the conceptus secretes interferon tau (IFNT), which prevents CL regression by inhibiting luteolytic release of PGF2α from uterine endometrium. In addition, IFNT and PGE2 reach the CL and may contribute to desensitizing the CL to the luteolytic effects of PGF2α. In the bovine CL, lymphangiogenesis, stimulated by IFNT, may occur during MRP, and thus a shift of local immunity might occur at this timing. The aforementioned evidence supports the possible involvement of PMN in the establishment of pregnancy via CL regulation. Further investigation could expand our understanding of the communication between zygotes, PMN, and reproductive organs during early pregnancy. This should provide new insight into the contribution of neutrophils to CL function and immune tolerance during early pregnancy in ruminants.

CELL BIOLOGY SYMPOSIUM: Impacts of maternal obesity on placental and gut inflammation and health1,2

Obesity in pregnant women is a growing public health concern that negatively affects fetal development and has long-term impacts on offspring health. The placenta plays an essential role in nutrient transport to the fetus and supports fetal growth and development. Maternal obesity (MO) induces an exacerbated proinflammatory milieu in the placenta providing an inflammatory environment for fetuses. The gut is one of the largest immune organs and mainly develops during the fetal stage. Maternal obesity and the corresponding inflammatory uteroplacental environment affect gut development, incurring inflammatory responses in the fetal intestine that further prime or program the offspring gut to enhance inflammation and impair intestinal barrier integrity. This review summarizes the impact of MO on inflammatory responses in placenta and fetal intestine and the long-term effects on offspring intestinal health. Because "leaky gut" is one of the main etiological factors for a number of common diseases, including inflammatory bowel diseases, type I diabetes, and related autoimmune diseases, the adverse effect of MO on the overall health of progeny is further discussed.

CELL BIOLOGY SYMPOSIUM: Genetics of feed efficiency in dairy and beef cattle1

Increasing food production for the growing human population off a constraining land base will require greater efficiency of production. Genetic improvement of feed efficiency in cattle, which is cumulative and permanent, is one likely vehicle to achieving efficiency gains. The objective of this review is to summarize genetic parameters for feed efficiency traits in dairy and beef cattle and also to address some of the misconceptions associated with feed efficiency in these sectors, as well as discuss the potential use of feed efficiency in breeding programs. A meta-analysis of up to 39 scientific publications in growing cattle clearly showed that genetic variation in feed efficiency exists with a pooled heritability for residual feed intake (RFI) and feed conversion efficiency of 0.33 ± 0.01 (range of 0.07 to 0.62) and 0.23 ± 0.01 (range of 0.06 to 0.46), respectively. Heritability estimates for feed efficiency in cows were lower; a meta-analysis of up to 11 estimates revealed heritability estimates for gross feed efficiency and RFI of 0.06 ± 0.010 and 0.04 ± 0.008, respectively. Meta-analysis of genetic correlations between feed intake, feed efficiency and other performance traits are presented, and selection index theory is used to calculate the proportion of genetic variation in feed intake that can be explained by easy to measure, and often already collected, data. A large proportion of the genetic variation in feed intake could be explained in both growing animals and lactating animals using up to 5 predictor traits, including BW, growth rate, milk yield, body composition, and linear type traits reflecting body size and muscularity. Knowledge of genetic merit for feed intake can be used, along with estimates of genetic merit for energy sinks, to calculate genetic merit for feed efficiency. Therefore, the marginal benefit of collecting actual feed intake data, using the genetic parameters used in this study, appears to be low. There is now sufficient information available to develop a road map on how best to direct research to ensure long-term food security for a growing human population. Gaps in knowledge are identified here, and possibilities to address these gaps are discussed.

CELL BIOLOGY SYMPOSIUM: Novel technologies and novel insights1

The Cell Biology Symposium titled “Novel technologies and novel insights” was held at the Joint Annual Meeting of the American Society of Animal Science and the American Dairy Science Association in New Orleans, Louisiana, July 10 to 14, 2011. The purpose of the symposium was to provide the animal science community with an update on novel molecular technologies that allow new insights into genome structure and function in livestock. The first speaker of the symposium, Jeffrey Whyte (University of Missouri, Columbia), provided an overview of conventional and emerging technologies to modify the genome in mammals with specific examples in swine (Whyte and Prather, 2011). Engineered zinc finger nucleases (ZFN) have recently been developed that bind and cleave DNA at specific sequences and lead to targeting efficiencies up to 10,000-fold greater than conventional gene targeting methods with somatic cell nuclear transfer. The ZFN technology provides a precise mechanism to either disrupt a gene coding sequence (i.e., gene knockout) or enhance insertion of a DNA construct (i.e., transgenesis or gene knock-in). Several laboratories have now used ZFN technology to knockout genes in the swine genome. Availability of the draft swine genome sequence in combination with ZFN technology to modify the swine genome should allow more rapid and efficient development of swine models for the dual benefit of agricultural and biomedical research. Christian Haudenschild (Illumina, Hayward, CA) provided an overview of next-generation sequencing technologies and the novel use of these technologies to measure gene expression in various biological systems (Haudenschild, 2011). These technologies allow scientists to study temporal expression of the entire transcriptome in specific cells or tissues. In addition, nextgeneration sequencing technologies also reveal new insights regarding the transcription of specific alleles, splice variants, and a better definition of gene structure and annotation. Use of next-generation sequencing technologies to study gene expression has generated extremely large sets of data that require development of novel analytical and statistical methods for appropriate analysis and interpretation. The final speaker, Rebecca Wattam (Virginia Polytechnic Institute and State University, Blacksburg), described the opportunities and challenges associated with accessing all of the available public information to analyze and interpret large sets of genomic data (Sobral, 2011). Novel bioinformatic tools were developed to mine large data resources of genomic information. The examples of Brucella spp. and the 40 sequenced genomes of Brucella were used to show how genome sequencing could be used to identify common genes (and gene families) across species of Brucella, as well as missing areas of genome sequence in some species of Brucella. Specific genes and gene families that are associated with various physiological events, including preferences of the various species of Brucella for specific hosts, were identified. In addition, some species of Brucella are missing many large areas of genomic sequences that may be involved with virulence or synthesis of lipopolysaccharide. The recent availability of draft genome sequences for livestock coupled with emerging computational technologies developed by biomedical scientists provide the animal science community with an increasing number of novel tools to gain new insights into the structure and function of livestock genomes. The ultimate goal of these studies is to improve the efficiency of food and fiber production. The Cell Biology Symposium provided the animal science community with an update on novel molecular technologies to better understand the structure and function of livestock genomes. Use of ZFN technology provides opportunities to precisely

CELL BIOLOGY SYMPOSIUM: Zinc finger nucleases to create custom-designed modifications in the swine (Sus scrofa) genome1,2

Engineered zinc finger nucleases (ZFN) are rapidly gaining popularity as a means to enhance the rate and specificity of DNA modifications in plant and animal cells. Repair-mediated gene modification by ZFN is driven by introducing DNA double-strand breaks via a nonspecific nuclease domain linked to a sequence-specific zinc finger nucleotide recognition domain. This review examines the use of ZFN to produce genetically modified swine and the potential of this technology for the future. By combining conventional gene targeting methods with somatic cell nuclear transfer, several genetically modified pig models have been produced. These conventional techniques are inefficient in mammalian somatic cells and provide little control over the site specificity and rate of exogenous DNA integration. The use of engineered ZFN that bind and cleave genomic DNA at specific loci can enhance targeting efficiencies by orders of magnitude. Recent publication of the first genetic modification in pigs by combining ZFN technology with somatic cell nuclear transfer has opened the door to genome targeting with a precision that was not previously possible in a large animal model. Since that time, model pigs with selective knockout of endogenous genes have been produced. This review will examine the use of ZFN to generate these pig models and the potential of ZFN to accelerate the production of genetically modified pigs of agricultural and biomedical importance. Current methods of ZFN design, important considerations for their safe and effective use in modification of the swine genome, and future innovative applications of this technology in pigs will be discussed.

CELL BIOLOGY SYMPOSIUM: Receptors and signaling1

CELL BIOLOGY SYMPOSIUM: Receptors and signaling1

CELL BIOLOGY SYMPOSIUM: Imaging the organization and trafficking of lipolytic effectors in adipocytes12

The storage and mobilization of lipid energy are central functions of adipocytes. Lipid energy is stored as triglyceride in lipid droplet structures that are now recognized as bona fide organelles and whose functions are greatly influenced by members of the perilipin family of lipid droplet scaffolds. Recent work indicates that the signaling events underlying fatty acid mobilization involve protein trafficking to a specialized subset of lipid droplets. Furthermore, the core lipolytic machinery is composed of evolutionarily conserved proteins whose functions are conserved in avian and mammalian production species. Lipolysis affects many aspects of animal nutrition and physiology, which can have an important influence on growth efficiency, lactation, and meat quality. This review focuses on recent research that addresses the organization and trafficking of key players in hormone-stimulated lipolysis, and the central role of perilipin1A in adipocyte lipolysis. The review emphasizes recent work from the laboratories of the authors that utilizes imaging techniques to explore the organization and interactions among lipolytic effectors in live cells during lipolytic activation. A mechanistic understanding of lipolysis may lead to new strategies for promoting human and animal health.

Cell Biology Symposium: Redox regulation of cell function1

), the American Dairy Science Association, and the Ca-nadian Society of Animal Science in Montreal, Quebec, Canada, July 12 to 16, 2009. The ASAS Board-spon-sored symposium was organized to encourage participa-tion by scientists working in cell biology. The intent was to bring scientists involved in basic physiology and cell biology into ASAS as active participants and provide a platform to increase interactions between basic and applied scientists. The Cell Biology Symposium Com-mittee elected to focus on reduction-oxidation (

Cell Biology Symposium: The role of microRNA in cell function1

Cell Biology Symposium: The role of microRNA in cell function1

Differentiation in Vitro. Proceedings of the British Society for Cell Biology Symposium Held at the University of Edinburgh, from 24 to 25 September 1980. The Fourth Symposium of the British Society for Cell Biology. M. M. Yeoman , D. E. S. Truman

Previous articleNext article No AccessNew Biological BooksDifferentiation in Vitro. Proceedings of the British Society for Cell Biology Symposium Held at the University of Edinburgh, from 24 to 25 September 1980. The Fourth Symposium of the British Society for Cell Biology. M. M. Yeoman , D. E. S. Truman Maurizio PacificiMaurizio Pacifici Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 58, Number 2Jun., 1983 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/413253 Views: 1Total views on this site Copyright 1983 Stony Brook Foundation, Inc.PDF download Crossref reports no articles citing this article.

BOOK REVIEWS

Book reivew in this article:The Pathogenesis of Colorectal Cancer. By B. C. Morson. W. B. SaundersStem Cells and Tissue Homeosasis Proceedings of the 2nd British Society for Cell Biology Symposium. Ed. B. I. Lord, C. S. Potten and R. J. Cole