Centromere identity and function put to use: construction and transfer of mammalian artificial chromosomes to animal models

2020 ◽  
Vol 64 (2) ◽  
pp. 185-192
Author(s):  
Ye Yang ◽  
Michael A. Lampson ◽  
Ben E. Black
Keyword(s):  
Gene Expression ◽  
Cell Culture ◽  
Animal Model ◽  
Synthetic Biology ◽  
Animal Models ◽  
Model Systems ◽  
Expression Vectors ◽  
Artificial Chromosomes ◽  
Conventional Expression ◽  
And Function

Abstract Mammalian artificial chromosomes (MACs) are widely used as gene expression vectors and have various advantages over conventional expression vectors. We review and discuss breakthroughs in MAC construction, initiation of functional centromeres allowing their faithful inheritance, and transfer from cell culture to animal model systems. These advances have contributed to advancements in synthetic biology, biomedical research, and applications in industry and in the clinic.

Structure and Function of the Normal Testis and Epididymis

1989 ◽  
Vol 8 (3) ◽  
pp. 457-471 ◽  
Author(s):  
Rupert P. Amann
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Developmental Stages ◽  
Structure And Function ◽  
Germinal Epithelium ◽  
Sperm Production ◽  
Human Male ◽  
Conventional Animal ◽  
And Function ◽  
Hormonal Interactions

The structure and function of the testis and epididymis are described, emphasizing the general similarities and specific differences between various species and humans. Current concepts of spermatogenesis are reviewed and the developmental stages of the germinal epithelium are discussed, as well as the complex hormonal interactions that take place. It is crucial to recognize that the efficiency of sperm production and the epididymal reserves in the human are considerably lower than those of conventional animal models. Therefore, the human male is more susceptible to a decline in fertility caused by a specific decrement in spermatogenesis than is an animal model.

Transcriptional regulation of murine Slc22a1 (Oct1) by peroxisome proliferator agonist receptor-α and -γ

2005 ◽  
Vol 288 (2) ◽  
pp. G207-G212 ◽  
Author(s):  
Wenxian Nie ◽  
Seth Sweetser ◽  
Mary Rinella ◽  
Richard M. Green
Keyword(s):  
Gene Expression ◽  
Organic Cation ◽  
Expression Vectors ◽  
Peroxisome Proliferator ◽  
Ppar Agonist ◽  
Cation Uptake ◽  
Ppar Agonists ◽  
Ppar Response Element ◽  
And Function ◽  
Hepatic Regulation

The transport and metabolism of organic cationic endobiotics, nutrients, and drugs are essential hepatic functions. Slc22A1 is the basolateral liver transporter mediating the uptake of organic cations; however, little is known about the regulation of this transport protein. Peroxisome proliferator agonist receptor (PPAR)-α and -γ agonists are commonly used agents that regulate many hepatocellular transport functions. Thus the purpose of this study was to examine the effects of PPAR agonists on the hepatic regulation and function of Slc22a1. Mice and H35 cells were administered PPAR-α and -γ agonists, and the effect on Slc22a1 gene expression was measured. We subsequently cloned the Slc22a1 promoter and employed chimeric constructs to assay Slc22a1 gene transcription. The effects of PPAR-agonist treatment on organic cation uptake was also assayed. Slc22a1 expression was increased by PPAR-α and -γ agonist treatment in both murine livers and H35 cells. Gene expression in H35 cells was further increased following transfection with expression vectors of PPAR transcription factors and PPAR agonist treatment. We cloned the promoter region of Slc22a1 and identified a PPAR-response element, and transfections with chimeric Slc22a1; promoter-reporter gene constructs demonstrate that the increased gene expression was transcriptionally regulated. Functional assays confirmed that cells treated with PPAR agonists displayed significant increases in organic cation uptake. PPAR-α and -γ agonists transcriptionally increase Slc22a1 gene expression, and the increased Slc22a1 expression results in enhanced cellular organic cation uptake. These studies may have implication for the uptake of organic cationic drugs and for lipid metabolism.

Animal models of psychosis

2020 ◽  
pp. 496-506
Author(s):  
Daniel Scott
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Psychiatric Illness ◽  
Behavioral Assessment ◽  
Underlying Disease ◽  
Human Condition ◽  
Model Systems ◽  
Behavioral Assessments ◽  
Validity Measures ◽  
Valid Animal Model

The creation of a valid animal model is of crucial importance to the study of the biological mechanisms underlying disease pathophysiology. This becomes difficult when studying psychiatric illness, most especially psychosis, as humans’ mental state is a strictly internally experienced phenomenon, and thus the biological readout of these conditions is often a behavioral assessment. Therefore, when designing appropriate animal model systems and behavioral assessments for the study of psychiatric illness, it is necessary that appropriate measures be taken to ensure the systems and tasks used fulfill rigorous demands of validity. This chapter discusses different forms of validity, expanding on the classical validity measures of face, predictive, and construct validity. Specific examples of behavioral assessments and animal preparations that adhere to these specific definitions of validity are presented. These include specific experimental paradigms that can be similarly assessed in humans with psychosis and animal models, methods to create an animal preparation based on known psychosis triggers and risk factors, and pharmacological means to demonstrate relevance to the human condition. The chapter argues for a systematic approach to design, verify, and validate an animal model system for research into psychosis specifically, and other psychiatric disorders more generally, based on these different classes of validity.

scholarly journals Understanding Cellular Mechanisms Underlying Airway Epithelial Repair: Selecting the Most Appropriate Animal Models

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
B. Yahaya
Keyword(s):  
Stem Cells ◽  
Animal Model ◽  
Animal Models ◽  
Model Systems ◽  
Large Animal ◽  
Airway Epithelial ◽  
Large Animal Models ◽  
Molecular Events ◽  
Epithelium Regeneration

Understanding the mechanisms underlying the process of regeneration and repair of airway epithelial structures demands close characterization of the associated cellular and molecular events. The choice of an animal model system to study these processes and the role of lung stem cells is debatable since ideally the chosen animal model should offer a valid comparison with the human lung. Species differences may include the complex three-dimensional lung structures, cellular composition of the lung airway as well as transcriptional control of the molecular events in response to airway epithelium regeneration, and repair following injury. In this paper, we discuss issues related to the study of the lung repair and regeneration including the role of putative stem cells in small- and large-animal models. At the end of this paper, the author discuss the potential for using sheep as a model which can help bridge the gap between small-animal model systems and humans.

scholarly journals Marking and Gene Expression by a Lentivirus Vector in Transplanted Human and Nonhuman Primate CD34+Cells

2000 ◽  
Vol 74 (3) ◽  
pp. 1286-1295 ◽  
Author(s):  
Dong Sung An ◽  
Robert P. Wersto ◽  
Brian A. Agricola ◽  
Mark E. Metzger ◽  
Stephanie Lu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
Animal Model ◽  
Gene Delivery ◽  
Retroviral Vectors ◽  
Model Systems ◽  
Lentivirus Vector ◽  
Alternative Mode ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Recently, gene delivery vectors based on human immunodeficiency virus (HIV) have been developed as an alternative mode of gene delivery. These vectors have a number of advantages, particularly in regard to the ability to infect cells which are not actively dividing. However, the use of vectors based on human immunodeficiency virus raises a number of issues, not the least of which is safety; therefore, further characterization of marking and gene expression in different hematopoietic lineages in primate animal model systems is desirable. We use two animal model systems for gene therapy to test the efficiency of transduction and marking, as well as the safety of these vectors. The first utilizes the rhesus animal model for cytokine-mobilized autologous peripheral blood CD34+ cell transplantation. The second uses the SCID-human (SCID-hu) thymus/liver chimeric graft animal model useful specifically for human T-lymphoid progenitor cell reconstitution. In the rhesus macaques, detectable levels of vector were observed in granulocytes, lymphocytes, monocytes, and, in one animal with the highest levels of marking, erythrocytes and platelets. In transplanted SCID-hu mice, we directly compared marking and gene expression of the lentivirus vector and a murine leukemia virus-derived vector in thymocytes. Marking was observed at comparable levels, but the lentivirus vector bearing an internal cytomegalovirus promoter expressed less efficiently than did the murine retroviral vector expressed from its own long terminal repeats. In assays for infectious HIV type 1 (HIV-1), no replication-competent HIV-1 was detected in either animal model system. Thus, these results indicate that while lentivirus vectors have no apparent deleterious effects and may have advantages over murine retroviral vectors, further study of the requirements for optimal use are warranted.

Animal Model Systems for the Study of Alcohol Teratology

2005 ◽  
Vol 230 (6) ◽  
pp. 389-393 ◽  
Author(s):  
Timothy A. Cudd
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Basic Science ◽  
Prenatal Alcohol Exposure ◽  
Alcohol Exposure ◽  
Model System ◽  
Higher Order ◽  
Model Systems ◽  
Large Animal ◽  
Prenatal Alcohol

The incidence of fetal alcohol syndrome has not been declining even though alcohol has been established as a teratogen and significant efforts have been made to educate women not to abuse alcohol during pregnancy. In addition to further educational efforts, strategies to prevent or mitigate the damages of prenatal alcohol exposure are now under development. Animal models will play a significant role in the effort to develop these strategies. Because prenatal alcohol exposure causes damage by multiple mechanisms, depending on dose, pattern, and timing of exposure, and because no species of animal is the same as the human, the choice of which animal model to use is complicated. To choose the best animal model, it is necessary to consider the specific scientific question that is being addressed and which model system is best able to addressthe question. Animal models that are currently in use include nonhuman primates, rodents (rats, mice, guinea pigs), large animal models (pig and sheep), the chick, and simple animals, including fish, insects, and round worms. Each model system has strengths and weaknesses, depending on the question being addressed. Simple animal models are useful in exploring basic science questions that relate to molecular biology and genetics that cannot be explored in higher-order animals, whereas higher-order animal models are useful in studying complex behaviors and validating basic science findings in an animal that is more like the human. Substantial progress in this field will require the judicious use of multiple scientific approaches that use different animal model systems.

scholarly journals CRISPR-Cas-mediated tethering recruits the yeast HMR mating-type locus to the nuclear periphery but fails to silence gene expression

2021 ◽  
Author(s):  
Emily R Cliff ◽  
Robin L Kirkpatrick ◽  
Daniel Cunningham-Bryant ◽  
Brianna Fernandez ◽  
Jesse G Zalatan
Keyword(s):  
Gene Expression ◽  
Genome Structure ◽  
Nuclear Periphery ◽  
Model Systems ◽  
Type Locus ◽  
Synthetic Genome ◽  
Structural Differences ◽  
And Function ◽  
The Relationship ◽  
Silence Gene

To investigate the relationship between genome structure and function, we have developed a programmable CRISPR-Cas system for nuclear peripheral recruitment in yeast. We benchmarked this system at the HMR and GAL2 loci, both well-characterized model systems for localization to the nuclear periphery. Using microscopy and gene silencing assays, we demonstrate that CRISPR-Cas-mediated tethering can recruit the HMR locus but does not silence reporter gene expression. A previously reported Gal4-mediated tethering system does silence gene expression, and we demonstrate that the silencing phenotype has an unexpected dependence on the structure of the protein tether. The CRISPR-Cas system was unable to recruit GAL2 to the nuclear periphery. Our results reveal potential challenges for synthetic genome structure perturbations and suggest that distinct functional effects can arise from subtle structural differences in how genes are recruited to the periphery.

scholarly journals Key Components of Human Myofibre Denervation and Neuromuscular Junction Stability are Modulated by Age and Exercise

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 893 ◽  
Author(s):  
Casper Soendenbroe ◽  
Cecilie J. L. Bechshøft ◽  
Mette F. Heisterberg ◽  
Simon M. Jensen ◽  
Emma Bomme ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Culture ◽  
Neuromuscular Junction ◽  
Molecular Targets ◽  
The Elderly ◽  
Muscle Fibres ◽  
Elderly Individuals ◽  
Healthy Elderly ◽  
Exercise Induced ◽  
And Function

The decline in muscle mass and function with age is partly caused by a loss of muscle fibres through denervation. The purpose of this study was to investigate the potential of exercise to influence molecular targets involved in neuromuscular junction (NMJ) stability in healthy elderly individuals. Participants from two studies (one group of 12 young and 12 elderly females and another group of 25 elderly males) performed a unilateral bout of resistance exercise. Muscle biopsies were collected at 4.5 h and up to 7 days post exercise for tissue analysis and cell culture. Molecular targets related to denervation and NMJ stability were analysed by immunohistochemistry and real-time reverse transcription polymerase chain reaction. In addition to a greater presence of denervated fibres, the muscle samples and cultured myotubes from the elderly individuals displayed altered gene expression levels of acetylcholine receptor (AChR) subunits. A single bout of exercise induced general changes in AChR subunit gene expression within the biopsy sampling timeframe, suggesting a sustained plasticity of the NMJ in elderly individuals. These data support the role of exercise in maintaining NMJ stability, even in elderly inactive individuals. Furthermore, the cell culture findings suggest that the transcriptional capacity of satellite cells for AChR subunit genes is negatively affected by ageing.

scholarly journals Baboon Model for the Study of Endometriosis

2007 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Cleophas M Kyama ◽  
Atilla Mihalyi ◽  
Daniel Chai ◽  
Peter Simsa ◽  
Jason M Mwenda ◽  
...  
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Early Detection ◽  
Delayed Diagnosis ◽  
Clinical Manifestations ◽  
Model Systems ◽  
Specific Method ◽  
Molecular Changes ◽  
Baboon Model ◽  
Insight Into

Endometriosis is a benign, estrogen-dependent disease and is now recognized as an enigmatic disease owing to its various clinical manifestations and locations. The lack of a reliable and specific method for the early detection of endometriosis often results in delayed diagnosis. So far, research has born inadequate findings regarding understanding the basic etiology or pathophysiology of endometriosis. Animal models that accurately represent the cellular and molecular changes associated with the initiation and progression of human endometriosis have significant potential to facilitate the development of better methods for the early detection and treatment of endometriosis. A number of animal model systems have been developed for the study of this disease. These models replicate many of the known salient features of human endometriosis. This review provides an insight into the use of the baboon model for studies focused on understanding human endometriosis.

scholarly journals De novo Design of Translational RNA Repressors

2018 ◽  
Author(s):  
Paul D. Carlson ◽  
Cameron J. Glasscock ◽  
Julius B. Lucks
Keyword(s):  
Gene Expression ◽  
Synthetic Biology ◽  
De Novo ◽  
Genetic Circuit ◽  
Bacterial Cells ◽  
Control Of Gene Expression ◽  
Sequence Characterization ◽  
Mrna Targets ◽  
Modern Drug ◽  
And Function

ABSTRACTA central goal of synthetic biology is the development of methods for the predictable control of gene expression. RNA is an attractive substrate by which to achieve this goal because the relationship between its sequence, structure, and function is being uncovered with increasing depth. In addition, design approaches that use this relationship are becoming increasingly effective, as evidenced by significant progress in the de novo design of RNA-based gene regulatory mechanisms that activate transcription and translation in bacterial cells. However, the design of synthetic RNA mechanisms that are efficient and versatile repressors of gene expression has lagged, despite their importance for gene regulation and genetic circuit construction. We address this gap by developing two new classes of RNA regulators, toehold repressors and looped antisense oligonucleotides (LASOs), that repress translation of a downstream gene in response to an arbitrary input RNA sequence. Characterization studies show that these designed RNAs robustly repress translation, are highly orthogonal, and can be multiplexed with translational activators. We show that our LASO design can repress endogenous mRNA targets and distinguish between closely-related genes with a high degree of specificity and predictability. These results demonstrate significant yet easy-to-implement improvements in the design of synthetic RNA repressors for synthetic biology, and point more broadly to design principles for repressive RNA interactions relevant to modern drug design.

Sign in / Sign up

Export Citation Format

Share Document