scholarly journals Deciphering the skeletome: Contributions from mouse forward genetics ENU mutagenesis campaigns

Bone Reports ◽  
2020 ◽  
Vol 13 ◽  
pp. 100594
Author(s):  
Robert Brommage
Keyword(s):  
Forward Genetics ◽  
Enu Mutagenesis

ENU mutagenesis as a tool for understanding lung development and disease

2009 ◽  
Vol 37 (4) ◽  
pp. 838-842 ◽  
Author(s):  
Laura Yates ◽  
Fiona McMurray ◽  
Youming Zhang ◽  
Andy Greenfield ◽  
Miriam Moffatt ◽  
...  
Keyword(s):  
Lung Development ◽  
Reverse Genetics ◽  
High Efficiency ◽  
Point Mutations ◽  
Forward Genetics ◽  
Mouse Lung ◽  
Enu Mutagenesis ◽  
Phd Finger ◽  
Mouse Mutants ◽  
Hypomorphic Alleles

ENU (N-ethyl-N-nitrosourea) is a chemical mutagen that randomly induces point mutations in DNA. Since the 1990s ENU has been successfully used as a means to obtain mouse mutants using both gene-driven (reverse genetics) and phenotype-driven (forward genetics) approaches. A high-efficiency ENU approach results in approx. 25 functional mutations per genome; most of these will result in hypomorphic alleles. Our group has recently begun using ENU mutagenesis as a tool for understanding lung development and disease. In collaboration with other groups at MRC Harwell, we have undertaken a screen for recessive mutations affecting mouse lung development. We are currently pursuing two lines identified from this screen, Hel (head, eye and lung) and RecBA17. Both these lines exhibit lung defects and we believe that by studying the phenotypes and identifying the causative mutations, we may also shed light on lung disease pathogenesis. In collaboration with Bill Cookson and Miriam Moffatt, we are also taking a gene-driven approach for understanding asthma. Using the Harwell ENU sperm archive, we have recovered mouse lines harbouring mutations in the asthma-susceptibility genes Phf11 (PHD finger protein 11) and Dpp10 (dipeptidylpeptidase 10). Functional analyses of these alleles are currently under way.

Microsatellite genetic analysis of ENU mutagenesis grass carp and gynogenesis offspring group

2017 ◽  
Vol 24 (5) ◽  
pp. 1013
Author(s):  
Chenglong WANG ◽  
Guodong ZHENG ◽  
Jie CHEN ◽  
Xiayun JIANG ◽  
Shuming ZOU
Keyword(s):  
Genetic Analysis ◽  
Grass Carp ◽  
Enu Mutagenesis

scholarly journals Massively parallel in vivo CRISPR screening identifies RNF20/40 as epigenetic regulators of cardiomyocyte maturation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nathan J. VanDusen ◽  
Julianna Y. Lee ◽  
Weiliang Gu ◽  
Catalina E. Butler ◽  
Isha Sethi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Screen ◽  
Forward Genetics ◽  
Epigenetic Mark ◽  
Biological Processes ◽  
Dynamic Changes ◽  
Forward Genetic Screen ◽  
High Resource ◽  
Organ Systems

AbstractThe forward genetic screen is a powerful, unbiased method to gain insights into biological processes, yet this approach has infrequently been used in vivo in mammals because of high resource demands. Here, we use in vivo somatic Cas9 mutagenesis to perform an in vivo forward genetic screen in mice to identify regulators of cardiomyocyte (CM) maturation, the coordinated changes in phenotype and gene expression that occur in neonatal CMs. We discover and validate a number of transcriptional regulators of this process. Among these are RNF20 and RNF40, which form a complex that monoubiquitinates H2B on lysine 120. Mechanistic studies indicate that this epigenetic mark controls dynamic changes in gene expression required for CM maturation. These insights into CM maturation will inform efforts in cardiac regenerative medicine. More broadly, our approach will enable unbiased forward genetics across mammalian organ systems.

scholarly journals Fast genetic mapping using insertion-deletion polymorphisms in Caenorhabditis elegans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ho-Yon Hwang ◽  
Jiou Wang
Keyword(s):  
Caenorhabditis Elegans ◽  
Genetic Mapping ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genetic Material ◽  
Mapping Method ◽  
Forward Genetics ◽  
Whole Genome ◽  
Nucleotide Polymorphisms ◽  
Large Populations

AbstractGenetic mapping is used in forward genetics to narrow the list of candidate mutations and genes corresponding to the mutant phenotype of interest. Even with modern advances in biology such as efficient identification of candidate mutations by whole-genome sequencing, mapping remains critical in pinpointing the responsible mutation. Here we describe a simple, fast, and affordable mapping toolkit that is particularly suitable for mapping in Caenorhabditis elegans. This mapping method uses insertion-deletion polymorphisms or indels that could be easily detected instead of single nucleotide polymorphisms in commonly used Hawaiian CB4856 mapping strain. The materials and methods were optimized so that mapping could be performed using tiny amount of genetic material without growing many large populations of mutants for DNA purification. We performed mapping of previously known and unknown mutations to show strengths and weaknesses of this method and to present examples of completed mapping. For situations where Hawaiian CB4856 is unsuitable, we provide an annotated list of indels as a basis for fast and easy mapping using other wild isolates. Finally, we provide rationale for using this mapping method over other alternatives as a part of a comprehensive strategy also involving whole-genome sequencing and other methods.

scholarly journals Toward genetic modification of plant-parasitic nematodes: delivery of macromolecules to adults and expression of exogenous mRNA in second stage juveniles

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  
Keyword(s):  
Food Security ◽  
Genetic Modification ◽  
The Body ◽  
Forward Genetics ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Cyst Nematodes ◽  
Plant Parasitic

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.

Behavioral Effects of Volatile Anesthetics in Caenorhabditis elegans

1996 ◽  
Vol 85 (4) ◽  
pp. 901-912 ◽  
Author(s):  
Michael C. Crowder ◽  
Laynie D. Shebester ◽  
Tim Schedl
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Time Course ◽  
Model Organism ◽  
Volatile Anesthetic ◽  
Volatile Anesthetics ◽  
Effective Concentration ◽  
Forward Genetics ◽  
C Elegans ◽  
Median Effective Concentration

Background The nematode Caenorhabditis elegans offers many advantages as a model organism for studying volatile anesthetic actions. It has a simple, well-understood nervous system; it allows the researcher to do forward genetics; and its genome will soon be completely sequenced. C. elegans is immobilized by volatile anesthetics only at high concentrations and with an unusually slow time course. Here other behavioral dysfunctions are considered as anesthetic endpoints in C. elegans. Methods The potency of halothane for disrupting eight different behaviors was determined by logistic regression of concentration and response data. Other volatile anesthetics were also tested for some behaviors. Established protocols were used for behavioral endpoints that, except for pharyngeal pumping, were set as complete disruption of the behavior. Time courses were measured for rapid behaviors. Recovery from exposure to 1 or 4 vol% halothane was determined for mating, chemotaxis, and gross movement. All experiments were performed at 20 to 22 degrees C. Results The median effective concentration values for halothane inhibition of mating (0.30 vol%-0.21 mM), chemotaxis (0.34 vol%-0.24 mM), and coordinated movement (0.32 vol% - 0.23 mM) were similar to the human minimum alveolar concentration (MAC; 0.21 mM). In contrast, halothane produced immobility with a median effective concentration of 3.65 vol% (2.6 mM). Other behaviors had intermediate sensitivities. Halothane's effects reached steady-state in 10 min for all behaviors tested except immobility, which required 2 h. Recovery was complete after exposure to 1 vol% halothane but was significantly reduced after exposure to immobilizing concentrations. Conclusions Volatile anesthetics selectively disrupt C. elegans behavior. The potency, time course, and recovery characteristics of halothane's effects on three behaviors are similar to its anesthetic properties in vertebrates. The affected nervous system molecules may express structural motifs similar to those on vertebrate anesthetic targets.

scholarly journals A Novel Mutation in Cse1l Disrupts Brain and Eye Development with Specific Effects on Pax6 Expression

2021 ◽  
Vol 9 (3) ◽  
pp. 27
Author(s):  
Lauren E. Blizzard ◽  
Chelsea Menke ◽  
Shaili D. Patel ◽  
Ronald R. Waclaw ◽  
Salil A. Lachke ◽  
...  
Keyword(s):  
Neural Development ◽  
Null Allele ◽  
Eye Development ◽  
Novel Mutation ◽  
Forward Genetics ◽  
Mammalian Development ◽  
Variants Of Unknown Significance ◽  
New Genes ◽  
Conditional Allele ◽  
Sequencing Studies

Forward genetics in the mouse continues to be a useful and unbiased approach to identifying new genes and alleles with previously unappreciated roles in mammalian development and disease. Here, we report a new mouse allele of Cse1l that was recovered from an ENU mutagenesis screen. Embryos homozygous for the anteater allele of Cse1l display a number of variable phenotypes, with craniofacial and ocular malformations being the most obvious. We provide evidence that Cse1l is the causal gene through complementation with a novel null allele of Cse1l generated by CRISPR-Cas9 editing. While the variability in the anteater phenotype was high enough to preclude a detailed molecular analysis, we demonstrate a very penetrant reduction in Pax6 levels in the developing eye along with significant ocular developmental phenotypes. The eye gene discovery tool iSyTE shows Cse1l to be significantly expressed in the lens from early eye development stages in embryos through adulthood. Cse1l has not previously been shown to be required for organogenesis as homozygosity for a null allele results in very early lethality. Future detailed studies of Cse1l function in craniofacial and neural development will be best served with a conditional allele to circumvent the variable phenotypes we report here. We suggest that human next-generation (whole genome or exome) sequencing studies yielding variants of unknown significance in CSE1L could consider these findings as part of variant analysis.

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