Download or read book Molecular Analysis of the Role of the FEM Proteins in Caenorhabditis Elegans Sex Determination written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Analysis of the Role of the FEM Proteins in Caenorhabditis Elegans Sex Determination microform written by Jeffrey P. C. (Jeffrey Paul Charlton) Gaudet and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2000 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Analysis of the Role of the FEM Proteins in Caenorhabditis Elegans Sex Determination written by Jeffrey P. C. Gaudet and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Male development in the nematode 'Caenorhabditis elegans' requires the activity of the three 'fem' genes, 'fem-1, fem-2,' and 'fem-3.' The products of these genes form part of a novel signal transduction pathway that controls 'C. elegans ' sex determination, but the mechanism by which the FEMs act remains unclear. I report the use of a 'fem-1' reporter construct to show that 'fem-1' is widely expressed throughout development in both sexes, indicating that 'fem-1' is regulated post-transcriptionally. I further characterize the sequences required for 'fem-1' expression, and characterize a dominant feminization of the germline caused by ' fem-1' transgenes. To identify regions of FEM-1 that are important for its activity, I cloned and characterized 'fem-1' homologues from two related nematode species. Overall, FEM-1 is more conserved than the other 'Caenorhabditis ' sex determining genes. Within FEM-1, the ANK repeats and a kinesin light chain-like repeat are the most conserved regions. Despite the sequence conservation, 'C. briggsae fem-1' is unable to functionally replace 'C. elegans fem-1.' A small region of ' fem-1' coding sequence, between the ANK and TPR encoding regions, appears to be responsible for the functional divergence. I also present data that suggests that in 'C. briggsae, fem-1' may not be required for germline sex determination, possibly revealing the rapid evolution of germline sex determination mechanisms. To elucidate how the FEMs function in the transduction of the sex determination signal, I examined the subcellular localization of each of the FEM proteins. I show that FEM-2 is cytosolic in both sexes, and can interact 'in vivo' with FEM-3, which also appears to function in the cytoplasm. In contrast, FEM-1 appears to localize to discrete compartments within the cell. This localization is at least partially dependent on the kinesin light chain-like repeat of FEM-1. I discuss the implications of the localization data and consider possible models for the mechanism of FEM activity.

Download or read book Molecular Analysis of Fem 3 a Sex determination Gene in the Nematode Caenorhabditis Elegans written by Thomas Allen Rosenquist and published by . This book was released on 1989 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular and Genetic Analysis of the Sex determining Proteins FEM 1 and FEM 3 microform written by Usha Vivegananthan and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: FEM-3, a protein with no recognizable functional motifs, acts as a developmental switch in sex determination. FEM-3 activity is both necessary and limiting for male development. Previous work showed that FEM-3 physically interacts with FEM-2, a type 2C protein phosphatase, but did not establish the biological significance of the interaction. I tested the hypothesis that the FEM-3/FEM-2 interaction is required for male development. Using a modified version of the yeast 2-hybrid system I isolated FEM-3(D313N), a mutant that is specifically defective in its ability to bind to FEM-2. Low-copy fem-3 transgenes that direct expression of the D313N variant under the control of native fem-3 regulatory sequences show significantly lower masculinizing activity than otherwise identical wild-type transgenes. These data suggest that the ability of FEM-3 to bind to FEM-2 is required for the masculinizing activity of FEM-3. Male development in Caenorhabditis elegans depends on the activities of the proteins FEM-1, FEM-2 and FEM-3. Extensive genetic analysis indicates that in XO animals the FEMs inhibit the activity of the female-determining transcription factor TRA-1A to promote male somatic development. In the germline, the FEMs act on TRA-1A and additional targets to promote spermatogenesis. Little is known about the molecular and biochemical mechanisms through which the FEMs act, especially the ankyrin (ANK) repeat protein FEM-1. I molecularly and genetically characterized a collection of fem-1 loss-of-function alleles and found that the N-terminal ANK repeats of FEM-1 are critical for its sex-determining activity. ANK repeats are evolutionarily conserved protein-protein interaction motifs suggesting that a FEM-1-ANK repeat mediated protein interaction is required for male development. Observations of a dominant-negative version of FEM-1 that carries a missense mutation in the sixth ANK repeat support this hypothesis. FEM-1 is unusual among the sex-determining proteins in that it has been well conserved through evolution: orthologues exist in insects and vertebrates. Others have suggested that the conservation of FEM-1 may be due to a role in apoptosis. However, my work demonstrates that FEM-1 is not essential for programmed cell death in C. elegans other than through its characterized role as a regulator of TRA-1A activity.

Download or read book Genetics of Sex Determination written by R.S. Verma and published by Elsevier. This book was released on 1996-04-23 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Genetical Theory of Natural Selection by R.A. Fisher (1930) dictated that sexual dimorphisms may depend upon a single medelian factor. This could be true for some species but his suggestion could not take off the ground as gender in Drosophila is determined by the number of X chromosomes. Technical advances in molecular biology have revived the initial thinking of Fisher and dictate that TDF or SRY genes in humans or Tdy in mice are sex determining genes. The fortuitous findings of XX males and XY female, which are generally termed sex reversal phenomenon, are quite bewildering traits that have caused much amazement concerning the pairing mechanism(s) of the pseudoautosomal regions of human X and Y chromosomes at meiosis. These findings have opened new avenues to explore further the genetic basis of sex determination at the single gene level.The aim of the fourth volume, titled Genetics of Sex Determination is to reflect on the latest advances and future investigative directions, encompassing 10 chapters. Commissioned several distinguished scientists, all pre-eminent authorities in each field to shed their thoughts concisely but epitomise their chapters with an extended bibliography. Obviously, during the past 60 years, the metoric advances are voluminous and to cover every account of genes, chromosomes, and sex in a single volume format would be a herculean task. Therefore, a few specific topics are chosen, which may be of great interest to scientists and clinicians. The seasoned scientists who love to inquire about the role of genes in sex determination should find the original work of these notable contributors very enlightening. This volume is intended for advanced students who want to keep abreast as well as for those who indulge in the search for genes of sex determination.

Download or read book The C Elegans Sex determining GLI Protein TRA 1A is Regulated by Sex specific Proteolysis microform written by Mara Schvarzstein and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2005 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: The C. elegans sex determination hierarchy specifies either one of two sexes: the hermaphrodite or the male. The tra-1 gene is the global terminal regulator of the somatic sex determination pathway. Active TRA-1 promotes female fates in the hermaphrodite by repressing the transcription of genes that direct male development. The objective of the work presented here is to understand how the activity of TRA-1 is regulated. The tra-1 gene encodes two transcripts, tra-1a and tra-1b. Males and hermaphrodites have similar levels of tra-1 transcripts, suggesting that tra-1 is regulated post transcriptionally. Using a new antibody against TRA-1 in whole mount immunostaining I observed that TRA-1 appears to be much more abundant in hermaphrodites than in males. Western blot analysis revealed similar levels of TRA-1A and TRA-1B in lysates from males and hermaphrodites. Additional TRA-1-specific species (90-110 kDa) were present in the hermaphrodite lysates but absent from male lysates. These isoforms are the most abundant form of TRA-1 protein in hermaphrodites. The hermaphrodite-specific TRA-1 isoforms appear to be phosphoisoforms of a single TRA-1 band. Here I also describe the identification of proteins that specifically interact with FEM-2 in affinity chromoatography experiments. Loss-of-function mutants and RNAi silencing of three of these genes appear to partially phenocopy fem-2 mutants. I show evidence that the hermaphrodite-specific isoform is generated by proteolytic processing of TRA-1A. Since the truncated TRA-1A isoforms are present in embryos before sexual differentiation is apparent, they are unlikely to be a result of female differentiation. Therefore I propose that these isoforms are responsible for the feminizing activity of the tra-1 gene. The truncation mapped to the region between amino acids 842 and 921. The observations that both a nonsense mutation that results in the production of a C-terminally truncated TRA-1A protein and truncated TRA-1A transgenes are feminizing, support my hypothesis that the truncated TRA-1 isoforms are responsible for the feminizing activity of the tra-1 gene. Genetic analyses indicate that the fem gene products regulate, directly or indirectly, the activity of TRA-1. Therefore, characterization of these putative FEM-2 binding proteins may identify the mechanism by which the FEMs regulate TRA-1 activity.

Download or read book Caenorhabditis Elegans written by Henry F. Epstein and published by Academic Press. This book was released on 1995 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first of its kind, this laboratory handbook emphasizes diverse methods and technologies needed to investigate C. elegans, both as an integrated organism and as a model system for research inquiries in cell, developmental, and molecular biology, as well as in genetics and pharmacology. Four primary sections--Genetic and Culture Methods, Neurobiology, Cell and Molecular Biology, and Genomics and Informatics--reflect the cross-disciplinary nature of C. elegans research. Because C. elegans is a simple and malleable organism with a small genome and few cell types, it provides an elegant demonstr.

Download or read book Molecular Analysis of X Chromosome Dosage Compensation in C Elegans written by Pao-Tien Chuang and published by . This book was released on 1995 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cis and Trans acting Factors Required for the 3 UTR mediated Repression of Fem 3 a Sex determining Gene in Caenorhabditis Elegans written by Maria Elena Gallegos and published by . This book was released on 1998 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Post transcriptional Regulation of Fem 3 a Sex Determining Gene of C Elegans written by Julie Ahringer and published by . This book was released on 1991 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The C Elegans Sex Determination Protein MOG 3 Functions in Meiosis and Binds to the CSL Co repressor CIR 1 written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the germ line of the Caenorhabditis elegans hermaphrodite, nuclei either proliferate through mitosis or initiate meiosis, finally differentiating as spermatids or oocytes. The production of oocytes requires repression of the fem-3 mRNA by cytoplasmic FBF and nuclear MOG proteins. Here we report the identification of the sex determining gene mog-3 and show that in addition to its role in gamete sex determination, it is necessary for meiosis by acting downstream of GLP-1/Notch. Furthermore, we found that MOG-3 binds both to the nuclear proteins MEP-1 and CIR-1. MEP-1 is necessary for oocyte production and somatic differentiation, while the mammalian CIR-1 homolog counters Notch signaling. We propose that MOG-3, MEP-1 and CIR-1 associate in a nuclear complex which regulates different aspects of germ cell development. While FBF triggers the sperm/oocyte switch by directly repressing the fem-3 mRNA in the cytoplasm, the MOG proteins play a more indirect role in the nucleus, perhaps by acting as epigenetic regulators or by controlling precise splicing events.

Download or read book Comparisons of Sex Determining Pathways Across Caenorhabditis Species written by Keith Reidy and published by . This book was released on 2015 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological pathways have the ability to tolerate mutations and evolve to control novel traits. Selection pressures act on these pathways playing a key role in the evolution and divergence of species. Sex determination in Caenorhabditis nematodes is a rapidly evolving trait which can provide insights into how biological pathways can be modified from a common set of ancestral genes. C. elegans and C. briggsae are two of three androdioecious species within the Elegans group of the Caenorhabditis genus. These two species are both morphologically and developmentally similar but their genetic control of hermaphroditism is different. XX animals in these species are somatically female but are capable of producing and storing sperm before switching to oocyte production. Genetic screens have been used to isolate mutants which disrupt the C. briggsae sex determining pathway, the results of which have identified orthologs of the C. elegans sex determining genes. Regulation of spermatogenesis differs in C. elegans and C. briggsae; C. elegans fem mutants are females whereas C. briggsae fem mutants are hermaphrodites. Identification of the molecular lesion in the fem mutants isolated from these screens have been useful for determining the functional domains of these important proteins. In the same genetic screen that identified the Cbr-fem mutants, three mutants were isolated which appeared to be novel members of the C. briggsae sex determining pathway. These mutants display phenotypes not seen in C. elegans. Whole genome sequencing followed by mapping has revealed that one of these appears to be a gain of function tra-1 allele, one of them appears to be a weak hypomorph of fem-3 and the third one does not contain a mutation in any known sex determining gene. The current candidate for this mutant is the kinase, pink-1. C. briggsae has a closely related sister species which uses a male/female sex determining system. Comparisons between sex determination gene orthologs in these two species show greater than ninety percent identity at the amino acid level. Sex determining genes that were known to be present in C. briggsae but not in C. elegans were also found in C. nigoni so their presence alone is not enough to facilitate hermaphroditism in C. briggsae.

Download or read book An Introduction to Nematology written by May Belle Hutson Chitwood and published by Andesite Press. This book was released on 2015-08-12 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Download or read book Cell Lineage and Fate Determination written by Sally A. Moody and published by Elsevier. This book was released on 1998-10-29 with total page 661 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cell Lineage and Fate Determination provides a comprehensive view of the mechanisms regulating cell lineage and fate determination in an effort to understand how the fertilized egg is transformed into a complex of specialized tissues. It presents basic information on eight different animal models and recent developmental biological research done in each model. The book provides a focused forum presenting key information for researchers studying various aspects of developmental and cellular biology. Extensive use of tables and black-and-white and color figures helps illustrate each model. The book concludes by discussing future goals for bringing cellular, molecular, and genetic research to clinical applications and tissue replacement therapies.Key Features* Presents eight different animal models* Provides a focused forum on cell fate determination that provides comprehensive and key information for researchers* Illustrates the transitional relationship between researchers and clinicians* Includes the extensive use of tables and color figures

Download or read book Sex Control in Aquaculture written by Hanping Wang and published by John Wiley & Sons. This book was released on 2018-11-08 with total page 1810 pages. Available in PDF, EPUB and Kindle. Book excerpt: Awarded Bookauthority's "Best Aquaculture Books of all Time" A comprehensive resource that covers all the aspects of sex control in aquaculture written by internationally-acclaimed scientists Comprehensive in scope, Sex Control in Aquaculture first explains the concepts and rationale for sex control in aquaculture, which serves different purposes. The most important are: to produce monosex stocks to rear only the fastest-growing sex in some species, to prevent precocious or uncontrolled reproduction in other species and to aid in broodstock management. The application of sex ratio manipulation for population control and invasive species management is also included. Next, this book provides detailed and updated information on the underlying genetic, epigenetic, endocrine and environmental mechanisms responsible for the establishment of the sexes, and explains chromosome set manipulation techniques, hybridization and the latest gene knockout approaches. Furthermore, the book offers detailed protocols and key summarizing information on how sex control is practiced worldwide in 35 major aquaculture species or groups, including fish and crustaceans, and puts the focus on its application in the aquaculture industry. With contributions from an international panel of leading scientists, Sex Control in Aquaculture will appeal to a large audience: aquaculture/fisheries professionals and students, scientists or biologists working with basic aspects of fish/shrimp biology, growth and reproductive endocrinology, genetics, molecular biology, evolutionary biology, and R&D managers and administrators. This text explores sex control technologies and monosex production of commercially-farmed fish and crustacean species that are highly in demand for aquaculture, to improve feed utilization efficiency, reduce energy consumption for reproduction and eliminate a series of problems caused by mixed sex rearing. Thus, this book: Contains contributions from an international panel of leading scientists and professionals in the field Provides comprehensive coverage of both established and new technologies to control sex ratios that are becoming more necessary to increase productivity in aquaculture Includes detailed coverage of the most effective sex control techniques used in the world's most important commercially-farmed species Sex Control in Aquaculture is the comprehensive resource for understanding the biological rationale, scientific principles and real-world practices in this exciting and expanding field.

Download or read book Gene Drives on the Horizon written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-08-28 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on gene drive systems is rapidly advancing. Many proposed applications of gene drive research aim to solve environmental and public health challenges, including the reduction of poverty and the burden of vector-borne diseases, such as malaria and dengue, which disproportionately impact low and middle income countries. However, due to their intrinsic qualities of rapid spread and irreversibility, gene drive systems raise many questions with respect to their safety relative to public and environmental health. Because gene drive systems are designed to alter the environments we share in ways that will be hard to anticipate and impossible to completely roll back, questions about the ethics surrounding use of this research are complex and will require very careful exploration. Gene Drives on the Horizon outlines the state of knowledge relative to the science, ethics, public engagement, and risk assessment as they pertain to research directions of gene drive systems and governance of the research process. This report offers principles for responsible practices of gene drive research and related applications for use by investigators, their institutions, the research funders, and regulators.