Different Evolutionary Strategies To Conserve Chromatin Boundary Function in the Bithorax Complex [Gene Expression]
Chromatin boundary elements subdivide chromosomes in multicellular organisms into physically independent domains. In addition to this architectural function, these elements also play a critical role in gene regulation. Here we investigated the evolution of a Drosophila Bithorax complex boundary element called Fab-7, which is required for the proper parasegment specific expression of the homeotic Abd-B gene. Using a "gene" replacement strategy, we show that Fab-7 boundaries from two closely related species, D. erecta and D. yakuba, and a more distant species, D. pseudoobscura, are able to substitute for the m...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Cleard, F., Wolle, D., Taverner, A. M., Aoki, T., Deshpande, G., Andolfatto, P., Karch, F., Schedl, P. Tags: Gene Expression Source Type: research
The Promiscuous sumA Missense Suppressor from Salmonella enterica Has an Intriguing Mechanism of Action [Gene Expression]
While most missense suppressors have very narrow specificities and only suppress the allele against which they were isolated, the sumA missense suppressor from Salmonella enterica serovar Typhimurium is a promiscuous or broad-acting missense suppressor that suppresses numerous missense mutants. The sumA missense suppressor was identified as a glyV tRNA Gly3(GAU/C) missense suppressor that can recognize GAU or GAC aspartic acid codons and insert a glycine amino acid instead of aspartic acid. In addition to rescuing missense mutants caused by glycine to aspartic acid changes as expected, sumA could also rescue a number of ot...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Cole, A. E., Hani, F. M., Altman, R., Meservy, M., Roth, J. R., Altman, E. Tags: Gene Expression Source Type: research
Zinc Cluster Transcription Factors Alter Virulence in Candida albicans [Gene Expression]
Almost all humans are colonized with Candida albicans. However, in immunocompromised individuals, this benign commensal organism becomes a serious, life-threatening pathogen. Here, we describe and analyze the regulatory networks that modulate innate responses in the host niches. We identified Zcf15 and Zcf29, two Zinc Cluster transcription Factors (ZCF) that are required for C. albicans virulence. Previous sequence analysis of clinical C. albicans isolates from immunocompromised patients indicates that both ZCF genes diverged during clonal evolution. Using in vivo animal models, ex vivo cell culture methods, and in vitro s...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Issi, L., Farrer, R. A., Pastor, K., Landry, B., Delorey, T., Bell, G. W., Thompson, D. A., Cuomo, C. A., Rao, R. P. Tags: Gene Expression Source Type: research
An Unexpected Regulatory Cascade Governs a Core Function of the Drosophila PRC1 Chromatin Protein Su(z)2 [Gene Expression]
Polycomb group (PcG) proteins are major chromatin-bound factors that can read and modify chromatin states to maintain gene silencing throughout development. Here we focus on a close homolog of the PcG protein Posterior sex combs to better understand how these proteins affect regulation. This homolog, called Suppressor 2 of zeste [Su(z)2] is composed of two regions: the N-terminal homology region (HR), which serves as a hub for protein interactions, and the C-terminal region (CTR), which is believed to harbor the core activity of compacting chromatin. Here, we describe our classical genetic studies to dissect the structure ...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Nguyen, S. C., Yu, S., Oberlick, E., Wu, C.-t. Tags: Gene Expression Source Type: research
The Role of +4U as an Extended Translation Termination Signal in Bacteria [Gene Expression]
Termination efficiency of stop codons depends on the first 3' flanking (+4) base in bacteria and eukaryotes. In both Escherichia coli and Saccharomyces cerevisiae, termination read-through is reduced in the presence of +4U; however, the molecular mechanism underlying +4U function is poorly understood. Here, we perform comparative genomics analysis on 25 bacterial species (covering Actinobacteria, Bacteriodetes, Cyanobacteria, Deinococcus-Thermus, Firmicutes, Proteobacteria, and Spirochaetae) with bioinformatics approaches to examine the influence of +4U in bacterial translation termination by contrasting highly- and lowly-...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Wei, Y., Xia, X. Tags: Gene Expression Source Type: research
Repair of Meiotic DNA Breaks and Homolog Pairing in Mouse Meiosis Requires a Minichromosome Maintenance (MCM) Paralog [Genome Integrity and Transmission]
The mammalian Mcm-domain containing 2 (Mcmdc2) gene encodes a protein of unknown function that is homologous to the minichromosome maintenance family of DNA replication licensing and helicase factors. Drosophila melanogaster contains two separate genes, the Mei-MCMs, which appear to have arisen from a single ancestral Mcmdc2 gene. The Mei-MCMs are involved in promoting meiotic crossovers by blocking the anticrossover activity of BLM helicase, a function presumably performed by MSH4 and MSH5 in metazoans. Here, we report that MCMDC2-deficient mice of both sexes are viable but sterile. Males fail to produce spermatozoa, and ...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: McNairn, A. J., Rinaldi, V. D., Schimenti, J. C. Tags: Genome Integrity and Transmission Source Type: research
Cooperation Between Kinesin Motors Promotes Spindle Symmetry and Chromosome Organization in Oocytes [Genome Integrity and Transmission]
The oocyte spindle in most animal species is assembled in the absence of the microtubule-organizing centers called centrosomes. Without the organization provided by centrosomes, acentrosomal meiotic spindle organization may rely heavily on the bundling of microtubules by kinesin motor proteins. Indeed, the minus-end directed kinesin-14 NCD, and the plus-end directed kinesin-6 Subito are known to be required for oocyte spindle organization in Drosophila melanogaster. How multiple microtubule-bundling kinesins interact to produce a functional acentrosomal spindle is not known. In addition, there have been few studies on the ...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Radford, S. J., Go, A. M. M., McKim, K. S. Tags: Genome Integrity and Transmission Source Type: research
Genetic Contributors to Intergenerational CAG Repeat Instability in Huntingtons Disease Knock-In Mice [Genome Integrity and Transmission]
Huntington’s disease (HD) is a neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in exon 1 of the HTT gene. Longer repeat sizes are associated with increased disease penetrance and earlier ages of onset. Intergenerationally unstable transmissions are common in HD families, partly underlying the genetic anticipation seen in this disorder. HD CAG knock-in mouse models also exhibit a propensity for intergenerational repeat size changes. In this work, we examine intergenerational instability of the CAG repeat in over 20,000 transmissions in the largest HD knock-in mouse model breeding ...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Neto, J. L., Lee, J.-M., Afridi, A., Gillis, T., Guide, J. R., Dempsey, S., Lager, B., Alonso, I., Wheeler, V. C., Pinto, R. M. Tags: Genome Integrity and Transmission Source Type: research
Improving the Identification of Phenotypic Abnormalities and Sexual Dimorphism in Mice When Studying Rare Event Categorical Characteristics [Methods, Technology, and Resources]
Biological research frequently involves the study of phenotyping data. Many of these studies focus on rare event categorical data, and functional genomics studies typically study the presence or absence of an abnormal phenotype. With the growing interest in the role of sex, there is a need to assess the phenotype for sexual dimorphism. The identification of abnormal phenotypes for downstream research is challenged by the small sample size, the rare event nature, and the multiple testing problem, as many variables are monitored simultaneously. Here, we develop a statistical pipeline to assess statistical and biological sign...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Karp, N. A., Heller, R., Yaacoby, S., White, J. K., Benjamini, Y. Tags: Methods, Technology, and Resources Source Type: research
DNA Repair in Drosophila: Mutagens, Models, and Missing Genes [FlyBook]
The numerous processes that damage DNA are counterbalanced by a complex network of repair pathways that, collectively, can mend diverse types of damage. Insights into these pathways have come from studies in many different organisms, including Drosophila melanogaster. Indeed, the first ideas about chromosome and gene repair grew out of Drosophila research on the properties of mutations produced by ionizing radiation and mustard gas. Numerous methods have been developed to take advantage of Drosophila genetic tools to elucidate repair processes in whole animals, organs, tissues, and cells. These studies have led to the disc...
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Sekelsky, J. Tags: FlyBook Source Type: research
A Bitter Taste of the Sun Makes Egg-Laying Flies Run [Commentary]
(Source: Genetics)
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Authors: Dahanukar, A., Han, C. Tags: Commentary Source Type: research
ISSUE HIGHLIGHTS [Issue Highlights]
(Source: Genetics)
Source: Genetics - February 1, 2017 Category: Genetics & Stem Cells Tags: Issue Highlights Source Type: research
Cell Biology of the Caenorhabditis elegans Nucleus [Cell and Organelle Biology]
Studies on the Caenorhabditis elegans nucleus have provided fascinating insight to the organization and activities of eukaryotic cells. Being the organelle that holds the genetic blueprint of the cell, the nucleus is critical for basically every aspect of cell biology. The stereotypical development of C. elegans from a one cell-stage embryo to a fertile hermaphrodite with 959 somatic nuclei has allowed the identification of mutants with specific alterations in gene expression programs, nuclear morphology, or nuclear positioning. Moreover, the early C. elegans embryo is an excellent model to dissect the mitotic processes of...
Source: Genetics - January 2, 2017 Category: Genetics & Stem Cells Authors: Cohen-Fix, O., Askjaer, P. Tags: Cell and Organelle Biology Source Type: research
Corrigendum [Corrigendum]
(Source: Genetics)
Source: Genetics - January 2, 2017 Category: Genetics & Stem Cells Tags: Corrigendum Source Type: research
Variability in a Short Tandem Repeat Mediates Complex Epistatic Interactions in Arabidopsis thaliana [Genetics of Complex Traits]
Short tandem repeats (STRs) are hypervariable genetic elements that occur frequently in coding regions. Their high mutation rate readily generates genetic variation, contributing to adaptive evolution and human diseases. We previously reported that natural ELF3 polyglutamine variants cause reciprocal genetic incompatibilities in two divergent Arabidopsis thaliana backgrounds. Here, we dissect the genetic architecture of this incompatibility, revealing as many as four loci putatively interacting with ELF3. We were able to specifically identify one such ELF3-interacting gene, LSH9. We further used a yeast two-hybrid strategy...
Source: Genetics - January 2, 2017 Category: Genetics & Stem Cells Authors: Press, M. O., Queitsch, C. Tags: Genetics of Complex Traits Source Type: research
