skip to main content

Explore Research Products in the NSF-PAR

This content will become publicly available on August 22, 2024

Title: cliffordB.4.1, an allele of CG1603, causes tissue overgrowth in the Drosophila melanogaster eye
Mutant B.4.1 , generated via EMS mutagenesis in Drosophila melanogaster, was studied by undergraduate students participating in the Fly-CURE. After inducing genetically mosaic tissue in the adult eye, B.4.1 mutant tissue displays a robust increase in cell division and a rough appearance. Complementation mapping and sequence analysis identified a nonsense mutation in the gene CG1603 , which we named clifford ( cliff ) due to observed increases in red-pigmented mutant tissue compared to controls. cliff encodes a zinc finger-containing protein implicated in transcriptional control. RNAi knockdown of cliff similarly results in rough eyes, confirming a role for Cliff in eye development.  more » « less
Award ID(s):
2021146
NSF-PAR ID:
10463066
Author(s) / Creator(s):
Date Published:
Journal Name:
microPublication biology
ISSN:
2578-9430
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ( , Developmental Dynamics)
    Abstract Background

    Vertebrate eye formation requires coordinated inductive interactions between different embryonic tissue layers, first described in amphibians. A network of transcription factors and signaling molecules controls these steps, with mutations causing severe ocular, neuronal, and craniofacial defects. Ineyelessmutant axolotls, eye morphogenesis arrests at the optic vesicle stage, before lens induction, and development of ventral forebrain structures is disrupted.

     Results

    We identified a 5‐bp deletion in therax(retina and anterior neural fold homeobox) gene, which was tightly linked to the recessiveeyeless(e) axolotl locus in an F2 cross. This frameshift mutation, in exon 2, truncates RAX protein within the homeodomain (P154fs35X). Quantitative RNA analysis shows that mutant and wild‐typeraxtranscripts are equally abundant inE/eembryos. Translation appears to initiate from dual start codons, via leaky ribosome scanning, a conserved feature among gnathostome RAX proteins. Previous data showraxis expressed in the optic vesicle and diencephalon, deeply conserved among metazoans, and required for eye formation in other species.

     Conclusion

    Theeyelessaxolotl mutation is a null allele in theraxhomeobox gene, with primary defects in neural ectoderm, including the retinal and hypothalamic primordia.

     
    more » « less
  2. ; ; ; ; ; ; ; ; ; ; et al ( , microPublication biology)
    null (Ed.)
    Genetic screens have been used to identify genes involved in the regulation of different biological processes. We identified growth mutants in a Flp/FRT screen using the Drosophila melanogaster eye to identify conditional regulators of cell growth and cell division. One mutant identified from this screen, B.2.16, was mapped and characterized by researchers in undergraduate genetics labs as part of the Fly-CURE. We find that B.2.16 is a non-lethal genetic modifier of the Dark82 mosaic eye phenotype. 
    more » « less
  3. ; ; ; ; ; ; ( , MicrobiologyOpen)
    Abstract

    Streptococcus mutansis a key pathogenic bacterium in the oral cavity and a primary contributor to dental caries. TheS. mutansCid/Lrg system likely contributes to tolerating stresses encountered in this environment ascidand/orlrgmutants exhibit altered oxidative stress sensitivity, genetic competence, and biofilm phenotypes. It was recently noted that thecidBmutant had two stable colony morphologies: a “rough” phenotype (similar to wild type) and a “smooth” phenotype. In our previously published work, thecidBrough mutant exhibited increased sensitivity to oxidative stress, and RNAseq identified widespread transcriptomic changes in central carbon metabolism and oxidative stress response genes. In this current report, we conducted Illumina‐based genome resequencing of wild type,cidBrough, andcidBsmooth mutants and compared their resistance to oxidative and acid stress, biofilm formation, and competence phenotypes. BothcidBmutants exhibited comparable aerobic growth inhibition on agar plates, during planktonic growth, and in the presence of 1 mM hydrogen peroxide. ThecidBsmooth mutant displayed a significant competence defect in BHI, which was rescuable by synthetic CSP. BothcidBmutants also displayed reduced XIP‐mediated competence, although this reduction was more pronounced in thecidBsmooth mutant. Anaerobic biofilms of thecidBsmooth mutant displayed increased propidium iodide staining, but corresponding biofilm CFU data suggest this phenotype is due to cell damage and not increased cell death. ThecidBrough anaerobic biofilms showed altered structure relative to wild type (reduced biomass and average thickness) which correlated with decreased CFU counts. Sequencing data revealed that thecidBsmooth mutant has a unique “loss of read coverage” of ~78 kb of DNA, corresponding to the genomic island TnSMU2 and genes flanking its 3′ end. It is therefore likely that the unique biofilm and competence phenotypes of thecidBsmooth mutant are related to its genomic changes in this region.

     
    more » « less
  4. ; ; ( , Journal of Morphology)
    Abstract

    Hagfish use forceful retractions of a dental plate to shear and ingest food. Retractile force is generated by the retractor muscle complex of the posterior hagfish feeding apparatus (HFA). While gross morphological descriptions exist, the organization of muscle and connective tissue fibers that form the soft tissue retractor complex do not. In this study, we used paraffin histology to prepare serial sections of Pacific (Eptatretus stoutii, Lockington, 1879) and Atlantic (Myxine glutinosa, Linnaeus, 1758) hagfishes in order to describe constituent soft tissue anatomy and fiber orientations. We generated 3D reconstructions in which digitized sections were segmented and fitted to volumetric scans of retractor complexes taken prior to microtomy. These models confirmed that the retractor complex is composed of a perpendicularis muscle that fits within the eye of a needle‐shaped clavatus muscle, which anteriorly bears the dental plate tendon, and in turn fits within a sleeve‐like tubulatus muscle. Analysis of fiber orientations within these muscles resulted in novel functional hypotheses: (a) The tubulatus muscle represents a novel tubular bipennate muscle with a considerable physiological cross‐sectional area. Its activation may indirectly create tension in the dental plate tendon: as the tubulatus muscle forcefully extends, it displaces the terminal bulb and the clavatus muscle posteriorly. (b) Within the HFA terminal bulb, the muscle fibers of the clavatus and perpendicularis muscles are mutually perpendicular and may cocontract to form a swelling stopper knot‐like muscular complex that resists being pulled through the tubulatus muscle. (c) While overall feeding apparatus muscle morphology is conserved, the physiological cross‐sectional area of the tubulatus muscle inE. stoutii, is relatively larger than that ofM. glutinosa, suggesting a more forceful retraction. The tubular bipennate construction of the tubulatus may represent a novel soft robotic actuator design.

     
    more » « less
  5. ; ; ; ; ; ; ( , The Plant Journal)
    Summary

    Small RNAs trigger repressive DNA methylation at thousands of transposable elements in a process called RNA‐directed DNA methylation (RdDM). The molecular mechanism of RdDM is well characterized in Arabidopsis, yet the biological function remains unclear, as loss of RdDM in Arabidopsis causes no overt defects, even after generations of inbreeding. It is known that 24 nucleotide Pol IV‐dependent siRNAs, the hallmark of RdDM, are abundant in flowers and developing seeds, indicating that RdDM might be important during reproduction. Here we show that, unlike Arabidopsis, mutations in the Pol IV‐dependent small RNA pathway cause severe and specific reproductive defects inBrassica rapa. High rates of abortion occur when seeds have RdDM mutant mothers, but not when they have mutant fathers. Although abortion occurs after fertilization, RdDM function is required in maternal somatic tissue, not in the female gametophyte or the developing zygote, suggesting that siRNAs from the maternal soma might function in filial tissues. We propose that recently outbreeding species such asB. rapaare key to understanding the role of RdDM during plant reproduction.

     
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email