ERA

Biological Sciences Research Material

Items in this Collection
  1. Investigation of meiotic organelle checkpoint functions by Drosophila Myt1

    Title: Investigation of meiotic organelle checkpoint functions by Drosophila Myt1
    Creator: Ramya Varadarajan
    Description: Meiosis in eukaryotes includes a developmentally programmed pre-meiotic G2 phase arrest before the onset of MI division mediated by inhibitory phosphorylation of Cdk1. There are two inhibitory kinases, Wee1 and Myt1. Myt1 mediated Cyclin B-Cdk1 regulation serves as a conserved mechanism for maintaining pre-meiotic oocyte arrest in many animal models. Earlier reports from the Campbell lab, however, have shown that loss of Myt1 activity affected multiple aspects of Drosophila spermatogenesis resulting in male sterility. The conserved meiotic checkpoint function of Myt1 was hypothesized to account for myt1 mutant male sterility, as Drosophila spermatocytes normally undergo a developmentally regulated pre-meiotic G2 phase arrest before MI. This possibility, however, has not been tested. Here I show that loss of Myt1 activity neither affects the timing of pre-meiotic G2 phase arrest nor the overall coordination of G2/MI transition. Instead, the phenotypic analysis of myt1 mutants indicated that Myt1 activity is required for structural integrity of a germline specific membranous cytoskeletal organelle called the fusome (or intercellular bridges). I found that inhibition of Cyclin A-Cdk1 during early spermatocyte development requires Myt1 activity to prevent fusomes from premature Cdk1 activation. Mis-regulation of Cyclin A-Cdk1 during spermatocyte development also perturbed premature centrioles dis-engagement, producing multipolar meiotic spindles resulting in aneuploidy of myt1 meiocytes. I conclude that the role of Myt1 during pre-meiotic G2 phase arrest of male meiosis is to regulate discrete checkpoint mechanisms that are used to spatially and temporally coordinate cytoplasmic organelle behavior with the nuclear events of meiotic progression that are triggered by Cdc25Twe-mediated Cdk1 activation, at G2/MI.
    Subjects: Myt1 kinase, Drosophila spermatogenesis, fusome
    Date Created: 2015/09/28
  2. Emergence Phenology of Adult Apanteles polychrosidis (Hymenoptera: Braconidae)

    Title: Emergence Phenology of Adult Apanteles polychrosidis (Hymenoptera: Braconidae)
    Creator: Dombrowsky, Emily A.
    Subjects: Apanteles polychrosidis
  3. Scale-eating cichlids: From hand(ed) to mouth.

    Title: Scale-eating cichlids: From hand(ed) to mouth.
    Creator: Palmer, A.R.
    Description: Two recent studies in BMC Biology and Evolution raise important questions about a textbook case of frequency-dependent selection in scale-eating cichlid fishes. They also suggest a fascinating new line of research testing the effects of handed behavior on morphological asymmetry.
    Subjects: scale-eating cichlids, morphological asymmetry, handed behavior, mouth bending
    Date Created: 2010
  4. Caloptilia fraxinella

    Title: Caloptilia fraxinella
    Creator: Wist, Tyler
    Subjects: Caloptila fraxinella
  5. On the Firm Foundation of Curiousity : The Early History of Biology at the University of Alberta

    Title: On the Firm Foundation of Curiousity : The Early History of Biology at the University of Alberta
    Creator: Acorn, John
    Description: History of the University of Alberta Department of Biological Sciences.
    Subjects: History, University of Alberta. Department of Biological Sciences
    Date Created: 2008
  6. Evaluation of Beauvericinas a Marker for Beauveria bassiana virulence and its implication for greenhouse pest management

    Title: Evaluation of Beauvericinas a Marker for Beauveria bassiana virulence and its implication for greenhouse pest management
    Creator: Rajput, Sunil
    Subjects: Beauveria bassiana, Biocontrol, Invertebrate pathology, thrips, Greenhouse, Mycotoxins
    Date Created: 2006
  7. Pollen-mediated gene flow from transgenic safflower (Carthamus tinctorius L.) intended for plant molecular farming to conventional safflower.

    Title: Pollen-mediated gene flow from transgenic safflower (Carthamus tinctorius L.) intended for plant molecular farming to conventional safflower.
    Creator: McPherson M.A.
    Subjects: gene flow, pollen/genetics, Plants, genetically modified/genetics, Carthamus tinctorius/genetics
    Date Created: 2009
  8. Insights into temperature adaptation in the Thermotogae gained through transcriptomics and comparative genomics - Appendices

    Title: Insights into temperature adaptation in the Thermotogae gained through transcriptomics and comparative genomics - Appendices
    Creator: Pollo, Stephen M. J.
    Description: These are appendices C - G for the University of Alberta M.Sc. thesis: Pollo, Stephen M. J. 2014. Insights into temperature adaptation in the Thermotogae gained through transcriptomics and comparative genomics
    Subjects: Bacteria, RNA-Seq, Temperature Adaptation, Kosmotoga olearia, Comparative genomics, Thermotogae, Transcriptomics
    Date Created: 2014
  9. Frankliniella occidentalis oviposition video

    Title: Frankliniella occidentalis oviposition video
    Creator: Rajput, S.
    Description: Frankliniella occidentalis probing and oviposition video. Ventral view of an adult female thrips ovipositing an egg into deionized water through stretched parafilm. Video recorded using a Nikon Coolpix 775 digital camera mounted on a stereo microscope. Please also refer to Frankliniella occidentalis and Hercinothrips femoralis embryogenesis laboratory notes.
    Subjects: Thrips embryogenesis, western flower thrips, thrips oviposition, thrips probing, thrips egg laying
    Date Created: 2002
  10. Eggs and 1st instar larvae

    Title: Eggs and 1st instar larvae
    Creator: Wist, Tyler
    Subjects: instar larvae, eggs