Tyler McDermott, Mellone Lab

Consequences of Activating a Retroelement Enriched at Fruit Fly Centromeres

Kaylah Samuelson, Hanlon Lab

Elucidating the role of Polo kinase activity and regulation in meiotic drive of the B chromosomes in D. melanogaster

All Biology Undergraduate Symposium

SCHEDULE:

livestream link: https://www.kaltura.com/index.php/extwidget/preview/partner_id/2090521/uiconf_id/37067881/entry_id/1_s3nhc431/embed/iframe?

MCB PRESENTERS:

Emma Beard
Investigating the Role of Bone Morphogenetic Protein Signaling in Drosophila Spermiogenesis

Olivia Bowes
The Effects of Phosphodiesterases on Sperm Storage in Female Drosophila melanogaster

Sindy Gorka
Investigation of Timing and Function of Post-mitotic Readthrough Transcription

EEB PRESENTERS:

Laurel Humphrey
The First Draft Genome of Cold-Water Octocoral Anthothela grandiflora, the Great Flowerbud Coral

Sila Inanoglu
Effect of α-pinene on ectoparasite resistance in tree swallows

Annaliese Seibel
Comparative Energy Allocation of Native Anadromous and Invasive Landlocked Sea Lamprey

PNB PRESENTERS:

Carrie Epstein
Diazocine Synthesis for Photocontrol of CRAC Channels

Alana Grant
Synaptic protein expression in hypothalamic arousal neurons regulates sleep-wake architecture

Akshara Iyer
Identifying Novel Upstream Regulators of the Hippo Pathway: Forward Genetic Screen in Drosophila Melanogaster

ABSTRACTS:

Carrie Epstein

Emma Beard

Investigating the Role of Bone Morphogenetic Protein Signaling in Drosophila Spermiogenesis

Department of Molecular and Cell Biology, University of Connecticut

Rachael P. Norris, Department of Cell Biology, University of Connecticut Health Center

Miki Furusho, Department of Cell Biology, University of Connecticut Health Center

Mark Terasaki, Department of Cell Biology, University of Connecticut Health Center

PI: Mayu Inaba, Department of Cell Biology, University of Connecticut Health Center

In the Drosophila testis, developing germ cells are encapsulated by somatic support cells throughout development. Soma-germline interactions are essential for successful spermiogenesis. However, it is still not fully understood what signaling events take place between the soma and the germline. In this study, we found that a Bone Morphogenetic Protein (BMP) ligand, Glass bottom boat (Gbb), secreted from somatic cyst cells (CCs), signals to differentiating germ cells to maintain proper spermiogenesis. Knockdown of Gbb in CCs or the type I BMP receptor Saxophone (Sax) in germ cells leads to a defect in sperm head bundling and decreased fertility. Electron microscopy analyses revealed that the mutant germ cells have aberrant morphology of mitochondria throughout the stages of spermiogenesis and exhibit a defect in nebenkern formation. Elongating spermatids show uncoupled nuclei and elongating mitochondrial derivatives, suggesting that improper mitochondrial development may cause the sperm bundling defect. Taken together, we propose a new role of soma-derived BMP signaling, which is essential for spermiogenesis.

Alana Grant

Synaptic protein expression in hypothalamic arousal neurons regulates sleep-wake

Architecture

-Jackson Laboratory
-Lab PI: Alexander Jackson
-Graduate student: William Armstrong

Hypocretin/orexin (H/OX) is a neuropeptide produced by a subpopulation of neurons in the lateral hypothalamus (LHA). H/OX neurons are critical regulators of wakefulness via their excitatory effects on wake-promoting neurons, and disruption of H/OX signaling is associated with the sleep disorder narcolepsy, which is characterized by frequent transitions into REM sleep, excessive daytime sleepiness, and sudden loss of muscle tone during wakefulness known as cataplexy. Despite much work describing H/OX’s role in arousal behavior, the molecular regulators of these neurons’ wake-promoting synapses remain unknown. We identified C1ql3 as a novel marker for H/OX neurons which encodes for a putative synaptic organizing protein in other brain regions. We therefore hypothesize that C1QL3 has a regulatory role in the excitatory synaptic transmission and the arousal-promoting effects of H/OX neurons. Utilizing a C1ql3f/f-mVenus mouse, we knocked out C1ql3 from H/OX neurons by injecting AAVDJ-hSyn-Cre into the LHA to generate C1ql3 conditional knockout mice (C1ql3 H/OX-cKO). Blinded EEG/ EMG analysis was done to analyze the sleep-wake architecture of these mice compared to uninjected controls. C1ql3 H/OX-cKO mice resulted in a largely REM-specific effect, showing an increase in total time spent and in the number of episodes of REM sleep compared to control animals. The latency to enter REM from falling asleep sleep, which is often decreased in human narcolepsy patients and animal models of H/OX dysfunction, was also found to be significantly decreased in C1ql3 H/OX-cKO mice. This data supports our hypothesis that C1QL3 might stabilize H/OX synapses to regulate arousal states.

Laurel Humphrey

The First Draft Genome of Cold-Water Octocoral Anthothela grandiflora, the Great Flowerbud Coral

Laurel Humphrey1, Michelle Neitzey2, Emily Trybulec2, Cynthia Webster1, Jill Wegrzyn1, Timothy Shank3, Rachel O’Neill2
1 Department of Ecology and Evolutionary Biology, University of Connecticut
2 Department of Molecular and Cellular Biology, University of Connecticut
3 Woods Hole Oceanographic Institution

Cold-water corals are important sources of ocean biodiversity, yet populations are increasingly threatened by human activity and global warming. Soft octocorals may endure higher ocean acidification levels in comparison to stony hexacorals, although the mechanisms of octocoral biomineralization are less understood. Building genomic resources for cold-water octocorals could help to close information gaps by elucidating coral phylogeny and identifying adaptive potential to climate change. This report describes the first reference genome for the cold-water octocoral species Anthothela grandiflora found throughout the Atlantic Ocean. Sequencing by Oxford Nanopore and Illumina generated 43.6 Gb of long reads at 35.9x coverage and 32.9 Mb of trimmed, paired-end mRNA reads. The final, scaffold-level genome assembly was 641 Mb in length, contained 22,669 scaffolds with N50 length of 82.5 Kb, and included 84.1% of the expected metazoan single-copy orthologs. A high proportion of repetitive content (67.8% of the genome) was masked and 14,837 protein-coding genes were identified with a functional annotation rate of 79%. Orthologous gene family analysis was used to identify expanding and contracting gene families specific to A. grandiflora and other octocorals. These de novo genomic resources will serve to augment the current understanding of various corals and benefit the protection of ecologically-important cold-water coral communities.

Annaliese Seibel

Comparative Energy Allocation of Native Anadromous and Invasive Landlocked Sea Lamprey

Annaliese Seibel and Eric Schultz
Department of Ecology and Evolutionary Biology, University of Connecticut

Determining differences in energy storage and metabolism of an invasive and native population of a species can be vital in understanding what factors make an invasive species successful. To investigate the comparative energetics of the native anadromous sea lamprey and the Great Lakes invasive sea lamprey populations, the lipid content and whole-body field metabolic rate of samples of invasive and native sea lamprey were determined. Native anadromous sea lamprey were collected from the Connecticut River and invasive landlocked sea lamprey were collected from the Hammond Bay Biological Station in Wisconsin at various weeks throughout their migration and spawning life phase. The Soxhlet extraction method was utilized to extract all metabolically accessible lipids from samples to determine their lipid content and samples were ashed in a muffle furnace to determine their lean content. Total energy (kcal) was calculated as the energy stored in both lipid and lean tissue and field metabolic rate was estimated as the change in total energy per day of migration. Results showed that although the invasive landlocked sea lamprey are smaller than the native sea lamprey, they store roughly the same percentage of lipids and have a higher whole-body field metabolic rate than the native anadromous sea lamprey. These results indicate that the Great Lakes environment could be more energetically demanding than the native range for Petromyzon marinus, leading to inflated energy storage and metabolism in the invasive population compared to the native population.

Sila Inanoglu

Effect of α-pinene on ectoparasite resistance in tree swallows

Sila Ecem Inanoglu, Sydney Horan, Lorraine Perez, Hannah Brewer, Sarah Knutie
Department of Ecology and Evolutionary Biology, University of Connecticut

Many bird species incorporate volatile plant material, such as pine needles, into their nests, which can correlate with reduced nest ectoparasite survival. However, it is unclear whether the material directly affects parasite survival or indirectly affects parasite survival through the effects of the plant material on the host’s immune system. For our study, we disentangled the direct and indirect effect of α-pinene (the volatile compound in pine needles) on tree swallow (Tachycineta bicolor) nestlings and their nest ectoparasite community. We experimentally treated nests with an α-pinene or control solution then identified and quantified nest ectoparasite taxa (blow flies [Protocalliphora sialia] and mites [Dermanyssus spp. and Ornithonyssus spp.]) and antibody response of nestlings. Blow fly abundances did not differ significantly between treatments, but pinene-treated nests had fewer mites. Preliminary evidence suggests that laboratory mites treated directly with α-pinene had lower survival than control mites. The antibody response of nestlings did not differ between treatments, nor did it correlate with mite abundance. These results suggest that the relationship between nest pine needles and parasite abundance is mediated by the direct effect of α-pinene on parasitic mite survival rather than an indirect effect through the host.

Sindy Gorka

Akshara Iyer

Identifying Novel Upstream Regulators of the Hippo Pathway: Forward Genetic Screen in Drosophila Melanogaster

Department of Physiology and Neurobiology, University of Connecticut
Mentor: Jianzhong Yu, Department of Physiology and Neurobiology, University of Connecticut

The Hippo pathway is an evolutionarily conserved developmental pathway that controls organ size and tissue homeostasis in all metazoan animals. Dysregulated Hippo pathway has been implicated in a wide range of human disorders, including cancer. The physiological function of the Hippo pathway is best understood in Drosophila, where inactivation of the Hippo pathway tumor suppressors, or overexpression of the Yorkie (Yki) oncoprotein, results in tissue overgrowth characterized by excessive cell proliferation and diminished apoptosis, and increased transcription of Hippo pathway target genes such as diap1 and expanded (ex). Despite the well-established Hippo pathway core signaling cascade, the upstream regulation of the Hippo pathway is less understood. This screening project attempts to identify novel upstream regulators of the Hippo pathway, specifically genes located on the X chromosome of Drosophila, through a forward genetic screen for overgrowth phenotypes. Random point mutations were induced through EMS treatment, and a merlin mutant background increased the sensitivity of the screen. After candidates were identified and validated, Diap1 levels were examined in third-instar larvae eye discs to determine the mutation’s impact on the Hippo pathway. A total of five overgrowth candidates were identified, and one was validated through reproducibility tests after establishing stocks. Diap1 staining suggests a role of the candidate mutation in regulating Hippo signaling. Future directions include mapping and characterizing the candidate mutations

Olivia Bowes

The Effects of Phosphodiesterases on Sperm Storage in Female Drosophila melanogaster.

MCB Major, Sun Lab (Dept of PNB), IDEA Grant Funded

Sperm storage is a process in Drosophila melanogaster where the male sperm is held in the female reproductive tract, in glands called spermathecae (SPT) and seminal receptacles (SR), to allow for prolonged sperm storage and maintenance in environments where regular mating may not be viable. While stored in these organs, the sperm is exposed to secretions produced by the SPT and parovaria (PO) which provide many proteins and nutrients vital for preparing the sperm for fertilization. While genes derived from the male reproductive tract and seminal fluids have been thoroughly investigated in their relationship to sperm maintenance (McCullough et al. 2022), the female-derived genes involved in the processes regulating sperm storage and maintenance have not been well-characterized. Therefore, we investigated possible roles of female-derived Phosphodiesterases (PDEs) in the process of sperm storage using the Gal4-UAS system to knock down genes coding for individual PDEs specifically in the secretory cells of the SPT and PO. Through this process, we identified Pde8, a probable catalyst for the hydrolysis of cAMP, as an involved enzyme in the process of sperm storage in the SPT. We also found through RNA-seq that Pde6, Pde11, and pn are present in the SPT and surrounding tissues, but they did not show a defect in sperm storage when knocked down in the SPT and parovaria (PO). This indicates that Pde8 plays an important role in sperm storage and future studies should investigate if the defect caused by Pde8 knockdown can be amplified by knocking out multiple PDEs simultaneously.

Join us in the Logic Colloquium!

Xinhe Wu (NCSU):

“Vague Identity: A Uniform Approach”

There are numerous apparent examples of vague identity, i.e. examples where two objects appear to be neither determinately identical nor determinately distinct. Philosophers disagree on whether the source of vagueness in identity is semantic or ontic/metaphysical. In this talk, I explore the use of Boolean-valued models as a many-valued semantic framework for identity. I argue that this semantics works well with both a semantic and ontic conception of vague identity. I also discuss, in the context of Boolean-valued logic, responses to the Evans’ argument under the two conceptions.

All welcome!

https://logic.uconn.edu/calendar/