More Like this

1. Flow cytometry methods for targeted isolation of ctenophore cells

   https://doi.org/10.3389/fmars.2023.1276041  

   Dieter, Abigail C ; True, Aliyah_B K ; Gilbertson, Emily A ; Snyder, Grace ; Lacy-Hulbert, Adam ; Traylor-Knowles, Nikki ; Browne, William E ; Vandepas, Lauren E ( October 2023 , Frontiers in Marine Science)

   Cell suspension fluidics, such as flow cytometry (FCS) and fluorescence-activated cell sorting (FACS), facilitates the identification and precise separation of individual cells based on phenotype. Since its introduction, flow cytometry has been used to analyze cell types and cellular processes in diverse non-vertebrate taxa, including cnidarians, molluscs, and arthropods. Ctenophores, which diverged very early from the metazoan stem lineage, have emerged as an informative clade for the study of metazoan cell type evolution. We present standardized methodologies for flow cytometry-mediated identification and analyses of cells from the model ctenophoreMnemiopsis leidyithat can also be applied to isolate targeted cell populations. Here we focus on the identification and isolation of ctenophore phagocytes. Implementing flow cytometry methods in ctenophores allows for fine scale analyses of fundamental cellular processes conserved broadly across animals, as well as potentially revealing novel cellular phenotypes and behaviors restricted to the ctenophore lineage.

    

   more » « less
2. The sex lives of ctenophores: the influence of light, body size, and self-fertilization on the reproductive output of the sea walnut, Mnemiopsis leidyi

   https://doi.org/10.7717/peerj.1846  

   Sasson, Daniel A. ; Ryan, Joseph F. ( March 2016 , PeerJ)

   Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience and biogeography). A few ctenophore species including, most notably,Mnemiopsis leidyi, are considered as invasive species, adding to the significance of studying ctenophore ecology. Despite the growing interest in ctenophore biology, relatively little is known about their reproduction. Like most ctenophores,M. leidyiis a simultaneous hermaphrodite capable of self-fertilization. In this study, we assess the influence of light on spawning, the effect of body size on spawning likelihood and reproductive output, and the cost of self-fertilization on egg viability inM. leidyi. Our results suggest thatM. leidyispawning is more strongly influenced by circadian rhythms than specific light cues and that body size significantly impacts spawning and reproductive output.Mnemiopsis leidyiadults that spawned alone produced a lower percentage of viable embryos versus those that spawned in pairs, suggesting that self-fertilization may be costly in this species. These results provide insight into the reproductive ecology ofM. leidyiand provide a fundamental resource for researchers working with them in the laboratory.

    

   more » « less
3. Par protein localization during the early development of Mnemiopsis leidyi suggests different modes of epithelial organization in the metazoa

   https://doi.org/10.7554/eLife.54927  

   Salinas-Saavedra, Miguel ; Martindale, Mark Q ( July 2020 , eLife)

   null (Ed.)

   In bilaterians and cnidarians, epithelial cell-polarity is regulated by the interactions between Par proteins, Wnt/PCP signaling pathway, and cell-cell adhesion. Par proteins are highly conserved across Metazoa, including ctenophores. But strikingly, ctenophore genomes lack components of the Wnt/PCP pathway and cell-cell adhesion complexes raising the question if ctenophore cells are polarized by mechanisms involving Par proteins. Here, by using immunohistochemistry and live-cell imaging of specific mRNAs, we describe for the first time the subcellular localization of selected Par proteins in blastomeres and epithelial cells during the embryogenesis of the ctenophore Mnemiopsis leidyi . We show that these proteins distribute differently compared to what has been described for other animals, even though they segregate in a host-specific fashion when expressed in cnidarian embryos. This differential localization might be related to the emergence of different junctional complexes during metazoan evolution. 

   more » « less
4. Still Enigmatic: Innate Immunity in the Ctenophore Mnemiopsis leidyi

   https://doi.org/10.1093/icb/icz116  

   Traylor-Knowles, Nikki ; Vandepas, Lauren E ; Browne, William E ( August 2019 , Integrative and Comparative Biology)

   Abstract Innate immunity is an ancient physiological response critical for protecting metazoans from invading pathogens. It is the primary pathogen defense mechanism among invertebrates. While innate immunity has been studied extensively in diverse invertebrate taxa, including mollusks, crustaceans, and cnidarians, this system has not been well characterized in ctenophores. The ctenophores comprise an exclusively marine, non-bilaterian lineage that diverged early during metazoan diversification. The phylogenetic position of ctenophore lineage suggests that characterization of the ctenophore innate immune system will reveal important features associated with the early evolution of the metazoan innate immune system. Here, we review current understanding of the ctenophore immune repertoire and identify innate immunity genes recovered from three ctenophore species. We also isolate and characterize Mnemiopsis leidyi cells that display macrophage-like behavior when challenged with bacteria. Our results indicate that ctenophores possess cells capable of phagocytosing microbes and that two distantly related ctenophores, M. leidyi and Hormiphora californiensis, possess many candidate innate immunity proteins. 

   more » « less
5. Morphological and dietary changes encoded in the genome of Beroe ovata , a ctenophore-eating ctenophore

   https://doi.org/10.1093/nargab/lqae072  

   Vargas, Alexandra M. ; DeBiasse, Melissa B. ; Dykes, Lana L. ; Edgar, Allison ; Hayes, T. Danielle ; Groso, Daniel J. ; Babonis, Leslie S. ; Martindale, Mark Q. ; Ryan, Joseph F. ( June 2024 , NAR Genomics and Bioinformatics)

   As the sister group to all other animals, ctenophores (comb jellies) are important for understanding the emergence and diversification of numerous animal traits. Efforts to explore the evolutionary processes that promoted diversification within Ctenophora are hindered by undersampling genomic diversity within this clade. To address this gap, we present the sequence, assembly and initial annotation of the genome of Beroe ovata. Beroe possess unique morphology, behavior, ecology and development. Unlike their generalist carnivorous kin, beroid ctenophores feed exclusively on other ctenophores. Accordingly, our analyses revealed a loss of chitinase, an enzyme critical for the digestion of most non-ctenophore prey, but superfluous for ctenophorivores. Broadly, our genomic analysis revealed that extensive gene loss and changes in gene regulation have shaped the unique biology of B. ovata. Despite the gene losses in B. ovata, our phylogenetic analyses on photosensitive opsins and several early developmental regulatory genes show that these genes are conserved in B. ovata. This additional sampling contributes to a more complete reconstruction of the ctenophore ancestor and points to the need for extensive comparisons within this ancient and diverse clade of animals. To promote further exploration of these data, we present BovaDB (http://ryanlab.whitney.ufl.edu/bovadb/), a portal for the B. ovata genome.

    

   more » « less