Publications by authors named "Laura Katz"

Article Synopsis
  • Ciliates serve as important models for understanding unique genome structures due to their dual nuclear system, consisting of somatic macronuclei (MAC) and germline micronuclei (MIC), formed after sexual reproduction through conjugation.
  • The study focuses on a specific non-model ciliate genus within the Class Phyllopharyngea, using advanced techniques like DAPI staining and fluorescence in situ hybridization (FISH) to analyze nuclear architecture and genome dynamics.
  • Results indicate distinct differences in MAC developmental stages compared to other ciliate species, contributing valuable insights into nuclear development and genome evolution among non-model ciliates.
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Article Synopsis
  • The text discusses a newly developed workflow for phylogenomic analyses of microbial eukaryotes using single-cell RNA sequencing, aimed at overcoming challenges related to genome complexity and non-target sequences.
  • The researchers tested the workflow on transcriptomes from the Oligotrichea group of marine ciliates, comparing their results with traditional ribosomal RNA analyses and examining phylogenomic approaches using both single-copy and multi-copy genes.
  • Overall, the study found that their workflow, particularly the use of the Asteroid method, yielded consistent and well-supported phylogenetic relationships, making it adaptable for studying other uncultivable microbial eukaryotes.
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Objective: The goal of this work is to reduce the amount of manual work required to go from data capture to regulatory submission. It will be shown that the use of Siamese networks will allow for the generation of embeddings that can be used by traditional machine learning classifiers to perform the classification at much higher levels of accuracy than standard approaches.

Methods: Siamese networks are a method for training data embeddings such that data within the same class are closer with respect to a given distance metric than they are to data points in another class.

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In contrast to the typified view of genome cycling only between haploidy and diploidy, there is evidence from across the tree of life of genome dynamics that alter both copy number (i.e. ploidy) and chromosome complements.

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The bulk of eukaryotic diversity is microbial, with macroscopic lineages such as plant, animals and fungi nesting among a plethora of diverse lineages that include amoebae, flagellates, ciliates, and many types of algae. Our understanding of the evolutionary relationships and genome properties of microbial eukaryotes is rapidly advancing through analyses of omics (transcriptomic, genomic) data. However, phylogenomic analyses are challenging for microeukaryotes, and particularly uncultivable lineages, as single-cell approaches generate a mixture of sequence data from hosts, associated microbiomes, and contaminants.

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Ciliates are single-celled microbial eukaryotes that diverged from other eukaryotic lineages over a billion years ago. The extensive evolutionary timespan of ciliate has led to enormous genetic and phenotypic changes, contributing significantly to their high level of diversity. Recent analyses based on molecular data have revealed numerous cases of cryptic species complexes in different ciliate lineages, demonstrating the need for a robust approach to delimit species boundaries and elucidate phylogenetic relationships.

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Published studies on the glycosylation, absorption, distribution, metabolism, excretion, and safety outcomes of orally ingested recombinant human lactoferrin (rhLF) were reviewed in the context of unanswered safety questions, including alloimmunization, allergenicity, and immunotoxicity potential of rhLF during repeated exposure. The primary objective was to summarize current safety data of rhLF produced in transgenic host expression systems. Overall, results from animal and human studies showed that rhLF was well tolerated and safe.

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In contrast to the canonical view that genomes cycle only between haploid and diploid states, many eukaryotes have dynamic genomes that change content throughout an individual's life cycle. However, the few detailed studies of microeukaryotic life cycles render our understanding of eukaryotic genome dynamism incomplete. Foraminifera (Rhizaria) are an ecologically important, yet understudied, clade of microbial eukaryotes with complex life cycles that include changes in ploidy and genome organization.

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The evolution of lineage-specific gene families remains poorly studied across the eukaryotic tree of life, with most analyses focusing on the recent evolution of de novo genes in model species. Here we explore the origins of lineage-specific genes in ciliates, a ~1 billion year old clade of microeukaryotes that are defined by their division of somatic and germline functions into distinct nuclei. Previous analyses on conserved gene families have shown the effect of ciliates' unusual genome architecture on gene family evolution: extensive genome processing-the generation of thousands of gene-sized somatic chromosomes from canonical germline chromosomes-is associated with larger and more diverse gene families.

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We are launching a series to celebrate the 40th anniversary of the first issue of Molecular Biology and Evolution. In 2024, we will publish virtual issues containing selected papers published in the Society for Molecular Biology and Evolution journals, Molecular Biology and Evolution and Genome Biology and Evolution. Each virtual issue will be accompanied by a perspective that highlights the historic and contemporary contributions of our journals to a specific topic in molecular evolution.

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Testate amoebae (order Arcellinida) are abundant in freshwater ecosystems, including low pH bogs and fens. Within these environments, Arcellinida are considered top predators in microbial food webs and their tests are useful bioindicators of paleoclimatic changes and anthropogenic pollutants. Accurate species identifications and characterizations of diversity are important for studies of paleoclimate, microbial ecology, and environmental change; however, morphological species definitions mask cryptic diversity, which is a common phenomenon among microbial eukaryotes.

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The enormous population sizes and wide biogeographical distribution of many microbial eukaryotes set the expectation of high levels of intraspecific genetic variation. However, studies investigating protist populations remain scarce, mostly due to limited 'omics data. Instead, most genetics studies of microeukaryotes have thus far relied on single loci, which can be misleading and do not easily allow for detection of recombination, a hallmark of sexual reproduction.

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Virophages are small dsDNA viruses that hijack the machinery of giant viruses during the co-infection of a protist (i.e., microeukaryotic) host and represent an exceptional case of "hyperparasitism" in the viral world.

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Article Synopsis
  • Idiopathic multicentric Castleman disease (iMCD) is a rare inflammatory disorder linked to cytokine storms, with interleukin-6 (IL-6) being a key driver in some cases.
  • The effectiveness of anti-IL-6 therapy with siltuximab varies among patients, and early biomarkers to predict treatment success are currently missing.
  • This study identifies CXCL13 as a potential predictive biomarker; a 17% reduction in CXCL13 levels by day 8 of siltuximab treatment can help differentiate between responders and non-responders.
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Knowledge of eukaryotic life cycles and associated genome dynamics stems largely from research on animals, plants, and a small number of "model" (i.e., easily cultivable) lineages.

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Many species of plants have evolved structures called phytotelmata that store water and trap detritus and prey. These structures house diverse communities of organisms, the inquiline microbiome, that aids breakdown of litter and prey. The invertebrate and bacterial food webs in these systems are well characterized, but less is known about microbial eukaryotic community dynamics.

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Article Synopsis
  • * The widely accepted view places the root between Unikonta (which includes Opisthokonta and Amoebozoa) and Bikonta (the rest of the eukaryotes), based on earlier studies, but there are complexities like gene duplications and losses that weren't fully considered.
  • * A recent study using gene tree parsimony with a large dataset suggests the root is likely between Opisthokonta and other eukaryotes, supporting this claim through multiple analyses and comparisons with existing hypotheses.
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Vertical inheritance is foundational to Darwinian evolution, but fails to explain major innovations such as the rapid spread of antibiotic resistance among bacteria and the origin of photosynthesis in eukaryotes. While lateral gene transfer (LGT) is recognized as an evolutionary force in prokaryotes, the role of LGT in eukaryotic evolution is less clear. With the exception of the transfer of genes from organelles to the nucleus, a process termed endosymbiotic gene transfer (EGT), the extent of interdomain transfer from prokaryotes to eukaryotes is highly debated.

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Foraminifera, classified in the supergroup Rhizaria, are a common and highly diverse group of mainly marine protists. Despite their evolutionary and ecological importance, only limited genomic data (one partial genome and nine transcriptomic datasets) have been published for this group. Foraminiferal molecular phylogeny is largely based on 18S rRNA gene sequence analysis.

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The purpose of this study is to determine which taxonomic methods can elucidate clear and quantifiable differences between two cryptic ciliate species, and to test the utility of genome architecture as a new diagnostic character in the discrimination of otherwise indistinguishable taxa. Two cryptic tintinnid ciliates, Schmidingerella arcuata and Schmidingerella meunieri, are compared via traditional taxonomic characters including lorica morphometrics, ribosomal RNA (rRNA) gene barcodes and ecophysiological traits. In addition, single-cell 'omics analyses (single-cell transcriptomics and genomics) are used to elucidate and compare patterns of micronuclear genome architecture between the congeners.

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Foraminifera include diverse shell-building lineages found in a wide array of aquatic habitats from the deep-sea to intertidal zones to brackish and freshwater ecosystems. Recent estimates of morphological and molecular foraminifera diversity have increased the knowledge of foraminiferal diversity, which is critical as these lineages are used as bioindicators of past and present environmental perturbation. However, a comparative analysis of foraminiferal biodiversity between their major habitats (freshwater, brackish, intertidal, and marine) is underexplored, particularly using molecular tools.

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Ciliates are defined by the presence of dimorphic nuclei as they have both a somatic macronucleus and germline micronucleus within each individual cell. The size and structure of both germline micronuclei and somatic macronuclei vary tremendously among ciliates. Except just after conjugation (i.

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Objective: The majority of U.S. mental health practitioners receive little to no foundational trauma education, and instead rely on in-service or continuing education to fill this deficit.

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