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6
result(s) for
"Chernyshova, Anna M."
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Novel probiotic approach to counter Paenibacillus larvae infection in honey bees
2020
American foulbrood (AFB) is a highly virulent disease afflicting honey bees (
Apis mellifera
). The causative organism,
Paenibacillus larvae
, attacks honey bee brood and renders entire hives dysfunctional during active disease states, but more commonly resides in hives asymptomatically as inactive spores that elude even vigilant beekeepers. The mechanism of this pathogenic transition is not fully understood, and no cure exists for AFB. Here, we evaluated how hive supplementation with probiotic lactobacilli (delivered through a nutrient patty; BioPatty) affected colony resistance towards a naturally occurring AFB outbreak. Results demonstrated a significantly lower pathogen load and proteolytic activity of honey bee larvae from BioPatty-treated hives. Interestingly, a distinctive shift in the microbiota composition of adult nurse bees occurred irrespective of treatment group during the monitoring period, but only vehicle-supplemented nurse bees exhibited higher
P. larvae
loads. In vitro experiments utilizing laboratory-reared honey bee larvae showed
Lactobacillus plantarum
Lp39,
Lactobacillus rhamnosus
GR-1, and
Lactobacillus kunkeei
BR-1 (contained in the BioPatty) could reduce pathogen load, upregulate expression of key immune genes, and improve survival during
P. larvae
infection. These findings suggest the usage of a lactobacilli-containing hive supplement, which is practical and affordable for beekeepers, may be effective for reducing enzootic pathogen-related hive losses.
Journal Article
Differential Selection on Caste-Associated Genes in a Subterranean Termite
by
Taylor, Cambrie
,
Thompson, Graham J.
,
Chernyshova, Anna M.
in
Altruism
,
Biology
,
caste differentiation
2022
Analyzing the information-rich content of RNA can help uncover genetic events associated with social insect castes or other social polymorphisms. Here, we exploit a series of cDNA libraries previously derived from whole-body tissue of different castes as well as from three behaviourally distinct populations of the Eastern subterranean termite Reticulitermes flavipes. We found that the number (~0.5 M) of single nucleotide variants (SNVs) was roughly equal between nymph, worker and soldier caste libraries, but dN/dS (ratio of nonsynonymous to synonymous substitutions) analysis suggested that some of these variants confer a caste-specific advantage. Specifically, the dN/dS ratio was high (~4.3) for genes expressed in the defensively specialized soldier caste, relative to genes expressed by other castes (~1.7–1.8) and regardless of the North American population (Toronto, Raleigh, Boston) from which the castes were sampled. The populations, meanwhile, did show a large difference in SNV count but not in the manner expected from known demographic and behavioural differences; the highly invasive unicolonial population from Toronto was not the least diverse and did not show any other unique substitution patterns, suggesting any past bottleneck associated with invasion or with current unicoloniality has become obscured at the RNA level. Our study raises two important hypotheses relevant to termite sociobiology. First, the positive selection (dN/dS > 1) inferred for soldier-biased genes is presumably indirect and of the type mediated through kin selection, and second, the behavioural changes that accompany some social insect urban invasions (i.e., ‘unicoloniality’) may be detached from the loss-of-diversity expected from invasion bottlenecks.
Journal Article
Lactobacillus spp. attenuate antibiotic-induced immune and microbiota dysregulation in honey bees
2020
Widespread antibiotic usage in apiculture contributes substantially to the global dissemination of antimicrobial resistance and has the potential to negatively influence bacterial symbionts of honey bees (
Apis mellifera
). Here, we show that routine antibiotic administration with oxytetracycline selectively increased
tetB
(efflux pump resistance gene) abundance in the gut microbiota of adult workers while concurrently depleting several key symbionts known to regulate immune function and nutrient metabolism such as
Frischella perrera
and
Lactobacillus
Firm-5 strains. These microbial changes were functionally characterized by decreased capped brood counts (marker of hive nutritional status and productivity) and reduced antimicrobial capacity of adult hemolymph (indicator of immune competence). Importantly, combination therapy with three immunostimulatory
Lactobacillus
strains could mitigate antibiotic-associated microbiota dysbiosis and immune deficits in adult workers, as well as maximize the intended benefit of oxytetracycline by suppressing larval pathogen loads to near-undetectable levels. We conclude that microbial-based therapeutics may offer a simple but effective solution to reduce honey bee disease burden, environmental xenobiotic exposure, and spread of antimicrobial resistance.
Daisley et al. show that antibiotic treatment with oxytetracycline impairs the gut microbiota and immune system of honey bees, and reduces capped brood counts. They also show that supplementation with lactobacilli during antibiotic recovery can reverse the harmful effects of the antibiotic treatment. Their findings offer a simple microbial-based solution that aims to reduce honey bee disease burden, environmental pollution by xenobiotics, and spread of antimicrobial resistance.
Journal Article
A Genetic Perspective on Social Insect Castes: A Synthetic Review and Empirical Study
2021
The process of caste differentiation is central to understanding insect sociality because it is castes that enable division of labor. Presumably selection favors colonies that can divide labor in response to environmental demands, and for many taxa genetic factors are an important part of this equation. In my thesis, I first provide a framework for understanding genetic and epigenetic effects on caste. From mostly ant, bee and termite examples, I make clear that genotype-caste associations can evolve in different and sometimes complex ways and can involve additive or non-additive genetic effects that, in turn, may arise directly from focal individuals or indirectly via their social partners. I use this framework to launch an empirical analysis of my own. In my second chapter, I test alternative hypotheses that describe how genes evolve under direct vs. indirect selection. I predict that genes associated with reproductive castes will evolve mostly under direct selection and show patterns of nucleotide substitution that differ from those associated with non-reproductive helper castes and thus evolving under indirect selection. Using an RNA-Seq dataset for the Eastern subterranean termite, I found that caste-biased and unbiased genes evolve at similar rates, most consistent with purifying selection. I therefore did not detect an obvious pattern of molecular evolution that is diagnostic of indirect or 'kin' selection. I did discover other, more subtle patterns of nucleotide substitution that I discuss in the context of termite social biology.
Dissertation
Variable CD18 expression in a 22‐year‐old female with leukocyte adhesion deficiency I: Clinical case and literature review
by
Bondarenko, Anastasiia V.
,
Hancharou, Andrei Y.
,
Lakhani, Saquib
in
Allergy
,
Antibiotics
,
Case Report
2023
Key Clinical Message Partial leukocyte adhesion deficiency type 1 (LAD‐1) deficiency is extremely rare condition with milder infectious manifestation and immune system imbalance leads to increased risks of autoinflammatory complications, such as pyoderma gangrenosum, that can be triggered by trauma or pregnancy. In patients with spice‐site ITGB2 variants, partial expression can occur due to different β2 integrin isophorms expression. LAD‐1, OMIM ID #116920 is a rare, autosomal recessive disorder that results from mutations in the ITGB2 gene that encodes the CD18 β2 integrin subunit. According to the CD18 expression, LAD‐1 is categorized as severe (<2%), moderate (2%–30%), or mild (>30%). Here, we describe a 22‐year‐old female, who presented with inflammatory skin disease and oral cavity, as well as respiratory tract infections during the first year of life. LAD‐1 was diagnosed at the age of 2 years by low expression of CD18 (1%). Whole‐exome sequencing identified homozygous c. 59‐10C>A variant in the ITGB2 gene. Despite severe phenotype, the patient survived to adulthood without hematopoietic stem cell transplantation and became pregnant at the age of 20 years, with pregnancy complicated by a pyoderma gangrenosum‐like lesion. During her life, CD18 expression increased from 1% to 9%; at 22 years of age, 5% of neutrophils and 9% of lymphocytes were CD18+. All CD18+‐lymphocytes were predominantly memory/effector cytotoxic T cells. However, revertant mosaicism was not being established suggesting that CD18 expression variability may be mediated by other mechanisms such as different β2 integrin isophorms expression.
Journal Article
Reconsidering stagnation in the brezhnev era
2016,2017
This collection brings together an interdisciplinary array of scholars of late socialism in the U.S.S.R. and challenges the dominant narrative of stagnation during the Brezhnev era. It demonstrates that the political and intellectual class remained ideologically committed, recognized systemic challenges, and embarked on a creative search for solutions.