scholarly journals Diverse wMel variants of Wolbachia pipientis differentially rescue fertility and cytological defects of the bag of marbles partial loss of function mutation in Drosophila melanogaster

2021 ◽  
Author(s):  
Jaclyn E Bubnell ◽  
Paula Fernandez-Begne ◽  
Cynthia K S Ulbing ◽  
Charles F Aquadro
Keyword(s):  
Drosophila Melanogaster ◽  
Adaptive Evolution ◽  
Genetic Interaction ◽  
Female Fertility ◽  
Single Amino Acid ◽  
Germline Stem Cell ◽  
Loss Of Function ◽  
Wolbachia Pipientis ◽  
Hypomorphic Mutation ◽  
Bag Of Marbles

Abstract In Drosophila melanogaster, the maternally inherited endosymbiont Wolbachia pipientis interacts with germline stem cell genes during oogenesis. One such gene, bag of marbles (bam) is the key switch for differentiation and also shows signals of adaptive evolution for protein diversification. These observations have led us to hypothesize that W. pipientis could be driving the adaptive evolution of bam for control of oogenesis. To test this hypothesis, we must understand the specificity of the genetic interaction between bam and W. pipientis. Previously, we documented that the W. pipientis variant, wMel, rescued the fertility of the bamBW hypomorphic mutant as a transheterozygote over a bam null. However, bamBW was generated more than 20 years ago in an uncontrolled genetic background and maintained over a balancer chromosome. Consequently, the chromosome carrying bamBW accumulated mutations that have prevented controlled experiments to further assess the interaction. Here, we used CRISPR/Cas9 to engineer the same single amino acid bam hypomorphic mutation (bamL255F ) and a new bam null disruption mutation into the w1118 isogenic background. We assess the fertility of wildtype bam, bamL255F/bamnull hypomorphic, and bamL255F/bamL255F mutant females, each infected individually with ten W. pipientis wMel variants representing three phylogenetic clades. Overall, we find that all of the W. pipientis variants tested here rescue bam hypomorphic fertility defects with wMelCS-like variants exhibiting the strongest rescue effects. Additionally, these variants did not increase wildtype bam female fertility. Therefore, both bam and W. pipientis interact in genotype-specific ways to modulate female fertility, a critical fitness phenotype.

scholarly journals Genetic variation among wMel strains of Wolbachia pipientis differentially rescues a bag of marbles partial loss of function mutant in Drosophila melanogaster

2021 ◽  
Author(s):  
Jaclyn E. Bubnell ◽  
Paula Fernandez-Begne ◽  
Cynthia K. Ulbing ◽  
Charles F. Aquadro
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Interaction ◽  
Female Fertility ◽  
Single Amino Acid ◽  
Germline Stem Cell ◽  
Loss Of Function ◽  
Genetic Conflict ◽  
Hypomorphic Mutation ◽  
Bag Of Marbles ◽  
Female Germline

AbstractWolbachia is an intracellular, maternally inherited endosymbiotic bacteria that infects over 65% of insects and manipulates their reproduction for its own transmission. In Drosophila melanogaster, Wolbachia genetically interacts with the adaptively evolving germline stem cell gene bag of marbles (bam). Since Wolbachia must enter the host female germline to propagate, one hypothesis is that Wolbachia and bam are in a genetic conflict for control of oogenesis. In order to understand if Wolbachia could be driving the adaptive evolution of bam, we must understand the nature of the genetic interaction between bam and Wolbachia. Previously, we documented that the wMel strain of Wolbachia rescued the fertility and cytological ovarian defect of a bam hypomorphic mutant. However, this mutant was generated in a variable genetic background, and thus we have not been able to perform controlled experiments to further assess the interaction. Here, we used CRISPR/Cas9 to engineer the same single amino acid bam hypomorphic mutation and a bam null mutation into the w1118 isogenic background. We assess the female fertility of wildtype bam, a bam hypomorph/null mutant, and a homozygous bam hypomorphic mutant, each infected individually with 10 diverse Wolbachia variants. Overall, we find that the Wolbachia variants tested here do not generally increase bam+ female fertility, but they do rescue bam hypomorphic defects with variation in the effect size of some wMel variants on female fertility. Therefore, both bam and Wolbachia interact in genotype-specific ways to modulate a critical fitness phenotype

scholarly journals Headcase is a Repressor of Lamellocyte Fate in Drosophila melanogaster

Genes ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 173 ◽  
Author(s):  
Gergely I. B. Varga ◽  
Gábor Csordás ◽  
Gyöngyi Cinege ◽  
Ferenc Jankovics ◽  
Rita Sinka ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Differentiation ◽  
Blood Cell ◽  
Cell Fate ◽  
Blood Cells ◽  
Mutational Analysis ◽  
Genetic Interaction ◽  
Lymph Gland ◽  
Loss Of Function ◽  
Hematopoietic Stem

Due to the evolutionary conservation of the regulation of hematopoiesis, Drosophila provides an excellent model organism to study blood cell differentiation and hematopoietic stem cell (HSC) maintenance. The larvae of Drosophila melanogaster respond to immune induction with the production of special effector blood cells, the lamellocytes, which encapsulate and subsequently kill the invader. Lamellocytes differentiate as a result of a concerted action of all three hematopoietic compartments of the larva: the lymph gland, the circulating hemocytes, and the sessile tissue. Within the lymph gland, the communication of the functional zones, the maintenance of HSC fate, and the differentiation of effector blood cells are regulated by a complex network of signaling pathways. Applying gene conversion, mutational analysis, and a candidate based genetic interaction screen, we investigated the role of Headcase (Hdc), the homolog of the tumor suppressor HECA in the hematopoiesis of Drosophila. We found that naive loss-of-function hdc mutant larvae produce lamellocytes, showing that Hdc has a repressive role in effector blood cell differentiation. We demonstrate that hdc genetically interacts with the Hedgehog and the Decapentaplegic pathways in the hematopoietic niche of the lymph gland. By adding further details to the model of blood cell fate regulation in the lymph gland of the larva, our findings contribute to the better understanding of HSC maintenance.

scholarly journals Molecular population genetics of Sex-lethal (Sxl) in the D. melanogaster species group - a locus that genetically interacts with Wolbachia pipientis in Drosophila melanogaster

2021 ◽  
Author(s):  
Vanessa L Bauer DuMont ◽  
Simone L White ◽  
Daniel Zinshteyn ◽  
Charles F Aquadro
Keyword(s):  
Population Genetics ◽  
Drosophila Melanogaster ◽  
Protein Evolution ◽  
Genetic Interaction ◽  
Critical Role ◽  
Drosophila Species ◽  
Careful Study ◽  
Evolutionary Analysis ◽  
Wolbachia Pipientis ◽  
Sex Lethal

Abstract Sex-lethal (Sxl) is the sex determination switch in Drosophila, and also plays a critical role in germ-line stem cell (GSC) daughter differentiation in Drosophila melanogaster. Three female-sterile alleles at Sxl in Drosophila melanogaster were previously shown to genetically interact to varying degrees with the maternally inherited endosymbiont Wolbachia pipientis. Given this genetic interaction and W. pipientis’ ability to manipulate reproduction in Drosophila, we carried out a careful study of both the population genetics (within four Drosophila species) and molecular evolutionary analysis (across 20 Drosophila species) of Sxl. Consistent with earlier studies, we find that selective constraint has played a prominent role in Sxl’s molecular evolution within Drosophila, but we also observe patterns that suggest both episodic bursts of protein evolution and recent positive selection at Sxl. The episodic nature of Sxl’s protein evolution is discussed in light of its genetic interaction with W. pipientis.

scholarly journals Two types of genetic interaction implicate the whirligig gene of Drosophila melanogaster in microtubule organization in the flagellar axoneme.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 961-973 ◽  
Author(s):  
L L Green ◽  
N Wolf ◽  
K L McDonald ◽  
M T Fuller
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Interaction ◽  
Dominant Male ◽  
Loss Of Function ◽  
Male Sterile ◽  
Microtubule Organization ◽  
Beta Tubulin ◽  
Absolute Level ◽  
Alpha Tubulin ◽  
Flagellar Axoneme

Abstract The mutant nc4 allele of whirligig (3-54.4) of Drosophila melanogaster fails to complement mutations in an alpha-tubulin locus, alpha 1t, mutations in a beta-tubulin locus, B2t, or a mutation in the haywire locus. However, wrl fails to map to any of the known alpha- or beta-tubulin genes. The extragenic failure to complement could indicate that the wrl product participates in structural interactions with microtubule proteins. The whirligig locus appears to be haploinsufficient for male fertility. Both a deficiency of wrl and possible loss of function alleles obtained by reverting the failure to complement between wrlnc4 and B2tn are dominant male sterile in a genetic background wild type for tubulin. The dominant male sterility of the revertant alleles is suppressed if the flies are also heterozygous for B2tn, for a deficiency of alpha 1t, or for the haync2 allele. These results suggest that it is not the absolute level of wrl gene product but its level relative to tubulin or microtubule function that is important for normal spermatogenesis. The phenotype of homozygous wrl mutants suggests that the whirligig product plays a role in postmeiotic spermatid differentiation, possibly in organizing the microtubules of the sperm flagellar axoneme. Flies homozygous for either wrlnc4 or revertant alleles are viable and female fertile but male sterile. Premeiotic and meiotic stages of spermatogenesis appear normal. However, in post-meiotic stages, flagellar axonemes show loss of the accessory microtubule on the B-subfiber of outer doublet microtubules, outer triplet instead of outer doublet microtubules, and missing central pair microtubules.

scholarly journals The Small Interfering RNA Pathway Is Not Essential for Wolbachia-Mediated Antiviral Protection in Drosophila melanogaster

2012 ◽  
Vol 78 (18) ◽  
pp. 6773-6776 ◽  
Author(s):  
Lauren M. Hedges ◽  
Ryuichi Yamada ◽  
Scott L. O'Neill ◽  
Karyn N. Johnson
Keyword(s):  
Drosophila Melanogaster ◽  
Small Interfering Rna ◽  
Rna Virus ◽  
Antiviral Defense ◽  
Loss Of Function ◽  
Content Type ◽  
Wolbachia Pipientis ◽  
Interfering Rna ◽  
Sirna Pathway

ABSTRACTWolbachia pipientisdelays RNA virus-induced mortality inDrosophilaspp. We investigated whetherWolbachia-mediated protection was dependent on the small interfering RNA (siRNA) pathway, a key antiviral defense. Compared toWolbachia-free flies, virus-induced mortality was delayed inWolbachia-infected flies with loss-of-function of siRNA pathway components, indicating thatWolbachia-mediated protection functions in the absence of the canonical siRNA pathway.

scholarly journals Functional divergence of the bag of marbles gene in the Drosophila melanogaster species group

2021 ◽  
Author(s):  
Jaclyn Elizabeth Bubnell ◽  
Cynthia KS Ulbing ◽  
Paula Fernandez Begne ◽  
Charles F. Aquadro
Keyword(s):  
Drosophila Melanogaster ◽  
Stem Cell ◽  
Cell Differentiation ◽  
Stem Cell Differentiation ◽  
Species Group ◽  
Germline Stem Cell ◽  
Genetic Conflict ◽  
Differentiation Factor ◽  
Bag Of Marbles ◽  
Cell Differentiation Factor

The combination of recent advances in both genomic and gene editing technologies have opened up new possibilities for assessing the functional consequences and drivers of positive selection. In Drosophila melanogaster, a key germline stem cell differentiation factor, bag of marbles (bam) shows rapid bursts of amino acid fixations between its D. melanogaster and its sibling species D. simulans, but not in the outgroup species D. ananassae. We previously hypothesized that a genetic conflict with the maternally inherited, intracellular bacteria W. pipientis could be driving the adaptive evolution of bam as W. pipientis increases the fertility of a bam partial loss of function mutant. However, we have not been able to further test this hypothesis by assessing bam variation in other Drosophila lineages and their interactions with W. pipientis because bam function has not been examined in non-melanogaster Drosophila species. Since bam is rapidly evolving at the protein level, its function may not be conserved between species, and therefore different evolutionary pressures may be shaping bam in individual lineages. Here, we ask if bam is necessary for GSC daughter differentiation in five Drosophila species in the melanogaster species group that span approximately 15 million years of divergence and show different patterns of nucleotide sequence evolution at bam. We find that bam function is not fully conserved across these species, and that bam function may change on a relatively short time scale. Ultimately, we conclude that a simple gain in function as the germline stem cell differentiation factor alone does not explain our population genetic and functional genetic results we have observed. Our findings provide a foundation on which to explore the evolution of bam as a GSC differentiation factor and its interactions with W. pipientis in specific lineages.

Генотип эндосимбионта Wolbachia pipientis влияет на метаболизм октопамина у самок Drosophila melanogaster

2019 ◽  
Vol 55 (5) ◽  
pp. 609-612
Author(s):  
Н. В. Адоньева ◽  
Е. В. Бурдина ◽  
Р. А. Быков ◽  
Н. Е. Грунтенко ◽  
И. Ю. Раушенбах
Keyword(s):  
Drosophila Melanogaster ◽  
Wolbachia Pipientis

scholarly journals Multiple Pathways of LRRK2-G2019S/Rab10 Interaction in Dopaminergic Neurons

2021 ◽  
pp. 1-16
Author(s):  
Alison Fellgett ◽  
C. Adam Middleton ◽  
Jack Munns ◽  
Chris Ugbode ◽  
David Jaciuch ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Genetic Interaction ◽  
In Vitro Assays ◽  
Rab Proteins ◽  
Circadian Activity ◽  
Loss Of Function ◽  
Lrrk2 G2019s

Background: Inherited mutations in the LRRK2 protein are the common causes of Parkinson’s disease, but the mechanisms by which increased kinase activity of mutant LRRK2 leads to pathological events remain to be determined. In vitro assays (heterologous cell culture, phospho-protein mass spectrometry) suggest that several Rab proteins might be directly phosphorylated by LRRK2-G2019S. An in vivo screen of Rab expression in dopaminergic neurons in young adult Drosophila demonstrated a strong genetic interaction between LRRK2-G2019S and Rab10. Objective: To determine if Rab10 is necessary for LRRK2-induced pathophysiological responses in the neurons that control movement, vision, circadian activity, and memory. These four systems were chosen because they are modulated by dopaminergic neurons in both humans and flies. Methods: LRRK2-G2019S was expressed in Drosophila dopaminergic neurons and the effects of Rab10 depletion on Proboscis Extension, retinal neurophysiology, circadian activity pattern (‘sleep’), and courtship memory determined in aged flies. Results: Rab10 loss-of-function rescued LRRK2-G2019S induced bradykinesia and retinal signaling deficits. Rab10 knock-down, however, did not rescue the marked sleep phenotype which results from dopaminergic LRRK2-G2019S. Courtship memory is not affected by LRRK2, but is markedly improved by Rab10 depletion. Anatomically, both LRRK2-G2019S and Rab10 are seen in the cytoplasm and at the synaptic endings of dopaminergic neurons. Conclusion: We conclude that, in Drosophila dopaminergic neurons, Rab10 is involved in some, but not all, LRRK2-induced behavioral deficits. Therefore, variations in Rab expression may contribute to susceptibility of different dopaminergic nuclei to neurodegeneration seen in people with Parkinson’s disease.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

scholarly journals Differences in a Single Extracellular Residue Underlie Adhesive Functions of Two Zebrafish Aqp0s

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2005
Author(s):  
Irene Vorontsova ◽  
James E. Hall ◽  
Thomas F. Schilling ◽  
Noriaki Nagai ◽  
Yosuke Nakazawa
Keyword(s):  
Cell Adhesion ◽  
Single Amino Acid ◽  
Amino Acid Difference ◽  
Adhesion Assay ◽  
Loss Of Function ◽  
Adhesive Properties ◽  
The Difference ◽  
In Vitro Adhesion ◽  
Cell To Cell Adhesion

Aquaporin 0 (AQP0) is the most abundant lens membrane protein, and loss of function in human and animal models leads to cataract formation. AQP0 has several functions in the lens including water transport and adhesion. Since lens optics rely on strict tissue architecture achieved by compact cell-to-cell adhesion between lens fiber cells, understanding how AQP0 contributes to adhesion would shed light on normal lens physiology and pathophysiology. We show in an in vitro adhesion assay that one of two closely related zebrafish Aqp0s, Aqp0b, has strong auto-adhesive properties while Aqp0a does not. The difference appears to be largely due to a single amino acid difference at residue 110 in the extracellular C-loop, which is T in Aqp0a and N in Aqp0b. Similarly, P110 is the key residue required for adhesion in mammalian AQP0, highlighting the importance of residue 110 in AQP0 cell-to-cell adhesion in vertebrate lenses as well as the divergence of adhesive and water permeability functions in zebrafish duplicates.

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