scholarly journals Control of testes mass by androgen receptor paralogs in a cichlid

2021 ◽  
Author(s):  
Andrew P. Hoadley ◽  
Russell D. Fernald ◽  
Beau A. Alward
Keyword(s):  
Cichlid Fish ◽  
Teleost Fishes ◽  
Wild Type ◽  
Regulatory Pathway ◽  
Physiological Plasticity ◽  
Exact Role ◽  
Astatotilapia Burtoni ◽  
Testes Size ◽  
Functional Receptor

AbstractSteroid hormones play numerous important and diverse roles in the differentiation and development of vertebrate primary and secondary reproductive characteristics. However, the exact role of androgen receptors (ARs)—which bind circulating androgens—in this regulatory pathway is unclear. Teleost fishes further complicate this question by having two paralogs of AR (ARα and ARβ) resulting from a duplication of their ancestral genome. We investigated the functional role of these two ARs on testes growth and development by experimentally eliminating receptor function of one or both paralogs using CRISPR/Cas9 genome edited Astatotilapia burtoni, an African cichlid fish. Fish with two or more functional receptor alleles were more likely to be male compared to fish with one or fewer, suggesting that the two paralogs of the receptor may be redundant in regulating early sex determination. In contrast, we found that adult testes size was significantly affected by distinct combinations of mutant and wild-type AR alleles. We present a working model whereby ARβ facilitates testes growth and ARα causes testes regression. This mechanism may contribute to the robust social and physiological plasticity displayed by A. burtoni and other social teleost fish.

scholarly journals Dynamic Regulation of GacA in Type III Secretion, Pectinase Gene Expression, Pellicle Formation, and Pathogenicity of Dickeya dadantii (Erwinia chrysanthemi 3937)

2008 ◽  
Vol 21 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Shihui Yang ◽  
Quan Peng ◽  
Qiu Zhang ◽  
Xuan Yi ◽  
Chang Jae Choi ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Lower Amount ◽  
Wild Type ◽  
Regulatory Pathway ◽  
Pellicle Formation ◽  
Dickeya Dadantii ◽  
Type D ◽  
Wild Type Bacterium ◽  
Lower Expression

Dickeya dadantii (Erwinia chrysanthemi 3937) secretes exoenzymes, including pectin-degrading enzymes, leading to the loss of structural integrity of plant cell walls. A type III secretion system (T3SS) is essential for full virulence of this bacterium within plant hosts. The GacS/GacA two-component signal transduction system participates in important biological roles in several gram-negative bacteria. In this study, a gacA deletion mutant (Ech137) of D. dadantii was constructed to investigate the effect of this mutation on pathogenesis and other phenotypes. Compared with wild-type D. dadantii, Ech137 had a delayed biofilm-pellicle formation. The production of pectate lyase (Pel), protease, and cellulase was diminished in Ech137 compared with the wild-type cells. Reduced transcription of two endo-Pel genes, pelD and pelL, was found in Ech137 using a green fluorescence protein-based fluorescence-activated cell sorter promoter activity assay. In addition, the transcription of T3SS genes dspE (an effector), hrpA (a structural protein of the T3SS pilus), and hrpN (a T3SS harpin) was reduced in Ech137. A lower amount of rsmB regulatory RNA was found in gacA mutant Ech137 compared with the wild-type bacterium by quantitative reverse-transcription polymerase chain reaction. Compared with wild-type D. dadantii, a lower amount of hrpL mRNA was observed in Ech137 at 12 h grown in medium. Although the role of RsmA, rsmB, and RsmC in D. dadantii is not clear, from the regulatory pathway revealed in E. carotovora, the lower expression of dspE, hrpA, and hrpN in Ech137 may be due to a posttranscriptional regulation of hrpL through the Gac-Rsm regulatory pathway. Consequently, the reduced exoenzyme production and Pel gene expression in the mutant may be partially due to the regulatory role of rsmB-RsmA on exoenzyme expression. Similar to in vitro results, a lower expression of T3SS and pectinase genes of Ech137 also was observed in bacterial cells inoculated into Saintpaulia ionantha leaves, perhaps accounting for the observed reduction in local maceration. Interestingly, compared with the wild-type D. dadantii, although a lower concentration of Ech137 was observed at day 3 and 4 postinoculation, there is no significant difference in bacterial concentration between the wild-type bacterium and Ech137 in the early stage of infection. Finally, the nearly abolished systemic invasion ability of Ech137 suggests that GacA of D. dadantii is essential for the pathogenicity and systemic movement of the bacterium in S. ionantha.

scholarly journals Modular genetic control of social status in a cichlid fish

2020 ◽  
Author(s):  
Beau A. Alward ◽  
Vibhav Laud ◽  
Christopher J. Skalnik ◽  
Ryan A. York ◽  
Scott Juntti ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Social Status ◽  
Gene Editing ◽  
Social Systems ◽  
Cichlid Fish ◽  
Social Hierarchies ◽  
African Cichlid ◽  
Astatotilapia Burtoni ◽  
And Behavior

AbstractSocial hierarchies are ubiquitous in social species and profoundly influence physiology and behavior. Androgens like testosterone have been strongly linked to social status, yet the molecular mechanisms regulating social status are not known. The African cichlid fish Astatotilapia burtoni is a powerful model species for elucidating the role of androgens in social status given their rich social hierarchy and genetic tractability. Dominant A. burtoni males possess large testes, bright coloration, and perform aggressive and reproductive behaviors while non-dominant males do not. Social status in A. burtoni is in flux, however, as males alter their status depending on the social environment. Due to a teleost-specific whole-genome duplication, A. burtoni possess two androgen receptor (AR) paralogs, ARα and ARβ, providing a unique opportunity to disentangle the role of gene duplication in the evolution of social systems. Here, we used CRISPR/Cas9 gene editing to generate AR mutant A. burtoni and performed a suite of experiments to interrogate the mechanistic basis of social dominance. We find that ARβ, but not ARα, is required for testes growth and bright coloration, while ARα, but not ARβ, is required for the performance of reproductive behavior and aggressive displays. Both receptors are required to reduce flees from females and either AR is sufficient for attacking males. Thus, social status in A. burtoni is inordinately dissociable and under the modular control of two AR paralogs. This type of non-redundancy may be important in facilitating social plasticity in A. burtoni and other species whose social status relies on social experience.Significance StatementSocial rank along a hierarchy determines physiological state and behavioral performance. A ubiquitous feature of social hierarchies is the communication of rank through non-physical signaling systems (e.g., coloration) and aggression, traits that correlate with the reproductive status of an individual. Despite the links identified between social status, physiology, and behavior, the molecular basis of social status is not known. Here, we genetically dissect social status in the African cichlid fish Astatotilapia burtoni using CRISPR/Cas9 gene editing. We show that two distinct androgen receptor (AR) genes control social status in a highly modular manner. This type of coordination of social status may be fundamental across species that rely on social information to optimally guide physiology and behavior.

scholarly journals Genetic evidence for signal transduction within the Bacillus subtilis GerA germinant receptor

2021 ◽  
Author(s):  
Jeremy D. Amon ◽  
Lior Artzi ◽  
David Z. Rudner
Keyword(s):  
Signal Transduction ◽  
Bacillus Subtilis ◽  
Signal Transduction Pathway ◽  
Dominant Negative ◽  
Bacterial Spores ◽  
Wild Type ◽  
Enrichment Strategy ◽  
Functional Receptor

Bacterial spores can rapidly exit dormancy through the process of germination. This process begins with the activation of nutrient receptors embedded in the spore membrane. The prototypical germinant receptor in Bacillus subtilis responds to L-alanine and is thought to be a complex of proteins encoded by the genes in the gerA operon: gerAA, gerAB, and gerAC. The GerAB subunit has recently been shown to function as the nutrient sensor, but beyond contributing to complex stability, no additional functions have been attributed to the other two subunits. Here, we investigate the role of GerAA. We resurrect a previously characterized allele of gerA (termed gerA*) that carries a mutation in gerAA and show it constitutively activates germination even in the presence of a wild-type copy of gerA. Using an enrichment strategy to screen for suppressors of gerA*, we identified mutations in all three gerA genes that restore a functional receptor. Characterization of two distinct gerAB suppressors revealed that one (gerAB-E105K) reduces the GerA complex's ability to respond to L-alanine, while another (gerAB-F259S) disrupts the germinant signal downstream of L-alanine recognition. These data argue against models in which GerAA is directly or indirectly involved in germinant sensing. Rather, our data suggest that GerAA is responsible for transducing the nutrient signal sensed by GerAB. While the steps downstream of gerAA have yet to be uncovered, these results validate the use of a dominant-negative genetic approach in elucidating the gerA signal transduction pathway.

scholarly journals ER-Targeted Beclin 1 Supports Autophagosome Biogenesis in the Absence of ULK1 and ULK2 Kinases

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 475 ◽  
Author(s):  
Tahira Anwar ◽  
Xiaonan Liu ◽  
Taina Suntio ◽  
Annika Marjamäki ◽  
Joanna Biazik ◽  
...  
Keyword(s):  
Beclin 1 ◽  
Autophagic Flux ◽  
Wild Type ◽  
Autophagosome Formation ◽  
Double Knockout ◽  
Exact Role ◽  
Initiation Phase ◽  
Cytoplasmic Material ◽  
Autophagy Induction

Autophagy transports cytoplasmic material and organelles to lysosomes for degradation and recycling. Beclin 1 forms a complex with several other autophagy proteins and functions in the initiation phase of autophagy, but the exact role of Beclin 1 subcellular localization in autophagy initiation is still unclear. In order to elucidate the role of Beclin 1 localization in autophagosome biogenesis, we generated constructs that target Beclin 1 to the endoplasmic reticulum (ER) or mitochondria. Our results confirmed the proper organelle-specific targeting of the engineered Beclin 1 constructs, and the proper formation of autophagy-regulatory Beclin 1 complexes. The ULK kinases are required for autophagy initiation upstream of Beclin 1, and autophagosome biogenesis is severely impaired in ULK1/ULK2 double knockout cells. We tested whether Beclin 1 targeting facilitated its ability to rescue autophagosome formation in ULK1/ULK2 double knockout cells. ER-targeted Beclin 1 was most effective in the rescue experiments, while mitochondria-targeted and non-targeted Beclin 1 also showed an ability to rescue, but with lower activity. However, none of the constructs was able to increase autophagic flux in the knockout cells. We also showed that wild type Beclin 1 was enriched on the ER during autophagy induction, and that ULK1/ULK2 facilitated the ER-enrichment of Beclin 1 under basal conditions. The results suggest that one of the functions of ULK kinases may be to enhance Beclin 1 recruitment to the ER to drive autophagosome formation.

scholarly journals PKCζ mediates disturbed flow-induced endothelial apoptosis via p53 SUMOylation

2011 ◽  
Vol 193 (5) ◽  
pp. 867-884 ◽  
Author(s):  
Kyung-Sun Heo ◽  
Hakjoo Lee ◽  
Patrizia Nigro ◽  
Tamlyn Thomas ◽  
Nhat-Tu Le ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Wild Type ◽  
Protein Inhibitor ◽  
Exact Role ◽  
P53 Expression ◽  
Endothelial Apoptosis ◽  
Kinase C ◽  
En Face

Atherosclerosis is readily observed in regions of blood vessels where disturbed blood flow (d-flow) is known to occur. A positive correlation between protein kinase C ζ (PKCζ) activation and d-flow has been reported, but the exact role of d-flow–mediated PKCζ activation in atherosclerosis remains unclear. We tested the hypothesis that PKCζ activation by d-flow induces endothelial cell (EC) apoptosis by regulating p53. We found that d-flow–mediated peroxynitrite (ONOO−) increased PKCζ activation, which subsequently induced p53 SUMOylation, p53–Bcl-2 binding, and EC apoptosis. Both d-flow and ONOO− increased the association of PKCζ with protein inhibitor of activated STATy (PIASy) via the Siz/PIAS-RING domain (amino acids 301–410) of PIASy, and overexpression of this domain of PIASy disrupted the PKCζ–PIASy interaction and PKCζ-mediated p53 SUMOylation. En face confocal microscopy revealed increases in nonnuclear p53 expression, nitrotyrosine staining, and apoptosis in aortic EC located in d-flow areas in wild-type mice, but these effects were significantly decreased in p53−/− mice. We propose a novel mechanism for p53 SUMOylation mediated by the PKCζ–PIASy interaction during d-flow–mediated EC apoptosis, which has potential relevance to early events of atherosclerosis.

scholarly journals The Choline Metabolite TMAO Inhibits NETosis and Promotes Placental Development in GDM of Humans and Mice

2021 ◽  
Author(s):  
Xiaojing Lin ◽  
Yunqi Zhang ◽  
Xiaoling He ◽  
Yan Chen ◽  
Nan Chen ◽  
...  
Keyword(s):  
Biological Function ◽  
Neutrophil Extracellular Traps ◽  
Wild Type ◽  
Placental Development ◽  
Exact Role ◽  
Extracellular Traps ◽  
Cord Plasma ◽  
Newborn Weight ◽  
Placental Thickness

Choline metabolite Trimethylamine N-oxide (TMAO) has been recognized as a risk factor of gestational diabetes mellitus (GDM), but its exact role in GDM has not been reported. In this study, we focused on the placenta development to reveal the role of TMAO in GDM. We found the TMAO levels in peripheral and cord plasma were increased in women with GDM, and TMAO levels were positively correlated with newborn weight and placental thickness. Neutrophil extracellular traps (NETs) in the peripheral and cord plasma and the myeloperoxidase expression in the placenta of women with GDM also increased. NETs could inhibit the proliferation, migration, invasion and angiogenesis of HTR-8/Svneo cells. However, TMAO could not only inhibit the formation of NETs, but also enhance the biological function of HTR-8/Svneo cells. By inducing GDM models in NETs deficient PAD4<sup>-/-</sup> and wild-type mice, the placental weight of PAD4<sup>-/-</sup> mice increased significantly. TMAO feeding also inhibited the formation of NETs and further increased the weight of the placenta and fetuses, and this increase did not affect the placental structure. Our data indicated that higher TMAO levels and the formation of abnormal NETs were associated with GDM. TMAO could not only promote the development of the placenta and fetuses, but also inhibit the formation of NETs.

scholarly journals The Choline Metabolite TMAO Inhibits NETosis and Promotes Placental Development in GDM of Humans and Mice

2021 ◽  
Author(s):  
Xiaojing Lin ◽  
Yunqi Zhang ◽  
Xiaoling He ◽  
Yan Chen ◽  
Nan Chen ◽  
...  
Keyword(s):  
Biological Function ◽  
Neutrophil Extracellular Traps ◽  
Wild Type ◽  
Placental Development ◽  
Exact Role ◽  
Extracellular Traps ◽  
Cord Plasma ◽  
Newborn Weight ◽  
Placental Thickness

Choline metabolite Trimethylamine N-oxide (TMAO) has been recognized as a risk factor of gestational diabetes mellitus (GDM), but its exact role in GDM has not been reported. In this study, we focused on the placenta development to reveal the role of TMAO in GDM. We found the TMAO levels in peripheral and cord plasma were increased in women with GDM, and TMAO levels were positively correlated with newborn weight and placental thickness. Neutrophil extracellular traps (NETs) in the peripheral and cord plasma and the myeloperoxidase expression in the placenta of women with GDM also increased. NETs could inhibit the proliferation, migration, invasion and angiogenesis of HTR-8/Svneo cells. However, TMAO could not only inhibit the formation of NETs, but also enhance the biological function of HTR-8/Svneo cells. By inducing GDM models in NETs deficient PAD4<sup>-/-</sup> and wild-type mice, the placental weight of PAD4<sup>-/-</sup> mice increased significantly. TMAO feeding also inhibited the formation of NETs and further increased the weight of the placenta and fetuses, and this increase did not affect the placental structure. Our data indicated that higher TMAO levels and the formation of abnormal NETs were associated with GDM. TMAO could not only promote the development of the placenta and fetuses, but also inhibit the formation of NETs.

Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

1999 ◽  
Vol 81 (04) ◽  
pp. 601-604 ◽  
Author(s):  
Hiroyuki Matsuno ◽  
Osamu Kozawa ◽  
Masayuki Niwa ◽  
Shigeru Ueshima ◽  
Osamu Matsuo ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Thrombus Formation ◽  
Endothelial Injury ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
Clot Lysis ◽  
Wild Type ◽  
Type Plasminogen Activator ◽  
Pai 1

SummaryThe role of fibrinolytic system components in thrombus formation and removal in vivo was investigated in groups of six mice deficient in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), or plasminogen activator inhibitor-1 (PAI-1) (u-PA-/-, t-PA-/- or PAI-1-/-, respectively) or of their wild type controls (u-PA+/+, t-PA+/+ or PAI-1+/+). Thrombus was induced in the murine carotid artery by endothelial injury using the photochemical reaction between rose bengal and green light (540 nm). Blood flow was continuously monitored for 90 min on day 0 and for 20 min on days 1, 2 and 3. The times to occlusion after the initiation of endothelial injury in u-PA+/+, t-PA+/+ or PAI-1+/+ mice were 9.4 ± 1.3, 9.8 ± 1.1 or 9.7 ± 1.6 min, respectively. u-PA-/- and t-PA-/- mice were indistinguishable from controls, whereas that of PAI-1-/- mice were significantly prolonged (18.4 ± 3.7 min). Occlusion persisted for the initial 90 min observation period in 10 of 18 wild type mice and was followed by cyclic reflow and reocclusion in the remaining 8 mice. At day 1, persistent occlusion was observed in 1 wild type mouse, 8 mice had cyclic reflow and reocclusion and 9 mice had persistent reflow. At day 2, all injured arteries had persistent reflow. Persistent occlusion for 90 min on day 0 was observed in 3 u-PA-/-, in all t-PA-/- mice at day 1 and in 2 of the t-PA-/-mice at day 2 (p <0.01 versus wild type mice). Persistent patency was observed in all PAI-1-/- mice at day 1 and in 5 of the 6 u-PA-/- mice at day 2 (both p <0.05 versus wild type mice). In conclusion, t-PA increases the rate of clot lysis after endothelial injury, PAI-1 reduces the time to occlusion and delays clot lysis, whereas u-PA has little effect on thrombus formation and spontaneous lysis.

scholarly journals Salicylic Acid Accumulation Controlled by LSD1 Is Essential in Triggering Cell Death in Response to Abiotic Stress

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 962
Author(s):  
Maciej Jerzy Bernacki ◽  
Anna Rusaczonek ◽  
Weronika Czarnocka ◽  
Stanisław Karpiński
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Abiotic Stress ◽  
Wild Type ◽  
Pr Genes ◽  
Genes Expression ◽  
Salicylic Acid Accumulation ◽  
Cell Death Phenotype ◽  
Insight Into

Salicylic acid (SA) is well known hormonal molecule involved in cell death regulation. In response to a broad range of environmental factors (e.g., high light, UV, pathogens attack), plants accumulate SA, which participates in cell death induction and spread in some foliar cells. LESION SIMULATING DISEASE 1 (LSD1) is one of the best-known cell death regulators in Arabidopsis thaliana. The lsd1 mutant, lacking functional LSD1 protein, accumulates SA and is conditionally susceptible to many biotic and abiotic stresses. In order to get more insight into the role of LSD1-dependent regulation of SA accumulation during cell death, we crossed the lsd1 with the sid2 mutant, caring mutation in ISOCHORISMATE SYNTHASE 1(ICS1) gene and having deregulated SA synthesis, and with plants expressing the bacterial nahG gene and thus decomposing SA to catechol. In response to UV A+B irradiation, the lsd1 mutant exhibited clear cell death phenotype, which was reversed in lsd1/sid2 and lsd1/NahG plants. The expression of PR-genes and the H2O2 content in UV-treated lsd1 were significantly higher when compared with the wild type. In contrast, lsd1/sid2 and lsd1/NahG plants demonstrated comparability with the wild-type level of PR-genes expression and H2O2. Our results demonstrate that SA accumulation is crucial for triggering cell death in lsd1, while the reduction of excessive SA accumulation may lead to a greater tolerance toward abiotic stress.

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