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Frontiers in Physiology 2021Bursicon is a neuropeptide belonging to the cystine knot family and is composed of burs and partner of burs (pburs) subunits. It can form heterodimers or homodimers to...
Bursicon is a neuropeptide belonging to the cystine knot family and is composed of burs and partner of burs (pburs) subunits. It can form heterodimers or homodimers to execute different biological functions. Bursicon heterodimers regulate cuticle sclerotization and wing maturation, whereas bursicon homodimers mediate innate immunity and midgut stem cell proliferation. A recent study has shown that bursicon potentially induces the expression of vitellogenin (Vg) in the black tiger shrimp ; however, the underlying mechanism remains unknown. In this study, we investigated the role of bursicon in the reproductive physiology of the red flour beetle, . The knockdown of burs, pburs, or its receptor in 2-day pupae significantly downregulated the expression levels of Vg1, Vg2, and Vg receptor (VgR) genes in females 3- and 5-day post-adult emergence, leading to abnormal oocytes with limited Vg content. The silencing of burs repressed the number of eggs laid and completely inhibited egg hatch, whereas the silencing of pburs dramatically decreased the number of eggs laid, hatch rate, and offspring larval size, and this RNA interference (RNAi) effects persisted to the next generation. Furthermore, the knockdown of burs or pburs downregulated the expression of the insulin/insulin-like signaling/target of rapamycin (TOR) signaling genes encoding insulin receptor (InR), protein kinase B (Akt), TOR, and ribosomal protein S6 kinase (S6K). Most importantly, the injection of recombinant pburs (r-pburs) protein was able to upregulate the expression of (), (), and () in normal females and rescue the expression of and in pburs RNAi females but failed to rescue and in Tcrk knockdown females. We infer that bursicon homodimers influence expression the receptor Tcrk, possibly by mediating the expression of the juvenile hormone (JH) and IIS/TOR pathway genes, thereby regulating reproduction in . .
PubMed: 34744761
DOI: 10.3389/fphys.2021.717437 -
Frontiers in Endocrinology 2021This review summarizes the bulk of evidence about the effect of glyphosate, both technical and formulated, on the ovarian maturation of female crabs, as well as the... (Review)
Review
This review summarizes the bulk of evidence about the effect of glyphosate, both technical and formulated, on the ovarian maturation of female crabs, as well as the effects of glyphosate on sperm production in males of the same species. After long-term assays, made during the 3-month pre-reproductive period of this species, both formulated and technical glyphosate were able to produce a significant incidence of oocyte reabsorption in the ovary, together with a concomitant decreased of vitellogenin content, at concentrations ranging from 0.2 to 1 mg/L. Despite this, after 32-day assays, glyphosate stimulated oocyte growth, in terms of a higher percentage of vitellogenic oocytes, suggesting that glyphosate could be acting as an endocrine disruptor. assays made with isolated ovarian pieces showed a decrease of vitellogenin content, in correlation with lower protein synthesis, although some advance in maturation was observed in the histological analysis. In male crabs exposed to both technical and formulated glyphosate at 1 mg/L, several reproductive imbalances were noted, such as a significant decrease of the sperm count, abnormal spermatophores, and possible disrupting effects of glyphosate on the androgenic gland.
Topics: Androgens; Animals; Brachyura; Dose-Response Relationship, Drug; Endocrine Disruptors; Female; Glycine; Herbicides; Male; Models, Animal; Oocytes; Ovary; Reproduction; Spermatozoa; Vitellogenins; Water Pollutants, Chemical; Glyphosate
PubMed: 33841335
DOI: 10.3389/fendo.2021.643168 -
International Journal of Molecular... Nov 2022Cotton is the most important crop for fiber production worldwide. However, the cotton boll weevil (CBW) is an insect pest that causes significant economic losses in...
Cotton is the most important crop for fiber production worldwide. However, the cotton boll weevil (CBW) is an insect pest that causes significant economic losses in infested areas. Current control methods are costly, inefficient, and environmentally hazardous. Herein, we generated transgenic cotton lines expressing double-stranded RNA (dsRNA) molecules to trigger RNA interference-mediated gene silencing in CBW. Thus, we targeted three essential genes coding for chitin synthase 2, vitellogenin, and ecdysis-triggering hormone receptor. The stability of expressed dsRNAs was improved by designing a structured RNA based on a viroid genome architecture. We transformed cotton embryos by inserting a promoter-driven expression cassette that overexpressed the dsRNA into flower buds. The transgenic cotton plants were characterized, and positive PCR transformed events were detected with an average heritability of 80%. Expression of dsRNAs was confirmed in floral buds by RT-qPCR, and the T cotton plant generation was challenged with fertilized CBW females. After 30 days, data showed high mortality (around 70%) in oviposited yolks. In adult insects fed on transgenic lines, chitin synthase II and vitellogenin showed reduced expression in larvae and adults, respectively. Developmental delays and abnormalities were also observed in these individuals. Our data remark on the potential of transgenic cotton based on a viroid-structured dsRNA to control CBW.
Topics: Humans; Animals; Weevils; RNA, Double-Stranded; Gossypium; Vitellogenins; Plants, Genetically Modified
PubMed: 36430188
DOI: 10.3390/ijms232213713 -
Ecotoxicology and Environmental Safety Nov 2023Vitellogenin (VTG), a biomarker for endocrine activity, is a mechanistic component of the regulatory assessment of potential endocrine-disrupting properties of... (Review)
Review
Vitellogenin (VTG), a biomarker for endocrine activity, is a mechanistic component of the regulatory assessment of potential endocrine-disrupting properties of chemicals. This review of VTG data is based on changes reported for 106 substances in standard fish species. High intra-study and inter-laboratory variability in VTG concentrations was confirmed, as well as discrepancies in interpretation of results based on large differences between fish in the dilution water versus solvent control, or due to the presence of outlier measurements. VTG responses in fish were ranked against predictions for estrogen receptor agonist activity and aromatase inhibition from bioactivity model output and ToxCast in vitro assay results, respectively. These endocrine mechanisms explained most of the VTG responses in the absence of systemic toxicity, the magnitude of the VTG response being proportional to the in vitro potency. Interpretation of the VTG data was sometimes confounded by an alternative endocrine mechanism of action. There was evidence for both false positive and negative responses for VTG synthesis, but overall, it was rare for substances without endocrine activity in vitro to cause a concentration-dependent VTG response in fish in the absence of systemic toxicity. To increase confidence in the VTG results, we recommend improvements in the VTG measurement methodologies and greater transparency in reporting of VTG data (including quality control criteria for assay performance). This review supports the application of New Approach Methodologies (NAMs) by demonstrating that endocrine activity in vitro from mammalian cell lines is predictive for in vivo VTG response in fish, suggesting that in vitro mechanistic data could be used more broadly in decision-making to help reduce animal testing.
Topics: Animals; Vitellogenins; Fishes; Estrogens; Endocrine Disruptors; Water Pollutants, Chemical; Mammals
PubMed: 37827093
DOI: 10.1016/j.ecoenv.2023.115563 -
Animals : An Open Access Journal From... Mar 2021The yolk is the principal part of the egg that contains vitamins, minerals, lipids, and proteins which are essential for embryo development and hatching. The egg yolk...
The yolk is the principal part of the egg that contains vitamins, minerals, lipids, and proteins which are essential for embryo development and hatching. The egg yolk contains significant amounts of lipoproteins, triacylglycerides, and cholesterol, whose dynamics are indistinct during embryogenesis. The effects of cholesterol on the yolk protein abundance, intensity, and function are ill-defined during embryonic development. Using two-dimensional gel electrophoresis, eggs with respective high and low cholesterol protein abundance were investigated after 0, 2, 6, and 13 days of embryogenesis and further analyzed by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. The results revealed that the vitellogenin proteins are the most abundant egg yolk protein that showed proximity and a high degree of variation in isoelectric point and molecular weight. The results demonstrated increased expression of vitellogenin-1 and vitellogenin-3 at two days and vitellogenin-2 protein at 13 days of embryogenesis in both egg types. The ovoinhibitor, immunoglobulin lambda light chain precursor, Ig-gamma (clone-36 chicken), and beta-2-glycoprotein-1 precursor proteins were significantly expressed in high cholesterol eggs while haptoglobin protein PIT-54 and vitelline membrane outer layer proteins intensities were significant in low cholesterol eggs at two days of embryogenesis. The high cholesterol eggs showed a modest increase in egg weight, yolk weight, albumen height, yolk color, and egg strength relative to the low cholesterol eggs. The gene ontology enrichment analysis revealed that the differentially expressed proteins such as vitellogenin proteins were involved in lipid transport and lipid localization biological processes and showed nutrient reservoir activity function. The ovotransferrin regulated the biological processes of plasminogen activation and extracellular matrix disassembly and characterized the anchored component of the plasma membrane. The ovoinhibitor protein was involved in response to mineralocorticoid and corticosterone biological processes whereas the vitellin membrane outer layer protein constituted the extracellular exosome, extracellular organelle, and membrane-bounded vesicle cellular components. Collectively, our study revealed yolk protein abundance, molecular function, cellular components, and biological processes and concluded that yolk protein intensities were significantly altered by cholesterol concentration.
PubMed: 33803097
DOI: 10.3390/ani11030744 -
PloS One 2023Ecdysteroids control ovary growth and egg production through a complex gene hierarchy. In the female Rhodnius prolixus, a blood-gorging triatomine and the vector of...
Ecdysteroids control ovary growth and egg production through a complex gene hierarchy. In the female Rhodnius prolixus, a blood-gorging triatomine and the vector of Chagas disease, we have identified the ecdysone response genes in the ovary using transcriptomic data. We then quantified the expression of the ecdysone response gene transcripts (E75, E74, BR-C, HR3, HR4, and FTZ-F1) in several tissues, including the ovary, following a blood meal. These results confirm the presence of these transcripts in several tissues in R. prolixus and show that the ecdysone response genes in the ovary are mostly upregulated during the first three days post blood meal (PBM). Knockdown of E75, E74, or FTZ-F1 transcripts using RNA interference (RNAi) was used to understand the role of the ecdysone response genes in vitellogenesis and egg production. Knockdown significantly decreases the expression of the transcripts for the ecdysone receptor and Halloween genes in the fat body and the ovaries and reduces the titer of ecdysteroid in the hemolymph. Knockdown of each of these transcription factors typically alters the expression of the other transcription factors. Knockdown also significantly decreases the expression of vitellogenin transcripts, Vg1 and Vg2, in the fat body and ovaries and reduces the number of eggs produced and laid. Some of the laid eggs have an irregular shape and smaller volume, and their hatching rate is decreased. Knockdown also influences the expression of the chorion gene transcripts Rp30 and Rp45. The overall effect of knockdown is a decrease in number of eggs produced and a severe reduction in number of eggs laid and their hatching rate. Clearly, ecdysteroids and ecdysone response genes play a significant role in reproduction in R. prolixus.
Topics: Animals; Female; Ecdysone; Ecdysteroids; Rhodnius; Ovary; Vitellogenesis
PubMed: 36940230
DOI: 10.1371/journal.pone.0283286 -
Frontiers in Physiology 2019The alligatorweed flea beetle is an insect used for biological control of the aquatic weed (alligatorweed). Because these insects are oviparous, synthesis, and...
The alligatorweed flea beetle is an insect used for biological control of the aquatic weed (alligatorweed). Because these insects are oviparous, synthesis, and transportation of yolk proteins is integral to reproduction. Vitellin, the chief protein constituent in egg yolk, is mainly synthesized in the fat body and its synthesis is regulated by the transcript levels of (). In our study, we first cloned and characterized three genes from and quantified the expression levels of these in different tissues and developmental stages by RT-qPCR. Analysis of the full-length cDNA sequences of the three genes revealed that the open reading frames of , , and were 5175, 5346, and 5385 bp, encoding 1724, 1781, and 1794 amino acids, respectively. RT-qPCR analysis revealed that these three have similar expression patterns; expression in the fat body was significantly higher than that in other tissues, and the highest expression was observed in the adult developmental stage. RNA interference was used to explore the functions of the . female adults injected with dsRNA targeting the genes showed decreased gene expression. Down regulation of all three significantly affected ovary development, reduced egg laying capacity, and reduced the egg hatch rate compared with the control groups. Our findings provide the basis for further study of the functions of genes in other insect species.
PubMed: 31001144
DOI: 10.3389/fphys.2019.00368 -
MicroPublication Biology 2023The genes encoding the mitogen-activated protein kinases DRL-1 and FLR-4 are required for growth and lipid homeostasis in . Interestingly, the mutant, which was...
The genes encoding the mitogen-activated protein kinases DRL-1 and FLR-4 are required for growth and lipid homeostasis in . Interestingly, the mutant, which was previously isolated in a forward genetic screen for mutations that confer fluoride resistance, phenocopies the and loss-of-function mutants; however, the genetic identity of is unknown. Through whole genome sequencing, we found that the mutation is an insertion in the locus and disrupts gene function, resulting in dramatic growth defects and impaired vitellogenin production.
PubMed: 38116473
DOI: 10.17912/micropub.biology.001047 -
Poultry Science May 2022Dietary supplementation of green tea powder (GTP) changes egg quality of hens, however, whether these changes affect incubation is still unknown. This study was to...
Dietary supplementation of green tea powder (GTP) changes egg quality of hens, however, whether these changes affect incubation is still unknown. This study was to compare the proteomic difference of incubated eggs from hens with GTP supplemented or not. Huainan partridge chickens (1,080) at 35 wk of age were allocated into 2 groups, one group fed basal diet (CG) and one group fed basal diet plus 1% GTP (EG). After 4 wk feeding, artificially fertilized eggs were collected for yolk cholesterol determination and incubation. During incubation, 6 embryos from each group were randomly selected in each day for yolk protein extraction and quantification. Yolk cholesterol content was significantly lower, while the hatchability was significantly higher in EG than that of the CG group (P < 0.05). Yolk protein concentration at embryonic days (ED) of 0, 2, 6, and 13 showed significant changes and were selected for proteomic analysis by 2-dimensional gel electrophoresis combined with liquid chromatography-tandem mass spectrometry. Fifty-one differentially expressed (DE) protein spots were identified among different incubation stages between CG and EG group which were mainly classified into vitellogenin, immunoglobulin, and ovoinhibitor, and occupied 45.1, 23.5, and 15.7%, respectively, to the total DE proteins. Ovotransferrin, participated in extracellular sequestering of iron ion process, was significantly lower in EG group than that of the CG group (P < 0.05). Ig light chain precursor (Immunoglobulin) exhibited higher expression at ED6 in EG group as compared with that of the CG group, and was participated in immune response related processes. Ovoinhibitor, mainly involved in protease binding activity, showed lower abundance at ED13 in EG group as compared with that of the CG group. Vitellogenin-3, showed lower expression in EG group as compared with that of the CG group, was mainly participated in lipid transportation and localization according to GO enrichment. Chickens fed diet with GTP provided eggs more antioxidant ability that increased hatchability, indicated that GTP could be considered as additive in breeding layer.
Topics: Animal Feed; Animals; Antioxidants; Chickens; Cholesterol; Diet; Egg Proteins; Egg Yolk; Female; Guanosine Triphosphate; Powders; Proteomics; Tea; Vitellogenins
PubMed: 35325830
DOI: 10.1016/j.psj.2022.101804 -
Proceedings of the National Academy of... Sep 2021Vitellogenin receptor (VgR) plays a pivotal role in ovarian vitellogenin (Vg) uptake and vertical transmission of pathogenic microbes and symbionts. However, the...
Vitellogenin receptor (VgR) plays a pivotal role in ovarian vitellogenin (Vg) uptake and vertical transmission of pathogenic microbes and symbionts. However, the regulatory mechanisms of VgR action as an endocytic receptor and translocation from oocyte cytoplasm to the membrane remain poorly understood. Here, by using the migratory locust as a model system, we report that juvenile hormone (JH) promotes VgR phosphorylation at Ser in the second EGF-precursor homology domain. A signaling cascade including GPCR, PLC, extracellular calcium, and PKC-ι is involved in JH-stimulated VgR phosphorylation. This posttranslational regulation is a prerequisite for VgR binding to Vg on the external surface of the oocyte membrane and subsequent VgR/Vg endocytosis. Acidification, a condition in endosomes, induces VgR dephosphorylation along with the dissociation of Vg from VgR. Phosphorylation modification is also required for VgR recycling from oocyte cytoplasm to the membrane. Additionally, VgR phosphorylation and its requirement for Vg uptake and VgR recycling are evolutionarily conserved in other representative insects including the cockroach and the cotton bollworm This study fills an important knowledge gap of low-density lipoprotein receptors in posttranslational regulation, endocytosis, and intracellular recycling.
Topics: Animals; Egg Proteins; Endocytosis; Female; Isoenzymes; Juvenile Hormones; Locusta migratoria; Oocytes; Phosphorylation; Protein Kinase C; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Type C Phospholipases; Vitellogenesis; Vitellogenins
PubMed: 34493670
DOI: 10.1073/pnas.2106908118