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BioRxiv : the Preprint Server For... May 2023The eggshell of the fruit fly is a useful model for understanding the synthesis of a complex extracellular matrix. The eggshell is synthesized during mid-to-late...
The eggshell of the fruit fly is a useful model for understanding the synthesis of a complex extracellular matrix. The eggshell is synthesized during mid-to-late oogenesis by the somatic follicle cells that surround the developing oocyte. We previously reported that female flies mutant for the gene ( ) are sterile, but the underlying cause of the sterility remained unknown. In this study, we examined the role of in eggshell synthesis. We show that eggs laid by mutant females are fertilized but arrest early in embryogenesis, and that the innermost layer of the eggshell, the vitelline membrane, is abnormally permeable to dye in these eggs. In addition, the major vitelline membrane proteins fail to become crosslinked by nonreducible bonds, a process that normally occurs during egg activation following ovulation, as evidenced by their solubility and detection by Western blot in laid eggs. In contrast, the Cp36 protein, which is found in the outer chorion layers of the eggshell, becomes crosslinked normally. To link the expression pattern with these phenotypes, we show that is expressed in the ovarian follicle cells beginning in mid-oogenesis, and, importantly, that all mutant eggshell phenotypes could be recapitulated by selective knockdown of expression in the follicle cells. To determine whether expression was required for the crosslinking itself, we performed in vitro activation and crosslinking experiments. The vitelline membranes of control egg chambers could become crosslinked either by incubation in hyperosmotic medium, which activates the egg chambers, or by exogenous peroxidase and hydrogen peroxide. In contrast, neither treatment resulted in the crosslinking of the vitelline membrane in mutant egg chambers. These results indicate that expression in the follicle cells is necessary for vitelline membrane proteins to serve as substrates for peroxidase-mediated cross-linking at the end of oogenesis.
PubMed: 37163052
DOI: 10.1101/2023.04.25.538335 -
Poultry Science Jun 2023The study aimed to assess various quality characteristics (physical, morphologic, mechanical) of hatching eggs during the early-mid incubation period. Hatching eggs...
The study aimed to assess various quality characteristics (physical, morphologic, mechanical) of hatching eggs during the early-mid incubation period. Hatching eggs (1,200) were bought from a broiler Ross 308 breeder flock. Before incubation, 20 eggs were analyzed for dimensions and morphologic composition. Eggs (1,176) were incubated for 21 d. Hatchability was analyzed. On d 1, 2, 4, 6, 8, 10, and 12, eggs were collected (n = 20). The eggshell surface temperature and water loss were measured. The eggshell strength and thickness and the vitelline membrane strength were analyzed. The pH of thick albumen, amniotic fluid, and yolk were determined. The viscosity and lysozyme activity were studied for the thick albumen and amniotic fluid. Water loss was proportional and significantly different between incubation days. The yolk vitelline membrane strength highly depended on incubation days, decreasing steadily within the first 2 d (R = 0.9643). The albumen pH decreased from d 4 till d 12 of incubation, whereas the yolk pH first increased from d 0 to d 2 before a decline on d 4. Albumen viscosity was highest on d 6. There was a strong dependence of viscosity decrease with increasing shear rate (R = 0.7976). On the first day of incubation, the highest lysozyme hydrolytic activity was demonstrated (33,790 U/mL) compared to the activity from the amniotic fluid (8-12 d). From d 6, lysozyme activity decreased to 70 U/mL (d 10). On d 12, amniotic fluid lysozyme activity increased by over 6,000 U/mL compared to d 10. The lysozyme hydrolytic activity was lower in the amniotic fluid (d 8-12) compared to the thick albumen (0-6 d) (P < 0.001). The embryo's protective barriers are changed, and the fractions are hydrated during incubation. It could be concluded that the lysozyme is transferred from the albumen to the amniotic fluid due to its activity.
Topics: Animals; Chickens; Muramidase; Ovum; Albumins; Egg Shell
PubMed: 37116284
DOI: 10.1016/j.psj.2023.102689 -
International Journal of Molecular... Mar 2023(1) Hematological malignancies are characterized by an immortalization, uncontrolled proliferation of blood cells and their differentiation block, followed by the loss...
(1) Hematological malignancies are characterized by an immortalization, uncontrolled proliferation of blood cells and their differentiation block, followed by the loss of function. The primary goal in the treatment of leukemias is the elimination of rapidly proliferating leukemic cells (named blasts). However, chemotherapy, which removes proliferating blasts, also prevents the remaining immune cells from being activated. Acute leukemias affect elderly people, who are often not fit to survive aggressive chemotherapy. Therefore, there is a need of milder treatment, named differentiation therapy, which might simulate the immune system of the patient. 1,25-Dihydroxyvitamin D, or low-calcemic analogs of this compound, were proposed as supporting therapy in acute leukemias. (2) Bone marrow blasts from patients with hematological malignancies, and leukocytes from healthy volunteers were ex vivo exposed to 1,25-dihydroxyvitamin D, and then their genomes and transcriptomes were investigated. (3) Our analysis indicates that 1,25-dihydroxyvitamin D regulates in blood cells predominantly genes involved in immune response, such as (cathelicidin antimicrobial peptide), (ceruloplasmin), (C-X-C motif chemokine ligand 9), (CD14 molecule) or (vitelline membrane outer layer 1 homolog). This concerns blood cells from healthy people, as well as blasts from patients with hematological malignancies. In addition, in one patient, 1,25-dihydroxyvitamin D significantly downregulated transcription of genes responsible for cell division and immortalization. (4) In conclusion, the data presented in this paper suggest that addition of 1,25-dihydroxyvitamin D to the currently available treatments would stimulate immune system, inhibit proliferation and reduce immortal potential of blasts.
Topics: Humans; Aged; Leukemia, Myeloid, Acute; Leukocytes; Blood Cells; Cell Differentiation; Dihydroxycholecalciferols; Hematologic Neoplasms
PubMed: 37047477
DOI: 10.3390/ijms24076504 -
Nanotoxicology Feb 2023Despite the great potential of using positively charged gold nanoparticles (AuNPs) in nanomedicine, no systematic studies have been reported on their synthesis...
Polyethyleneimine/polyethylene glycol-conjugated gold nanoparticles as nanoscale positive/negative controls in nanotoxicology: testing in frog embryo teratogenesis assay- and mammalian tissue culture system.
Despite the great potential of using positively charged gold nanoparticles (AuNPs) in nanomedicine, no systematic studies have been reported on their synthesis optimization or colloidal stability under physiological conditions until a group at the National Institute of Standards and Technology recently succeeded in producing remarkably stable polyethyleneimine (PEI)-coated AuNPs (Au-PEI). This improved version of Au-PEI (Au-PEI25kB) has increased the demand for toxicity and teratogenicity information for applications in nanomedicine and nanotoxicology. In vitro assays for Au-PEI25kB in various cell lines showed substantial active cytotoxicity. For advanced toxicity research, the frog embryo teratogenesis assay- (FETAX) method was employed in this study. We observed that positively-charged Au-PEI25kB exhibited significant toxicity and teratogenicity, whereas polyethylene glycol conjugated AuNPs (Au-PEG) used as comparable negative controls did not. There is a characteristic avidity of Au-PEI25kB for the jelly coat, the chorionic envelope (also known as vitelline membrane) and the cytoplasmic membrane, as well as a barrier effect of the chorionic envelope observed with Au-PEG. To circumvent these characteristics, an injection-mediated FETAX approach was utilized. Like treatment with the FETAX method, the injection of Au-PEI25kB severely impaired embryo development. Notably, the survival/concentration curve that was steep when the standard FETAX approach was employed became gradual in the injection-mediated FETAX. These results suggest that Au-PEI25kB may be a good candidate as a nanoscale positive control material for nanoparticle analysis in toxicology and teratology.
Topics: Animals; Teratogenesis; Gold; Polyethyleneimine; Polyethylene Glycols; Xenopus laevis; Metal Nanoparticles; Embryo, Nonmammalian; Teratogens; Mammals
PubMed: 36919473
DOI: 10.1080/17435390.2023.2187322 -
Development (Cambridge, England) Mar 2023Dying cells in the epithelia communicate with neighboring cells to initiate coordinated cell removal to maintain epithelial integrity. Naturally occurring apoptotic...
Dying cells in the epithelia communicate with neighboring cells to initiate coordinated cell removal to maintain epithelial integrity. Naturally occurring apoptotic cells are mostly extruded basally and engulfed by macrophages. Here, we have investigated the role of Epidermal growth factor (EGF) receptor (EGFR) signaling in the maintenance of epithelial homeostasis. In Drosophila embryos, epithelial tissues undergoing groove formation preferentially enhanced extracellular signal-regulated kinase (ERK) signaling. In EGFR mutant embryos at stage 11, sporadic apical cell extrusion in the head initiates a cascade of apical extrusions of apoptotic and non-apoptotic cells that sweeps the entire ventral body wall. Here, we show that this process is apoptosis dependent, and clustered apoptosis, groove formation, and wounding sensitize EGFR mutant epithelia to initiate massive tissue disintegration. We further show that tissue detachment from the vitelline membrane, which frequently occurs during morphogenetic processes, is a key trigger for the EGFR mutant phenotype. These findings indicate that, in addition to cell survival, EGFR plays a role in maintaining epithelial integrity, which is essential for protecting tissues from transient instability caused by morphogenetic movement and damage.
Topics: Animals; Drosophila; Epidermal Growth Factor; Epithelium; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Phosphorylation; Signal Transduction
PubMed: 36897356
DOI: 10.1242/dev.201231 -
Animals : An Open Access Journal From... Feb 2023This study evaluates the effect of housing environment on the egg quality characteristics of brown egg layers as many different environments are currently used in the...
This study evaluates the effect of housing environment on the egg quality characteristics of brown egg layers as many different environments are currently used in the industry. Battery cages, barren colony cages, enriched colony cages, cage-free, and free-range environments were evaluated. Overall, all egg quality measurements were affected by housing environment ( < 0.01) except for vitelline membrane strength, elasticity, and egg solids. Eggshells and yolks were lightest in barren colony cages and darkest from free-range hens ( < 0.0001). Free-range eggs were heavier than eggs from all other environments ( < 0.0001). Cage-free eggs had lower albumen height and Haugh units than other environments ( < 0.0001). Lastly, cage-free and free-range eggs had stronger eggshells than the other environments ( < 0.0001), and free-range eggs had more elastic eggshells than eggs from conventional battery cages and barren colony cages ( < 0.01). Access to the range seemed to give free-range hens different nutritional advantages, which allowed for the darker yolks and shells. Furthermore, eggs from barren colony cages seemed to exhibit more negative characteristics. Simply adding enrichments to colony cages did not improve or detract from egg quality. From this research, it appears that, as the industry moves toward extensive environments, the egg quality of brown egg layers will improve.
PubMed: 36830504
DOI: 10.3390/ani13040716 -
FEBS Open Bio Mar 2023C-mannosylation is a rare type of protein glycosylation whereby a single mannose is added to the first tryptophan in the consensus sequence Trp-Xaa-Xaa-Trp/Cys (in which...
C-mannosylation is a rare type of protein glycosylation whereby a single mannose is added to the first tryptophan in the consensus sequence Trp-Xaa-Xaa-Trp/Cys (in which Xaa represents any amino acid). Its consensus sequence is mainly found in proteins containing a thrombospondin type-1 repeat (TSR1) domain and in type I cytokine receptors. In these proteins, C-mannosylation affects protein secretion, intracellular localization, and protein stability; however, the role of C-mannosylation in proteins that are not type I cytokine receptors and/or do not contain a TSR1 domain is less well explored. In this study, we focused on human vitelline membrane outer layer protein 1 homolog (VMO1). VMO1, which possesses two putative C-mannosylation sites, is a 21-kDa secreted protein that does not contain a TSR1 domain and is not a type I cytokine receptor. Mass spectrometry analyses revealed that VMO1 is C-mannosylated at Trp but not at Trp . Although C-mannosylation does not affect the extracellular secretion of VMO1, it destabilizes the intracellular VMO1. In addition, a structural comparison between VMO1 and C-mannosylated VMO1 showed that the modification of the mannose changes the conformation of three loops in VMO1. Taken together, our results demonstrate the first example of C-mannosylation for protein destabilization of VMO1.
Topics: Humans; Glycosylation; Mannose; Vitelline Membrane; Protein Transport; Receptors, Cytokine
PubMed: 36680395
DOI: 10.1002/2211-5463.13561 -
Gene Jan 2023In birds, vitelline membrane outer layer protein 1 (VMO1) is an exogenous protein that can be absorbed by eggs as a barrier to prevent the mixing of yolk and egg white....
Pacific white shrimp (Litopenaeus vannamei) vitelline membrane outer layer protein 1 (VMO1) is produced in the hepatopancreas and transported into ovarian oocytes during vitellogenesis.
In birds, vitelline membrane outer layer protein 1 (VMO1) is an exogenous protein that can be absorbed by eggs as a barrier to prevent the mixing of yolk and egg white. However, researches on VMO1 are limited in birds but not other non-avian species until now. In this study, we first identified a novel Vmo1 cDNA (Lv-Vmo1) in Pacific white shrimp (Litopenaeus vannamei), the most important cultured shrimp in the world. We further analyzed its gene organization, phylogenetic relationship and protein structure. The Lv-Vmo1 transcript was specifically expressed in the hepatopancreas without sexual dimorphism. During ovarian development in female, the hepatopancreatic Lv-Vmo1 mRNA levels showed a significant increase. By in situ hybridization, Lv-Vmo1 mRNA was present in three cell types of the hepatopancreas but neither oocytes nor follicle cells of the ovary. In contrast, immunofluorescence revealed that Lv-VMO1 protein was distributed in the cytoplasms of both hepatopancreatic cells and ovarian oocytes. Western blot showed that Lv-VMO1 protein was produced in the hepatopancreas and transported to the ovary via hemolymph circulation. Identification of a species-specific egg-entry guide protein is the key to the receptor-mediated ovarian transduction of cargo, a novel gene editing approach in oviparous animals. This study lays the mechanism for exogenous transport into penaeid shrimp eggs by VMO1, as a foundation for achieving exogenous protein-mediated incorporation into oocytes.
Topics: Animals; Female; Hepatopancreas; Vitellogenesis; Penaeidae; Ovary; Vitelline Membrane; Phylogeny; Oocytes; RNA, Messenger
PubMed: 36332838
DOI: 10.1016/j.gene.2022.147027 -
Cells Sep 2022In sea urchins, the sequence of the cellular and molecular events characterizing the fertilization process has been intensively studied. We have learned that to activate...
In sea urchins, the sequence of the cellular and molecular events characterizing the fertilization process has been intensively studied. We have learned that to activate the egg, the fertilizing sperm must undergo morphological modifications (the acrosome reaction, AR) upon reaching the outer gelatinous layer enveloping the egg (egg jelly), which triggers the polymerization of F-actin on the sperm head to form the acrosomal process. The AR exposes bindin, an adhesive sperm protein essential for the species-specific interaction with the cognate receptor on the egg vitelline layer. To investigate the specific roles of the egg jelly and vitelline layer at fertilization of sea urchin eggs, eggs were incubated in acidic seawater, which removes the egg jelly, i.e., experimental conditions that should prevent the occurrence of the AR, and inseminated in the same medium. At variance with the prevailing view, our results have shown that these dejellied eggs can still interact with sperm in acidic seawater, albeit with altered fertilization responses. In particular, the eggs deprived of the vitelline layer reacted with multiple sperm but with altered Ca signals. The results have provided experimental evidence that the plasma membrane, and not the vitelline layer, is where the specific recognition between gametes occurs. The vitelline layer works in unfertilized eggs to prevent polyspermy.
Topics: Actins; Animals; Fertilization; Male; Ovum; Sea Urchins; Semen; Sperm-Ovum Interactions
PubMed: 36230946
DOI: 10.3390/cells11192984