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Insect Biochemistry and Molecular... Oct 2015BmECM25 (previously reported as BmVMP25) was previously predicted as a gene encoding the vitelline membrane protein in silkworm, Bombyx mori. In this study, we...
BmECM25 (previously reported as BmVMP25) was previously predicted as a gene encoding the vitelline membrane protein in silkworm, Bombyx mori. In this study, we investigated the detail temporal and spatial patterns of BmECM25 protein. Western blot results showed that BmECM25 was expressed in the follicular epithelium cells from stages -6 to +1, and was then secreted into the oocytes. However, the abundance of BmECM25 decreased during the subsequent oogenesis and finally disappeared in the mature follicles. Immunofluorescence detection showed that BmECM25 locates inside the VM layer and forms a discontinuous layer. These features of BmECM25 suggest that it is an oocyte membrane matrix protein, not a vitelline membrane protein.
Topics: Amino Acid Sequence; Animals; Bombyx; Extracellular Matrix Proteins; Female; Gene Expression Regulation, Developmental; Insect Proteins; Oocytes; Oogenesis; Ovarian Follicle; Vitelline Membrane
PubMed: 26070472
DOI: 10.1016/j.ibmb.2015.06.004 -
Poultry Science Nov 2018In this study, we aimed to evaluate the effect of canthaxanthin (CX) and iodine (I) on the production of laying hens, on counteracting debilitation of the vitelline...
In this study, we aimed to evaluate the effect of canthaxanthin (CX) and iodine (I) on the production of laying hens, on counteracting debilitation of the vitelline membrane, and on inhibiting Salmonella growth in eggs stored at 30°C. Three hundred hens were reared in cages. Birds were divided into six feeding groups (10 hens × 5 repetitions) that were administered 0, 3 or 6 ppm of CX and 1 or 10 ppm of I with their diets. Laying rate, egg weights, and feed conversion ratios were controlled. The quality of fresh eggs was assessed in wks 25-26, 48-50 and 62-63 of hens lives. An additional batch of eggs was incubated at the temperature of 30°C, and egg quality changes were monitored on days 3, 6 and 9 of storage. Additionally, eggs collected from four experimental groups of hens whose diets had been iodated with 1 or 10 ppm of I and supplemented with 0 or 6 ppm of CX were infected under laboratory conditions with Salmonella, and incubated for 5 and 10 d. The laying rate, egg weights, and feed conversion ratio were significantly improved. Dietary inclusion of CX contributed to a higher resistance of the vitelline membrane of egg yolks, but only for fresh eggs. Vitelline membrane degradation during egg storage at 30°C was significantly counteracted by dietary inclusion of I at a dose of 10 ppm. The same I dose resulted in the complete inhibition of Salmonella growth until day 10 of incubation, but exclusively for eggs collected from 40-week-old hens. Dietary supplementation with 10 ppm of I was found to impart high level of resistance to the vitelline membrane against the growth of Salmonella in case of eggs stored at 30°C; therefore, I was found to be more beneficial by ensuring longer preservation than that of CX. However, dietary supplementation with CX was found to increase the resistance of vitelline membrane in fresh eggs.
Topics: Animal Feed; Animals; Antioxidants; Canthaxanthin; Chickens; Diet; Dietary Supplements; Dose-Response Relationship, Drug; Female; Iodine; Ovum; Poultry Diseases; Salmonella Infections, Animal; Salmonella enteritidis; Salmonella typhimurium; Temperature; Time Factors; Trace Elements; Vitelline Membrane
PubMed: 29931093
DOI: 10.3382/ps/pey264 -
Journal of Veterinary Science Sep 2023Hystricomorpha rodents display a similar placentation model to humans. The present study was carried out considering the scarcity of information concerning the placental...
BACKGROUND
Hystricomorpha rodents display a similar placentation model to humans. The present study was carried out considering the scarcity of information concerning the placental development in agouti.
OBJECTIVE
Describe the microscopy of the placenta, subplacenta and yolk sac of agoutis in early pregnancy and report on the inversion of the yolk sac.
METHODS
Fifteen females between the 14-32 day of gestation were used following euthanasia. Gestational buttons were collected, fixed, processed, stained to optical microscopy or immunohistochemistry.
RESULTS
Chorioallantoic placenta (CP) ranged from conical to a half-sphere, as follows: from the 14 to 17 day, the CP displays an inverted "V" shape, predominantly formed by cytotrophoblasts; from 20 to 22 days, formed almost entirely by cytotrophoblasts; at 28 days, a half sphere, with distinct lobes and interlobular area, numerous maternal gaps delimited by syncytiotrophoblasts and trophoblast giant cells; at 32 days, globose and undergoing the maturation process. Subplacenta, located between decidua and CP, initially presents septa consisting of simple columnar epithelium and after 17 days, comprising stratified epithelium. Visceral yolk sac (VYS) is attached to two CP projections between 14 and 17 days, formed by a simple cubic epithelium and inverted. Between 20 and 22 days, the epithelium displays apical villous projections with cytoplasmic vacuoles and a vascularized mesoderm. After the 24 day, the VYS near the placenta is pleated, very vascularized and villous, with decreased villi sizes further away from the placenta.
CONCLUSION
The agouti CP displays similar characteristics to other hystricomorpha, including placenta lobulation, a subplacenta and an inverted vitelline placenta.
Topics: Pregnancy; Female; Animals; Humans; Placentation; Placenta; Dasyproctidae; Rodentia; Yolk Sac
PubMed: 38031643
DOI: 10.4142/jvs.22323 -
PeerJ 2015Embryonic cell division is a mechanical process which is predominantly driven by contraction of the cleavage furrow and response of the remaining cellular matter. While...
On the embryonic cell division beyond the contractile ring mechanism: experimental and computational investigation of effects of vitelline confinement, temperature and egg size.
Embryonic cell division is a mechanical process which is predominantly driven by contraction of the cleavage furrow and response of the remaining cellular matter. While most previous studies focused on contractile ring mechanisms of cytokinesis, effects of environmental factors such as pericellular vitelline membrane and temperature on the mechanics of dividing cells were rarely studied. Here, we apply a model-based analysis to the time-lapse imaging data of two species (Saccoglossus kowalevskii and Xenopus laevis) with relatively large eggs, with the goal of revealing the effects of temperature and vitelline envelope on the mechanics of the first embryonic cell division. We constructed a numerical model of cytokinesis to estimate the effects of vitelline confinement on cellular deformation and to predict deformation of cellular contours. We used the deviations of our computational predictions from experimentally observed cell elongation to adjust variable parameters of the contractile ring model and to quantify the contribution of other factors (constitutive cell properties, spindle polarization) that may influence the mechanics and shape of dividing cells. We find that temperature affects the size and rate of dilatation of the vitelline membrane surrounding fertilized eggs and show that in native (not artificially devitellinized) egg cells the effects of temperature and vitelline envelope on mechanics of cell division are tightly interlinked. In particular, our results support the view that vitelline membrane fulfills an important role of micromechanical environment around the early embryo the absence or improper function of which under moderately elevated temperature impairs normal development. Furthermore, our findings suggest the existence of scale-dependent mechanisms that contribute to cytokinesis in species with different egg size, and challenge the view of mechanics of embryonic cell division as a scale-independent phenomenon.
PubMed: 26713241
DOI: 10.7717/peerj.1490 -
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 -
Molecular and Cellular Endocrinology Jan 2015Vitelline membrane outer layer protein 1 (VMO1), a basic protein present in the outer layer of the vitelline membrane of eggs, plays essential roles in separating the...
Vitelline membrane outer layer protein 1 (VMO1), a basic protein present in the outer layer of the vitelline membrane of eggs, plays essential roles in separating the yolk from the egg white and preventing infection from bacteria by forming a barrier of fibrous layers in avian eggs. Although VMO1 is expressed in the oviduct of hens, little is known about endocrine regulation of transcription of VMO1 in the oviduct and its expression in cancerous ovaries of laying hens. Results of present study indicated that expression of VMO1 mRNA increased in the chick oviduct in response to diethylstilbestrol (DES, a synthetic non-steroidal estrogen). VMO1 mRNA and protein were particularly abundant in the glandular epithelium (GE) and luminal epithelium (LE) of the magnum of the oviducts of chicks treated with DES. Also, during the regression and recrudescence phases of the oviduct during induced molting with zinc feeding, VMO1 expression decreased as the oviduct regressed and increased with remodeling and recrudescence of the oviduct in laying hens. In addition, changes in relative expression of specific microRNAs (miR-1623, miR-1552-3p, miR-1573, miR-22-3p, miR-124a and miR-1764) regulating VMO1 gene were detected in the oviducts during the molting period. Moreover, abundant expression of VMO1 was found in GE of cancerous, but not normal ovaries of laying hens. Results of the present study suggest that VMO1 is regulated by estrogen and target microRNAs in the chicken oviduct and that it is a potential diagnostic marker of ovarian cancer in laying hens.
Topics: Animals; Biomarkers, Tumor; Chickens; Estrogens; Female; Gene Expression Regulation, Neoplastic; Membrane Proteins; MicroRNAs; Neoplasm Proteins; Ovarian Neoplasms; Oviducts; Ovum; Poultry Diseases; RNA, Neoplasm
PubMed: 25458700
DOI: 10.1016/j.mce.2014.10.015 -
Biology of Reproduction Nov 2018Both transcriptionally and translationally inactive sperm need preassembled pathways into specific cellular compartments to function. Although initiation of the acrosome...
Both transcriptionally and translationally inactive sperm need preassembled pathways into specific cellular compartments to function. Although initiation of the acrosome reaction (AR) involves several signaling pathways including protein kinase A (PKA) activation, how these are regulated remains poorly understood in avian sperm. Membrane rafts are specific membrane regions enriched in sterols and functional proteins and play important roles in diverse cellular processes, including signal transduction. Our recent studies on chicken sperm demonstrated that membrane rafts exist and play a role in multistage fertilization. These, combined with the functional importance of membrane rafts in mammalian sperm AR, prompted us to investigate the roles of membrane rafts in signaling pathways leading to AR in chicken sperm. Using 2-hydroxypropyl-β-cyclodextrin (2-OHCD), we found that the disruption of membrane rafts inhibits PKA activity and AR without affecting protein tyrosine phosphorylation; however, these inhibitions were abolished in the presence of a cyclic 3,5-adenosine monophosphate (cAMP) analog. In addition, biochemical experiments showed a decrease in cAMP content in 2-OHCD-treated sperm, suggesting the involvement of soluble adenylyl cyclase (sAC) and transmembrane adenylyl cyclase (tmAC). Pharmacological experiments, combined with transcriptome analysis, showed that sAC and tmAC are present and involved in AR induction in chicken sperm. Furthermore, stimulation of both isoforms reversed the inhibition of PKA activity and AR in 2-OHCD-treated sperm. In conclusion, our results demonstrated that membrane rafts play an important role in AR induction by regulating the cAMP-dependent pathway and that they provide a mechanistic insight into membrane regulation of AR and sperm function in birds.
Topics: Acrosome Reaction; Adenylyl Cyclases; Animals; Chick Embryo; Chickens; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Female; Male; Membrane Microdomains; Signal Transduction; Sperm Motility; Spermatozoa; Sterols; Vitelline Membrane
PubMed: 29788183
DOI: 10.1093/biolre/ioy120 -
Developmental Cell Jan 2024During morphogenesis, mechanical forces induce large-scale deformations; yet, how forces emerge from cellular contractility and adhesion is unclear. In Drosophila...
During morphogenesis, mechanical forces induce large-scale deformations; yet, how forces emerge from cellular contractility and adhesion is unclear. In Drosophila embryos, a tissue-scale wave of actomyosin contractility coupled with adhesion to the surrounding vitelline membrane drives polarized tissue invagination. We show that this process emerges subcellularly from the mechanical coupling between myosin II activation and sequential adhesion/de-adhesion to the vitelline membrane. At the wavefront, integrin clusters anchor the actin cortex to the vitelline membrane and promote activation of myosin II, which in turn enhances adhesion in a positive feedback. Following cell detachment, cortex contraction and advective flow amplify myosin II. Prolonged contact with the vitelline membrane prolongs the integrin-myosin II feedback, increases integrin adhesion, and thus slows down cell detachment and wave propagation. The angle of cell detachment depends on adhesion strength and sets the tensile forces required for detachment. Thus, we document how the interplay between subcellular mechanochemical feedback and geometry drives tissue morphogenesis.
Topics: Animals; Drosophila; Drosophila melanogaster; Drosophila Proteins; Actomyosin; Myosin Type II; Integrins; Morphogenesis
PubMed: 38103554
DOI: 10.1016/j.devcel.2023.11.022 -
Zoo Biology May 2017Advanced reproductive technologies (ART's) are often employed with various taxa to enhance captive breeding programs and maintain genetic diversity. Perivitelline...
Advanced reproductive technologies (ART's) are often employed with various taxa to enhance captive breeding programs and maintain genetic diversity. Perivitelline membrane-bound (PVM-bound) sperm detection has previously been demonstrated in avian and chelonian species as a useful technique for breeding management. In the absence of embryotic development within an egg, this technique can detect the presence of sperm trapped on the oocyte membrane confirming breeding, male reproductive status, and pair compatibility. PVM-bound sperm were successfully detected in three clutches of Cuban crocodile (Crocodylus rhombifer) eggs at the Smithsonian's National Zoological Park (NZP) for the first time in any crocodilian species. PVM-bound sperm were detected in fresh and incubated C. rhombifer eggs, as well as eggs that were developing (banded) and those that were not (not banded). The results of this study showed significant differences in average sperm densities per egg between clutches (p = 0.001). Additionally, there was not a significant difference within clutches between eggs that banded and those that did not band (Clutch A, p = 0.505; Clutch B, p = 0.665; Clutch C, p = 0.266). The results of this study demonstrate the necessity to microscopically examine eggs that do not develop (do not band), to determine if sperm is present, which can help animal managers problem solve reproductive shortcomings. PVM-bound sperm detection could be a useful technique in assessing crocodilian breeding programs, as well as have potential uses in studies assessing sperm storage, artificial insemination, and artificial incubation.
Topics: Alligators and Crocodiles; Animals; Male; Ovum; Sperm Count; Sperm-Ovum Interactions; Spermatozoa; Vitelline Membrane
PubMed: 28497618
DOI: 10.1002/zoo.21367 -
Parasitology Research Jul 2017The origin, differentiation and functional ultrastructure of oncospheral or egg envelopes in Echinococcus multilocularis Leuckart, 1863 were studied by transmission...
The origin, differentiation and functional ultrastructure of oncospheral or egg envelopes in Echinococcus multilocularis Leuckart, 1863 were studied by transmission electron microscopy (TEM) and cytochemistry. The purpose of our study is to describe the formation of the four primary embryonic envelopes, namely vitelline capsule, outer envelope, inner envelope and oncospheral membrane, and their transformation into the oncospheral or egg envelopes surrounding the mature hexacanth. This transformation takes place in the preoncospheral phase of embryonic development. The vitelline capsule and oncospheral membrane are thin membranes, while the outer and inner envelopes are thick cytoplasmic layers formed by two specific types of blastomeres: the outer envelope by cytoplasmic fusion of two macromeres and the inner envelope by cytoplasmic fusion of three mesomeres. Both outer and inner envelopes are therefore cellular in origin and syncytial in nature. During the advanced phase of embryonic development, the outer and inner envelopes undergo great modifications. The outer envelope remains as a metabolically active layer involved in the storage of glycogen and lipids for the final stages of egg development and survival. The inner envelope is the most important protective layer because of its thick layer of embryophoric blocks that assures oncospheral protection and survival. This embryophore is the principal layer of mature eggs, affording physical and physiological protection for the differentiated embryo or oncosphere, since the outer envelope is stripped from the egg before it is liberated. The embryophore is very thick and impermeable, consisting of polygonal blocks of an inert keratin-like protein held together by a cementing substance. The embryophore therefore assures extreme resistance of eggs, enabling them to withstand a wide range of environmental temperatures and physicochemical conditions.
Topics: Animals; Cell Differentiation; Cytoplasm; Echinococcus multilocularis; Female; Microscopy, Electron, Transmission; Ovum
PubMed: 28593390
DOI: 10.1007/s00436-017-5479-x