High impact information on Vitelline Membrane

• Several genes are normally required for activating tor and appear to define a system in which a gene product tethered to the extracellular vitelline membrane at each end of the egg provides a local source for an extracellular tor ligand [1].
• A new protein fold with internal symmetry has been observed in two proteins: vitelline membrane outer layer protein I (VMO-I) and delta-endotoxin [2].
• Large, immature starfish oocytes, arrested in prophase I of meiosis (germinal vesicle stage), underwent vitelline membrane elevation when treated with divalent ionophore A-23187 or starfish sperm [3].
• The protein was found to be identical or closely related to ovomucin, a 600 X 10(3) relative molecular mass glycoprotein, and a major constituent of the vitelline membrane of the avian yolk [4].
• Trunk (Trk), the proposed ligand for Tor, is secreted as an inactive precursor into the perivitelline fluid that lies between the embryonic membrane and the vitelline membrane (VM), the inner layer of the eggshell [5].

Biological context of Vitelline Membrane

• Pyruvate kinase type M1 from egg yolk was a weak substrate of protein kinase C. An activation of pyruvate kinase type M2 from vitelline membrane was observed at suboptimal concentrations of phosphoenolpyruvate under the conditions of phosphorylation, in the presence of phosphatidylserine [6].
• Hydrolysis of the hen egg vitelline membrane by cock sperm acrosin and other enzymes [7].
• Characterization of vitelline membrane outer layer protein I, VMO-I: amino acid sequence and structural stability [8].

Anatomical context of Vitelline Membrane

• Cross-linking of vitelline membrane protein sV23 also increases progressively as the egg moves through the oviducts and the uterus [9].
• Immunogold studies demonstrate that newly synthesized YPs in the normal and mutant strains share secretory vesicles with putative, vitelline membrane proteins and that the translocation of follicle cell YP is not through the membrane along the interfollicular spaces but directly through the plasmalemma facing the oocyte [10].
• We propose that this highly anionic peptide, exposed at the surface of RBP, is the principal determinant for the uptake of RBP by the vitelline membrane of the ovarian follicle [11].
• Drosophila vitelline membrane cross-linking requires the fs(1)Nasrat, fs(1)polehole and chorion genes activities [12].
• The mean CO2 production of the whole blastoderm (1) increased from 16 nmol/h at laying to 231 nmol/h at early neurulation, (2) became dependent on exogenous glucose and (3) was closely linked to mechanical tension generated in the blastoderm (loosening from vitelline membrane resulted in a decrease of 56%) [13].

Associations of Vitelline Membrane with chemical compounds

• A class of six mutants with potential vitelline membrane defects was identified on the basis of the response of mutant eggs to hypochlorite solutions [14].
• The predicted protein had unusually high contents of alanine, histidine, and proline and contained a region of hydrophobic amino acids that was highly conserved in the predicted protein of the D. melanogaster vitelline membrane protein genes [15].
• As observed by 33258 Hoechst staining and fluorescent microscopy, these sequences are consistently found to be located on the sides of the nuclei nearest to the vitelline membrane [16].
• Pyruvate kinase type M2 from vitelline membrane was obtained in a homogeneous form after a 1150-fold purification to a specific enzymatic activity of 450 mumol X min-1 X mg-1 [6].
• The ionophore caused release of nine proteins and six of them were characterized and found to be a masquerade-like protein, a masquerade-like serine proteinase, a mannose receptor protein, a vitelline membrane outer layer protein I, and two anti-microbial peptides [17].

Gene context of Vitelline Membrane

• The dec-1 gene, which is required for proper eggshell assembly, produces three proproteins that are cleaved within the vitelline membrane layer to multiple derivatives [18].
• On the contrary, in the fs(1)Nasrat and fs(1)polehole alleles showing defects only at the termini of the embryo the vitelline membrane is properly formed, confirming a multifunctional activity of their gene products [12].
• A study was made of the localization and assembly of the VM32E protein, a putative vitelline membrane component of the Drosophila eggshell [19].
• Immunoelectron microscopy was used to follow the distribution of four different eggshell proteins in the assembling and mature eggshell. sV23 and sV17, follicle cell proteins synthesized during the early stages of eggshell formation (stages 8-10), were distributed within the vitelline membrane layer at all stages [20].
• Our results suggest that the products of fs(1)Nas and fs(1)ph are required for the stability of the vitelline membrane and are also involved in a morphogenetic pathway necessary for the correct differentiation of the terminal regions of the embryo [21].

Analytical, diagnostic and therapeutic context of Vitelline Membrane

• Crystallization and preliminary crystallographic data of vitelline membrane outer layer protein I, VMO-I [22].
• CONCLUSION: 2PN stage embryo cryosurvival may be negatively affected by ICSI, possibly caused by disruption of the zona pellucida and vitelline membrane before cryopreservation, and/or because ICSI promotes fertilization of some compromised eggs (producing compromised 2PN embryos) that would not have fertilized by conventional IVF [23].
• Significant progress was made when permeabilization of the vitelline membrane was optimized, a vitrification solution containing ethylene glycol, polyethylene glycol, and trehalose was formulated, and when cooling and recovery of the cryopreservation protocol included a step which passed the embryos through liquid nitrogen vapor [24].

References