Incorporation of ZP1 into perivitelline membrane after in vivo treatment with exogenous ZP1 in Japanese quail (Coturnix japonica)

Abstract

The avian vitelline membrane in laid eggs consists of three layers: the outer layer; the continuous membrane; and the inner layer [1]. The outer layer, which is composed of a varying number of sublayers of latticed fine fibrils, is formed in the infundibulum part of the oviduct [2]. The continuous membrane, which is a very thin granular membrane, is also formed in the infundibulum [2]. The inner layer, a 3D network of coarse fibers, is found between the granulosa cells and the oocyte in follicles before ovulation and is called the perivitelline membrane (PL) [3]. The PL is a homologue of the egg envelope in other vertebrates, the zona pellucida in mammals, the vitelline membrane in amphibians and the chorion in teleosts. These egg In birds, the egg envelope surrounding the oocyte prior to ovulation is called the perivitelline membrane and it plays important roles in fertilization. In a previous study we demonstrated that one of the components of the perivitelline membrane, ZP3, which is secreted from the ovarian granulosa cells, specifically interacts with ZP1, another constituent that is synthesized in the liver of Japanese quail. In the present study, we investigated whether ZP1 injected exogenously into the blood possesses the ability to reconstruct the perivitelline membrane of Japanese quail. When ZP1 purified from the serum of laying quail was injected into other female birds, the signal of this exogenous ZP1 was detected in the perivitelline membrane. In addition, we revealed, by means of ligand blot analysis, that serum ZP1 interacts with both ZP1 and ZP3 of the perivitelline membrane. By contrast, when ZP1 derived from the perivitelline membrane was administered, it failed to become incorporated into the perivitelline membrane. Interestingly, serum ZP1 recovered from other Galliformes, including chicken and guinea fowl, could be incorporated into the quail perivitelline membrane, but the degree of interaction between quail ZP3 and ZP1 of the vitelline membrane of laid eggs from chicken and guinea fowl appeared to be weak. These results demonstrate that exogenous ZP1 purified from the serum, but not ZP1 from the perivitelline membrane, can become incorporated into the perivitelline membrane upon injection into other types of female birds. To our knowledge, this is the first demonstration that the egg envelope component, when exogenously administered to animals, can reconstruct the egg envelope in vivo.Abbreviations CBB, Coomassie Brilliant Blue; DIG, digoxigenin; PL, perivitelline membrane; PVDF, poly(vinylidene difluoride); ZP, zona pellucida.

Sperm proteasome degrades egg envelope glycoprotein ZP1 during fertilization of Japanese quail (Coturnix japonica)

“…Additionally, we found that ZP1, which circulates in the bloodstream, received some modifications during transport to the pvm. It is from the fact that when ZP1 purified from the serum of laying quail was injected into different birds, the signal of exogenous ZP1 was detected in the pvm, whereas ZP1 derived from the pvm failed to incorporate into the pvm (Kinoshita et al 2008). In this report, we demonstrate for the first time that the ubiquitin-proteasome system functions in avian fertilization.…”

“…To prepare the affinity gel for the separation of serum ZP1, the IgG fractionated from anti-ZP1 antiserum (Kinoshita et al 2008) with a HiTrap Protein A FF affinity column (Amersham Pharmacia Biotech) that had been covalently coupled to NHS-activated sepharose (Amersham Pharmacia Biotech) according to the manufacturer's instructions. The serum of laying birds was incubated with the affinity gel for 16 h at 4 8C.…”

Zona pellucida protein ZP2 is expressed in the oocyte of Japanese quail (Coturnix japonica)

“…As was mentioned earlier, the PL in quail as well as in chicken is constructed mainly by ZP1 and ZP3, and these components specifically bind to form the PL fiber , Sasanami et al 2006, Okumura et al 2007a, 2007b, Kinoshita et al 2008. In fact, in vitro incubation of ZP1 with ZP3 spontaneously produced fibrous aggregates, which were visible under optical microscopy (Okumura et al 2007b).…”

Sperm-Egg Interaction during Fertilization in Birds

“…We found that ZP1, which circulates in the bloodstream, received some modifications during transport to the pvm. It is from the fact that when ZP1, purified from the serum of laying quail, was intravenously injected into different birds, the signal of exogenous ZP1 was detected in the pvm, whereas ZP1 derived from the pvm failed to incorporate into the pvm (Kinoshita et al, 2008). As described above, egg envelope glycoprotein ZP1 is the authentic AR inducer in birds.…”