免疫グロブリンスーパーファミリーのタンパク質Izumoは,精子が卵と融合するために必要です
Naokazu Inoue1, Masahito Ikawa, Ayako Isotani
1Genome Information Research Center, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan.
Nature
|March 11, 2005
まとめ
研究者らは,受精時に精子と卵の融合に不可欠な新しいタンパク質であるIzumoを特定しました. Izumoが欠けていた雄性マウスは不妊であり,雄性生殖能力と生殖における重要な役割を示した.
科学分野:
- 生殖生物学 生殖生物学
- 分子生物学と細胞生物学について
- 免疫学 免疫学とは
背景:
- 受精は精子と卵の融合を伴うもので,生殖のための重要なステップです.
- CD9のような卵因子は知られているが,精子関連の融合因子は未だに不明である.
研究 の 目的:
- 受精時に膜融合に関与する未知の精子関連の要因を特定する.
- 特定された因子と,男性の生育能力におけるその役割を特徴づける.
主な方法:
- 融合阻害モノクローナル抗体を用いて精子の抗原を特定した.
- 遺伝子クローニングを行い,遺伝子破壊された (Izumo-/-) マウスを生み出した.
- 人間の精子機能とハムスター卵融合アッセイをテストしました.
主要な成果:
- 新しい免疫グロブリンスーパーファミリーのタンパク質,イズモ (Izumo) を,重要な精子融合抗原として特定しました.
- Izumo/-雄マウスは不妊で,正常なゾナペルシダの浸透にもかかわらず,精子は卵と融合することができなかった.
- 人間のイズモに対する抗体は,精子と卵の融合を阻害した.
結論:
- Izumoは,マウスとヒトの受精の精子膜融合ステップに不可欠です.
- この発見は,男性の不妊症を理解し,潜在的に治療するための新しいターゲットを提供します.
関連する概念動画
Meiosis II
169.4K
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each...
169.4K
Spermatogenesis
91.1K
Spermatogenesis is the process by which haploid sperm cells are produced in the male testes. It starts with stem cells located close to the outer rim of seminiferous tubules. These spermatogonial stem cells divide asymmetrically to give rise to additional stem cells (meaning that these structures “self-renew”), as well as sperm progenitors, called spermatocytes. Importantly, this method of asymmetric mitotic division maintains a population of spermatogonial stem cells in the male...
91.1K
Fertilization
68.9K
During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm...
68.9K
Spermatogenesis
8.4K
Spermatogenesis is a complex process that involves the development of sperm cells from undifferentiated stem cells in the seminiferous tubules of the testes. The process is essential for the production of mature and functional sperm cells that are capable of fertilizing an egg.
The process of spermatogenesis can be divided into mitosis, meiosis, and spermiogenesis. During mitosis, the spermatogonia or stem cells divide to produce two identical daughter cells, type A and B spermatogonia. Type-A...
The process of spermatogenesis can be divided into mitosis, meiosis, and spermiogenesis. During mitosis, the spermatogonia or stem cells divide to produce two identical daughter cells, type A and B spermatogonia. Type-A...
8.4K
Sperm Transport
5.6K
The journey of sperm from its origin to the point of ejaculation begins within the seminiferous tubules of the testis. Here, Sertoli cells produce fluid that propels non-motile sperm through a series of conduits, starting with the straight tubules leading to the rete testis. This interconnected network of tubules acts as the initial pathway for sperm, guiding them into the efferent ductules and then into the epididymis for maturation.
The maturation phase occurs in the epididymis, where sperm...
The maturation phase occurs in the epididymis, where sperm...
5.6K
Infertility in Males
668
Male infertility affects millions of couples worldwide, arising from various factors that impact different stages of the reproductive process. An endocrine imbalance resulting from conditions like hypogonadism, Klinefelter syndrome, or pituitary disorders can disrupt hormone levels and reduce sperm production. Testicular defects, such as tumors, cryptorchidism, atrophic testes, abnormal sperm morphology, and low sperm count or motility, may arise due to genetic factors, structural...
668


