A well-known putative tumor suppressor WW domain–containing oxidoreductase (Wwox) is highly expressed in hormonally regulated tissues and is considered important for the normal development and function of reproductive organs. In this study, we investigated the cellular and subcellular localization of Wwox in normal testes during postnatal days 0–70 using Western blotting and immunohistochemistry. Wwox is expressed in testes at all ages. Immunohistochemistry showed that fetal-type and adult-type Leydig cells, immature and mature Sertoli cells, and germ cells (from gonocytes to step 17 spermatids) expressed Wwox except peritubular myoid cells, step 18–19 spermatids, and mature sperm. Wwox localized diffusely in the cytoplasm with focal intense signals in all testicular cells. These signals gradually condensed in germ cells with their differentiation and colocalized with giantin for cis-Golgi marker and partially with golgin-97 for trans-Golgi marker. Biochemically, Wwox was detected in isolated Golgi-enriched fractions. But Wwox was undetectable in the nucleus. This subcellular localization pattern of Wwox was also confirmed in single-cell suspension. These findings indicate that Wwox is functional in most cell types of testis and might locate into Golgi apparatus via interaction with Golgi proteins. These unique localizations might be related to the function of Wwox in testicular development and spermatogenesis:

众所周知的推定的肿瘤抑制因子WW结构域的氧化还原酶（Wwox）在激素调节的组​​织中高度表达，被认为对生殖器官的正常发育和功能很重要。在这项研究中，我们使用免疫印迹和免疫组织化学方法研究了出生后0–70天正常睾丸中Wwox的细胞和亚细胞定位。Wwox在所有年龄段的睾丸中都有表达。免疫组织化学显示，胎儿型和成年型的Leydig细胞，未成熟和成熟的Sertoli细胞，以及生殖细胞（从性腺细胞到第17步精子），均表达Wwox，除了管周肌样细胞，第18-19步精子和成熟精子。Wwox分散在细胞质中，在所有睾丸细胞中均具有局灶性强信号。这些信号在分化过程中逐渐凝结在生殖细胞中，与巨蛋白共定位于顺式高尔基体，部分与golgin-97共定位于反式高尔基体。生化方面，在分离的高尔基体富集馏分中检测到Wwox。但是Wwox在细胞核中是无法检测到的。Wwox的这种亚细胞定位模式也在单细胞悬浮液中得到证实。这些发现表明，Wwox在大多数睾丸细胞类型中均具有功能，并且可能通过与高尔基体蛋白相互作用而定位于高尔基体中。这些独特的定位可能与Wwox在睾丸发育和精子发生中的功能有关：但是Wwox在细胞核中是无法检测到的。Wwox的这种亚细胞定位模式也在单细胞悬浮液中得到证实。这些发现表明，Wwox在大多数睾丸细胞类型中均具有功能，并且可能通过与高尔基体蛋白相互作用而定位于高尔基体中。这些独特的定位可能与Wwox在睾丸发育和精子发生中的功能有关：但是Wwox在细胞核中是无法检测到的。Wwox的这种亚细胞定位模式也在单细胞悬浮液中得到证实。这些发现表明，Wwox在大多数睾丸细胞类型中均具有功能，并且可能通过与高尔基体蛋白相互作用而定位于高尔基体中。这些独特的定位可能与Wwox在睾丸发育和精子发生中的功能有关：