Medaka gcnf is a component of chromatoid body during spermiogenesis

Abstract

Germ cells of many organisms exhibit a unique perinuclear cytoplasmic cloud-like structure called the chromatoid body (CB). Specific components of the CB, such as vasa, are crucial for germline development. Herein we identify another component of the CB, the Oryzias latipes gcnf homolog (Olgcnf). By reverse transcription polymerase chain reaction (RT-PCR), Olgcnf transcript was restricted to gonads in the adult tissues and was maternally provided and persisted throughout embryogenesis. By in situ hybridization on gonadal sections, Olgcnf transcript was restricted to germ cells. In the ovary, Olgcnf was predominantly expressed in the early stages of oocytes. In the testis, Olgcnf showed dynamic expression in round spermatids and sperm, accumulated in the CB during spermatid morphogenesis and concentrated in elongated spermatids of acrosome cap region and flagellar manchette. Moreover, Olgcnf was colocalized with vasa, which is the best-characterized component of the CB. Therefore, Olgcnf is specific to germ cells of both sexes and is a component of the CB during spermiogenesis.

Keywords

• Gcnf
• Medaka
• Ovary
• Testis