Planar cell polarity protein Dishevelled 3 (Dvl3) regulates ectoplasmic specialization (ES) dynamics in the testis through changes in cytoskeletal organization

Linxi Li,Renshan Ge,Ming Yan,Siwen Wu,Qingquan Lian,C Yan Cheng,Baiping Mao

doi:10.1038/s41419-019-1394-7

Abstract

In the mammalian testes, such as in rats, the directional alignment of polarized elongating/elongated spermatids, in particular step 17–19 spermatids, across the plane of seminiferous epithelium resembles planar cell polarity (PCP) found in hair cells of the cochlea. It is obvious that spermatid PCP is necessary to support the simultaneous development of maximal number of elongating/elongated spermatids to sustain the daily production of > 50 million sperm per adult rat. Studies have shown that the testis indeed expresses multiple PCP proteins necessary to support spermatid PCP. Herein, using physiological and biochemical assays, and morphological analysis, and with the technique of RNA interference (RNAi) to knockdown PCP protein Dishevelled (Dvl) 1 (Dvl1), Dvl2, Dvl3, or Dvl1/2/3, Dvl proteins, in particular Dvl3, it was shown that Dvl3 played a crucial role of support Sertoli cell tight junction (TJ)-permeability barrier function through changes in the organization of actin- and microtubule (MT)-based cytoskeletons. More important, an in vivo knockdown of Dvl1/2/3 in the testis, defects of spermatid polarity were remarkably noted across the seminiferous epithelium, concomitant with defects of spermatid adhesion and spermatid transport, leading to considerably defects in spermatogenesis. More important, Dvl1/2/3 triple knockdown in the testis also impeded the organization of actin- and MT-based cytoskeletons owing to disruptive spatial expression of actin- and MT-regulatory proteins. In summary, PCP Dishevelled proteins, in particular, Dvl3 is a regulator of Sertoli cell blood–testis barrier (BTB) and also spermatid PCP function through its effects on the actin- and MT-based cytoskeletons in Sertoli cells.

Highlights

During spermatogenesis, developing step 17–19 spermatids in the rat testis displays conspicuous planar cell polarity (PCP)[1]
Using primer pairs specific to Dvl[1, 2], and 3 vs. S16 in rats for RT-PCR (Table 2), all Dvls were shown to be expressed in the testis (T), Sertoli cells (SC), and germ cells (GC), in which complementary DNAs (cDNAs) obtained from small intestine (Int) and liver (Liv) served as the positive controls (Fig. 1a)
Dvl[1], Dvl[2], and Dvl[3], act as adaptors that are working in partnership with Fzd to create the PCP protein complex of

Summary

Introduction

During spermatogenesis, developing step 17–19 spermatids in the rat testis displays conspicuous planar cell polarity (PCP)[1]. Studies have shown that the testis is equipped with multiple PCP proteins necessary to confer spermatid PCP, such as the PCP core proteins Van Goghlike (Vangl) proteins (e.g., Vangl2), Dishevelled (Dvl) (e.g., Dvl[2], Dvl3), and Frizzled (Fzd) class receptors (e.g., Fzd[3], Fzd5)[10]. It is established that PCP protein Vangl[2] is necessary to support spermatogenesis through its regulatory effects on actin- and microtubule (MT)based cytoskeletons[10]. The selection of Dvl[3] instead of Dvl[1] and Dvl[2] for more detailed analysis was based on initial observations that its knockdown by RNAi led to considerably more disruptive effects on the Sertoli cell TJ-barrier function compared to Dvl[1] and Dvl[2]. For our in vivo studies, Dvl1/2/3 were simultaneously silenced by RNAi to confirm changes in phenotypes, correlating the function of Dvl to support spermatogenesis

Methods

Results

Conclusion