Protein Cell 2013, 4(6): 456–466 DOI 10.1007/s13238-013-3019-8 Protein & Cell RESEARCH ARTICLE Cytosolic Ca2+ as a multifunctional modulator is required for spermiogenesis in Ascaris suum Yunlong Shang1,2, Lianwan Chen1, Zhiyu Liu1,2, Xia Wang1, Xuan Ma1, Long Miao1 1 Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China 2 University of Chinese Academy of Sciences, Beijing 100049, China Correspondence:
[email protected] Received March 6, 2013 Accepted April 7, 2013 Cell & ABSTRACT tial for many biological processes such as embryogenesis, immune surveillance and wound healing. Typically, actin and The dynamic polar polymers actin fi laments and microtu- microtubule cytoskeletons are employed to establish and bules are usually employed to provide the structural ba- maintain cell polarity (Li and Gundersen, 2008). Spermiogen- sis for establishing cell polarity in most eukaryotic cells. esis (sperm activation), in which round sessile spermatids dif- Protein Radially round and immotile spermatids from nematodes ferentiate into asymmetric motile spermatozoa, is a symmetry- contain almost no actin or tubulin, but still have the abil- breaking process. Dynamic and pronounced morphological ity to break symmetry to extend a pseudopod and initiate changes occur in the radially symmetrical spermatids during the acquisition of motility powered by the dynamics of the process of mammalian sperm activation, including the cytoskeleton composed of major sperm protein (MSP) formation of an elongated nucleus with condensed chromatin during spermiogenesis (sperm activation). However, covered by a well-shaped acrosome in the head and a long the signal transduction mechanism of nematode sperm fl agellum.