Sperm and Spermatids Contain Different Proteins and Bind Distinct Egg Factors

International Journal of Molecular Sciences

Marta Teperek¹  Kei Miyamoto¹  Angela Simeone¹  Renata Feret²  Michael J. Deery²  John B. Gurdon¹ 

[1] Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK; E-Mails:;Cambridge Centre for Proteomics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK; E-Mails:

关键词: sperm;    spermatid;    egg extract;    proteome;    chromatin;    mass spectrometry;    spermiogenesis;    chromatin remodelers;    transcription;    programming;   

DOI  :  10.3390/ijms150916719

来源: mdpi

【 摘 要 】

Spermatozoa are more efficient at supporting normal embryonic development than spermatids, their immature, immediate precursors. This suggests that the sperm acquires the ability to support embryonic development during spermiogenesis (spermatid to sperm maturation). Here, using Xenopus laevis as a model organism, we performed 2-D Fluorescence Difference Gel Electrophoresis (2D-DIGE) and mass spectrometry analysis of differentially expressed proteins between sperm and spermatids in order to identify factors that could be responsible for the efficiency of the sperm to support embryonic development. Furthermore, benefiting from the availability of egg extracts in Xenopus, we also tested whether the chromatin of sperm could attract different egg factors compared to the chromatin of spermatids. Our analysis identified: (1) several proteins which were present exclusively in sperm; but not in spermatid nuclei and (2) numerous egg proteins binding to the sperm (but not to the spermatid chromatin) after incubation in egg extracts. Amongst these factors we identified many chromatin-associated proteins and transcriptional repressors. Presence of transcriptional repressors binding specifically to sperm chromatin could suggest its preparation for the early embryonic cell cycles, during which no transcription is observed and suggests that sperm chromatin has a unique protein composition, which facilitates the recruitment of egg chromatin remodelling factors. It is therefore likely that the acquisition of these sperm-specific factors during spermiogenesis makes the sperm chromatin suitable to interact with the maternal factors and, as a consequence, to support efficient embryonic development.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.