Atypical centrioles during sexual reproduction.

Tomer Avidor-Reiss,Atul Khire,Kyoung H Jo,Emily L Fishman

doi:10.3389/fcell.2015.00021

Tomer Avidor-Reiss, Atul Khire + Show 2 more

Open Access

https://doi.org/10.3389/fcell.2015.00021

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Abstract

Centrioles are conserved, self-replicating, microtubule-based, 9-fold symmetric subcellular organelles that are essential for proper cell division and function. Most cells have two centrioles and maintaining this number of centrioles is important for animal development and physiology. However, how animals gain their first two centrioles during reproduction is only partially understood. It is well established that in most animals, the centrioles are contributed to the zygote by the sperm. However, in humans and many animals, the sperm centrioles are modified in their structure and protein composition, or they appear to be missing altogether. In these animals, the origin of the first centrioles is not clear. Here, we review various hypotheses on how centrioles are gained during reproduction and describe specialized functions of the zygotic centrioles. In particular, we discuss a new and atypical centriole found in sperm and zygote, called the proximal centriole-like structure (PCL). We also discuss another type of atypical centriole, the “zombie” centriole, which is degenerated but functional. Together, the presence of centrioles, PCL, and zombie centrioles suggests a universal mechanism of centriole inheritance among animals and new causes of infertility. Since the atypical centrioles of sperm and zygote share similar functions with typical centrioles in somatic cells, they can provide unmatched insight into centriole biology.

Highlights

Centrioles and atypical centrioles can be defined using a variety of structural and functional criteria
Centrioles recruit proteins from the cytoplasm that surround them in a matrix, which is known as the pericentriolar material (PCM), forming the centrosome (Figure 1A)
Since centriole number is so precisely controlled during development, and the zygote gives rise to all other cells of an animal, it is expected that during reproduction, centrioles will form via centriole duplication

Summary

Introduction

Centrioles and atypical centrioles can be defined using a variety of structural and functional criteria. We discuss a new and atypical centriole found in sperm and zygote, called the proximal centriole-like structure (PCL). Since centriole number is so precisely controlled during development, and the zygote gives rise to all other cells of an animal, it is expected that during reproduction, centrioles will form via centriole duplication.

Results

Conclusion