Sperm Centrioles and Their Dual Role in Flagellogenesis and Cell Cycle of the Zygote - The Centrosome - page 31

Chapter 2
Sperm Centrioles and Their Dual Role
in Flagellogenesis and Cell Cycle
of the Zygote

Structure, Function, and Pathology

Hector E. Chemes

Abstract This chapter examines the current knowledge on the role of the sper-
matid centrosome. The dual role of the centrosome as a spermatid basal body that
generates the sperm flagellum and as the nucleation site for sperm aster formation
in the zygote is mirrored in different sperm pathologies in infertile men that are
reviewed in detail. Information is discussed on different sperm centriolar and
centrosomal anomalies that are involved in failed fertilizations or abnormal
development of the embryo. Particular attention is paid to specific centrosomal
anomalies of genetic origin that cause dysfunction of the sperm centrosome with
abnormal assembly of the sperm aster and failed pronuclear apposition and
cleavage of the zygote. The studies highlight the key role played by sperm cen-
trosomes in flagellogenesis and early zygote development and encourage further
investigation on the physiopathology of sperm centrosome-related fertility failures
to fully expose the basic mechanisms involved.

2.1 Centrosomes, Centrioles, and Basal Bodies

Centrosomes are ubiquitous organelles found in eukaryotic cells. They are com-
posed of a pair of barrel-shaped centrioles, hollow cylindrical structures with their
walls composed of nine triplet microtubules in a ''pinwheel'' arrangement. The
two centrioles, perpendicular to each other (diplosomes), are surrounded by a
dense fibro-granular ''cloud'' of pericentriolar material (PCM) that constitutes the

H. E. Chemes ( )

División Endocrinología, Centro de Investigaciones Endocrinológicas,
CEDIE-CONICET, Gallo 1330, C1425SEFD Buenos Aires, Argentina
e-mail: [e-mail]; [e-mail]

&