Autor(es):
Ramalho-Santos, J. 
; Amaral, Sandra
Data: 2013
Identificador Persistente: http://hdl.handle.net/10316/25628
Origem: Estudo Geral - Universidade de Coimbra
Assunto(s): Reproduction; Mitochondria; Gametogenesis; Fertilization; Steroidogenesis
Descrição
Mitochondria are cellular organelles with crucial roles in ATP synthesis, metabolic integration, reactive
oxygen species (ROS) synthesis and management, the regulation of apoptosis (namely via the intrinsic
pathway), among many others. Additionally, mitochondria in different organs or cell types may have distinct
properties that can decisively influence functional analysis. In terms of the importance of mitochondria
in mammalian reproduction, and although there are species-specific differences, these aspects
involve both energetic considerations for gametogenesis and fertilization, control of apoptosis to ensure
the proper production of viable gametes, and ROS signaling, as well as other emerging aspects. Crucially,
mitochondria are the starting point for steroid hormone biosynthesis, given that the conversion of
cholesterol to pregnenolone (a common precursor for all steroid hormones) takes place via the activity
of the cytochrome P450 side-chain cleavage enzyme (P450scc) on the inner mitochondrial membrane.
Furthermore, mitochondrial activity in reproduction has to be considered in accordance with the very
distinct strategies for gamete production in the male and female. These include distinct gonad
morpho-physiologies, different types of steroids that are more prevalent (testosterone, estrogens,
progesterone), and, importantly, the very particular timings of gametogenesis. While spermatogenesis
is complete and continuous since puberty, producing a seemingly inexhaustible pool of gametes in a fixed
environment; oogenesis involves the episodic production of very few gametes in an environment that
changes cyclically. These aspects have always to be taken into account when considering the roles of
any common element in mammalian reproduction. Part of the work in the Authors lab was funded by
FEDER and COMPETE, via FCT (Fundação para a Ciência e Tecnologia),
Portugal in grants PTDC/EBB-EBI/101114/2008, PTDC/EBBEBI/
120634/2010 and PTDC/QUI-BIQ/120652/2010. Sandra Amaral
is the recipient of a FCT fellowship (SFRH/BPD/63190/2009) and
the Center for Neuroscience and Cell Biology (CNC) funding is also
supported by FCT (PEst-C/SAU/LA0001/2011).
