Translational Control in the Germ Line
Germ cells are unique cells with the essential function of transmitting geneticinformation to the progeny. They are highly specialized cells that maintain some ofthe properties of a pluripotent cell being able to reprogram to totipotency togenerate a zygo
- PDF / 738,356 Bytes
- 28 Pages / 439.37 x 666.14 pts Page_size
- 91 Downloads / 156 Views
Translational Control in the Germ Line Marco Conti, João Pedro Sousa Martins, Seung Jin Han, and Federica Franciosi
1
Introduction
Given their critical function in transmitting the genetic information across generations, germ cells are unique cells of the body and the only ones with the capacity to generate a complete organism. They use a specialized meiotic cell cycle to generate haploid cells, and, although differentiating into one of the most specialized cell of the body, they maintain some of the traits specific to pluripotent cells. To accomplish this, they often use unusual molecular strategies to control gene expression during their life cycle. Among these unique strategies is the extensive use of posttranscriptional control of mRNA to regulate important transitions throughout lineage specification, lineage expansion, and differentiation. In model organisms, maternal mRNAs accumulated during growth drive development up to the midblastula transition prior to gastrulation and with few exceptions in the absence of significant transcription (Lee et al. 2014). Moreover, the polarity of the female gamete is defined by mRNA deposited at one pole of the oocyte marking the region of the cytoplasm that will be inherited by and will define the germ lineage. The presence of the so called “germ granules” in the cytosol of most germ cells is the physical manifestation of mRNA storage/accumulation found in one form or another in most organisms. Although mammalian embryos have adopted a different strategy and become independent of maternal input earlier during embryo development (Li et al. M. Conti (*) • J.P.S. Martins • F. Franciosi Center for Reproductive Sciences, University of California, San Francisco, CA, USA Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA Department of Obstetrics and Gynecology and Reproductive Sciences, University of California, San Francisco, CA, USA e-mail: [email protected] S.J. Han Department of Biological Sciences, Inje University, Gimhae, Republic of Korea © Springer International Publishing Switzerland 2016 K.M.J. Menon, A.C. Goldstrohm (eds.), Post-transcriptional Mechanisms in Endocrine Regulation, DOI 10.1007/978-3-319-25124-0_7
129
130
M. Conti et al.
2010), regulation of translation, in the absence of transcription, is the only form of gene expression that drives oocyte maturation and early embryo development up to the activation of the zygote genome (ZGA) (Clarke 2012). Similarly, translational regulations control critical spermatogenesis steps at the time of transition from mitosis to meiosis, during meiosis itself, as well as during the differentiation of the haploid gamete into a spermatozoon. The teleological explanation for the extensive use of translational regulations on a background of reduced or absent transcription is matter of debate. It may include the need to rapidly reprogram the genome to totipotency in a short period of time, hence the need to transfer regulation of gene expression to th
Data Loading...
