Portal de Periódicos da CAPES

Mammalian RNA Binding Proteins ECAT1 and HOEP19 Reveal Oocyte Prepatterning Locus.

2008; Oxford University Press; Volume: 78; Issue: Suppl_1 Linguagem: Inglês

10.1093/biolreprod/78.s1.163b

1529-7268

Monika Sachdev, Arabinda Mandal, Olga Chertihin, Laura Digilio, Theodore Thomas, Henry F. Frierson, Charles J. Flickinger, John C. Herr,

Reproductive Biology and Fertility

One of the hallmarks of prepatterning in oocytes of animals with external development is the localization of RNAs and RNA binding proteins to selective domains of ooplasm which apportion asymmetrically following cleavage and segregate to different blastomeres. Whether prepatterning occurs in mammalian oocytes has remained controversial. In the present study ECAT1, a KH domain containing RNA binding protein, was observed first in mouse mammalian oocyte cytoplasm in primary follicles and subsequently concentrated in the cortex of ovulated oocytes and to a restricted cortical cytoplasmic crescent in blastomeres of 2, 4 and 8 cell embryos. In morula, ECAT1 was concentrated at the apex of outer, polarized blastomeres and was undetectable in blastomeres of the inner cell mass. The ECAT1 pattern of morphogenetic distribution in early embryogenesis was similar to another KH domain containing RNA binding protein MOEP19 (Mouse Oocyte and Early Embryo Protein 19). HOEP19, the human orthologue of MOEP19, localized to a symmetrical cortical domain in human oocytes. ECAT1 and HOEP19 were found immediately adjacent on opposite strands of human chromosome 6 at q13. The similar staging of expression during oogenesis and co-distribution of ECAT1 and MOEP19/HOEP19 in the oocyte and pre-implantation embryo supports an oocyte pre-patterning locus at 6q13 in humans [and 9E1, 9D in mice] and a molecular mosaicism model of oocyte prepatterning involving a cortical domain in the oocyte that remains polarized in zygote and early blastomeres. This research was supported by the Kenneth A Scott Trust, a Keybank Trust, NIH R03 HD055129 and D43 TW/HD 00654 from the Fogarty International Center.