Λουτράδης Δημήτριος, Καθηγητής, Ιατρική, ΕΚΠΑ
Δρακάκης Πέτρος, Αναπλ. Καθηγητής, Ιατρική, ΕΚΠΑ
Ντόμαλη Αικατερίνη, Επίκουρος Καθηγήτρια, Ιατρική, ΕΚΠΑ
In mammals, the formation of the zygote results from the fusion of the female and male gametes in the ampulla of the fallopian tube. The fertilized egg is transferred from the fallopian tube to the uterus where it is implanted. On this path, the pre-embryo undergoes many structural changes. Initially, the fertilized egg is divided into 2, 4 and 8 cells, then it is condensed by forming morula and finally, by creating a cavity, forming the blastocyst. In mice, the maternal developmental control stops at the 2-cell stage, the zygotic genome is activated, and the embryo undertakes the control of its own growth.
The Circadian clock is the 24-hour self-sustaining functional entity located in the brain, more specifically in the suprachiasmatic nucleus (SCN) of the brain and is coordinated with the surrounding in order to permit organisms to respond appropriately to stimuli. It has been found that a series of genes, known as clock genes, function as the "machine" of the circadian rhythm and they are responsible for the regulation of the circadian mechanism on the molecular level. The regulation is performed through positive and negative feedback on the transcriptional and translational level. The most well-known nuclear clock genes are: clock, per1, per2, per3, cry1, cry2, Bmal / Mop3, Bmal2 / Mop9, Npas2 / Mop4, Tim, CKIe, Rev-Erba. The positive feedback of the regulation is implemented through two transcription factors, Clock and Bmal1.
The purpose of this thesis is to investigate the expression of the Clock and Bmal genes in mouse pre-embryos, from the 2-cell stage to the blastocyst stage, in order to be established an embryonic transcriptional profile and to be identified the potential molecular and cellular mechanisms involved with a normal embryonic development.
During this experimental study, the mouse embryos were cultured in vitro under conditions and protocols which imitated the physiological environment of the uterus. To evaluate the expression of these two circadian genes, after the isolation of mRNA from each developmental stage and cDNA preparation, the method of Real-Time Polymerase Chain Reaction (RT-PCR) was used in order to determine the expression of these under-studied genes.
Maternal developmental control, Zygotic genome activation, Circadian clock, Circadian rhythm, Circadian genes, Suprachiasmatic nucleus, Clock gene, Bmal gene