الفهرس 
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Abstract
In Vitro Fertilization Offers Great Promise To Multiply Elite Genetics . As With Other Advanced Reproductive Technologies Understanding The Status Of This Exciting Technology Will Help Breeders Better Apply IVF In Their Breeding Programs Today And In The Future . Embryogenesis The Period from Fertilization To Implantation Involves Various Morphological Cellular And Biochemical Changes Related To Genomic Activity . In Particular the 5 to 6 Day Post Fertilization Period Of In Vitro Production Of Embryos is The Time When Various Developmentally Important Events Occur Including The First Cleavage Division Which is Critical in Determining The Subsequent Development Of The Embryo Activation Of The Embryonic Genome Or The Maternal To Zygotic Transition Compaction Of The Morula Which Involves The Establishment Of The First Cell To Cell Contacts With in The embryo .
The study intended for determining the relationship between the embryonic development and the gene expression of the bovine embryos obtained from IVP with the; zygote development stage, oocytes morphological quality, culture conditions system, cryopreservation and vitrification.
a- Experiment 1: Relationship between the zygote Development Stage and Gene Expression Levels of IVP Bovine Embryos.
The results exhibited the followings:
1- The RQ level of Oct-4 gene transcripts was higher significant (P < 0.05) in the development stage which was > 4 cell as compared to the other development stages (2 – 4 cell, Morula and blastocyst, respectively).
2- Transcript RQ for Nanog gene transcripts were detected at significantly higher levels (P < 0.05) in 2 – 4 cells as compared to > 4 cell, Morula and blastocyst stages respectively.
3- The RQ levels of Connexin-43 gene transcripts were insignificant (P < 0.05) across the different development stages of bovine embryos obtained from IVP.
4- The RQ levels of GLUT-1 gene transcripts was significantly (P < 0.05) higher in the blastocyst as compared to the 2 – 4 cell or > 4 cell stages respectively.
5- There were no significant differences on GLUT-1 levels between the blastocyst and Morula stage or between the Morula stage from side and 2 – 4 cell stage and > 4 cell stage from the other side.
b- Experiment 2: Relationship between the Oocytes Morphological Quality with the Embryonic Development and the Gene Expression of the Bovine Embryos Produced In Vitro.
The consequences exhibited the followings:
1- The percentage of the cleavage ratio was higher significant (P < 0.05) in grade 1 and 2 oocytes as compared to grade 3 and 4 oocytes (75.0 %, 72.7 %, 36.9 % and 33.3 % for grade 1, 2, 3 and 4 oocytes respectively).
2- Likewise, the percentage of blastocyst rate was higher significant in grade 1 and 2 oocytes as compared to grade 3 and 4 oocytes (38.7 %, 38.0 %, 14.7 %, 7.7 % for grade 1, 2, 3 and 4 oocytes respectively).
3- The total cell number (mean ± SEM) in blastocyst which obtained from the grade 1 oocytes was highest significant (P < 0.05) as compared to those obtained from grade 2 and 3 oocytes (211 ± 4.74, 156.9 ± 5.23 and 134 ± 4.23 for grade 1, 2 and 3 oocytes respectively).
4- Also, the total cell number of blastocyst obtained from grade 2 oocytes was more significant (156.9 ± 5.23) as compared to that obtained from grade 3 oocytes (134 ± 4.23).
5- The RQ level of Oct-4 gene transcripts was higher significant (P < 0.05) in the in the blastocyst which obtained from the grade (1) oocytes as compared to that which obtained from the oocytes of other grades.
6- Also, the RQ of Oct-4 in blastocyst which obtained from the grade 2 oocytes was more significant (P < 0.05) as compared to that which obtained from grade 4 oocytes.
7- The RQ level of Nanog gene transcripts was higher significant (P < 0.05) in the blastocyst which obtained from the grade 1 and 2 oocytes as compared to those obtained from grade 3 and 4 oocytes.
8- There were no significant differences on Nanog levels between the blastocyst which obtained from the grade 1 and 2 oocytes or between the blastocyst which obtained from the grade 3 and 4 oocytes.
9- The RQ levels of connexin-43 across the different oocytes grades were insignificant (P < 0.05).
10- The RQ levels for GLUT-1 gene transcripts were significantly higher (P < 0.05) in the blastocyst which obtained from the grade 1 and 4 oocytes as compared to the blastocyst which obtained from the grade 2 and 3 oocytes.
11- Even so, the Glut-1 level in the blastocyst which obtained from the grade 4 oocytes was significantly lower (P < 0.05) as compared to that which obtained from the grade (1) oocytes.
c- Experiment 3: Effect of Culture Conditions System on the Embryonic Development and Gene Expression Profiles of IVP Bovine Embryos.
The results exhibited the followings:
1- There were no significant differences (P < 0.05) were observed for the cleavage ratio between the different culture systems (73.5 %, 67.5 %, 72.7 %, 70.3 %, 69.4 %, 70.2 %, 66.7 % and 65.3 % for 1, 3, 5 or 20 oocytes per 3 or 5 μl of culture medium, respectively).
2- Also, the percentage of blastocyst rate between the different culture systems were insignificant (38.8 %, 34.2 %, 43.3 %, 36.0 %, 33.7 %, 36.0 %, 33.3 % and 36.0 % for 1, 3, 5 or 20 oocytes per 3 or 5 μl of culture medium respectively).
3- The total cell number (mean ± SEM) of blastomere per blastocyst were insignificant (103±10.5, 92.7±12.4, 99.9±9.1, 111.8±7.8, 95.7±8.8, 120±9.8, 98.1±12.4 and 104.6±7.6 for 1, 3, 5 or 20 oocytes per 3 or 5 μl of culture medium respectively).
4- There were no significant differences (P < 0.05) were shown between the different culture systems with respect to Oct-4 expression levels.
5- The average RQ levels of Nanog gene transcripts in different culture groups of IVP bovine embryos were insignificant (P < 0.05).
6- The RQ levels of connexin-43 across the different culture systems were insignificant (P < 0.05).
7- The RQ of GLUT-1 gene expression profile in different culture groups of IVP bovine embryos was non significant (P < 0.05).
d- Experiment 4: Relationship between the Cryopreservation or the Vitrification with the Embryonic Development and Gene Expression Levels of IVP Bovine Embryos.
The results exhibited the followings:
1- The percentage of the cleavage ratio was (74.0 %) and the embryonic development rate was (37.4 %).
2- The embryonic reexpansion was significantly higher (P < 0.05) in the vitrification treatment as compared to cryopreservation treatment (92.9 % and 36.4 % for the vitrification and cryopreservation treatments respectively).
3- There were no significant differences (P < 0.05) were shown between the different freezing treatments with respect to Oct-4 expression levels.
4- The differences of RQ levels for Nanog gene transcripts between the vitrification and cryopreservation groups were insignificant (P < 0.05).
5- The RQ levels of connexin-43 across the different freezing treatments were insignificant (P < 0.05).
6- The RQ of GLUT-1 gene expression profile in different freezing treatments of IVP bovine embryos was non significant (P < 0.05).