الفهرس 
ACKNOWLEDGMENT
REPRODUCTIVE PHYSILOGY OF SHE-CAMELSOnly 14 pages are availabe for public view
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Abstract
Camel fertility facing many problems which could be solved by assisted reproductive technologies (ART). Oocyte cryopreservation as recent ART can be used not only to overcome infertility disorders but also to maintain the genetic pool of superior female camels.
Six experiments were conducted to test and establish a standard method for cryopreservation of camel oocytes by vitrification. Vitrification is an alternative method of cryopreservation which overcomes several drawbacks of slow freezing.Its requires high concentrations of cryoprotectants which may cause osmotic and cytotoxic effect to cells.To reduce these problems, several methods were applied through investigating the effect of different equilibration times, different cryoprotectant concentrations and combinations, effect of different cryodevices on preservation of immature camel oocytes and effect of supplementation of different substances with vitrification solution on maturation rate of vitrified immature oocytes.
Generally ovaries were collected directly after slaughtering from local abattoir. Then ovaries transported to laboratory in thermo flask contain normal physiological saline. Oocytes aspirated from follicles (2 – 8 mm) in diameter. Oocytes were washed three times in TCM-199 then examined under stereomicroscope for selection. Morphologically normal oocytes with an evenly granulated cytoplasm and a compact cumulus cell layer were selected. Morphologically normal oocytes equilibrated in equilibration solution (ES) (which is half concentration of vitrification one). After a period of equilibration, oocytes transported to vitrification solution. Oocytes of all experiments were maintained in the vitrification solution (VS) (different concentration and combinations of cryoprotectants were used) for few seconds. During this time (few seconds), oocytes were loaded into different cryodevices (straw, OPS or SSV). Then cryodevices plunged into liquid nitrogen (LN2). After a period of storage, oocytes warmed and subjected to assessment of quality using different methods (assessment of morphology, recovery rate, staining of viability and maturation rate).
Experiment (1) was focused on the effect of different equilibration times (30 sec, 1 min, 2 min and 4 min) on normal morphological vitrified camel oocyte. Equilibration for 4 min, exhibited significantly higher % of morphologically normal oocytes with EG 10 %, DMSO 10 % and EG 10 % + DMSO 10 % (84.86 %, 68.60 %and 87.55, %, respectively) than that of 1 min (65.55 %, 35.11 % and 72.85 %, respectively and 30 sec (49.97 %, 16.38 % and 70.10 %, respectively).
Experiment (2) was designed to explore the effect of different cryoprotectant concentrations and combinations on viability and maturation rates of vitrified-warmed immature camel oocytes using (EG 40 %, DMSO 40 % and EG 40 % + DMSO 40 %). This experiment demonstrated that (EG 40 % + DMSO 40%) resulted in the best quality vitrified-warmed oocytes which demonstrated by higher percent (90.16 %) survival rate and (58.95 %) maturation rate. While DMSO 40 % resulted in (62.79% and 29.54%, respectively), EG 40 % reported (86.11% and 53.47 %, respectively).
Experiment (3) was dedicated to explain the effect of different cryodevices. In this experiment SSV and OPS techniques reported higher survival (86.26 % and 76.52 %) and maturation rates (64.02 % and 66.11 %) respectively than 0.25 ml straw techniques.
Experiment (4) was targeted to study the effect of different concentrations of EGF on maturation rate. This experiment recorded that using 20ng/ml of EGF with EG 40 % + DMSO 40 % and EG 40 % resulted in significantly higher maturation rates (68.76 % and 63.07 %, respectively) than using 20ng/ml of EGFwith DMSO 40 % (45.36 %).
Experiment (5)was planned to investigate the effect of different concentrations of lecithin on maturation rate. This experiment showed that 0.05 mg/ml lecithin with EG 40 % + DMSO 40 % and EG 40 % resulted in significantly higher maturation rates (72.46 % and 58.89 %, respectively) than0.05mg/ml lecithin DMSO 40 % (46.67 %).
Experiment (6) was aimed to study the effect of different incubation times on maturation of freshimmature camel oocytes. This experiment recorded that 36 h and 42 h resulted in higher maturation rate (79 % and 80.25 %, respectively in comparison with other maturation times (18 h, 24 h, 32 h and 48 h) (9.56 %, 21.47 %, 44.29 % and 32.22 %, respectively).