Effect of different levels of nanoparticles of lecithin- based extender on freezability and fertility of goat spermatozo

Publish Year: 1396
نوع سند: مقاله کنفرانسی
زبان: English
View: 460

نسخه کامل این Paper ارائه نشده است و در دسترس نمی باشد

  • Certificate
  • من نویسنده این مقاله هستم

این Paper در بخشهای موضوعی زیر دسته بندی شده است:

استخراج به نرم افزارهای پژوهشی:

لینک ثابت به این Paper:

شناسه ملی سند علمی:

ISERB03_392

تاریخ نمایه سازی: 11 خرداد 1397

Abstract:

Background: Cryopreservation is a method that is widely used in assisted reproductive techniques (Said, Gaglani et al. 2010). Frozen bull sperm is widely a critical tool in the livestock industry, particularly regarding dissemination of genetic material and genetic resource bank is used to keep the valuable lines (Bucak, Tuncer et al. 2010). Sperm cryopreservation including freezing and thawing processes, which reduces sperm viability and changes in membrane structure, properties and causes the death of sperm (Watson 2000). Egg yolk and skim milk of animal origin are the most common additives used for freezing of sperm (Andersen, Aamdal et al. 1973). Recent studies showed concerns about these two cryoprotectants mainly due to their varied and diverse composition that makes their quality certification difficult (Moussa, Martinet et al. 2002, Gil, Rodriguez-Irazoqui et al. 2003, Amirat, Tainturier et al. 2004). However, the effective component of egg yolk protein is low-density lipoprotein, which protects sperm against cold shock (Salmani, Towhidi et al. 2014). Furthermore, an extender should contain an source of energy and lipoprotein or high-molecular weight substance to avoid cold shock (such as egg yolk, milk, or soybean lecithin), ionic or nonionic substances to maintain a suitable pH and osmotic pressure, and other additives (Aires, Hinsch et al. 2003).Methods: For this study, six ejaculates from each goat were collected by artificial vagina twice a week during the breeding season from four mature Mahabadi bucks (3 and 4 yr of age) known to have good fertility. Volume varying between 0.75 and 2 mL, sperm concentration of 3 × 109 sperm/mL, motile sperm percentage higher than 70%, and less than 10% abnormal sperm were the criteria. To eliminate individual differences, semen samples from the four bucks were pooled. Each pooled sample was split into five equal aliquots and diluted with five extenders. The basic extender used in this study composed of 30.7 g tris (Merck, Darmstadt, Germany), 12.6 g fructose (Merck) and 16.4 g citric acid (Merck). The osmolarity and pH were set at 420 mOsm and 7.2, respectively. Five different extenders were prepared by the addition of 1%, 2%, 3% and 4% soybean lecithin and extender containing 15% egg yolk as control treatment. Concentration of glycerol and the procedure for freezing was based on previous study (Salmani, Towhidi et al. 2014). For the production of lecithin nanoparticles, four different levels of soybean lecithin were prepared using sonicated. The diluted semen samples were maintained at room temperature (∼25 ◦C) for 5 min and then equilibrated at 4 ◦C for 2.5 h. The cooled semen was loaded into 0.25-mL. French straws were at concentration of 1×109 sperm/ mL, according to the method described (Matsuoka, Imai et al. 2006), then sealed with polyvinyl alcohol powder. The straws were exposed to liquid nitrogen vapor, 4 cm above the liquid nitrogen for 12 min (Purdy 2006). Subsequently, the straws were plunged into the liquid nitrogen for storage. After storage for 2 months, the frozen straws were thawed individually at 37 ˚C for 30 s in a water bath for microscopic evaluation.Result: The results of this study showed that addition of 2% nanoparticles of soy lecithin increased (P Conclusion: Our experiment showed that, optimum level of nanoparticle of soybean lecithin for cryopreservation of goat sperm was 2%. Salmani et al. reported that the 1.5% of soy lecithin in diluent for freezing goat semen is the most appropriate level (Salmani, Towhidi et al. 2014). The main reason for the decline of sperm motility after freeze-thaw is biochemical and ultrastructural damage during the freezing process that can occur at different times (Aires, Hinsch et al. 2003). Freeze-thaw process results in changes in sperm morphology, which cause damage in cell membranes, mitochondria and sperm acrosome. Only a little percentage of sperms has the integrated membrane and normal activity of mitochondria is followed by freeze-thaw which results in less active sperm count after freezing-thawing (Huopalahti, Anton et al. 2007). Sperm membranes release phospholipids into the surrounding medium during cold shock (Darin-Bennett, Poulos et al. 1973). Presumably phospholipids are implicated by interaction with the spermatozoa membranes and replacing some lipids, thus decreasing their phase lk extenders contain about 20 ml of egg yolk and contain 6–7% w/v of LDL (Huopalahti, Anton et al., 2007). studies demonstrate that defined media containing specified lipids can protect bull sperm during cooling and during freezing (Graham and Foote, 1987). Furthermore, the required phospholipids in the extender in the goat would be similar to the ram which has been reported 1% soybean lecithin by Sharafi et al. (Sharafi, Forouzanfar et al., 2009).

Authors

Touba Nadri

PhD student of Animal physiology university of Tehran

Armin Towhidi

Supervisor