ABSTRACT
Background: Sericin, because of its ability to remove free radicals and its antioxidant properties, has been used to successfully cryopreserve various mammalian cell types. However, the effects of sericin on cryopreservation of mouse sperm has not been reported
Objective: The current study intended to determine the protective role of different concentrations of sericin [0, 0.25, 0.5, and 0.75%] on mouse spermatozoa during cryopreservation, in addition to its effect on in vitro fertilization and subsequent embryo development
Materials and Methods: Mouse sperm from epididymides were frozen in cryoprotective agent with 18% raffinose, 3% skim milk, and different concentrations of sericin [0, 0.25, 0.5, 0.75%]. Thawed sperm were used for in vitro fertilization. The obtained embryos were cultured in Ksom medium for 6 days. The post-thawed motility, viability, fertilizing ability, and subsequent development to the 2-cell embryo and blastocyst stages were evaluated
Results: Our findings show that frozen-thawed sperm cells with 5% sericin indicate significantly [p
Conclusion: Supplementation by 0.5% sericin in cryoprotective agent improved frozen-thawed mouse epididymal sperm cell quality and resulted in increased embryo development
ABSTRACT
Background: This study aimed to investigate the maturation and fertilization rates of immature mouse oocytes using Embryonic Stem Cell Conditioned Medium [ESCM]
Methods: Germinal Vesicle [GV] stage oocytes were observed in 120 NMRI mice, aged 4-6 weeks. GV oocytes with or without cumulus cells were subjected to IVM in either ESCM, Embryonic Stem Cell Growth Medium [ESGM], or alpha-minimum essential medium [alpha-MEM]. After recording the Metaphase II [MII] oocyte maturation rate, the oocytes were fertilized in vitro. The fertilization success rate was recorded after 24 hr. The embryos were maintained in potassium Simplex Optimization Medium [KSOM] for 96 hr and allowed to grow until the blastocyst stage. After recording developmental competence, they were transferred into the uteri of pseudopregnant mice and their birth rates were recorded
Results: No significant difference existed between the maturation rates in alpha-MEM [68.18%] and ESCM [64.67%; p>0.05], whereas this rate was significantly higher for both alpha-MEM and ESCM compared to ESGM [32.22%; p<0.05]. A significant difference in IVF success rate existed for oocytes grown in alpha-MEM [69.44%], ESCM [61.53%], and ESGM [0%]. A significantly higher developmental competence was observed at the blastocyst stage for oocytes grown in alpha-MEM [51.2%] compared to ESCM [35%; p<0.05]. 17 days after embryo transfer into the uteri of pseudopregnant mice, there was a nonsignficant [p>0.05], similar birth rate between alpha-MEM and ESCM [47 vs. 40%]
Conclusion: ESCM is an effective medium for preantral follicle growth, oocyte maturation, and subsequent embryo development
ABSTRACT
Relapsing fever caused by Borrelia persica is an acute tick-borne disease which is transmitted by soft ticks of Ornithodoros tholozani to human. The disease is reported from Middle East and many regions of Iran. Detection of infection is problematic since the suspected infected ticks should be fed on animal hosts such as guinea pigs and subsequently after 7-14 days, the animal blood should be microscopically investigated for Borellia spirochetes on a Giemsa stainined thick smear. This classic method named xenodiagnosis is hard, time consuming, and less reliable. In this study, the application of PCR technique has been examined for detection of Borellia persica in soft ticks of O. tholozani. Tick specimens were collected from northwestern Iran and were fed on Borellia persica infected guinea pigs. DNA of the animal blood were extracted and used as target for PCR amplification of 16rDNA gene. Subsequently the products were subjected to sequencing. The effect of tick sex and post digestion as well as the minimum nyjcrilper of spirochetes on the efficiency of PCR were also tested. The xenodiagnosis assay was able to detect infection in only 13.3% of the tick-bitten animal bloods whereas all of these blood specimens were PCR positive against the 16rDNA gene. There was no difference in results of PCR for male and female of the ticks. Post digestion of infected blood meal in ticks did not affect the efficacy of PCR and the recently-fed samples showed similar results to those of completely gravid ones. A test on the threshold sensitivity of PCR assay indicated that only one spirochete is enough for the primers to anneal and to amplify the target gene. This study describes the first molecular assay for diagnosis of B. persica infected ticks in Iran and due to its high speed, accuracy, and applicability is a substitution method for diagnostic purposes inTBRF foci