Effect of Angiotensin on the quality of In Vitro Produced [IVP] sheep embryos and expression of Na[+] /K[+] /ATPase

Background: The presence of rennin-angiotensin components in mammalian ovaries and their involvement in ovarian physiology have been established. In the present study, effects of angiotensin II [Ang II] on sodium-potassium adenosine triphosphatase [Na[+] /K[+] /ATPase] expression and development of sheep embryos was evaluated

Methods: The abattoir-derived Cumulus Oocyte Complexes [COC] were randomly allocated into three experimental groups; group I] in vitro Maturation [IVM] of oocytes in the presence of Ang II followed by in vitro fertilization [IVF]/in vitro Culture [IVC] [IVM group], group II] IVM/IVF of oocytes followed by IVC wherein the embryos were exposed to Ang II on day 4 of IVC [D4 group], and group III] IVM/IVF and IVC of oocytes without any angiotensin [Control]. The blastocyst and hatching rates were recorded on days 6 to 8. Day 8 embryos were immunostained with primary and secondary antibodies against Na[+] /K[+] /ATPase alpha 1 and beta 1 subunits

Results: Addition of Ang II during IVM and IVC significantly increased the hatching rate of blastocysts on day 8 compared to the control. The trophectoderm and total blastocyst cells' numbers were significantly increased by addition of Ang II to the IVM and IVC media, though the expression of Na[+] /K[+] /ATPase alpha 1 and beta 1 subunits were positively influenced by the addition of Ang II on day 4 [D4 group]

Conclusion: In conclusion, it seems Ang II through positive effects on embryos, expressed as the greater hatching rate and blastocyst cell number, could increase the sheep embryo developmental rate. These improvements might be partly related to the greater expression of Na[+] /K[+] /ATPase alpha 1 and beta 1 subunits when Ang II was added during IVC

Comparison of different electroporation parameters on transfection efficiency of sheep testicular cells

Objective: electroporation can be a highly efficient method for introducing the foreign genetic materials into the targeted cells for transient and/or permanent genetic modification. Considering the application of this technique as a very efficient method for drug, oligonucleotide, antibody and plasmid delivery for clinical applications and production of transgenic animals, the present study aimed to optimize the transfection efficiency of sheep testicular cells including spermatogonial stem cells [SSCs] via electroporation

Materials and Methods: this study is an experimental research conducted in Biotechnology Research Center [Avicenna Research Institute, Tehran, Iran] from September 2013 to March 2014. Following isolation and propagation of one-month lamb testicular cells [SSCs and somatic testicular cells including; Sertoli, Leydig, and myoid cells], the effect of different electroporation parameters including total voltages [280, 320, and 350 V], burst durations [10, 8, and 5 milliseconds], burst modes [single or double] and addition of dimethyl sulfoxide [DMSO] were evaluated on transfection efficiency, viability rate and mean fluorescent intensity [MFI] of sheep testicular cells

Results: the most transfection efficiency was obtained in 320 V/8 milliseconds/single burst group in transduction medium with and without DMSO. There was a significantly inverse correlation between transfection efficiency with application of both following parameters: addition of DMSO and double burst. After transfection, the highest and lowest viability rates of testicular cells were demonstrated in 320 V/8 milliseconds with transduction medium without DMSO and 350 V/5 milliseconds in medium containing DMSO. Addition of DMSO to transduction medium in all groups significantly decreased the viability rate. The comparison of gene expression indicated that Sertoli and SSCs had the most fluorescence intensity in 320 V/double burst/DMSO positive. However, myoid and Leydig cells showed the maximum expression in 320 V/single burst and/or 350 V/double burst/DMSO positive

Conclusion: we optimized the electroporation method for transfection of sheep testicular cells and recommended the application of 320 V/8 milliseconds/single pulse/DMSO negative for transduction of plasmid vector into these cells. Among testicular cells, the most external gene expression was demonstrated in SSC population

effect of media supplementation with angiotensin on developmental competence of ovine embryos derived from vitrified-warmed oocytes

Background: This study was aimed to assess the effects of angiotensin II [Ang II] supplementationto the In Vitro Maturation [IVM] and In Vitro Culture [IVC] media ofvitrified-warmed ovine oocytes on their developmental competence and expression ofNa +/K +/ATPase in resulting embryos

Methods: The slaughterhouse-derived immature oocytes [n=1069] were randomly distributedinto four experimental groups: groups I and II] IVM/IVF and IVC of fresh andvitrified oocytes without angiotensin supplementation [Control-Fresh and Control-Vitgroups, respectively]; group III] IVM of vitrified oocytes in the presence of Ang II followedby IVF/IVC [Vit-IVM group]; and group IV] IVM/IVF of vitrified oocytes followedby IVC wherein the embryos were exposed to Ang II on day 4 of IVC [Vit-D4 group].The embryos were immunostained with primary antibodies against Na +/K +/ATPasealpha 1andbeta 1 subunits

Results: In Vit-IVM and Vit-D4 groups, the rates of expanded and total blastocysts onday 7 as well as the proportion of blastocysts on day 8 were increased. The expressionof Na +/K +/ATPasealpha 1 andbeta 1 subunits were positively influenced by the addition of AngII on day 4 [Vit-D4 group].Conclusion: The addition of Ang II to the IVM and IVC media could improve blastocystsformation in vitrified sheep oocytes. This improvement might be related to thegreater expression of Na +/K +/ATPasealpha 1 andbeta 1 subunits when Ang II was added duringIVC

Design of Electrospun Poly vinyl alcohol/Chitosan Scaffoldand Its Cellular Study

Poly vinyl alcohol/Chitosan nanofibrous mat were prepared by electrospinning method with suitable pore sizes as potential matrices for soft tissue engineering. The designed scaffolds by electrospinning method evaluated by differentanalyses such morphological, mechanical, and cellular analysis.Microscopic results showed diameters of poly vinyl alcohol/Chitosan nanofibers were approximately 150 nm. Mechanical investigations illustratedstress - strain curve of poly vinyl alcohol /chitosan mat indicate good flexibility with average strain and good percentage of yield stress. The cellular resultsrevealthat addition of chitosan to poly vinyl alcohol enhances viability and proliferationof fibroblast cells, which increases the biocompatibility of the scaffold. In fact, addition of a smallpercentage of chitosan to the poly vinyl alcoholproved to be a promising approach for designof a scaffold

Enrichment of undifferentiated type a spermatogonia from goat testis using discontinuous percoll density gradient and differential plating

The well documented source for adult multipotent stem cells is Spermatogonial Stem Cells [SSCs]. They are the foundation of spermatogenesis in the testis throughout adult life by balancing self-renewal and differentiation. The aim of this study was to assess the effect of percoll density gradient and differential plating on enrichment of undifferentiated type A spermatogonia in dissociated cellular suspension of goat testes. Additionally, we evaluated the separated fractions of the gradients in percoll and samples in differential plating at different times for cell number, viability and purification rate of goat SSCs in culture. Testicular cells were successfully isolated from one month old goat testis using two-step enzymatic digestion and followed by two purification protocols, differential plating with different times of culture [3, 4, 5, and 6 hr] and discontinuous percoll density with different gradients [20, 28, 30, and 32%]. The difference of percentage of undifferentiated SSCs [PGP9.5 positive] in each method was compared using ANOVA and comparison between the highest percentage of corresponding value between two methods was carried out by t-test using Sigma Stat [ver. 3.5]. The highest PGP9.5 [94.6 +/- 0.4] and the lowest c-Kit positive [25.1 +/- 0.7] in Percoll method was significantly [p

Comparison of proliferative and multilineage differentiation potential of sheep mesenchymal stem cells derived from bone marrow, liver, and adipose tissue

Despite major progress in our general knowledge related to the application of adult stem cells, finding alternative sources for bone marrow Mesenchymal Stem Cells [MSCs] has remained to be challenged. In this study successful isolation, multilineage differentiation, and proliferation potentials of sheep MSCs derived from bone marrow, adipose tissue, and liver were widely investigated. The primary cell cultures were prepared form tissue samples obtained from sheep 30-35 day fetus. Passage-3 cells were plated either at varying cell densities or different serum concentrations for a week. The Population Doubling Time [PDT], growth curves, and Colony Forming Unit [CFU] of MSCs was determined. The stemness and trilineage differentiation potential of MSCs were analyzed by using molecullar and cytochemical staining approaches. The data was analyzed through one way ANOVA using SigmaStat [ver. 2]. The highest PDT and lowest CFU were observed in adipose tissue group compared with other groups [p<0.001]. Comparing different serum concentrations [5, 10, 15, and 20%], irrespective of cell sources, the highest proliferation rate was achieved in the presence of 20% serum [p<0.001]. Additionally, there was an inverse relation between cell seeding density at culture initiation and proliferation rate, except for L-MSC at 300 cell seeding density. All three sources of fetal sheep MSCs had the identical trilineage differentiation potential. The proliferative capacity of liver and bone marrow derived MSCs were similar at different cell seeding densities except for the higher fold increase in B-MSCs at 2700 cells/cm2 density. Moreover, the adipose tissue derived MSCs had the lowest proliferative indices

effect of macromolecule source and type of media during in vitro maturation of sheep oocytes on subsequent embryo development

Oocyte maturation and subsequent in vitro production [IVP] of embryos are affected by diverse groups of chemicals in maturation medium which are needed for successful mammalian oocyte maturation during which the dramatic cytoplasmic and nuclear reprogramming events take place. This study was designed to evaluate the effects of protein source [fetal bovine serum, FBS, and bovine serum albumin, BSA] as well as two different maturation media during in vitro maturation of ovine oocytes on subsequent embryo development. Cumulus oocyte complexes were recovered from ovaries obtained from slaughter house and cultured for 24 hr in either TCM-199 or SOFaa maturation medium supplemented with 10% [v/v] FBS or 0.8% [w/v] BSA. Data were analyzed by one-way ANOVA using Sigma Stat [Ver. 2]. A p-value smaller than 0.05 was considered statistically significant. The proportions of cleavage and total blastocyst [evaluated on days 3 and 6, respectively] were significantly higher in FBS than BSA supplemented groups, though no differences were observed between the two used different maturation media. The cryotolerance of blastocysts was negatively influenced by the presence of FBS rather than BSA during IVM. The quality of produced embryos, however, was affected neither by the source of macromolecules nor the maturation medium in terms of hatching rate, total blastocyst cells and inner cell mass/total cell ratio. The rate of oocyte development was improved by the presence of FBS, though the cryosurvival of resulting blastocysts was negatively influenced by the presence of the serum during in vitro production of sheep oocytes

[Cloning and interfering factors]

The term "Cloning" has originated from "Klon", a Greek word with the meaning of a small twig that can multiply by itself and turn to a generative tree. Cloning is an asexual reproduction in which a copy or multiple copies of an organism are generated by transferring the nucleus [DNA] of a somatic cell into an enucleated metaphase-II oocyte. Despite the benefits and potentially broad applications of this technology, its low efficiency, especially in the production of viable offspring, has implicated its application with serious challenges. In this article, we will review papers related to its emerging principles, with an emphasis on epigenetic modifications, which appear to govern the efficiency of cloning. The literature review was carried out by searching through knowledge-based data bases such as ScienceDirect, PubMed and Scopus on the internet. No time limit was considered for literature review of the relevant articles up to the time of submission. Considering the large varieties of factors affecting cloning, improvements in cloning efficiency are dependent on the increment of theoretical knowledge and technical expertise of its procedures. This can be achieved by improving oocyte and cytoplasmic maturation, optimizing synchronization between the nucleus of the donor cell and cytoplasm of MII stage oocyte, minimizing the physical insults to the cytoskeleton of oocyte during enucleation and nuclear transfer, improving the cellular fusion and culture conditions of reconstructed oocytes and in particular and more importantly by employing effective methods to qualitatively alter the epigenetic status of the incoming nucleus to an embryonic or totipotent state, leading to the improvement of donor cell reprogramming. Considering the importance of inherited maternal transcripts and proteins in cytoplasm of fully matured oocytes in supporting the embryos up to the embryonic genomic activation [EGA] and the capability of MII stage cytoplasm in dedifferentiating mammalian somatic cells and coincident of EGA with depletion of maternally originated transcripts, reprogramming of the somatic cell nuclei must be completed by the time that the embryonic genome is activated. Since the patterns of epigenetic modification are dynamic and not static during development, the optimum procedure to properly induce nuclear reprogramming should follow the pattern of epigenetic modifications in normal embryo development. Besides the all progresses in reproductive cloning using highly efficient methods, any deviation from the normal pattern of mRNA expression due to epigenetic changes induced by chemical interventions in early preimplantation embryo may persist throughout fetal development. The effects of these aberrations may manifest later in development. Nonetheless, understanding the kinetics of normal molecular events related to epigenetic modifications and identification of the specific factors present in the ooplasm, which are necessary for epigenetic reprogramming, will provide a better understanding of the underlying mechanisms and would improve cloning efficiency and other related technologies

effect of biopsy during precompacted morula stage on post vitrification development blastocyst derived bovine embryos

Improvements on embryo micromanipulation techniques led to the use of embryo biopsy in commercial embryo transfer programs for genetic analysis of preimplantation bovine embryos. The aim of this study was to evaluate the quality of bovine blastocyst derived from embryos biopsied at different precompacted morulae stages by assessment of cryosurvivability of the resulting blastocysts. The in vitro produced bovine embryos were subjected to biopsy at days 2,3, and 4 post-isemination with different cell numbers [4 to 16-cells]. Embryo cell biopsy was carried out in a 100 micro l drop of H-SOF following pronase drilling by aspiration of one blastomrere. The biopsied embryos were then cutured in SOFFaaBSA co-cultured with oviduct cells-monolayer until blastocyst formation. The blastocysts were cryopreserved at room temperature after exposure of equilibration [glycerol 1.4 M for 5 min and then glycerol 1.4 M and ethylene glycol 3.6 M for 5 min] and vitrification solutions [3.4 M glycerol and 4.6 M ethylene glycol]. The blastocysts were loaded into the center of 0.25 ml straws separated by air bubbles from 2 columns of sucrose 0.5 M and plunged immediately into liquid nitrogen. There was no significant difference in cryosurvivability of vitrified-warmed blastocysts derived from biopsied embryos at different pre-compacted morula stages. The quality of biopsy derived blastocysts was identical to that of non-biopsy derived ones in terms of post vitrification survival and hatching rates. In conclusion there was no preference between different times of embryo biopsy at precompacted morula stages in term of cryosurvivability of biopsy derived bovine blastocysts

Effects of timing on cell biopsy from pre-compacted morula stage bovine embryos on subsequent embryonic development

Embryo biopsy has potential applications in molecular research processes in domestic animals, besides its application in sex determination in embryo transfer programs. The objective of the present study was to assess the in vitro development of bovine embryos biopsied on different days of precompacted morula stage. Slaughterhouse-derived oocytes were matured in vitro, fertilized [Day-0] by frozen-thawed, Percol-separated spermatozoa and cultured on oviductal cell monolayer. The embryos were subjected to cell biopsy on Days 2, 3, and 4 postinsemination at 4-16-cell stages. The data were analyzed using ANOVA and Chi-squared tests [SigmaStat, version 2]. A p-value < 0.05 was considered significant. Biopsies carried out at 16-cell stage [Day-4] resulted in 94% of embryos developing to the blastocyst stage, which was significantly higher [p < 0.05] than the ones biopsied at 8-cell stage on Day-4 [64%], and those undergoing the procedure on Day-3 [49% and 46% at 4-cell and 8-cell stages, respectively] and Day-2 [39% and 33% at 4-cell and 8-cell stages, respectively]. No significant differences were observed between biopsied and non-biopsied embryos on a given day. The total cell number in biopsy-derived blastocysts ranged between 103 and 135. The difference in the number of total cells, dead cells and cell allocation to trophectoderm and inner cell mass between non-biopsied and biopsy-derived blastocysts was insignificant. Biopsy of bovine embryos at 4-16-cell stages had no adverse effects on in vitro developmental potentials and the 16-cell stage embryos, biopsied on Day-4 was the best stage for blastomere removal

effect of the duration of in vitro maturation [IVM] on parthenogenetic development of ovine Oocytes

The aim of this study was to compare the effect of time of parthenogenetic activation [22 hr versus 27 hr after In Vitro Maturation-IVM] on in vitro development of ovine oocytes using either single [lonomycin 5 microM for 5 minor Ethanol 7% for 7 m/n] or combined [ionomycin and ethanol with 6-DMAP 2 mM for 3 hr] activation treatments. The abattoir-derived in vitro matured activated oocytes were cultured in modified synthetic oviductal fluid and assessed for the cleavage, blastocyst, and hatching rates. The single-activated oocytes had a reduction in cleavage, blastocyst and hatching rates compared to the combined-activated oocytes [except for the cleavage at 27 hr]. In single-treated groups the rates of cleavage and blastocyst were increased as the maturation time was extended from 22 hrto 27 hr. The numbers of total cells and Inner Cell Mass [ICM], though insignificant, were greater in combined-treated groups compared to the single treatment. The number of ICM in Eth+6-DMAP group activated at 27 hr was lower than 22 hr. Nonetheless, irrespective of the activation protocol, development to the blastocyst stage, the numbers of total cell, ICM, and cell allocation [ICM/total cells] were significantly lower in parthenogenetic than fertilized embryos. In conclusion, though the cleavage and blastocyst rates in single-treated groups were positively influenced by the extension of duration of IVM [27 hr], there was a trend of decreased numbers of total cells and ICM in slightly aged oocytes. Moreover, developmental potential of ovine parthenotes, especially in young oocytes, was improved by the addition of 6-DMAP to the activation regimen