De novo reconstruction of a functional in vivo-like equine endometrium using collagen-based tissue engineering

To better understand molecular aspects of equine endometrial function, there is a need for advanced in vitro culture systems that more closely imitate the intricate 3-dimensional (3D) in vivo endometrial structure than current techniques. However, development of a 3D in vitro model of this complex tissue is challenging. This study aimed to develop an in vitro 3D endometrial tissue (3D-ET) with an epithelial cell phenotype optimized by treatment with a Rho-associated protein kinase (ROCK) inhibitor. Equine endometrial epithelial (eECs) and mesenchymal stromal (eMSCs) cells were isolated separately, and eECs cultured in various concentrations of Rock inhibitor (0, 5, 10 µmol) in epithelial medium (EC-medium) containing 10% knock-out serum replacement (KSR). The optimal concentration of Rock inhibitor for enhancing eEC proliferation and viability was 10 µM. However, 10 µM Rock inhibitor in the 10% KSR EC-medium was able to maintain mucin1 (Muc1) gene expression for only a short period. In contrast, fetal bovine serum (FBS) was able to maintain Muc1 gene expression for longer culture durations. An in vitro 3D-ET was successfully constructed using a collagen-based scaffold to support the eECs and eMSCs. The 3D-ET closely mimicked in vivo endometrium by displaying gland-like eEC-derived structures positive for the endometrial gland marker, Fork headbox A2 (FOXA2), and by mimicking the 3D morphology of the stromal compartment. In addition, the 3D-ET expressed the secretory protein MUC1 on its glandular epithelial surface and responded to LPS challenge by upregulating the expression of the interleukin-6 (IL6) and prostaglandin F synthase (PGFS) genes (P < 0.01), along with an increase in their secretory products, IL-6 (P < 0.01) and prostaglandin F2alpha (PGF2α) (P < 0.001) respectively. In the future, this culture system can be used to study both normal physiology and pathological processes of the equine endometrium.

Dietary Lasia spinosa Thw. improves reproductive performance of aged roosters

The application of artificial insemination is particularly, owing to which breeder animals are considered an important resource in breeding farms. However, the reproductive performance of roosters typically declines with age, and the economic loss experienced by breeders is attributable to this shortened reproductive lifespan. Lasia spinosa Thw. (LST) reportedly improved reproductive capacity in male rodents. The objective of this study was to investigate the effects of LST on the reproductive performance of aged roosters. Male Guangxi Partridge chicken (mean weight, 3032.41 ± 34.48 g; age, 500 days; n = 72) randomly received the following three dietary treatments: LST0 group (a basal diet), LST2 group (a basal diet with 2% LST powder), and LST4 group (a basal diet with 4% LST powder). Computer-aided sperm analysis revealed that dietary LST supplementation significantly improved semen volume, sperm motility, and concentration. Furthermore, the most potent effects were observed in the treatment group with the administration of 2% LST, which significantly improved the weight of the testes. Hematoxylin-eosin staining revealed the increase in diameter of the seminiferous tubule and height of the seminiferous tubule epithelium possibly caused as a result of LST treatment. A significant increase in fructose and glucose concentrations were observed in the testis and seminal plasma; in addition, a significant increase was observed in the α-glycosidase levels in the testis and spermatozoa. However, the monoaldehyde levels in the spermatozoa appeared to decline significantly. Additionally, the fertility rate increased significantly following 2% LST supplementation. RNA-seq analysis revealed that 34 and 16 unigenes were upregulated and downregulated, respectively, in testicular tissues from roosters that received dietary supplementation of 2% LST. The assigned functions of the unigenes revealed that LST primarily influenced the mechanisms underlying catalytic activity and cellular processes. Kyoto Encyclopedia of Genes and Genomes enrichment analysis suggested that spermatogenesis-related pathways were significantly enriched, including ABC transporters, ribosome biogenesis in eukaryotes, and VEGF, cAMP, and ErbB signaling pathways.

Expression of oxytocin receptors and oxytocin assisted electroejaculation in the domestic cat (Felis catus)

Oxytocin is a peptide hormone that mainly functions to control the contractility of smooth muscles and sex related steroidogenesis in male reproductive tracts. However, specific information concerning this hormone in controlling the reproductive organs of cats is limited. This study aimed to investigate the expression of oxytocin receptors (OTRs) and their signal mediator via prostacyclin synthase (PTGIS) in reproductive structures following oxytocin assisted electroejaculation. In Experiment 1, the testis, cauda epididymis and vas deferens from five cats were examined by immunohistochemistry and quantitative polymerase chain reaction in order to study the responses of OTR and PTGIS mRNA to oxytocin injection. Experiment 2 examined the effect of oxytocin administration prior to electroejaculation on ejaculate characteristics and sperm quality in terms of motility, viability and fertilising ability. Immunohistochemistry revealed the expression of OTRs in Leydig's, peritubular myoid cells and some spermatogenic cells. The expression was found in the epithelium and smooth muscle of the epididymis and vas deferens. After oxytocin administration, the OTR mRNA was upregulated in the epididymis (p > 0.05) and vas deferens (p = 0.01). The expression level of PTGIS mRNA increased in the response to oxytocin treatment only for the vas deferens (p > 0.05). Oxytocin treatment before electroejaculation resulted in an approximately two-fold increase in sperm concentration and total sperm output/ejaculate, while this intervention did not significantly affect ejaculate volume, sperm quality or fertilising ability. This study concluded that the oxytocin cascade is locally present in the reproductive structures and plays a role in promoting sperm delivery during electroejaculation in cats.

Dietary Lasia spinosa Thw. Improves Growth Performance in Broilers

This study aimed to evaluate the effects of dietary Lasia spinosa Thw. (LST) powder supplementation on growth performance, blood metabolites, antioxidant status, intestinal morphology, and cecal microbiome in broiler chickens. A total of 400 1-day-old male Guangxi partridge broilers (initial body weight: 42.52 ± 0.06 g) were randomly allotted to 4 dietary treatments: LST0 group (a basal diet), LST1 group (a basal diet with 1% LST powder), LST2 group (a basal diet with 2% LST powder), LST4 group (a basal diet with 4% LST powder), 10 replicates for each treatment, and 10 broilers in each treatment group. Results indicated that the average daily feed intake of broilers during 22-42 days and the average daily gain of chickens during 1-42 days significantly increased by dietary supplementation of LST powder (p < 0.01), while the feed conversion ratio during the overall periods was decreased by dietary supplementation of LST powder (p < 0.01). Except for the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in liver (p > 0.05), the levels of SOD, catalase (CAT) and GSH-Px in serum, liver, and breast muscle were significantly increased in the LST supplemented groups (p < 0.05), while the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in serum, liver, and breast muscle were significantly decreased in the LST supplemented groups (p < 0.05). Furthermore, the levels of triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased by the addition of dietary LST powder (p < 0.01), while the levels of HDL-C, Ca, Fe, Mg, and P were linearly increased by the addition of dietary LST powder (p < 0.01). With respect to the gut morphometric, crypt depth was significantly decreased by LST supplementation (p < 0.05), while villus height and the ratio of villus height to crypt depth were notably increased by LST supplementation (p < 0.05). Sequencing of 16S ribosomal RNA (16S rRNA) from the cecal contents of broilers revealed that the composition of the chicken gut microbiota was altered by LST supplementation. The α-diversity of microbiota in broilers was increased (p < 0.05) in the LST1 group, but was decreased (p < 0.05) in the LST2 and LST4 groups compared with the LST0 group. The differential genera enriched in the LST1 group, such as Bacillus, Odoribacter, Sutterella, Anaerofilum, Peptococcus, were closely related to the increased growth performance, antioxidant status, intestinal morphology, Ca, Mg, and reduced blood lipid in the treated broilers.

Membrane-permeable trehalose improves the freezing ability and developmental competence of in-vitro matured feline oocytes

Oocytes are highly sensitive to cryopreservation, which frequently results in an irreversible loss of developmental competence. We examined the effect of membrane-permeable trehalose on the freezing ability of feline oocytes matured in vitro. In Experiment 1, intracellular trehalose (trehalose hexaacetate; Tre-(OAc)₆) was synthesized from trehalose precursor and subjected to spectroscopic characterization. The membrane permeability of the Tre-(OAc)₆ was investigated by incubating oocytes with different concentrations of Tre-(OAc)₆ (3, 15, and 30 mM). Optimum concentration and the toxicity of Tre-(OAc)₆ were assessed in Experiment 2. The effects of Tre-(OAc)₆ on freezing ability in terms of apoptotic gene expression and developmental competence of in-vitro matured oocytes were examined in Experiments 3 and 4, respectively. The Tre-(OAc)₆ permeated into the ooplasm of cat oocytes in a dose- and time-dependent manner. The highest concentration of intracellular trehalose was detected when the oocytes were incubated for 24 h with 30 mM Tre-(OAc)₆. For the toxicity test, incubation of oocytes with 3 mM Tre-(OAc)₆ for 24 h did not affect maturation rate and embryo development. However, high doses of Tre-(OAc)₆ (15 and 30 mM) significantly reduced maturation and fertilization rates (p < 0.05). In addition, frozen-thawed oocytes treated with 3 mM Tre-(OAc)₆ significantly upregulated anti-apoptotic (BCL-2) gene expression compared with the control (0 mM) and other Tre-(OAc)₆ concentrations (15 and 30 mM). Oocyte maturation in the presence of 3 mM Tre-(OAc)₆ prior to cryopreservation significantly improved oocyte developmental competence in terms of cleavage and blastocyst rates when compared with the control group (p < 0.05). Our results lead us to infer that increasing the levels of intracellular trehalose by Tre-(OAc)₆ during oocyte maturation improves the freezing ability of feline oocytes, albeit at specific concentrations.

Aberrant levels of DNA methylation and H3K9 acetylation in the testicular cells of crossbred cattle-yak showing infertility

Although the interspecies hybridization of bovids, such as cattle-yak (Bos taurus × Bos grunniens), has heterosis benefits, the infertility of hybrid males affects the maintenance of dominant traits in subsequent generations. To achieve reproductive capacity, male germ cell development requires coordinated changes in gene expression, including DNA methylation and generalized histone modifications. Although gene expression-related mechanisms underlying hybrid male sterility have been investigated recently, information on the cell types and stage-specific controls remains limited. Here, we used immunohistochemistry and image analyses to evaluate the 5-methylcytosine (5MC) and acetyl-histone H3 Lys9 (AcK9) expression in all spermatogonia and testicular somatic cell types to determine their roles in cattle-yak spermatogenesis. Testicular tissues from yak (1-3 years old) and backcrossed hybrids (2 years old) were used. In yak, the AcK9 expression levels increased in all cell types during maturation, but the 5MC expression levels did not change until reaching 3 years when they increased in all testicular cell types, except spermatogonia. Cattle-yak hybrids showed higher 5MC expression levels and different AcK9 expression levels in all cell types compared to the same-aged yak. These results suggested that both gene modulation by AcK9 and constant levels of DNA methylation are required for spermatogenesis during maturation in yak. Therefore, inappropriate expression levels of both AcK9 and DNA methylation might be the major factors for disruption of normal germ cell development in cattle-yak. Additionally, various modulations occurred depending on the cell type. Further experiments are needed to identify the stage-specific gene expression modulations in each cell type in yak and cattle-yak to potentially solve the infertility issue in crossbreeding.

Oocyte Cryopreservation in Domestic Animals and Humans: Principles, Techniques and Updated Outcomes

Oocyte cryopreservation plays important roles in basic research and the application of models for genetic preservation and in clinical situations. This technology provides long-term storage of gametes for genetic banking and subsequent use with other assisted reproductive technologies. Until recently, oocytes have remained the most difficult cell type to freeze, as the oocytes per se are large with limited surface area to cytoplasm ratio. They are also highly sensitive to damage during cryopreservation, and therefore the success rate of oocyte cryopreservation is generally poor when compared to noncryopreserved oocytes. Although advancement in oocyte cryopreservation has progressed rapidly for decades, the improvement of cryosurvival and clinical outcomes is still required. This review focuses on the principles, techniques, outcomes and prospects of oocyte cryopreservation in domestic animals and humans.

Exogenous LIN28 Is Required for the Maintenance of Self-Renewal and Pluripotency in Presumptive Porcine-Induced Pluripotent Stem Cells

Porcine species have been used in preclinical transplantation models for assessing the efficiency and safety of transplants before their application in human trials. Porcine-induced pluripotent stem cells (piPSCs) are traditionally established using four transcription factors (4TF): OCT4, SOX2, KLF4, and C-MYC. However, the inefficiencies in the reprogramming of piPSCs and the maintenance of their self-renewal and pluripotency remain challenges to be resolved. LIN28 was demonstrated to play a vital role in the induction of pluripotency in humans. To investigate whether this factor is similarly required by piPSCs, the effects of adding LIN28 to the 4TF induction method (5F approach) on the efficiency of piPSC reprogramming and maintenance of self-renewal and pluripotency were examined. Using a retroviral vector, porcine fetal fibroblasts were transfected with human OCT4, SOX2, KLF4, and C-MYC with or without LIN28. The colony morphology and chromosomal stability of these piPSC lines were examined and their pluripotency properties were characterized by investigating both their expression of pluripotency-associated genes and proteins and in vitro and in vivo differentiation capabilities. Alkaline phosphatase assay revealed the reprogramming efficiencies to be 0.33 and 0.17% for the 4TF and 5TF approaches, respectively, but the maintenance of self-renewal and pluripotency until passage 40 was 6.67 and 100%, respectively. Most of the 4TF-piPSC colonies were flat in shape, showed weak positivity for alkaline phosphatase, and expressed a significantly high level of SSEA-4 protein, except for one cell line (VSMUi001-A) whose properties were similar to those of the 5TF-piPSCs; that is, tightly packed and dome-like in shape, markedly positive for alkaline phosphatase, and expressing endogenous pluripotency genes (pOCT4, pSOX2, pNANOG, and pLIN28), significantly high levels of pluripotent proteins (OCT4, SOX2, NANOG, LIN28, and SSEA-1), and a significantly low level of SSEA-4 protein. VSMUi001-A and all 5F-piPSC lines formed embryoid bodies, underwent spontaneous cardiogenic differentiation with cardiac beating, expressed cardiomyocyte markers, and developed teratomas. In conclusion, in addition to the 4TF, LIN28 is required for the effective induction of piPSCs and the maintenance of their long-term self-renewal and pluripotency toward the development of all germ layers. These piPSCs have the potential applicability for veterinary science.

Molecular signature and colony morphology affect in vitro pluripotency of porcine induced pluripotent stem cells

Overall efficiency of cell reprogramming for porcine fibroblasts into induced pluripotent stem cells (iPSCs) is currently poor, and few cell lines have been established. This study examined gene expression during early phase of cellular reprogramming in the relationship to the iPSC colony morphology and in vitro pluripotent characteristics. Fibroblasts were reprogrammed with OCT4, SOX2, KLF4 and c-MYC. Two different colony morphologies referred to either compact (n = 10) or loose (n = 10) colonies were further examined for proliferative activity, gene expression and in vitro pluripotency. A total of 1,697 iPSC-like colonies (2.34%) were observed after gene transduction. The compact colonies contained with tightly packed cells with a distinct-clear border between the colony and feeder cells, while loose colonies demonstrated irregular colony boundary. For quantitative expression of genes responsible for early phase cell reprogramming, the Dppa2 and EpCAM were significantly upregulated while NR0B1 was downregulated in compact colonies compared with loose phenotype (p < .05). Higher proportion of compact iPSC phenotype (5 of 10, 50%) could be maintained in undifferentiated state for more than 50 passages compared unfavourably with loose morphology (3 of 10, 30%). All iPS cell lines obtained from these two types of colony morphologies expressed pluripotent genes and proteins (OCT4, NANOG and E-cadherin). In addition, they could aggregate and form three-dimensional structure of embryoid bodies. However, only compact iPSC colonies differentiated into three germ layers. Molecular signature of early phase of cell reprogramming coupled with primary colony morphology reflected the in vitro pluripotency of porcine iPSCs. These findings can be simply applied for pre-screening selection of the porcine iPSC cell line.

On-farm lambing outcomes after transfer of vitrified and slow frozen embryos

The aim of the present study was to determine the most suitable embryonic stage and embryo freezing technique for commercial implementation of frozen embryo trading by small-scale sheep producers. There was a 2 × 2 factorial design utilized for conducting the study consisting of two embryo stages (2-8 cells or morula/blastocyst) and two cryopreservation protocols (vitrification or slow-freezing). For the in vivo produced embryos, there were treatments of crossbred donor ewes to induce superovulation. Embryos were recovered surgically on either Day 2 or 5.5 after estrous onset. The embryos were cryopreserved using either a vitrification or slow-freezing method before there was transfer to recipients. Ovarian response, embryo survival and lambing outcomes were analyzed. There were no differences in number of recovered and fertilized embryos at the two embryonic developmental stages. There were no effects of embryonic stages and cryopreservation methods on pregnancy rate, twinning rate, fetal birth weights and lamb weight at 1 month of age. When there was use of vitrified embryos for transfers, there was a greater lamb weight at 2 months of age (8.38 ± 0.20 compared with 7.78 ± 0.21 kg; P =  0.044) than when there was transfer of embryos cryopreserved using slow freezing procedures. Considering economic and practical benefits to small-scale sheep farms, morula/blastocyst stage-embryo collection and transfer into the uterus is more efficacious than transferring 2-8 cells embryos into the oviduct. Results of this study may contribute to the genetic improvement in the flocks of small-scale sheep producers.

Optimal concentration of Rho-associated coiled-coil kinase (ROCK) inhibitor improved sperm membrane functionality and fertilizing ability of cryopreserved-thawed feline sperm

Sperm cryopreservation induces irreversible loss of viability and fertilizing ability. This study aimed at examining the effects of Rho-associated, coiled-coil kinase (ROCK) inhibitor on quality of frozen-thawed feline sperm. Ejaculated semen from individual cats (n = 6) was examined for the expression of LIMK1 and LIMK2 mediated ROCK cascade. The effects of ROCK inhibitor during cooling and cryopreservation on sperm quality and fertilizing ability were also examined. Feline sperm were treated with different concentrations of ROCK inhibitor (10, 20 and 40 μM) during cooling at 4 °C and cryopreservation. Sperm cooled and conventionally cryopreserved without ROCK inhibitor (0 μM) served as a control group. The ROCK cascade was confirmed in feline sperm as they expressed mRNA of LIMK1 and LIMK2 genes. Cryopreservation significantly reduced sperm quality in terms of viability (91.63 ± 3.96 vs. 60.11 ± 8.93), progressive motility (91.67 ± 3.54 vs. 46.67 ± 8.66) and acrosome integrity (93.49 ± 3.64 vs. 63.81 ± 5.31) for fresh and frozen-thawed sperm, respectively (p < 0.05). The positive effects of ROCK inhibitor on sperm quality were pronounced at 1 and 3 h post-thaw. ROCK inhibitor at 10 μM significantly improved sperm motility and membrane functionality compared to those observed in a control group (0 μM) (p < 0.05). In vitro fertilization revealed that supplement ROCK inhibitor at 10 μM during cryopreservation significantly improved in vitro fertilizing ability of the frozen-thawed sperm (p < 0.05). However, it did not subsequently increase morula and blastocyst rates (p > 0.05). Increased concentrations of ROCK inhibitor to 20 and 40 μM did not further improve the quality of frozen-thawed sperm. In conclusion, an optimal concentration (10 μM) of the ROCK inhibitor added into cooling medium could improve post-thaw sperm quality.

Rabbit induced pluripotent stem cells retain capability of in vitro cardiac differentiation

Stem cells are promising cell source for treatment of multiple diseases as well as myocardial infarction. Rabbit model has essentially used for cardiovascular diseases and regeneration but information on establishment of induced pluripotent stem cells (iPSCs) and differentiation potential is fairly limited. In addition, there is no report of cardiac differentiation from iPSCs in the rabbit model. In this study, we generated rabbit iPSCs by reprogramming rabbit fibroblasts using the 4 transcription factors (OCT3/4, SOX2, KLF4, and c-Myc). Three iPSC lines were established. The iPSCs from all cell lines expressed genes (OCT3/4, SOX2, KLF4 and NANOG) and proteins (alkaline phosphatase, OCT-3/4 and SSEA-4) essentially described for pluripotency (in vivo and in vitro differentiation). Furthermore, they also had ability to form embryoid body (EB) resulting in three-germ layer differentiation. However, ability of particular cell lines and cell numbers at seeding markedly influenced on EB formation and also their diameters. The cell density at 20,000 cells per EB was selected for cardiac differentiation. After plating, the EBs attached and cardiac-like beating areas were seen as soon as 11 days of culture. The differentiated cells expressed cardiac progenitor marker FLK1 (51 ± 1.48%) on day 5 and cardiac troponin-T protein (10.29 ± 1.37%) on day 14. Other cardiac marker genes (cardiac ryanodine receptors (RYR2), α-actinin and PECAM1) were also expressed. This study concluded that rabbit iPSCs remained their in vitro pluripotency with capability of differentiation into mature-phenotype cardiomyocytes. However, the efficiency of cardiac differentiation is still restricted.

Generation of porcine induced-pluripotent stem cells from Sertoli cells

Induced pluripotent stem cells (iPSCs) are generated by reprogramming of somatic cells using four transcription factors: OCT4, SOX2, KLF-4, and c-MYC (OSKM). However, reprogramming efficiency of iPSCs is currently poor. In this study, we used the Sertoli line as a novel cell source for somatic cell reprogramming. Neonatal testes were collected from 1-week-old piglets. The testes were digested by a two-step enzymatic method to isolate Sertoli cells. The latter were transfected with retroviral vectors expressing OSKM. The Sertoli iPSC-like colonies were subjected to morphological analysis, alkaline phosphatase staining, RT-PCR, G-banding karyotyping, in vitro differentiation, and in vivo differentiation. Primary Sertoli cells had polygon-shaped morphology and manifested phagocytic activity as determined by a fluorescent bead assay. Sertoli cells also expressed the anti-Müllerian hormone protein in the cytoplasm. According to RT-PCR results, these cells expressed Sertoli cell markers (FSHR, KRT18, and GATA6) and endogenous transcription factors genes (KLF4 and c-MYC). A total of 240 colonies (0.3% efficiency) were detected by day 7 after viral transduction of 72500 cells. The Sertoli iPSC-like colonies contained small cells with a high nucleus-to-cytoplasm ratio. These colonies tested positive for alkaline phosphatase staining, expressed endogenous pluripotency genes, and had a normal karyotype. All these cell lines could form in vitro three-dimensional aggregates that represented three germ layers of embryonic-like cells. A total of two cell lines used for in vivo differentiation produced high-efficiency teratoma. In conclusion, Sertoli cells can efficiently serve as a novel cell source for iPSC reprogramming.

186 Improving Success Rate of Establishment and Maintenance of Porcine Induced Pluripotent Stem Cells by Investigation of Colony Morphology

Induced pluripotent stem cells (iPS cells) are generated by reprogramming of somatic cells using ectopic introduction of 4 transcription factors, including OCT4, SOX2, KLF4, and c-MYC (OSKM). Fibroblast cells are the most commonly used as a primary cell source for iPS cells because they are easy to harvest and culture. However, reprogramming efficiency of porcine fibroblasts is poor (~0.1%). During reprogramming process, mixed populations of primary colonies become the major obstacle in iPS establishment. In this study, we characterised 2 different colony morphologies at colony pick-up (compact and loose iPS morphology). We hypothesised that compact colonies will proceed to long-term culture and pluripotency. The fibroblast cells were isolated from tails of piglets and transfected with retroviral vectors expressing OSKM. The primary colonies were counted on Day 7 after gene transduction. The iPS-like colonies were divided into compact (n = 10) and loose (n = 10) morphology at colony pick-up. The characteristics of iPS-like cell lines were analysed by morphology, alkaline phosphatase staining, G-banding karyotype, immunofluorescence staining (OCT4), pluripotent gene expression (RT-PCR), and embryoid body formation. A total of 1,697 iPS-like colonies (2.34%) were observed. The compact colonies contained with tightly packed cells with distinct border between iPS colony and feeder cells, while colonies with irregular shape and border were classified as loose colonies. These 2 types of iPS-like colonies expressed alkaline phosphatase and OCT4. A total 5 of 10 (50%) compact morphology cell lines could be maintained in the undifferentiated state for more than 50 passages. But only 3 of 10 (30%) loose morphology cell lines demonstrated pluripotent characteristics. G-Banding karyotype analysis revealed normal chromosome number (n = 38). All of the cell lines also expressed endogenous pluripotent genes, including OSKM and NANOG and formed three-dimensional aggregating masses. In this study, we found that the cell lines from compact morphology could be maintained for longer than those of the loose morphology. A high rate of differentiation of loose iPS colony may also indicate that this type of colony has different pluripotency signals or incomplete reprogramming compared with compact colony. In conclusion, selection of compact colony morphology at colony pick-up is simple and reflects long-term propagation of porcine iPS cell lines. This information is important for improving the success rate of establishment and maintenance of porcine iPS cells.

184 Establishment of Porcine Induced Pluripotent Stem Cell Lines by Adding LIN 28 Transcription Factor

The establishment of porcine induced pluripotent stem cells (piPSC) is important in the field of human biomedical regenerative medicine. The pig model is a more representative model than current rodent models because it better mimics human physiology in different organ systems. The piPSC can be traditionally generated by reprogramming somatic cells using 4 transcription factors (4TF: OCT4, SOX2, KLF4, and c-MYC), similarly in human. However, it is difficult to maintain the pluripotent state of reprogrammed cells and they exhibit poor differentiation capacity. Hence, the 4TF may be not enough to reprogram porcine somatic cells. This study aimed to establish piPSC by adding LIN28 (referred to as 5TF) to the traditional 4TF, via retroviral vector. Here, we report the successful establishment of 3 piPSC lines by using the 5TF. All 5TF-piPSC lines exhibited a normal karyotype (38, XY) and a typical mouse embryonic stem cell (ESC) morphology, including tightly packed and dome-like shape, even after they were propagated over 40 passages. All 5TF-piPSC lines were positive for alkaline phosphatase staining and expressed high levels of ESC-like markers (OCT4, SOX2, NANOG, and SSEA-1). Importantly, the 5TF-piPSC lines showed pluripotent capacity, as evidenced by differentiation into 3 germ layers in vitro following cystic embryoid body formation, as well as by efficiently forming teratomas containing all 3 embryonic germ layers in vivo. Moreover, the 5TF-piPSC lines showed spontaneously contractile cardiomyocytes and expressed cardiomyocyte markers (cardiac troponin T) during spontaneous cardiac differentiation using cell aggregation into spherical-like structures referred to as embryoid bodies. Thus, the addition of LIN28 TF promoted long-term pluripotency of piPSC and enhanced the ability to differentiate towards 3 embryonic germ layers and cardiac lineage. This research project is supported by grants from the Mahidol University, Thailand.

Effects of vitrification and a Rho-associated coiled-coil containing protein kinase 1 inhibitor on the meiotic and developmental competence of feline oocytes

Oocyte cryopreservation is the technique of choice for the long-term storage of female gametes. However, it induces an irreversible loss of oocyte viability and function. We examined the effects of vitrification and a Rho-associated coiled-coil containing protein kinase 1 (ROCK1) inhibitor (ROCKi) on the meiotic and developmental competence of feline oocytes. We examined the expression of LIM kinase (LIMK) 1 and 2, with and without ROCKi treatment. Cumulus oocyte complexes (COCs) were matured in vitro with 0, 10, 20, and 40 µM ROCKi. The oocytes were subsequently assessed for maturation rate and embryo development following in vitro fertilization. We repeated the COC experiment, but vitrified and warmed the COCs prior to culture. We detected LIMK1 and LIMK2 expression in feline oocytes, which could be downregulated by ROCKi treatment. The ROCKi at 10 µM affected neither meiotic nor developmental competence (P > 0.05, versus control). However, high concentrations of ROCKi during maturation induced meiotic arrest at metaphase I. Appropriate concentrations of ROCKi significantly improved the normal fertilization rate of vitrified warmed oocytes (49.4 ± 3.4%) compared with that of the control (42.8 ± 8.6%, P < 0.05). The ROCKi also significantly improved the embryo cleavage rate (36.1 ± 3.8%) as compared with the non-treated control (27.4 ± 2.5%, P < 0.05). Thus, this study revealed that the main mediators of the ROCK cascade (LIM kinases) are expressed in feline oocytes. The ROCKi (10 µM) did not compromise the meiotic or developmental competence of feline oocytes. In addition, 10 µM ROCKi improved the cytoplasmic maturation of vitrified–warmed oocytes as indicated by their fertilization competence.

Establishment of a rabbit induced pluripotent stem cell (RbiPSC) line using lentiviral delivery of human pluripotency factors

Rabbit Embryonic Fibroblast (RbEF) cells (from Hycole hybrid rabbit foetus) were reprogrammed by lentiviral delivery of a self-silencing hOKSM polycistronic vector. The pluripotency of the newly generated RbiPSC was verified by the expression of pluripotency-associated markers and by in vitro spontaneous differentiation towards the 3 germ layers. Furthermore, the spontaneous differentiation potential of the iPSC was also tested in vivo by teratoma assay. The iPSC line showed normal karyotype. The advantages of using RbiPSC are the easy access to primary material and the possibility to study the efficacy and safety of the iPSC-based therapies on a non-rodent animal model.

Low-density Lipoprotein Improves Motility and Plasma Membrane Integrity of Cryopreserved Canine Epididymal Spermatozoa

Cryopreservation of caudal epididymal spermatozoa is an effective technique to conserve genetic potentials of superior dogs when it is not possible to collect ejaculated spermatozoa. Although hen egg yolk is commonly supplemented into the semen extender, active substances within the egg yolk which protect sperm against cryoinjury remain to be discovered. Among its compositions, low-density lipoprotein (LDL) has been reported to have a cryoprotective property for sperm cryopreservation. However, the effects of LDL on dog epididymal spermatozoa during cryopreservation have not yet been investigated. This study aimed to investigate the effects of LDL on epididymal spermatozoa quality following cryopreservation and thawing. After routine castration of 12 dogs, caudal epididymides from individuals were separated from the testes and cut into a few pieces in a Tris-buffer. Spermatozoa recovered from each sample were examined at once for sperm quality and divided into six groups of extender: no LDL, 20% egg yolk, 4%, 8%, 16%, and 24% LDL, before cryopreservation. The sperm aliquots were then equilibrated and conventionally frozen. After thawing, sperm motility, morphology, plasma membrane integrity, and acrosome integrity were evaluated. The results revealed that 4% LDL and 20% egg yolk yielded significantly higher sperm motility (57.69% and 52.69%, respectively, p<0.05) than other LDLs. In addition, 4% LDL yielded the significantly highest plasma membrane integrity (70.54%, p<0.05). In conclusion, the supplementation of 4% LDL in Tris-glucose extender could be applied for cryopreservation of canine epididymal spermatozoa.

Determination phase at transition of gonocytes to spermatogonial stem cells improves establishment efficiency of spermatogonial stem cells in domestic cats

The development of germ cells has not been entirely documented in the cat especially the transition phase of the gonocyte to the spermatogonial stem cell (G/SSC). The aims of study were to examine testicular development and to identify the G/SSC transition in order to isolate and culture SSCs in vitro. Testes were divided into 3 groups according to donor age (I, < 4 months; II, 4–6 months; and III, > 6 months). In Exp. 1, we studied testicular development by histology, transmission electron microscopy and immunohistochemistry. In Exp. 2, we determined the expression of GFRα-1, DDX-4 and c-kit and performed flow cytometry. The SSCs isolated from groups II and III were characterized by RT-PCR and TEM (Exp. 3). Chronological changes in the G/SSC transition were demonstrated. The size, morphology and ultrastructure of SSCs were distinguishable from those of gonocytes. The results demonstrated that group II contained the highest numbers of SSCs per seminiferous cord/tubule (17.66 ± 2.20%) and GFRα-1⁺ cells (14.89 ± 5.66%) compared with the other groups. The findings coincided with an increased efficiency of SSC derivation in group II compared with group III (74.33 ± 2.64% vs. 23.33 ± 2.23%). The colonies expressed mRNA for GFRA1, ZBTB16, RET and POU5F1. Our study found that the G/SSC transition occurs at 4–6 months of age. This period is useful for isolation and improves the establishment efficiency of cat SSCs in vitro.

Simplified isolation and enrichment of spermatogonial stem-like cells from pubertal domestic cats (Felis catus)

The efficiency of spermatogonial stem cell (SSC) isolation and culture from pubertal donors is currently poor primarily, because of contamination with other testicular cells. This study aimed to purify SSC-like cells using different extracellular matrixes and a discontinuous gradient density. In experiment 1, testes (n=6) were analyzed for histology and SSC-related protein expressions (laminin, SSEA-4, DDX-4 and GFRα-1). After enzymatic digestion, the cell suspension was plated onto either a laminin- or gelatin-coated dish. The number of SSC-like cells was determined at 15, 30 and 60 min of culture (experiment 2). Experiment 3 was performed to test whether or not the additional step of Percoll gradient density centrifugation could really improve purification of SSC-like cells. Testicular histology revealed complete spermatogenesis with laminin expression essentially at the basal lamina of the seminiferous tubules. SSEA-4 and GFRα-1 co-localized with DDX-4 in the spermatogonia. The relative percentage of SSC-like cells, as determined by cells expressing SSEA-4 (59.42 ± 2.18%) and GFRα-1 (42.70 ± 1.28%), revealed that the highest SSC-like cell purity was obtained with the 15-min laminin-coated dish compared with other incubation times and gelatin treatment (P<0.05). Percoll treatment prior to laminin selection (15 min) significantly improved SSC-like cell recovery (91.33 ± 0.14%, P<0.001) and purity (83.82 ± 2.05% for SSEA-4 and 64.39 ± 1.51% for GFRα-1, P<0.05). These attached cells demonstrated a typical SSC-like cell morphology and also expressed POU5F1, RET and ZBTB16 mRNA. In conclusion, double enrichment with Percoll gradient density centrifugation and laminin plating highly enriched the SSC-like cells population.

Epidermal growth factor improves developmental competence and embryonic quality of singly cultured domestic cat embryos

This study examined the influence of EGF on the expression of EGF receptors (EGFR) and developmental competence of embryos cultured individually versus those cultured in groups. Cat oocytes were in vitro matured and fertilized (IVM/IVF), and cleaved embryos were randomly assigned to one of seven culture conditions: one group each in which embryos were subjected to group culture supplemented with or without 5 ng/ml EGF and five groups in which embryos were subjected to single-embryo culture supplemented with EGF (0, 5, 25, 50 or 100 ng/ml). Morulae, blastocysts and hatching blastocysts were assessed at days 5 and 7; post IVF, respectively, and total blastocyst cell numbers were assessed at day 7. Relative mRNA expressions of EGFR of 2–4-cell embryos, 8–16-cell embryos, morulae and blastocysts cultured in groups or singly with or without EGF supplementation were examined. OCT3/4 and Ki67 in blastocysts derived from the group or single-embryo culture systems with or without EGF supplementation were localized. A higher rate of embryos cultured in groups developed to blastocysts than individually incubated cohorts. Although EGF increased blastocyst formation in the single-embryo culture system, EGF did not affect embryo development in group culture. Expression levels of EGFR decreased in morulae and blastocysts cultured with EGF. An increased ratio of Ki67-positive cells to the total number of cells in the blastocyst was observed in singly cultured embryos in the presence of EGF. However, EGF did not affect the expression of OCT3/4. These findings indicate that EGF enhanced developmental competence of cat embryos cultured singly by stimulating cell proliferation and modulating the EGFR expression at various developmental stages.

341 FELINE EMBRYONIC STEM-LIKE CELLS DERIVED FROM IN VITRO-PRODUCED BLASTOCYSTS RETAIN IN VITRO DIFFERENTIATION POTENTIAL

Embryonic stem (ES) cells are pluripotent cells that can differentiate into all 3 germ layers, including endoderm, mesoderm, and ectoderm. Embryonic stem cells are generally divided into 2 types, naïve and primed-state, depending on their signaling pathways. Domestic cat is a useful animal model for the study of human diseases because many genetic and infectious diseases in the cat are analogous with similar aetiology to human diseases. The cat can also be used as a research model for reproductive physiology and conservation of wild felids. Until recently, information on establishment of feline ES cells is limited. The objectives of this study were to isolate cat ES cells from in vitro-produced blastocysts and to examine the effect of different concentrations of basic fibroblast growth factor (bFGF) on the expression of pluripotent genes. Inner cell masses (ICM) from cat blastocysts (n = 40, Day 7 after in vitro fertilization) that were matured, fertilized, and cultured entirely in vitro, were isolated by immunosurgery and plated on mitmycin-treated mouse embryonic fibroblasts. The ICM (n = 20) were then cultured in embryonic stem cell medium containing 1000 IU mL–1 of leukemia inhibitory factor (LIF) and different bFGF concentrations (0, 4, 10, and 20 ng mL–1). The ICM outgrowths at 7 days postplating were collected and analysed for expression of pluripotent genes (SOX-2, OCT-4, and NANOG). Results showed that transcription levels of all 3 pluripotent genes were higher in ICM outgrowths cultured in 20 ng mL–1 of bFGF compared with the lower concentrations. For isolation of ES cells, ICM (n = 20) were cultured in embryonic stem cell medium supplemented with 1000 IU mL–1 of LIF and 20 ng mL–1 of bFGF due to the results obtained from the above experiment. Established ES cells were characterised by detecting alkaline phosphatase (AP) activity and expression of ES markers (SOX-2, OCT-4, SSEA-4) at protein level, and karyotyped at passage 20 and 40. In vitro differentiation into embryoid bodies (EB) was induced by the hanging drop technique, and EB samples (n = 5 for each time point) were tested for the expression of TTR, AFP, T (Bracyury), NKX2.5, MAP-2, and NESTIN genes at 0, 7, and 14 days of culture. A total of 3 ES-like cell lines were established with a typical ES morphology, such as a well-defined colony, a large nucleus to cytoplasm ratio with 1 to 2 prominent nucleoli. The 3 ES-like cell lines were passaged up to 40 times with a normal diploid karyotype (n = 38). They were strongly positive for AP, SOX-2, OCT-4, and SSEA-4. Following EB culture, cell aggregation and cystic-like structure were observed. The EB samples also expressed all differentiation markers. This study reports that feline ES-like cell lines can be generated from in vitro-produced feline blastocysts. The ES cell lines can be repeatedly passaged indicating self-renewal ability, and gene expression of the EB demonstrates cellular differentiation into all 3 germ layers.

94 CHRONOLOGICAL TRANSITION OF GONOCYTES TO SPERMATOGONIAL STEM CELLS DURING PREPUBERTAL AND PUBERTAL PERIODS IN DOMESTIC CATS

The pubertal age of domestic cat (Felis catus) as defined as a complete spermatogenesis has been reported to occur around 8 months of age. During the initial phase of testicular development, the transition of gonocytes to spermatogonial stem cells (SSC) takes place within the seminiferous cords. This stage-specific transition has been demonstrated to facilitate SSC isolation and enrichment. Because information for this aspect in domestic cats is limited, this study aimed to identify the phase transition of gonocytes to SSC during newborn to puberty. Cat testes were collected and classified by age into 3 groups: group 1: 0–4 months (n = 5), group 2: 4–6 months (n = 5), and group 3: 6–12 months (n = 5). Testes were studied for conventional histology, transmission electron microscopy (TEM), and FACS analysis on GFRα-1 expression, a SSC marker. For histology, tissues were fixed, sectioned, and stained with H&E. Serial changes of germ cell development within the testes were observed using light microscopy. In addition, ultrathin sections (60 nm thickness) of testes were cut and examined with TEM for ultrastructure analysis. Immunolabelling and flow cytometry of GFRα-1 were used to identify the SSC population after testicular cell dissociation. The percentages of spermatogonia per tubule were analysed by one-way ANOVA, and data are presented as mean ± s.e. The development of testicular germ cells from gonocyte to spermatozoon was gradually demonstrated in histological sections, depending on age of the cats. For group 1, the gonocytes were clearly presented in the seminiferous cord. These gonocytes were in proliferative phase, as they frequently contained homogeneous euchromatin and less organelles. In group 2, the gonocytes transformed to spermatogonia as indicated by their small size (range 8.11–13.55 μm) with oval to flattened shape, chromatin condensation, and darkened cytoplasm. These cells migrated and settled onto the basement membrane of seminiferous cord. At this stage, mitochondria and small clumps of heterochromatin increased when compared with group 1. Some spermatogonia occasionally developed through the meiosis by 6 months of age (group 2), whereas complete spermatogenesis was first identified in 9-month testes (group 3). The percentage of spermatogonium/tubule in group 2 (15.84 ± 0.67) was significantly higher (P < 0.001) than group 1 and 3 (1.99 ± 0.22 and 6.88 ± 0.53, respectively). Because the SSC-like cells (based on their histological morphology) were predominantly found in group 2, the testes (n = 5, 4–6 months of age) were additionally digested to confirm GFRα-1 expression. Of total testicular cells, a high proportion of GFRα-1 positive cells (12.32 ± 6.31%) were identified by FACS. In conclusion, this study provides information regarding the age-dependent development of testicular germ cells in domestic cats. The findings provide the transition period of gonocytes to SSC that occurs around 4 to 6 months of age. This study can be applied for the enrichment of feline SSC upon testicular digestion.

L-carnitine Supplemented Extender Improves Cryopreserved-thawed Cat Epididymal Sperm Motility

Cryopreservation of epididymal sperm is an effective technique to preserve genetic materials of domestic cats and wild felids when they unexpectedly die. However, this technique inevitably causes detrimental changes of cryopreserved-thawed spermatozoa, for example, by physical damage and excessive oxidative stress. L-carnitine is an antioxidant that has been used to improve sperm motility in humans and domestic animals. This study aimed to investigate the effects of L-carnitine on cat epididymal sperm quality following cryopreservation and thawing. After routine castration, cauda epididymides were collected from 60 cat testes. The epididymal spermatozoa from 3 cauda epididymides were pooled as 1 replicate. Spermatozoa samples (16 replicates) were examined for spermatozoa quality and then randomly divided into 4 groups: 0 mM L-carnitine (control), 12.5 mM, 25 mM and 50 mM L-carnitine. The sperm aliquots were then equilibrated and conventionally frozen. After thawing, sperm motility, plasma membrane integrity, DNA integrity and acrosome integrity were evaluated. The 25 mM L-carnitine significantly improved sperm motility compared with a control group (p<0.05), although this was not significantly different among other concentrations. In conclusion, supplementation of 25 mM L-carnitine in freezing extender improves cauda epididymal spermatozoa motility. The effects of L-carnitine on the levels of oxidative stress during freezing and thawing remains to be examined.

Selective TGF-β1/ALK inhibitor improves neuronal differentiation of mouse embryonic stem cells

The transforming growth factor-β1 (TGF-β1), a polypeptide member of the TGF-β superfamily, has myriad cellular functions, including cell fate differentiation. We hypothesized that suppression of TGF-β1 signaling would improve the efficacy of neuronal differentiation during embryoid body (EB) development. In this study, mouse embryonic stem cells (ESCs) were allowed to differentiate into their neuronal lineage, both with, and without the TGF-β1 inhibitor (A83-01). After 8 days of EB suspension culture, the samples were examined by morphological analysis, immunocytochemistry and immunohistochemistry with pluripotent (Oct4, Sox2) and neuronal specific markers (Pax6, NeuN). The alteration of gene expressions during EB development was determined by quantitative RT-PCR. Our results revealed that the TGF-β1/ALK inhibitor potentially suppressed pluripotent gene (Oct4) during a rapidly up-regulation of neuronal associated genes including Sox1 and MAP2. Strikingly, during EB development, the expression of GFAP, the astrocyte specific gene, remarkably decreased compared to the non-treated control. This strategy demonstrated the beneficial function of TGF-β1/ALK inhibitor that rapidly and uniformly drives cell fate alteration from pluripotent state toward neuronal lineages.

Insulin-like growth factor-1 (IGF-1) enhances developmental competence of cat embryos cultured singly by modulating the expression of its receptor (IGF-1R) and reducing developmental block

OBJECTIVE

The aim of this study is to determine the effects of insulin-like growth factor-1 (IGF-1) and the mRNA expression of IGF-1 receptor (IGF-1R) during the in vitro development of cat embryos cultured in groups versus singly.

METHODS

Cumulus-oocyte complexes (COCs) were matured and fertilized in vitro with frozen-thawed semen. Cleaved embryos (48h post-fertilization) were randomly assigned to one of the following treatments: 1) group embryo culture without IGF-1 (10 embryos per 50μl droplet), 2) single-embryo culture without IGF-1, and 3) to 6) single-embryo culture (50μl droplet per embryo) supplemented with different concentrations of IGF-1 (5, 25, 50 and 100ng/ml, respectively). During in vitro culture, the embryos were analyzed for development to the morula, blastocyst and hatching blastocyst stage. Relative mRNA expression of IGF-1R was also examined by qPCR at the morula and blastocyst stages. In addition, the mRNA expression of IGF-1R in morula-stage embryos treated with IGF-1 was determined. The influence of IGF-1 to preimplantation embryo development was then explored by co-incubation with 0.5μM IGF-1R inhibitor (Picropodophyllin; PPP).

RESULTS

Group embryo culture led to a significantly higher blastocyst development rate compared with single-embryo culture (P<0.05). The poor development of singly cultured embryos coincided with the significantly lower IGF-1R expression in morulae than in group-cultured morulae. IGF-1 (25 or 50ng/ml) supplementation significantly improved the blastocyst formation rate of single embryos to a level similar to group culture by promoting the morula-to-blastocyst transition. IGF-1 supplementation (25 or 50ng/ml) of singly cultured embryos upregulated the expression of IGF-1R mRNA in morula-stage embryos to the same level as that observed in group-cultured embryos (without IGF-1). The beneficial effects of IGF-1 on singly cultured embryo were (P<0.05) suppressed by PPP even in the group culture embryo without growth factor supplementation.

CONCLUSION

IGF-1 supplementation improves the developmental competence of feline embryos cultured individually and also increases IGF-1R gene expression to levels similar to group-cultured embryos.

Advancing maternal age predisposes to mitochondrial damage and loss during maturation of equine oocytes in vitro

In many mammalian species, reproductive success decreases with maternal age. One proposed contributor to this age-related decrease in fertility is a reduction in the quantity or functionality of mitochondria in oocytes. This study examined whether maternal age or (in vitro maturation). IVM affect the quantity of mitochondria in equine oocytes. Oocytes were collected from the ovaries of slaughtered mares categorized as young (<12 years) or aged (≥12 years) and either denuded and prepared for analysis immediately (not-IVM) or matured in vitro for 30 hours before preparation (IVM). The mean oocyte mitochondrial DNA copy number was estimated by quantitative polymerase chain reaction and found to be significantly lower in oocytes from aged mares and that had been subjected to IVM than in any other group. Transmission electron microscopy demonstrated that mitochondria in aged mare oocytes subjected to IVM experienced significantly more swelling and loss of cristae than in other groups. We conclude that maternal aging is associated with a heightened susceptibility to mitochondrial damage and loss in equine oocytes, which manifests during IVM. This predisposition to mitochondrial degeneration probably contributes to reduced fertility in aged mares.

16 SPERM DISTRIBUTION AFTER LAPAROSCOPIC INTRAUTERINE INSEMINATION OF FROZEN GOAT SEMEN

Generally, laparoscopic intrauterine insemination (LII) provides a higher success rate than that of cervical insemination in goat. However, the sperm distribution following LII in goat remains unknown, especially when frozen semen is used. This study aimed to evaluate the distribution of frozen-thawed goat sperm after LII. In experiment 1, the frozen-thawed sperm were stained with CellTrackerTM Green CMFDA (CT-Green) or CellTrackerTM Red CMPTX (CT-Red), and then evaluated in vitro for viability and motility at 0, 3, 6, and 9 h after staining. In experiment 2, the CT-Green and CT-Red labelled sperm (30 × 106 sperm in 0.125 mL in each side) were laparoscopicaly inseminated into the left and right uterine horns, respectively (n = 4). After ovariohysterectomy at 6 h post-insemination, the distributions of green and red coloured sperm were assessed by tissue section and sperm flushing. The comparison of semen parameters among groups (control, CT-Green, and CT-Red) were statistically analysed by a general linear model. The results revealed that the fluorochromes used in this study did not impair the sperm motility and viability (P > 0.05). The frozen-thawed goat sperm transuterine-migrated following LII, as both CT-Green (left insemination) and CT-Red labelled sperm (right insemination) were found in both sides of the reproductive tracts. This study concludes that LII in goat would be simpler and consume less time if the semen was unilaterally deposited. Supported by a grant from Chulalongkorn University Centenary Academic Development Project and RGJ-PhD-industrial link program, Thailand Research Fund (PHD/0156/2550).

Slow turning lateral vessel bioreactor improves embryoid body formation and cardiogenic differentiation of mouse embryonic stem cells

Embryonic stem cells (ESCs) have the ability to form aggregates, which are called embryoid bodies (EBs). EBs mimic early embryonic development and are commonly produced for cardiomyogenesis. Here, we describe a method of EB formation in hydrodynamic conditions using a slow-turning lateral vessel (STLV) bioreactor and the subsequent differentiation of EBs into cardiomyocytes. EBs formed in the STLV were compared with conventional techniques, such as hanging drop (HD) or static suspension cell culture (SSC), for homogeneity of EB size, shape, proliferation, apoptosis, and in vitro cardiac differentiation. After 3 days of culture, a four-fold improvement in the yield of EB formation/mL, a six-fold enhancement in total yield of EB/mL, and a nearly 10-fold reduction of cells that failed to incorporate into EBs were achieved in STLV versus SSC. During cardiac differentiation, a 1.5- to 4.2-fold increase in the area of cardiac troponin T (cTnT) per single EB in STLV versus SSC and HD was achieved. These results demonstrate that the STLV method improves the quality and quantity of ES cells to form EBs and enhances the efficiency of cardiac differentiation. We have demonstrated that the mechanical method of cell differentiation creates different microenvironments for the cells and thus influences their lineage commitments, even when genetic origin and the culture medium are the same. Ascorbic acid (ASC) improved further cardiac commitment in differentiation assays. Hence, this culture system is suitable for the production of large numbers of cells for clinical cell replacement therapies and industrial drug testing applications.

Birth of kittens after the transfer of frozen-thawed embryos produced by intracytoplasmic sperm injection with spermatozoa collected from cryopreserved testicular tissue

The aim of this study is to produce live kittens from oocytes fertilized by intracytoplasmic sperm injection (ICSI) with frozen/thawed testicular spermatozoa. Spermatozoa were collected from thawed testicular tissue and subsequently injected into in vitro matured cat oocytes. At 24 h post-ICSI, presumptive zygotes/cleaved embryos were treated with 10 μm forskolin for 24 h to reduce intracellular lipid content of embryos (delipidation). At 48 h after oocyte injection, cleaved embryos (2- to 8-cell stage) were frozen in 10% (v/v) ethylene glycol-based medium by a slow controlled rate method and stored in liquid nitrogen. To evaluate in vitro and in vivo developmental competence, frozen embryos were thawed and then cultured for 6 days (n = 155) or cultured for 2 h before transferred (n = 209) to hormonal (equine chorionic gonadotropin/hCG)-treated cat recipients. Cleavage frequency at day 2 after ICSI with frozen/thawed testicular spermatozoa was ~30%. The percentages of frozen/thawed embryos that developed to morula and blastocyst stage (on day 3 and day 6 of in vitro culture, respectively) were significantly lower than that of fresh ICSI embryos (22.6 vs 45.2% and 21.3 vs 38.7%, respectively; p < 0.05). However, no difference was found in the number of blastomeres between frozen/thawed (242.5 ± 43.1) and fresh (320.2 ± 28.1) blastocysts. Three of seven cat recipients were pregnant and one pregnant cat delivered two healthy kittens. This is the first report of the birth of kittens after the transfer of frozen-thawed embryos produced by ICSI with frozen/thawed testicular sperm.

In vitro culture of feline embryos increases stress-induced heat shock protein 70 and apoptotic related genes

Developmental competence and quality of in vitro produced embryos has been demonstrated to be lower than in vivo derived embryos. This study aimed specifically to determine the effects of in vitro culture of feline embryos using various culture densities on developmental competence and expression of stress- and apoptotic-related genes in terms of heat shock protein 70 (HSP70) and apoptotic-related (BAX and BCL-2) gene expressions. In experiment 1, we characterized the inducible form of a feline-specific HSP70 mRNA sequence, as it has not been previously reported. The primers for feline HSP70 mRNA were synthesized and tested on heat-treated cat fibroblasts. In experiment 2, feline embryos were cultured at different culture densities (embryo:culture volume; 1:1.25, 1:5 and 1:20). The developmental competence was determined along with HSP70, BAX and BCL-2 transcript abundances using quantitative RT-PCR. In vivo derived embryos were used as a control group. A partial cat HSP70 mRNA sequence (190 bp) was characterized and exhibited high nucleotide identity (93 to 96%) with other species. Cleaved embryos cultured at high density (1:1.25) developed to blastocysts at a lower rate than those generated from lower densities. Irrespective of the culture densities used, in vitro cultured blastocysts showed increased levels of HSP70 and BAX transcripts compared with in vivo counterparts. Blastocysts derived from the highest culture density (1:1.25) showed higher levels of upregulation of HSP70 and BAX transcripts than those cultured at lower culture densities (1:5 and 1:20). In conclusion, increased levels of pro-apoptotic (BAX) and stress-response (HSP70) transcripts correlated with developmental incompetence of embryos cultured at high embryonic density, indicating that stress accumulated during in vitro embryo culture affected the fate for embryo development and quality.

Characterization and in vitro culture of putative spermatogonial stem cells derived from feline testicular tissue

Spermatogonial stem cells (SSCs) function to regulate the balance of self-renewal and differentiation of male gametes. SSCs have been successfully isolated and cultured in vitro in several species, but not in feline. Therefore, in this study, we aimed to culture and characterize feline SSCs. In experiment 1, testes (n=5) from different pubertal domestic cats were cryosectioned and fluorescently immunolabeled to examine the expression of SSC (GFRα-1), differentiated spermatogonium (c-kit) and germ cell (DDX-4) markers. In experiments 2 and 3, testicular cells were digested and subsequently cultured in vitro. The resultant presumptive SSC colonies were then collected for SSC identification (experiment 2), or further cultured in vitro on feeder cells (experiment 3). Morphology, gene expression and immunofluorescence were used to identify the SSCs. Experiment 1 demonstrated that varying types of spermatogenic cells existed and expressed different germ cell/SSC markers. A rare population of putative SSCs located at the basement membrane of the seminiferous tubules was specifically identified by co-expression of GFRα-1 and DDX-4. Following enzymatic digestion, grape-like colonies formed by 13-15 days of culture. These colonies expressed GFRA1 and ZBTB16, but did not express KIT. Although we successfully isolated and cultured feline SSCs in vitro, the SSCs could only be maintained for 57 days. In conclusion, this study demonstrates, for the first time, that putative SSCs from testes of pubertal domestic cats can be isolated and cultured in vitro. These cells exhibited SSC morphology and expressed SSC-specific genes. However, long-term culture of these putative SSCs was compromised.

Sperm pretreatment with dithiothreitol increases male pronucleus formation rates after intracytoplasmic sperm injection (ICSI) in swamp buffalo oocytes

Failure of male pronucleus formation has hampered the success of intracytoplasmic sperm injection (ICSI) in swamp buffalo. The aim of the present study was to improve male pronucleus formation by pretreating sperm with various chemicals before ICSI. In Experiments1 and 2, sperm were treated according to one of the following protocols: (1) 0.1% Triton-X 100 (TX) for 1 min, (2) 10 µM calcium ionophore (CaI) for 20 min, (3) freezing and thawing (FT) without any cryoprotectant, or (4) no treatment (control). These sperm treatment groups then either did or did not receive additional sperm treatment with 5 mM dithiothreitol (DTT) for 20 min. Acrosomal integrity (Experiment 1) and DNA fragmentation (Experiment 2) were evaluated in the sperm before ICSI. In Experiment 3, oocytes matured in vitro were subjected to ICSI using pretreated sperm as described above and then were cultured either with or without activation. The TX- and CaI-treated sperm caused an increase in the number of acrosome-loss sperm, whereas the FT treatment and control increased the proportion of acrosome-reacted sperm (P<0.05). The DNA fragmentation did not differ among treatments (P>0.05). At 18 h post-ICSI, pronucleus (PN) formation was found only in activated oocytes. The majority of the activated ICSI oocytes contained intact sperm heads. Normal fertilization was observed in the CaI and FT treatment groups and control group when sperm were treated with DTT before ICSI. In conclusion, DTT treatment of sperm with reacted acrosomes before ICSI together with activation of the ICSI oocytes is important for successful male pronucleus formation.

Generation of neuronal progenitor cells and neurons from mouse sleeping beauty transposon-generated induced pluripotent stem cells

Mouse embryonic stem cells (ESCs) and induced pluripotent stem (iPS) cells can be used as models of neuronal differentiation for the investigation of mammalian neurogenesis, pharmacological testing, and development of cell-based therapies. Recently, mouse iPS cell lines have been generated by Sleeping Beauty (SB) transposon-mediated transgenesis (SB-iPS). In this study, we determined for the first time the differentiation potential of mouse SB-iPS cells to form neuronal progenitor cells (NPCs) and neurons. Undifferentiated SB-iPS and ES cells were aggregated into embryoid bodies (EBs) and cultured in neuronal differentiation medium supplemented with 5 μM all-trans retinoic acid. Thereafter, EBs were dissociated and plated to observe further neuronal differentiation. Samples were fixed on days 10 and 14 for immunocytochemistry staining using the NPC markers Pax6 and Nestin and the neuron marker βIII-tubulin/Tuj1. Nestin-labeled cells were analyzed further by flow cytometry. Our results demonstrated that SB-iPS cells can generate NPCs and differentiate further into neurons in culture, although SB-iPS cells produced less nestin-positive cells than ESCs (6.12 ± 1.61 vs. 74.36 ± 1.65, respectively). In conclusion, the efficiency of generating SB-iPS cells-derived NPCs needs to be improved. However, given the considerable potential of SB-iPS cells for drug testing and as therapeutic models in neurological disorders, continuing investigation of their neuronal differentiation ability is required.

Improved cryopreservability of stallion sperm using a sorbitol-based freezing extender

Cryopreservation of stallion semen is often associated with poor post-thaw sperm quality. Sugars are among the important components of a freezing extender and act as non-permeating cryoprotectants. This study aimed to compare the quality of stallion sperm frozen with glucose, fructose or sorbitol-containing freezing extenders. Semen was collected from six stallions of proven fertility and cryopreserved using a freezing extender containing different types of monosaccharide sugars (glucose, fructose or sorbitol). After thawing, the semen was examined for sperm motility, viability, acrosome integrity, plasma membrane functionality and sperm longevity. The fertility of semen frozen in the presence of sorbitol was also tested by artificial insemination. Sperm quality was significantly decreased following freezing and thawing (P < 0.05). Fructose was inferior for protecting sperm during cryopreservation when compared to sorbitol and glucose (P < 0.05). Although the viability, motility and acrosome integrity of sperm cryopreserved with a glucose-containing extender did not significantly differ from sperm frozen in the sorbitol-based extender when examined at 2 and 4 h post-thaw, all of these parameters plus plasma membrane functionality were improved for sperm frozen in the sorbitol extender than in the glucose extender when examined 10 min post-thaw. Two of four mares (50%) inseminated with semen frozen with a sorbitol-containing freezing extender became pregnant. It is concluded that different sugars have different abilities to protect against cryoinjury during freezing and thawing of stallion sperm. This study demonstrated that an extender containing sorbitol as primary sugar can be used to successfully cryopreserve equine sperm; moreover, the quality of frozen-thawed sperm appeared to be better than when glucose or fructose was the principle sugar in the freezing extender.

95 THE EFFECT OF FREEZING TECHNIQUES ON QUALITY OF CAT TESTICULAR SPERM

Cryopreservation of testicular tissue is beneficial for valuable animals that die unexpectedly or when elective castration is required. Until recently, knowledge regarding cryopreservation of testicular tissue/sperm in the domestic cat has been limited. The objective of this study was to determine the effects of freezing techniques and cryoprotectants on quality of testicular sperm. In Experiment 1, each testis was cut into 10 equal small pieces (∼2 × 3 × 5 mm) and cryopreserved in freezing medium containing with 5% (v/v) glycerol using conventional (10 min in liquid nitrogen vapors) or controlled-rate freezing techniques. In Experiment 2, testicular tissues were conventionally frozen with different types of 5% (v/v) cryoprotectants [glycerol (Gly), dimethylsulphoxide (DMSO), 1,2-propanediol (PrOH), or ethylene glycol (EG)]. Non-cryopreserved testicular sperm was used as a control. After thawing, testicular sperm were extracted and examined for viability and DNA integrity using non-membrane-permeable DNA staining (Ethidium homodimer-1) and TUNEL assay, respectively. Viability of testicular sperm cryopreserved by controlled-rate cryopreservation (45.9 ± 3.7) was significantly lower than non-frozen control (60.3 ± 0.9) and conventional freezing technique (55.0 ± 2.7). Gly (58.2 ± 2.6) and EG (53.3 ± 2.3) yielded a similar viability compared with non-frozen control (P > 0.05), whereas DMSO and PrOH demonstrated an inferior cryoprotectant for feline testicular sperm (% viability for DMSO and PrOH: 46.3 ± 3.3 and 44.3 ± 2.9, respectively). In both experiments, DNA integrity of frozen–thawed testicular sperm did not significantly differ from the control group. In conclusion, cat testicular tissue can be frozen as small pieces using both conventional technique and controlled rate freezing. However, freezing technique and type of cryoprotectant markedly affect the post-thawed quality of testicular sperm. Further study requires examination of the optimal cooling rate during cryopreservation and also the fertilizability of frozen–thawed testicular sperm. This study was financially supported by CHE-TRF Senior Research Scholars RTA-5080010.

96 THE EFFECT OF CHEMICAL DELIPIDATION ON CRYOPRESERVABILITY OF CAT EMBRYOS

Embryo cryopreservation is a desired technique for long-term preservation of embryos. However, the success rate of cryopreserved in vitro produced cat embryos is currently poor. Until recently, the mechanism underlying the cause of cryoinjury that occurs during cooling and cryopreservation is not well understood. This study aimed to examine the effect of chemical delipidation (forskolin) before cryopreservation of 4- to 8-cell cat embryos on post-thaw embryo survival and in vitro developmental capability. A total of 333 cumulus oocyte complexes (COCs) were matured and fertilized in vitro. At 24 h post-IVF, the presumptive embryos were randomly assigned into one of the following groups: 1) non-frozen control (n = 63); 2) forskolin treatment without freezing (n = 52); 3) freezing without forskolin (n = 77); and 4) freezing after forskolin treatment (n = 89). The embryos were cryopreserved using a programmable controlled-rate freezer. After freezing and thawing, the embryos were subsequently cultured in vitro for a further 6 days. The development competence was assessed by morula and blastocyst rates on Days 5 and 8 of their development, respectively. Percentages of cleaved embryos on Day 2 (IVF = Day 0) did not significantly differ among groups, indicating that there was no adverse effect of forskolin on cleavage rates. Furthermore, blastocyst formation rates of cat embryos treated with forskolin (53.5 ± 3.1) did not significantly differ when compared with non-treated controls (54 ± 9.3). Forskolin-treated embryos survived after cryopreservation at a higher rate than non-forskolin treatment, in terms of survival (93.1 ± 2.6 v. 88.2 ± 1.4), morula (56.9 ± 7.6 v. 40.8 ± 5.7), and blastocyst formation (47.6 ± 6.4 v. 35.6 ± 3.6) rates. It is concluded that partial delipidation of cat embryos before cryopreservation improves the cryopreservability of cat embryos. This study demonstrates that intracellular lipid has an impact on cryopreservability of cat embryos. Further study is required to examine in utero development of these delipidated embryos after embryo transfer. This study was financially supported by the Zoo organisation of Thailand and CHE-TRF Senior Research Scholars RTA-5080010.

Chronological Reorganization of Microtubules, Actin Microfilaments, and Chromatin during the First Cell Cycle in Swamp Buffalo (Bubalus bubalis) Embryos

This paper aimed to study the dynamics of early embryonic development, in terms of redistribution of cytoskeleton (microtubules, actin microfilaments) and chromatin configurations during the first cell cycle in swamp buffalo embryos. Oocytes were matured and fertilized in vitro, and they were fixed at various time points after IVF. At 6 h after IVF, 44.4% matured oocytes were penetrated by spermatozoa. Partial ZP digestion, however, did not improve fertilization rate compared to control (P > .05). At 12 h after IVF, the fertilized oocytes progressed to the second meiotic division and formed the female pronucleus simultaneously with the paternal chromatin continued to decondense. A sperm aster was observed radiating from the base of the decondensing sperm head. At 18 h after IVF, most presumptive zygotes had reached the pronuclear stage. The sperm aster was concurrently enlarged to assist the migration and apposition of pronuclei. Cell cleavage was facilitated by microfilaments and firstly observed by 30 h after IVF. In conclusion, the cytoskeleton actively involves with the process of fertilization and cleavage in swamp buffalo oocytes. The centrosomal material is paternally inherited. Fertilization failure is predominantly caused by poor sperm penetration. However, partial digestion of ZP did not improve fertilization rate.

The effects of roscovitine on cumulus cell apoptosis and the developmental competence of domestic cat oocytes

The developmental competence of cat oocytes matured in vitro is relatively poor when compared with that of in vivo oocytes. The study aimed to investigate the effect of roscovitine on the developmental competence of cat Felis catus oocytes matured in vitro. Cumulus-oocyte complexes (COCs) were classified as Grade I and II to III. Groups of COCs were cultured in 0, 12.5, 25, 50, 100, and 200 microM roscovitine for 24h and were either fixed to assess the stages of nuclear maturation (Experiment 1) or additionally matured in vitro for 24h before fixation (Experiment 2). In Experiment 3, cumulus cells from the COCs treated with roscovitine were examined for apoptosis. Experiment 4 examined the developmental competence of cat oocytes after roscovitine treatment and in vitro fertilization in terms of cleavage and morula and blastocyst formation rates. Roscovitine reversibly arrested cat oocytes at an immature stage in a dose-dependent manner. Roscovitine at 12.5 and 25 microM demonstrated less efficiency compared with that of other doses. However, higher doses of roscovitine induced cumulus cell apoptosis and resulted in a high number of degenerated oocytes after in vitro maturation. Roscovitine at 12.5 and 25 microM were therefore used to evaluate their effect on embryo development. Pretreatment with 12.5 and 25 microM roscovitine prior to in vitro maturation decreased the developmental competence of cat oocytes compared with that of non-roscovitine-treated controls. In conclusion, roscovitine reversibly maintained cat oocytes at the germinal vesicle stage without detrimental effect on nuclear maturation. However, it negatively affected cumulus cell viability and developmental competence.

134 THE DISTRIBUTION OF CYTOSKELETON AND CHROMATIN CONFIGURATIONS DURING EARLY EMBRYO DEVELOPMENT OF SWAMP BUFFALO (BUBALUS BUBALIS)

Microtubules and actin microfilaments have been demonstratedto be actively involved with fertilization and early embryo development. The objective of this study was to examine the redistribution of cytoskeleton and chromatin configurations in swamp buffalo oocytes through the initial cleavage event after in vitro fertilization. Sperm penetration was analysed at 6 h post IVF in 63 oocytes (3 replicates), whereas the chronology embryonic development in terms of the redistribution of cell cytoskeleton and chromatin configurations was studied in a total of 462 oocytes (7 to 8 replicates) at 12, 18, 24, 30, and 48 h after IVF. The oocytes were matured in vitro for 22 h. Then, IVF was performed as described previously (Totey et al. 1993). After fertilization, presumptive zygotes and embryos were fixed at various times (6, 12, 18, 24, 30, and 48 h) to examine spermatozoa penetration, redistribution of the cytoskeleton (microtubules and actin filaments), and chromatin configurations using epifluorescent microscopy. Staining was undertaken with wheat germ agglutinin to visualize the zona pellucida, monoclonal-α-tubulin-TRIT C to show the microtubules, 488 phalloidin to identify microfilaments, and DAPI to label the chromatin. At 6 h after fertilization, sperm penetration was observed in 44.4% of examined oocytes. At 12 h post IVF, maternal chromosomes of fertilized oocytes progressed to the second meiotic division and formed the female pronucleus simultaneously with the decondensation of paternal chromosomes. A dense network of microtubules was observed radiating from the base of the decondensing sperm head (referred to as sperm aster) At 18 h post IVF, the sperm chromatins became the male pronucleus. Simultaneously, the sperm aster increased in size and filled the whole ooplasm. The syngamy of the male and female pronuclei was completed by 24 h post IVF, which was associated with a dense array of microtubules. Cell cleavage was observed by 30 h post IVF. This was apparently facilitated by a dense network of actin microfilaments that formed in the middle of the dividing embryo. These results indicated that microtubules and actin microfilaments undergo changes after fertilization consistent with a crucial role during fertilization in swamp buffalo. The centrosomal material was paternally inherited. This work was supported by TRF-MAG (MRG-WII515S056) and CHE-TRF Senior Research Fund (RTA5080010).