Infiltrating Foxp3+ regulatory T cells and histopathological features in canine classical and spermatocytic seminomas

In humans, regulatory T (T reg) cells are known to play a critical role in both the regulation of immune homoeostasis and the progression of cancer. However, there is little information about the identification, characterization and the function of T reg cells in canine tumours. We identified T reg cells in 28 canine seminoma samples using a Forkhead box P3 (Foxp3) antibody and investigated the relationship between T reg cell infiltration and histopathological features of classical and spermatocytic seminomas (SE and SS, respectively). The Foxp3 protein showed nuclear immunostaining in infiltrating lymphocytes, and Foxp3+ cells were diffused or focally distributed in seminoma tissues. Foxp3+ cells were frequently present in the SS histotype, in seminomas that showed no evidence of tumour cell invasion into the vessels and in seminomas showing a diffuse growth pattern with three cell types. Neither the SE/SS histotype nor the histopathological features of the tumour correlated with Foxp3+ cell counts. These results indicate that Foxp3+ T reg cells may be associated with a less malignant histological phenotype or may not play a critical role in the immune response of canine seminomas. Moreover, Foxp3+ T reg cells may be associated with SS seminoma, but further studies, involving a larger number of samples, are required to better understand whether these cells play a critical role in the immune response in canine seminomas. This is the first report to demonstrate the characteristics of T reg cell infiltration in canine seminoma.

Autophagy influences maternal mRNA degradation and apoptosis in porcine parthenotes developing in vitro

Autophagy, an essential process for cellular maintenance, cell viability, and development, is the bulk degradation of proteins and organelles. This study investigated the expression levels of autophagy-related genes and the effect of 3-methyladenine (3-MA, an autophagy inhibitor) or rapamycin (an autophagy inducer) on maternal gene degradation and apoptosis in porcine parthenotes developing in vitro. LC3, which is essential for the formation of autophagosomes, was widely expressed in porcine parthenotes. High levels of autophagy-related genes, Atg5, Beclin1 and Lc3 transcripts were expressed in the 1-cell (1C) stage and gradually decreased through the 2-cell (2C) to blastocyst stages. The mRNA expression of Gdf9, c-mos and cyclin B maintained high levels in 2C and 4-cell (4C) embryos treated with 3-MA compared with the control. The Bmp15 and cyclin B mRNA levels were significantly reduced in embryos treated with rapamycin compared with the control. These results suggest that autophagy influences the degradation of these maternal genes. Furthermore, 3-MA-treated embryos exhibited significantly reduced developmental rates, decreased total cell numbers and increased rates of apoptosis. Expression of Atg5, Beclin1 and Lc3 and synthesis of LC3 protein were significantly reduced at the blastocyst stage. Although rapamycin treatment did not affect the developmental rate, it decreased the cell number and increased the rate of apoptosis, and the expression of Atg5, Beclin1 and Lc3 and LC3 protein synthesis were increased. Finally, blastocysts derived following treatment with 3-MA or rapamycin exhibited significantly decreased expression of selected transcription factors, including Pou5f1, Sox2 and Nanog. In conclusion, our results demonstrate that autophagy influences maternal mRNA degradation and apoptosis at the blastocyst stage and suggest that autophagy plays an important role in early embryo development in the pig.

Risk factors for chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a form of pulmonary hypertension caused by obstruction and vascular remodelling of pulmonary arteries following pulmonary embolism. Risk factors that predispose patients to CTEPH include the size of the initial thrombus and numerous associated host or medical conditions. Haemostatic risk factors include elevated levels of factor VIII and phospholipid antibodies or intrinsic abnormalities in fibrinogen. Medical conditions that are associated with an increased risk of CTEPH include a history of splenectomy, cancer, ventriculoatrial shunt, chronic inflammatory disease, antiphospholipid antibodies and hypothyroidism. Although CTEPH is potentially curable by pulmonary endarterectomy (PEA), up to 40% of patients evaluated for PEA may be denied surgery depending on the level of surgical experience and disease accessibility after pre-operative assessment. Furthermore, an estimated 10-15% of patients are at risk for residual pulmonary hypertension following PEA surgery, due to significant concomitant small-vessel disease. However, pre-operative identification of small-vessel involvement remains a challenge. The current medications effective in the treatment of pulmonary arterial hypertension have not demonstrated efficacy in CTEPH. Accordingly, identification of CTEPH, followed by early referral for evaluation and treatment by an experienced PEA centre, is recommended.

Classification of Cryptococcus neoformans and yeast-like fungus isolates from pigeon droppings by colony phenotyping and ITS genotyping and their seasonal variations in Korea

Cryptococcus neoformans (C neoformans) is a frequent cause of invasive fungal disease in immunocompromised human hosts. Ninety-eight samples of pigeon droppings were collected from the pigeon shelters in Seoul, and cultured on birdseed agar (BSA) and Sabouraud dextrose agar (SDA). One hundred yeast-like colonies were selected and identified via phenotype characteristics, such as colony morphology and biochemical characteristics. This was then followed with genotyping via sequencing of the internal transcribed spacer (ITS) region. The colonies were classified into four kinds of colony color types: brown type (BrT), beige type (BeT), pink type (PT), and white type (WT). Numbers of isolated BrT, BeT, PT, and WT colonies were 22 (22%), 30 (30%), 19 (19%), and 39 (39%), respectively. All BrT colonies were identified as C neoformans. BeT were identified as 19 isolates of Cryptococcus laurentii, 10 isolates of Malassezia furfur, and 1 isolate of Cryptococcus uniguttulatus. PT was divided into two colony color types: light-PT (l-PT) and deep-PT (d-PT). Eighteen of l-PT and one of d-PT were identified as Rhodotorula glutinis and Rhodotorula mucilaginosa, respectively. WT were identified as 34 isolates of Cryptococcus guilliermondii, 3 isolates of Cryptococcus zeylanoides, 1 isolate of Cryptococcus sake, and 1 isolate of Stephanoascus ciferrii. Most strains were classified identically with the use of either phenotype or genotyping techniques, but C uniguttulatus and C sake classified by phenotyping were Pseudozyma aphidis and Cryptococcus famata by genotyping. This rapid screening technique of pathogenic yeast-like fungi by only colony characteristics is also expected to be very useful for primary yeast screening. Additionally, we investigated the seasonal variations of C neoformans and other yeast-like fungi from 379 pigeon-dropping samples that were collected from February 2011 to March 2011. We isolated 685 yeast-like fungi from the samples. Almost all C neoformans and yeast-like fungi were isolated in the fall (298 strains, 43.5%) and spring (244 strains, 35.6%). A few yeast-like fungi were isolated in winter (98 strains, 14.3%) and summer (45 strains, 6%). These results would be used as an important indicator related to epidemiology and prevention of pathogenic yeast-like fungi infections transmitted through pigeon droppings.

Identification of a putative nuclear export signal motif in human NANOG homeobox domain

NANOG is a homeobox-containing transcription factor that plays an important role in pluripotent stem cells and tumorigenic cells. To understand how nuclear localization of human NANOG is regulated, the NANOG sequence was examined and a leucine-rich nuclear export signal (NES) motif ((125)MQELSNILNL(134)) was found in the homeodomain (HD). To functionally validate the putative NES motif, deletion and site-directed mutants were fused to an EGFP expression vector and transfected into COS-7 cells, and the localization of the proteins was examined. While hNANOG HD exclusively localized to the nucleus, a mutant with both NLSs deleted and only the putative NES motif contained (hNANOG HD-ΔNLSs) was predominantly cytoplasmic, as observed by nucleo/cytoplasmic fractionation and Western blot analysis as well as confocal microscopy. Furthermore, site-directed mutagenesis of the putative NES motif in a partial hNANOG HD only containing either one of the two NLS motifs led to localization in the nucleus, suggesting that the NES motif may play a functional role in nuclear export. Furthermore, CRM1-specific nuclear export inhibitor LMB blocked the hNANOG potent NES-mediated export, suggesting that the leucine-rich motif may function in CRM1-mediated nuclear export of hNANOG. Collectively, a NES motif is present in the hNANOG HD and may be functionally involved in CRM1-mediated nuclear export pathway.

Interleukin-6 enhances porcine parthenote development in vitro, through the IL-6/Stat3 signaling pathway

Signal transducer and activator of transcription-3 (Stat3) plays a central role in interleukin-6 (IL-6)-mediated cell proliferation by inhibiting apoptosis in a variety of cell types. The Stat3 pathway is essential for embryonic development. The aim of this study was to determine the effects of recombinant IL-6 on the viability and development of porcine diploid parthenotes cultured in vitro. Four-cell parthenotes, derived in vitro, were cultured to the blastocyst stage, with or without recombinant IL-6. The addition of 10 or 100 ng/ml of recombinant swine IL-6 into PZM3 medium increased the development rate of parthenotes to the blastocyst stage (P<0.05). When supplemented with 10 ng/ml of recombinant swine IL-6, the number of parthenotes at the blastocyst stage increased (P<0.05) and apoptosis decreased (P<0.05). Real-time RT-PCR experiments revealed that the addition of recombinant swine IL-6 decreased the mRNA expression of the pro-apoptotic gene Caspase3 (P<0.01) but increased the expression levels of the anti-apoptotic genes Bcl2l1 and Survivin. IL-6 receptors and Stat3 mRNA expression were upregulated after treatment with 10 ng/ml recombinant swine IL-6. Immunoblots and fluorescence labeling experiments showed that the levels of phosphorylated Stat3 were upregulated. These results suggest that recombinant swine IL-6 prevents apoptosis of porcine parthenotes and enhances porcine embryo viability through the IL-6/Stat3 signaling pathway in vitro.

Degradation of actin nucleators affects cortical polarity of aged mouse oocytes

OBJECTIVE

To investigate the molecular mechanism of mouse oocyte polarity loss during aging.

DESIGN

Experimental study.

SETTING

Academic basic research laboratory.

ANIMAL(S)

Mice.

INTERVENTION(S)

Oocytes were collected 16 hours after injection of hCG and cultured in M16 medium for an additional 14 hours with or without caffeine.

MAIN OUTCOME MEASURE(S)

Expression and localizations of actin nucleators actin-related protein 2/3 complex, JMY, and WAVE2 were examined by immunofluorescence staining, and their messenger RNA levels were examined by real-time reverse transcription-polymerase chain reaction.

RESULT(S)

The protein and messenger RNA levels of actin-related protein 2/3 complex, JMY, and WAVE2 were decreased in aged oocytes, but the levels were normal in caffeine-treated aged oocytes.

CONCLUSION(S)

Our data indicated that the loss of oocyte polarity may be due to the degradation of actin nucleators in aged oocytes.

Correlation of Foxp3 positive regulatory T cells with prognostic factors in canine mammary carcinomas

Regulatory T cells (Treg) cells play a crucial role in tumor progression by suppressing anti-tumor immunity, but are not well-documented in veterinary oncology. To identify the characteristics of Treg cells in tumor microenvironments, the numbers of Treg cells were analyzed and compared with histological prognostic factors and molecular biomarkers in canine mammary carcinoma (MC) tissues (n=37). Abundant Treg cells were associated with high histological grade and lymphatic invasion. The numbers of Treg cells infiltrating intratumoral areas markedly increased in tumors with poor prognostic factors, such as high histological grade, lymphatic invasion, and necrosis. These findings suggest that Treg cells play a role in canine MC progression. Furthermore, Treg cell numbers in intratumoral compartments may provide a potential prognostic factor when assessing canine MCs, which may in turn lead to the development of new immunologic therapeutics.

Prevalence and classification of toxigenic Staphylococcus aureus isolated from refrigerated ready-to-eat foods (sushi, kimbab and California rolls) in Korea

AIMS

To investigate the presence of toxigenic Staphylococcus aureus in ready-to-eat (RTE) Korean foods and determine the distribution of genes related to various types of toxin production.

METHODS AND RESULTS

A total of 3293 commercial RTE refrigerated foods (sushi, n = 1882; kimbab, n = 975; California rolls, n = 436) were collected from Korean grocery stores, department stores and convenience stores between January 2006 and June 2007. Of these, 197 (5.98%) RTE samples were contaminated with coagulase-positive Staph. aureus, that is, 61 (6.26%) kimbab, 110 (5.84%) sushi and 26 (5.96%) California rolls. Multiplex PCR determined the presence of 12 toxigenic genes: sea, seb, sec, sed, see, seg, seh, sei, sej, tst-1, eta and etb. Approximately half (49.75%) of the Staph. aureus isolates had toxigenic properties, and most of the toxigenic isolates possessed genes coding for the simultaneous production of two or more types of toxin. The most frequent toxigenic types found in Korean RTE foods were as follows: seg = sei > sea > tst-1 > etb > seh > eta > sec > sej.

CONCLUSIONS

This study provided a comprehensive analysis of toxigenic S. aureus isolates from Korean RTE foods and their toxigenicity types. This emphasizes the potential risk of various types of toxigenic Staph. aureus in refrigerated RTE food products, which should be better managed to establish safer food chains in global food markets.

SIGNIFICANCE AND IMPACT OF THE STUDY

This result may contribute to an extended database on Staph. aureus food contamination and mitigate the lack of available information on microbiological hazards in Southeast Asian Nations.

Expression of aldo-keto reductase family 1 member C1 (AKR1C1) gene in porcine ovary and uterine endometrium during the estrous cycle and pregnancy

BACKGROUND

The aldo-keto reductase family 1 member C1 (AKR1C1) belongs to a superfamily of NADPH-dependent reductases that convert a wide range of substrates, including carbohydrates, steroid hormones, and endogenous prostaglandins. The 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) is a member of AKR family. The aims of this study were to determine its expression in the ovary and uterus endometrium during the estrous cycle and pregnancy.

METHODS

Rapid amplification of cDNA ends (RACE) experiments were performed to obtain the 5' and 3' ends of the porcine 20 alpha-HSD cDNA. Reverse-transcriptase-PCR (RT-PCR), real-time PCR, northern blot analysis, and western blot analysis were performed to examine the expression of porcine 20 alpha-HSD. Immunohistochemical analysis was also performed to determine the localization in the ovary.

RESULTS

The porcine 20 alpha-HSD cDNA is 957 bp in length and encodes a protein of 319 amino acids. The cloned cDNA was virtually the same as the porcine AKR1C1 gene (337 amino acids) reported recently, and only differed in the C-terminal region (the AKR1C1 gene has a longer C-terminal region than our sequence). The 20 alpha-HSD gene (from now on referred to as AKR1C1) cloned in this paper encodes a deletion of 4 amino acids, compared with the C-terminal region of AKR1C1 genes from other animals. Porcine AKR1C1 mRNA was expressed on day 5, 10, 12, 15 of the cycle and 0-60 of pregnancy in the ovary. The mRNA was also specifically detected in the uterine endometrium on day 30 of pregnancy. Western blot analysis indicated that the pattern of AKR1C1 protein in the ovary during the estrous cycle and uterus during early pregnancy was similar to that of AKR1C1 mRNA expression. The recombinant protein produced in CHO cells was detected at approximately 37 kDa. Immunohistochemical analysis also revealed that pig AKR1C1 protein was localized in the large luteal cells in the early stages of the estrous cycle and before parturition.

CONCLUSIONS

Our study demonstrated that AKR1C1 mRNA and protein are coordinately expressed in the luteal cell of ovary throughout the estrous cycle and in the uterus on day 30 of pregnancy. Thus, the porcine AKR1C1 gene might control important mechanisms during the estrous cycle.

Serum selenoprotein P levels in patients with type 2 diabetes and prediabetes: implications for insulin resistance, inflammation, and atherosclerosis

CONTEXT AND OBJECTIVE

The dysregulation of hepatokines may be associated with the pathogenesis of insulin resistance and type 2 diabetes. A recent study has suggested that selenoprotein P (SeP), a novel hepatokine, may play a role in the regulation of glucose metabolism and insulin sensitivity. We examined the relationship between circulating SeP levels and clinical parameters associated with insulin resistance in humans.

PARTICIPANTS AND METHODS

We compared serum SeP concentrations in 100 subjects with diverse glucose tolerance statuses. Furthermore, we evaluated the relationship between SeP and cardiometabolic risk factors including insulin resistance, high-sensitivity C-reactive protein, and carotid intima-media thickness.

RESULTS

Serum SeP concentrations were significantly higher in patients with type 2 diabetes or prediabetes than those with normal glucose tolerance (all P < 0.01) and decreased in a stepwise manner [1032.4 (495.9-2149.4) vs. 867.3 (516.3-1582.7) vs. 362.0 (252.5-694.5), P = 0.004]. In addition, overweight and obese subjects had significantly increased SeP levels compared with lean subjects (P = 0.002). Spearman's partial correlation analysis adjusted for age and gender showed a significant relationship between SeP and cardiometabolic factors including body mass index, waist circumference, systolic blood pressure, triglycerides, glucose, hemoglobin A1c, aspartate aminotransferase, and insulin resistance. Furthermore, in multiple regression analyses, SeP showed an independent association with carotid intima-media thickness as well as high-sensitivity C-reactive protein, even after adjustment for other confounding factors.

CONCLUSIONS

Circulating SeP concentrations were elevated in patients with glucose metabolism dysregulation and were related to various cardiometabolic parameters including insulin resistance, inflammation, and atherosclerosis.

Modulation of autophagy influences development and apoptosis in mouse embryos developing in vitro

Autophagyis, the bulk degradation of proteins and organelles, is essential for cellular maintenance, cell viability, and development, and is often involved in type II programmed cell death in mammals. This study investigated the expression levels of autophagy-related genes and the effect of 3-methyladenine (3-MA, an autophagy inhibitor) or rapamycin (an autophagy inducer) on the in vitro development and apoptosis of mouse embryos. LC3, which is essential for the formation of autophagosomes, was widely expressed in mouse embryos, and high levels of transcript were present from 1 to 4 cells but gradually decreased through the morula and blastocyst stages. 3-MA-treated embryos exhibited significantly reduced developmental rates and total cell numbers, but increased rates of apoptosis. Furthermore, both the expression of Lc3, Gabarap, Atg4A, and Atg4B, and the synthesis of LC3 were significantly reduced at the blastocyst stage. Although rapamycin treatment did not affect developmental rates, cell numbers decreased, and the apoptosis rate increased. Expression of Lc3, Gabarap, Atg4A, and Atg4B, and synthesis of LC3 increased as well. Modulation of Lc3 mRNA and LC3 protein levels using 3-MA or rapamycin significantly increased apoptotic cell death through the disruption of mitochondrial morphology and reduction of mtDNA copy number at the blastocyst stage. Interestingly, the inner cell mass, detected by immunostaining with POU5F1 (OCT3/4) after 3-MA or rapamycin treatment of embryos, was significantly increased compared to controls. These results suggest that autophagy influences developmental patterning and apoptosis, and may play a role in early mouse embryogenesis.

Ndc80 regulates meiotic spindle organization, chromosome alignment, and cell cycle progression in mouse oocytes

Ndc80 (called Hec1 in human), the core component of the Ndc80 complex, is involved in regulation of both kinetochore-microtubule interactions and the spindle assembly checkpoint in mitosis; however, its role in meiosis remains unclear. Here, we report Ndc80 expression, localization, and possible functions in mouse oocyte meiosis. Ndc80 mRNA levels gradually increased during meiosis. Immunofluorescent staining showed that Ndc80 was restricted to the germinal vesicle and associated with spindle microtubules from the Pro-MI to MII stages. Ndc80 was localized on microtubules and asters in the cytoplasm after taxol treatment, while Ndc80 staining was diffuse after disruption of microtubules by nocodazole treatment, confirming its microtubule localization. Disruption of Ndc80 function by either siRNA injection or antibody injection resulted in severe chromosome misalignment, spindle disruption, and precocious polar body extrusion. Our data show a unique localization pattern of Ndc80 in mouse oocytes and suggest that Ndc80 may be required for chromosome alignment and spindle organization, and may regulate spindle checkpoint activity during mouse oocyte meiosis.

Arp2/3 complex regulates asymmetric division and cytokinesis in mouse oocytes

Mammalian oocyte meiotic maturation involves oocyte polarization and a unique asymmetric division, but until now, the underlying mechanisms have been poorly understood. Arp2/3 complex has been shown to regulate actin nucleation and is widely involved in a diverse range of processes such as cell locomotion, phagocytosis and the establishment of cell polarity. Whether Arp2/3 complex participates in oocyte polarization and asymmetric division is unknown. The present study investigated the expression and functions of Arp2/3 complex during mouse oocyte meiotic maturation. Immunofluorescent staining showed that the Arp2/3 complex was restricted to the cortex, with a thickened cap above the meiotic apparatus, and that this localization pattern was depended on actin. Disruption of Arp2/3 complex by a newly-found specific inhibitor CK666, as well as by Arpc2 and Arpc3 RNAi, resulted in a range of effects. These included the failure of asymmetric division, spindle migration, and the formation and completion of oocyte cytokinesis. The formation of the actin cap and cortical granule-free domain (CGFD) was also disrupted, which further confirmed the disruption of spindle migration. Our data suggest that the Arp2/3 complex probably regulates oocyte polarization through its effect on spindle migration, asymmetric division and cytokinesis during mouse oocyte meiotic maturation.

DNA synthesis and epigenetic modification during mouse oocyte fertilization by human or hamster sperm injection

PURPOSE

To evaluate DNA synthesis and epigenetic modification in mouse oocytes during the first cell cycle following the injection of human or hamster sperm.

METHODS

Mouse oocytes following the injection of human and hamster sperm and cultured in M16 medium.

RESULTS

Male and female pronucleus formation, DNA synthesis, histone protein modification, and heterochromatin formation were similar in mouse oocytes injected with human or hamster sperm. However, DNA methylation patterns were altered in mouse oocytes following human sperm injection. Immunocytochemical staining with a histone H3-MeK9 antibody revealed that human and hamster sperm chromatin associated normally with female mouse chromatin, then entered into the metaphase and formed normal, two-cell stage embryos.

CONCLUSIONS

Although differences in epigenetic modification of DNA were observed, fertilization and cleavage occurred in a species non-specific manner in mouse oocytes.

Perturbation of Spc25 expression affects meiotic spindle organization, chromosome alignment and spindle assembly checkpoint in mouse oocytes

Spc25 is a component of the Ndc80 complex which consists of Ndc80, Nuf2, Spc24, and Spc25. Previous work has shown that Spc25 is involved in regulation of kinetochore microtubule attachment and the spindle assembly checkpoint in mitosis. The roles of Spc25 in meiosis remain unknown. Here, we report its expression, localization and functions in mouse oocyte meiosis. The Spc25 mRNA level gradually increased from the GV to MI stage, but decreased by MII during mouse oocyte meiotic maturation. Immunofluorescent staining showed that Spc25 was restricted to the germinal vesicle, and associated with chromosomes during all stages after GVBD. Overexpression of Spc25 by mRNA injection resulted in oocyte meiotic arrest, chromosome misalignment and spindle disruption. Conversely, Spc25 RNAi by siRNA injection resulted in precocious polar body extrusion and caused severe chromosome misalignment and aberrant spindle formation. Our data suggest that Spc25 is required for chromosome alignment, spindle formation, and proper spindle checkpoint signaling during meiosis.

Mitochondrial dysfunction influences apoptosis and autophagy in porcine parthenotes developing in vitro

Mitochondria are important regulators of both apoptosis and autophagy. One of the triggers for mitochondrial-mediated apoptosis is the production of reactive oxygen species (ROS), which include hydrogen peroxide, superoxide, hydroxyl radical, nitric oxide and peroxynitrite. Recently, several studies have indicated that ROS may also be involved in the induction of autophagy. In the present study, we used H(2)O(2) to induce mitochondrial stress, examined apoptotic- and autophagic-related gene expression and observed LC3 protein (autophagosome presence marker) expression in porcine parthenotes developing in vitro. In porcine four-cell parthenotes cultured for 5 days in NCSU37 medium containing 0.4% BSA, the developmental rate and mitochondrial distribution did not differ from that of the group supplemented with 100 µM H(2)O(2) but was significantly decreased in the group supplemented with 500 µM H(2)O(2) (P<0.05). Transmission electron microscopy (TEM) indicated that whereas normal shaped mitochondria were observed in blastocysts from the control group, abnormal mitochondria (mitophagy) and autophagic vacuoles were observed in blastocysts from the group that received 500 µM H(2)O(2). Furthermore, addition of H(2)O(2) (100 µM and 500 µM) decreased cell numbers (P<0.05) and increased both apoptosis (P<0.05) and LC3 protein expression in the blastocysts. Real-time RT-PCR showed that H(2)O(2) significantly decreased mRNA expression of anti-apoptotic gene Bcl-xL but increased pro-apoptotic genes, Caspase 3 (Casp3) and Bak, and autophagy-related genes, microtubule-associated protein 1 light chain 3 (Map1lc3b) and lysosomal-associated membrane protein 2 (Lamp2). However, the addition of H(2)O(2) had no effect on mRNA expression levels in nuclear DNA-encoded mitochondrial-related genes, cytochrome oxidase (Cox) 5a, Cox5b and Cox6b1, in blastocysts. These results suggest that H(2)O(2) leads to mitochondrial dysfunction that results in apoptosis and autophagy, which is possibly related to porcine early embryo development.

Expression of HER-2 and nuclear localization of HER-3 protein in canine mammary tumors: histopathological and immunohistochemical study

HER-2 and HER-3 are transmembrane receptor proteins that are considered to be important but poorly understood biomarkers in canine tumors. In this study, the expression and the localization of HER-2 and HER-3 were evaluated immunohistochemically in canine mammary tumors (n=64; 12 benign, 52 malignant). HER-2 overexpression was identified in 2/12 (16.7%) benign and in 18/51 (35.3%) malignant cases. HER-3 was expressed in a non-nuclear localization in 11/12 (91.7%) benign and 18/52 (34.6%) malignant tumors. In contrast, HER-3 was expressed in the nucleus of neoplastic cells in 0/12 (0%) benign and 22/52 (42.3%) malignant tumors. Nuclear HER-3 expression was higher in neoplastic epithelial cells compared to myoepithelial cells, and positively correlated with high histological grade and lymphatic vessel invasion. These results suggest that nuclear HER-3 expression is significantly associated with tumor progression and metastasis and may serve as a useful prognostic biomarker in canine malignant mammary tumors.

Borealin regulates bipolar spindle formation but may not act as chromosomal passenger during mouse oocyte meiosis

In mitosis, Borealin is a member of the chromosomal passenger complex (CPC), which plays interaction roles with INCENP and survivin in the complex. Its roles in mammalian meiosis are unknown. Here, we report the expression, localization, and function of Borealin and its relation with survivin in mouse oocyte meiosis. Borealin expression was gradually increased from GV stage to MII. Immunofluorescence results revealed that Borealin accumulated near chromosomes after GVBD, localized at the spindle poles in MI, AI and MII, and at the midbody in TI stage. Taxol and nocodazole treatment showed that the localization of Borealin was dependent on microtubule dynamics, whereas survivin was independent of this. Disruption of Borealin function by antibody injection resulted in severe spindle assembly defects, but did not affect PBE. We also found that depletion of survivin by MO injection had no effect on the localization of Borealin. In conclusion, our data suggest that Borealin is required for bipolar spindle formation, but may not regulate spindle checkpoint activity as a component of the CPC during mouse oocyte meiosis.

Molecular characterization of pig alpha2,3-Gal-beta1,3-GalNAc-alpha2,6-sialyltransferase (pST6GalNAc IV) gene specific for Neu5Acalpha2-3Galbeta1-3GalNAc trisaccharide structure

Sialic acids of glycoconjugates play crucial roles in various biological processes, such as cell-cell communication and cell-substrate interaction. A sisalyltransferase, ST6GalNAc IV (Neu5Ac-alpha2,3-Gal-beta1,3-GalNAc-alpha2,6-sialyltransferase), catalyzes the formation of alpha2-6-linkages onto GalNAc residues of O-glycosidically linked Ser/Thr of proteins. In this study, we cloned the pig ST6GalNAc IV (pST6GalNAc IV) and investigated its functional characterization. pST6GalNAc IV cDNA has been isolated from pig liver tissues and it contains an entire open reading frame (ORF, 906 bp) coding for 302 amino acid residues. Entire ORF of pST6GalNAc IV containing sialylmotif 'L'-(Large), 'S'-(Small) and '-VS' (Very small) has a high degree of sequence similarity with Homo sapiens (90%), Pan troglodytes (91%) and Mus musculus (87%). Expression of pST6GalNAc IV mRNA in various pig tissues was identified by reverse transcription polymerase chain reaction (RT-PCR) analysis. pST6GalNAc IV mRNA was highly expressed in tongue, muscle and heart, whereas it was not expressed in pancreas. For functional characterization of pST6GalNAc IV gene in pig kidney PK15 cells, we have also established pST6GalNAc IV-transfected PK15 cells, which are stably expressing the pST6GalNAc IV gene. The glycosylation pattern of pST6GalNAc IV-transfected PK15 cells was detected by flow cytometry and immunofluorescence analysis with Maackia amurensis agglutinin (MAA), Maackia amurensis hemagglutinin (MAL II), Sambucus nigra agglutinin (SNA) and peanut agglutinin (PNA) lectins. The specific carbohydrate structures of Neu5Acalpha2-3Galbeta1-3(Neu5Acalpha2-6)GalNAc tetrasaccharide or Neu5Acalpha2-6GalNAc disaccharide recognized by MAL-II and SNA were revealed to be newly synthesized by pST6GalNAc IV. From the results, it was suggested that the pig pST6GalNAc IV gene is capable of synthesizing Neu5Acalpha2-3Galbeta1-3(Neu5Acalpha2-6)GalNAc tetrasaccharide structures on O-glycoproteins.

Role of CK1 in GSK3beta-mediated phosphorylation and degradation of snail

The epithelial to mesenchymal transition (EMT) that occurs during embryonic development has begun to attract attention as a potential mechanism for tumor cell metastasis. Snail is a well-known Zn-finger transcription factor that promotes EMT by repressing E-cadherin expression. It is known that Snail is phosphorylated by GSK3beta and degraded by beta-TrCP-mediated ubiquitination. Here we described another protein kinase, CK1, whose phosphorylation of Snail is required for the subsequent GSK3beta phosphorylation. Specific inhibition or depletion of CK1varepsilon inhibits the phosphorylation and degradation of Snail and promotes cell migration, suggesting a central role of CK1varepsilon in the EMT process. Furthermore, our study uncovered distinct roles and steps of Snail phosphorylation by CK1varepsilon and GSK3beta. Taken together, we identified CK1varepsilon as a new component of the Snail-mediated EMT process, providing insight into the mechanism of human cancer metastasis.

Molecular characterization and polyadenylation-regulated expression of cyclin B1 and Cdc2 in porcine oocytes and early parthenotes

Meiotic maturation of mammalian oocytes is controlled by the maturation/M-phase promotion factor (MPF), a complex of Cdc2 kinase and cyclin B protein. To better understand the molecular mechanism of oocyte maturation, we characterized porcine cyclin B1 and Cdc2 genes, both of which are widely expressed in pig tissues. We further analyzed their expression profiles during in vitro maturation of pig oocyte and early embryonic development at both the mRNA and protein level. Two isoforms of cyclin B1, comprising the same open reading frame but differing in 3'-UTR length, were identified. Cyclin B1 transcripts was up-regulated after 30 hr of maturation, while Cdc2 mRNA levels were unchanged during maturation except for a sharp decline at 44 hr. Cyclin B1 protein synthesis increased with oocyte maturation. Cdc2 protein expression was relatively low during 0-18 hr, followed by a higher level of expression up to 44 hr of maturation. Poly(A)-test PCR clearly revealed that both cyclin B1 isoforms underwent cytoplasmic polyadenylation starting around 18-24 hr during maturation, while a substantial de-adenylation and degradation of Cdc2 isoforms were observed in metaphase II oocytes and during embryo development after parthenogenetic activation. Porcine MII oocytes derived from small follicles (< or = 3 mm) and bad quality 2-cell parthenotes showed lower developmental competence and lower levels of cyclin B1 protein, and Cdc2 mRNA or both gene mRNAs, respectively, compared to their control counterparts. These results suggested that cyclin B1 was regulated posttranscriptionally by cytoplasmic polyadenylation during porcine oocyte maturation. Further, the decreased expression of maternal cyclin B1 and Cdc2 at the mRNA or protein level in developmentally incompetent oocytes and embryos was responsible for, at least in part, a profound defect in further embryonic development.

Ago2 and GW182 expression in mouse preimplantation embryos: a link between microRNA biogenesis and GW182 protein synthesis

MicroRNA-mediated RNA interference appears to play a role in early development and differentiation processes in preimplantation embryos. However, the expression of its key effectors, including Ago2, a key component of the RNA-induced silencing complex, and GW182, a critical component of GW bodies (GWBs), has not been assessed in preimplantation embryos. To characterise the roles of Ago2 and GW182 in early embryo development, we determined their transcription and protein synthesis in mouse embryos. Transcript levels of Ago2 and GW182 increased steadily from the one-cell stage through to the blastocyst stage when data were not normalised against an internal reference. However, when normalised against the internal standard, transcript levels for both genes were highest in four-cell stage embryos and decreased steadily through to the blastocyst stage. Indirect immunocytochemistry showed that both AGO2 and GW182 proteins were expressed in each stage in the early embryo and were observed to colocalise in the morula and blastocyst stages. Specific silencing of mRNA expression by short interference (si) RNA against Ago2 or Dicer1 decreased the expression of selected apoptosis- and development-related microRNAs, but did not inhibit development up to the blastocyst stage. However, transcription levels of Oct3/4, Nanog and Sox2 were decreased in both Ago2- and Dicer1-knockdown embryos at the blastocyst stage. Furthermore, although knockdown of these genes did not change transcript levels of GW182, GW182 protein synthesis was decreased in blastocyst stage embryos. These results suggest that Ago2 and Dicer1 regulate GW182 protein expression in mouse embryos, which is linked to microRNA biogenesis and likely to be important for differentiation in the blastocyst stage.

A link between the interleukin-6/Stat3 anti-apoptotic pathway and microRNA-21 in preimplantation mouse embryos

Signal transducers and activators of transcription-3 (Stat3) plays a central role in interleukin-6 (IL-6)-mediated cell proliferation by inhibiting apoptosis in a variety of cell types. MicroRNA-21 (miRNA-21), a ubiquitous miRNA, acts as an anti-apoptotic factor that seems to be indirectly but strictly linked to Stat3. In order to determine whether the IL-6 induced Stat3 anti-apoptosis pathway is linked with miRNA-21, we first determined the effects of recombinant mouse IL-6 on Stat3 expression, mouse embryo viability, and the mRNA levels of apoptosis related genes and miRNA-21 during mouse embryo development in vitro. Addition of 10 or 100 ng/ml of recombinant IL-6 to the culture medium did not affect the developmental ability of 2-cell stage embryos into blastocysts. However, total cell number was significantly increased and apoptosis was reduced in blastocyst stage embryos cultured in the presence of 100 ng/ml of recombinant IL-6. Furthermore, addition of recombinant IL-6 to the culture medium significantly increased the copy numbers of anti-apoptotic miRNA-21, up-regulated Bcl2l1, and down-regulated casp3. Similarly, the injection of mature miRNA-21 into cells up-regulated Bcl2l1 and down-regulated casp3. These results suggest that the induction of the Stat3 anti-apoptotic pathway by IL-6 is linked to miRNA-21 expression, which possibly results in the regulation of cell apoptosis in early mouse embryo development.

Perturbation of survivin expression affects chromosome alignment and spindle checkpoint in mouse oocyte meiotic maturation

Survivin is a member of inhibitors of apoptosis proteins (IAPs), which have multiple regulatory functions in mitosis, but its roles in meiosis remain unknown. Here, we report its expression, localization and functions in mouse oocyte meiosis. Survivin displayed a maximal expression level in GV stage, and then gradually decreased from Pro-MI to MII stages. Immunofluorescent staining showed that survivin was restricted to the germinal vesicle, associated with centromeres from pro-metaphase I to metaphase I stages, distributed at the midzone and midbody of anaphase and telophase spindles, and located to centromeres at metaphase II stages. Depletion of survivin by antibody injection and morpholino injection resulted in severe chromosome misalignment, precocious polar body extrusion, and larger-than-normal polar bodies. Overexpression of survivin resulted in severe chromosome misalignment and prometaphase I or metaphase I arrest in a large proportion of oocytes. Our data suggest that survivin is required for chromosome alignment and that it may regulate spindle checkpoint activity during mouse oocyte meiosis.

Involvement of polyadenylation status on maternal gene expression during in vitro maturation of porcine oocytes

During mammalian oocyte maturation, protein synthesis is mainly controlled through cytoplasmic polyadenylation of stored maternal mRNAs. In this study, the role of polyadenylation modification of maternal transcripts in pig oocytes was investigated by adding cordycepin (3'-dA), a potent polyadenylation inhibitor, to the culture medium of porcine oocytes maturing in vitro. 3'-dA significantly prevented cumulus expansion regardless of the concentration used, and inhibited pig oocyte maturation in a dose-dependent manner. Further, 3'-dA 1 microg/ml-treated MII oocytes experienced significantly lower rates of cleavage (29%) and blastocyst formation (15.35%) compared to control MII oocytes (58.6% and 35.3%, respectively). Western blotting revealed that the activity of mitogen-activated protein kinase (MAPK) and p34(cdc2) was significantly decreased in oocytes and cumulus cells treated with 3'-dA at a concentration of 1 microg/ml or greater. To further explore the underlying molecular mechanisms, expression patterns and polyadenylation states of four important genes, C-mos, cyclin B, GDF9 and BMP15, were studied as representative maternal transcripts by real-time PCR and the PAT assay. 3'-dA at concentrations above 1 microg/ml significantly prevented polyadenylation and caused aberrant expression of C-mos and GDF9 during oocyte maturation. These results suggest that polyadenylation inhibitor blocked pig oocyte maturation in vitro by one or more of the following actions: (1) inactivation of MAPK and MPF in oocytes, especially at the late stages (MI and MII); (2) prevention of cumulus cell expansion through inactivation of cellular MAPK; and (3) inhibition of the maternal mRNA polyadenylation process, which in reverse, disrupted the maternal mRNA patterns in pig oocytes' maturation in vitro.

Tetracycline-dependent expression of the human erythropoietin gene in transgenic chickens

A critical problem in the production of transgenic animals is the uncontrolled constitutive expression of the foreign gene, which occasionally results in serious physiological disorders in the transgenic animal. In this study, we report successful production of transgenic chickens that express the human erythropoietin (hEPO) gene under the control of a tetracycline-inducible promoter. A recombinant Moloney murine leukemia virus (MoMLV)-based retrovirus vector encapsidated with vesicular stomatitis virus G glycoprotein (VSV-G) was injected beneath the blastoderm of unincubated chicken embryos (stage X). Out of 198 injected eggs, 15 chicks hatched after 21 days of incubation and 14 hatched chicks expressed the vector-encoded hEPO gene when fed doxycycline, a tetracycline derivative, without any significant physiological dysfunctions. The expression of hEPO reverted to the pre-induction state by removing doxycycline from the diet. The biological activity of the hEPO produced in the transgenic chickens was comparable to commercially available CHO cell-derived hEPO. Successful germline transmission of the transgene was also confirmed in G1 transgenic chicks produced from crossing G0 transgenic roosters with non-transgenic hens. Tetracycline-inducible expression of the hEPO gene was also confirmed in the blood and eggs of the transgenic chickens.

Hyperglycemia reduces mitochondrial content and glucose transporter expression in mouse embryos developing in vitro

The objective of this research was to examine the effects of high concentrations of glucose on mouse embryos developing in vitro by studying embryo viability, mitochondrial content and expression of glucose transporters. Addition of 55 mM glucose to the culture medium of two-cell stage embryos significantly reduced the formation of morulae and blastocysts, resulting in fewer cells in the blastocyst stage embryos and increased levels of apoptosis. Quantitative reverse transcriptase (RT) PCR analysis revealed that the expression levels of the pro-apoptotic genes Bax and Casp3 at the blastocyst stage were increased significantly by the addition of either 25 or 55 mM glucose to the culture medium. However, addition of 25 or 55 mM glucose to the culture medium did not change the copy numbers of the apoptosis-related miRNAs mmu-mir-15a, mmu-mir-16 and mmu-mir-21. MitoTracker Green fluorescence revealed a decrease in the mitochondrial mass. The expression levels of the mitochondrial DNA-encoded genes Cox1 and Cox2 decreased sharply with the addition of 25 or 55 mM glucose to the culture medium. Both transcripts and protein synthesis of the glucose transporters Glut1 and Glut3 were reduced in blastocysts cultured in the presence of either 25 or 55 mM glucose. These results suggest that hyperglycemia reduces both mitochondrial content and expression levels of glucose transporters in mouse embryos developing in vitro and that this may result in apoptosis in these embryos.

High mobility group box 1 (HMGB1) is implicated in preimplantation embryo development in the mouse

High mobility group box 1 (HMGB1) regulates multiple cell functions, including transcription, DNA repair, differentiation, and apoptosis. In order to obtain insight into the role of HMGB1 in embryo development, we first evaluated its gene expression levels in mouse preimplantation embryos. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed high expression levels in zygotes, and expression steadily increased after zygotic genome activation when normalized to the rabbit Globin mRNA. Indirect immunocytochemistry showed that the HMGB1 protein was also produced in mouse embryos. Injection of a small interfering RNA (siRNA) specific for HMGB1 into zygotes specifically reduced both mRNA expression (P < 0.001) and protein synthesis of HMGB1 in early embryos developed in vitro. Injection of siRNA into the zygote did not affect development to the blastocyst stage, but significantly decreased cell numbers (P < 0.01) in the blastocyst and increased caspase3 (Casp3, P < 0.05) gene expression and apoptosis (P < 0.005). Addition of recombinant HMGB1 (Sigma, H-4652) into the culture medium enhanced the development of zygote stage mouse embryos to blastocysts, in the absence of BSA supplementation. These findings suggest that endogenous and exogenous HMGB1 are implicated in preimplantation embryo development in the mouse.

Auranofin promotes retinoic acid- or dihydroxyvitamin D3-mediated cell differentiation of promyelocytic leukaemia cells by increasing histone acetylation

BACKGROUND AND PURPOSE

To investigate the molecular mechanism for the effect of auranofin on the induction of cell differentiation, the cellular events associated with differentiation were analysed in acute promyelocytic leukaemia (APL) cells.

EXPERIMENTAL APPROACH

The APL blasts from leukaemia patients and NB4 cells were cotreated with auroanofin and all-trans-retinoic acid (ATRA) at suboptimal concentration. The HL-60 cells were treated with auroanofin and a subeffective dose of 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2 vit D3) in combination. The effect of auroanofin was investigated on histone acetylation at the promoter of differentiation-associated genes and expression of cell cycle regulators.

KEY RESULTS

Treatment with auroanofin and ATRA cooperatively induced granulocytic differentiation of fresh APL blasts isolated from patients and NB4 cells. The combined treatment also increased reorganization of nuclear PML bodies and histone acetylation at the promoter of the RARbeta2 gene. Auroanofin also promoted monocytic differentiation of the HL-60 cells triggered by subeffective concentration of 1,25(OH)2 vit D3. The combined treatment of auroanofin and 1,25(OH)2 vit D3 stimulated histone acetylation at p21 promoters and increased the accumulation of cells in the G0/G1 phase. Consistent with this, the expressions of p21, p27 and PTEN were increased and the levels of cyclin A, Cdk2 and Cdk4 were decreased. Furthermore, the hypophosphorylated form of pRb was markedly increased in cotreated cells.

CONCLUSIONS AND IMPLICATIONS

These findings indicate that auroanofin in combination with low doses of either ATRA or 1,25(OH)2 vit D3 promotes APL cell differentiation by enhancing histone acetylation and the expression of differentiation-associated genes.

Serum retinol-binding protein 4 levels are elevated in non-alcoholic fatty liver disease

OBJECTIVE

Retinol-binding protein 4 (RBP4) is a recently identified adipokine that is elevated in the serum in several insulin-resistant states. We investigated the relationship between non-alcoholic fatty liver disease (NAFLD) and serum RBP4 in nondiabetic adults.

METHODS

One hundred and fifty-nine nondiabetic, non-alcoholic subjects (95 males and 64 females) participated in this study. Division of subjects into a NAFLD group (n = 73; 45 males and 28 females) or a normal group (n = 86; 50 males and 36 females) was based on the presence of fatty liver disease determined by sonography.

RESULTS

Serum RBP4 levels in the NAFLD group were significantly higher than those in the normal group (62.8 +/- 16.0 mg/l vs. 51.7 +/- 14.6 mg/l, P < 0.0001). Multiple logistic regression analysis revealed that the RBP4 level was an independent factor associated with NAFLD (P = 0.0042). In addition, serum RBP4 levels were positively correlated with serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltranspeptidase (GGT) levels. The significant association between serum RBP4 and GGT levels remained even after adjusting for age, gender, body mass index, the homeostasis model of assessment (HOMA) value and the presence of NAFLD (r = 0.3097, P = 0.0002).

CONCLUSION

Serum RBP4 levels are significantly associated with NAFLD and liver enzymes.

Respiratory rate detection algorithms by photoplethysmography signal processing

Photoplethysmography (PPG) offers the clinically meaningful parameters, such as, heart rate, and respiratory rate. In this study, we presented three respiratory signal detection algorithms using photoplethysmography raw data generated from commercial PPG sensor: (1)Min-Max (2)Peak-to-Peak (3)Pulse Shape. As reference signal, nasal sensor signal was acquired simultaneously and compared and analyzed. We used two types of moving average filtering technique to process three PPG parameters. In laboratory experiment, 6 subjects' PPG signals were measured when they respire ten and fifteen, and arbitrary times per minute. From the results, following conclusions were drawn. Min-Max and Peak-to-Peak algorithms perform better than Pulse shape algorithm. They can be used to detect respiratory rate. But, Pulse Shape algorithm was accurate for subject 4 only. More experimental data is necessary to improve the accuracy and reliability.

Porcine embryos produced after intracytoplasmic sperm injection using xenogeneic pig sperm from neonatal testis tissue grafted in mice

Embryo development after homologous intracytoplasmic sperm injection (ICSI) with sperm from testis tissue xenografts from pigs or any other farm animal species has not been evaluated critically. Here, we report development of porcine embryos in vitro following ICSI with sperm retrieved from xenografted neonatal pig testis. Small pieces of testis tissue from newborn piglets were grafted under the back skin of castrated immunodeficient mice (n = 4) and the xenografts were collected 8 months after grafting. Spermatozoa were recovered by mincing of the grafted tissue. For comparison, testicular, epididymal and ejaculated spermatozoa were also collected from mature boars. Oocytes injected with xenogeneic spermatozoa were either fixed to determine fertilisation processes (n = 89 in five replicates) or allowed to develop in vitro (n = 143 in four replicates). Xenogeneic porcine spermatozoa were fertilisation competent (24% v. 58%, 68%, 62% or 0% for xenogeneic v. control testicular, epididymal and ejaculated spermatozoa or no spermatozoa, respectively) and embryos developed to the blastocyst stage (8% v. 22%, 27%, 25% or 0%, respectively). These results demonstrate that porcine spermatozoa derived from immature testis tissue xenografted into mice are fertilisation competent, albeit at a lower rate than testicular, epididymal or ejaculated spermatozoa from control boars, and support embryo development after ICSI.

Germinal vesicle chromatin configuration and meiotic competence is related to the oocyte source in canine

This study investigated the effect of deriving oocytes from different stages of the estrous cycle on oocyte diameter, germinal vesicle (GV) chromatin configuration, and in vitro meiotic competence in canine oocytes. Cumulus oocyte complexes (COCs) were recovered from both ovaries during anestrous, follicular, and luteal phases and in vivo ovulated oocytes. The diameter of canine oocyte was compared with or without the zona pellucida (ZP) before in vitro maturation (IVM). Also, GV chromatin configuration was evaluated before (0 h) or 72 h after IVM by fixation with 3.7% formaldehyde supplemented with 10 microg/ml Hoechst 33342 for 30 min. COCs were matured in TCM199 supplemented with 10% fetal bovine serum (FBS), 0.6 mM cysteine, 0.2 mM pyruvic acid, 50 microg/ml gentamycin sulfate, and 20 microg/ml 17beta-estradiol (E(2)) at 39 degrees C and 5% CO(2) in air for 72 h. The diameter of in vivo ovulated oocytes with the ZP (167.5+/-12.7 microm) or without ZP (133.9+/-5.3 microm) was significantly greater (p<0.05) than those of anestrous, follicular, and luteal oocytes (with ZP, 151.2+/-7.4, 153.1+/-8.8 and 152.8+/-5.4 microm, respectively; without ZP, 115.3+/-7.6, 122.1+/-4.9 and 114.3+/-6.6 microm, respectively). At 0 h, the GV-II configuration was more prevalent in oocytes from anestrual ovaries than from follicular or luteal ovaries or in vivo ovulated oocytes (63.6% versus 14.8%, 33.0%, and 0.0%; p<0.05), whereas the proportion of oocytes with the GV-V configuration was higher in follicular phase and ovulated oocytes than in oocytes from anestrus and luteal phase (57.4% and 100% versus 2.0% and 22.7%; p<0.05). However, oocytes in luteal phase exhibited diverse GV configurations (10.3%, 33.0%, 16.5%, 13.4%, and 22.7% in GV-I, GV-II, GV-III, GV-IV, and GV-V, respectively). After 72 h post-IVM, a greater percentage of in vivo ovulated oocytes progressed to MII than those oocytes collected during anestrous, follicular, and luteal phases (50.0% versus 5.5%, 11.5%, and 9.1%; p<0.05). In conclusion, the oocyte diameter, GV chromatin configuration, and meiotic maturation of canine COCs are related to the oocyte source. These results indicated that the oocyte source could be critical to nuclear progression to MII stage in canines.

Reproductive fertility of cloned male cats derived from adult somatic cell nuclear transfer

This study was designed to investigate the reproductive fertility by the natural breeding of cloned male cats with domestic female cats, and to measure endocrine hormone concentration related to male reproduction such as testosterone, leutinizing hormone (LH), and follicle stimulating hormone (FSH). Cloned A, B, C, and D cats produced three, two, four, and five kittens after natural mating with four domestic female cats, respectively, despite later puberty of the cloned D cat than those of the other cloned male cats. Three of the 14 kittens expressed an odd eye color, which was produced by 1 and 2 from cloned A and B cats. The eye color of the other F1 kittens varied from nine brown to two blue. Body weight at birth ranged from 72.9 to 134.0 g. Although clone D had a poorer libido and entered puberty later than those of the other cloned male cats, he produced gonadal hormones within the average range. Four of the cloned male cats had normal fertility. The concentration of gonadal hormones in cloned male cats was similar to two control and donor cats. The concentration of testosterone was not significantly different among clones A, B, C, D, and control cats (5.99 +/- 5.68; 3.46 +/- 2.81; 6.41 +/- 2.17; 3.75 +/- 0.34; 4.0 +/- 3.63 ng/mL, p < 0.05). The concentrations of LH and FSH were not significantly different among the cloned cats (p < 0.05). Seven male and seven female (in total 14) kittens were produced by the natural breeding with four domestic female cats. These results indicated that cloned male cats have normal reproductive fertility and lie within the normal range of gonadal hormone production. All F1 kittens were produced by natural breeding and delivery, and are still alive and have normal growth health (27 months age).

Cdc42 is implicated in polarity during meiotic resumption and blastocyst formation in the mouse

Cell division cycle 42 (Cdc42), a member of the Rho family of small guanosine triphosphatase (GTPase) proteins, regulates multiple cell functions, including: motility, proliferation, apoptosis, and cell morphology. In order to obtain insight into the role of Cdc42 in meiotic resumption and embryo development, we first evaluated its gene expression levels in mouse oocytes and embryos during in vitro development. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed high-expression levels in GV stage oocytes that steadily decreased up to the 2-cell (2C) stage embryo, and then expression increased during morulae and blastocyst formation. Indirect Immunocytochemistry also showed protein synthesis of CDC42 in the mouse oocytes and early embryos. Introducing small interference RNA (siRNA) of Cdc42 into germinal vesicle stage oocytes or zygotes specifically reduced both mRNA expression and protein synthesis of CDC42 in in vitro developed metaphase II oocytes and early embryos. Meiotic maturation and cytoskeleton assembly were significantly altered following siRNA injection into germinal vesicle stage oocytes. Injection of siRNA into the zygote did not affect cleavage or cell numbers in morulae, but significantly decreased in vitro development to the morula or blastocyst. These findings suggest that gene expression of Cdc42 is involved in meiotic resumption and blastocyst formation in the mouse, possibly through maintaining polarity.