Extratropical cyclone climatology across eastern Canada

Plante, Mathieu,Son, Seok‐,Woo,Atallah, Eyad,Gyakum, John,Grise, Kevin John Wiley Sons, Ltd 2015 International journal of climatology Vol.35 No.10

<P><B>ABSTRACT</B></P><P>Extratropical cyclone (ETC) tracks across eastern Canada are examined by applying a Lagrangian tracking algorithm to the lower‐tropospheric relative vorticity field of reanalysis data. Both the seasonal cycle and the interannual variability of ETCs are quantified in terms of overall cyclone frequency, intensity, and regions of development and decay. We find that ETCs travelling to eastern Canada tend to develop over the Rockies, the Great Lakes and the US East Coast. The ETCs are most intense over Newfoundland and the North Atlantic Ocean, confirming previous findings. While ETCs at cities along the Atlantic coastline (e.g. St. John's) are dominated by East Coast cyclones (which are intense in winter), those inland (e.g. Toronto) track primarily from the Great Lakes. ETCs that develop over the Gulf of Mexico affect eastern Canada infrequently, but those that do tend to be intense. The interannual variability of the wintertime ETCs is influenced by the El Niño‐Southern Oscillation (ENSO). Significant ENSO‐related variability is found over most regions of southern Canada, except on the east coast. Although ETCs at Toronto are significantly modulated by ENSO, no visible changes are found at St. John's. These ENSO‐related ETC changes are mostly due to the shifts in ETC development regions, with minor changes in the travelling direction of ETCs.</P>

Behaviors of ATP-dependent chromatin remodeling factors during maturation of bovine oocytes in vitro

Wee, Gabbine,Shin, Sang-Tae,Koo, Deog-Bon,Han, Yong-Mahn JOHN WILEY & SONS LTD 2010 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.77 No.2

<P>The mammalian oocyte undergoes dynamic changes in chromatin structure to reach complete maturation. However, little known is about behaviors of ATP-dependent chromatin remodeling factors (ACRFs) during meiosis. Here, we found that respective ACRFs may differently behave in the process of oocyte maturation in the bovine. All ACRFs interacted with oocytic chromatin at the germinal vesicle (GV) stage. Mi-2 and hSNF2H disappeared from GV-chromatin within 1 hr of in vitro culture whereas Brg-1 and BAF-170 were retained throughout germinal vesicle break down (GVBD). Brg-1 was localized on the condensed chromatin outside, whereas BAF-170 was entirely excluded from condensed chromatin. Thereafter, Brg-1 and BAF-170 interacted with metaphase I and metaphase II chromosomes. These results imply that Mi-2 and hSNF2H may initiate the meiotic resumption, and Brg-1 and BAF-170 may support chromatin condensation during meiosis. In addition, DNA methylation and methylation of histone H3 at lysine 9 (H3K9) seem to be constantly retained in the oocyte chromatin throughout in vitro maturation. Inhibition of ACRF activity by treatment with the inhibitor apyrase led to retarded chromatin remodeling in bovine oocytes, thereby resulting in poor development of fertilized embryos. Therefore, these results indicate that precise behaviors of ACRFs during meiosis are critical for nuclear maturation and subsequent embryonic development in the bovine. Mol. Reprod. Dev. 77: 126–135, 2010. © 2009 Wiley-Liss, Inc.</P>

Characterization of pig vasa homolog gene and specific expression in germ cell lineage

Lee, Gab Sang,Kim, Hye Soo,Lee, So Hyun,Kang, Min Soo,Kim, Dae Yong,Lee, Chang Kyu,Kang, Sung Keun,Lee, Byeong Chun,Hwang, Woo Suk JOHN WILEY & SONS LTD 2005 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.72 No.3

<P>The vasa gene is known to be an important factor for germ cell development in both invertebrates and vertebrates. In the present study, we cloned the porcine vasa homolog (Pvh, 2,172 bps) and investigated its expression at mRNA and protein levels. The isolated cDNA had deduced 724 amino acid residues with significant homology to mouse (85%) and human (91%) vasa. In adult tissues, Pvh transcript was restricted to the ovary and testis, and was undetectable in somatic tissues. During preimplantation embryo development, Pvh was transcribed in oocytes and fertilized 2-cell embryos, but not in other preimplantation embryos. In fetal stage, the transcript of Pvh gene was expressed in all fetal stage, except in day 17–18. Immunohistochemical analysis of fetal and adult gonad revealed that the Pvh protein was localized in oocytes and spermatocytes, consistent with mRNA expression. Interestingly, Pvh protein was also observed in proliferating primordial germ cells (PGCs) and freshly isolated PGCs, but not in embryonic germ cells. Our results suggest that Pvh gene can be a useful marker for germ cell development in pigs. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc.</P>

Fragmentation and development of preimplantation porcine embryos derived by parthenogenetic activation and nuclear transfer

Im, Gi-Sun,Yang, Boh-Suk,Lai, Liangxue,Liu, Zhonghua,Hao, Yanhong,Prather, Randall S. JOHN WILEY & SONS LTD 2005 Molecular Reproduction and Development Vol.71 No.2

<P>Fragmentation occurs during early developmental stages of electrically activated oocytes and nuclear transfer (NT) embryos. It might contribute to the low developmental rate of porcine NT embryos. The present study was conducted to investigate whether the addition of sugars such as sorbitol or sucrose suppresses fragmentation and supports the development of electrically activated oocytes and NT embryos. The activated oocytes were cultured in Porcine Zygote Medium-3 (PZM-3) supplemented with sorbitol or sucrose for 2 days after electric activation, and then cultured in the PZM-3 for the remaining 4 days. The osmolarities of PZM-3, PZM-3 supplemented with 0.05 or 0.1 M sorbitol, and PZM-3 with 0.05 M sucrose were 269 ± 6.31, 316 ± 3.13, 362 ± 4.37, and 315 ± 5.03 mOsm, respectively. When parthenogentically activated oocytes were cultured in PZM-3 supplemented with 0.05 M sorbitol or sucrose for the first 2 days and then cultured in PZM-3 without sugar, a significantly higher (P < 0.05) cleavage rate and blastocyst rate were observed. Interestingly, addition of sugar to PZM-3 for 2 days reduced the fragmentation rate compared to PZM-3 without sugar. In NT embryos, sugar addition into PZM-3 increased the fusion rate (84.2% ± 6.07 vs. 95.1% ± 2.52), cleavage rate (67.6% ± 5.80 vs. 77.3% ± 3.03), and developmental rate to the blastocyst stage (10.2% ± 0.79 vs. 19.4% ± 1.77). There was no significant difference between treatments for the number of the blastocysts. In addition the fragmentation rate was reduced compared to PZM-3 without sorbitol (26.1 ± 4.30 vs. 14.5 ± 1.74). In conclusion, increasing the osmolarity of PZM-3 through addition of either sorbitol or sucrose for 48 hr increased the cleavage and developmental rate to the blastocyst stage by reducing the fragmentation rate through increasing osmolarity. Mol. Reprod. Dev. 71: 159–165, 2005. © 2005 Wiley-Liss, Inc.</P>

Effects of thiol compounds on in vitro maturation of canine oocytes collected from different reproductive stages

Hossein, Mohammad Shamim,Kim, Min Kyu,Jang, Goo,Oh, Hyun Joo,Koo, OkJae,Kim, Jeong Joo,Kang, Sung Keun,Lee, Byeong Chun,Hwang, Woo Suk JOHN WILEY & SONS LTD 2007 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.74 No.9

<P>Various thiol compounds are known to improve cytoplasmic and/or nuclear maturation of oocytes in vitro. The present study examined the effects of two thiol compounds, cysteine (0.1, 0.5, and 1.0 mM) and cysteamine (50, 100, and 200 µM), on cytoplasmic and nuclear maturation of canine oocytes. Oocytes collected from different reproductive stages were cultured in TCM-199 supplemented with 10% fetal bovine serum, 2.2 mg/ml sodium carbonate, 2.0 µg/ml estrogen, 0.5 µg/ml FSH, 0.03 IU/ml hCG, and 1% penicillin–streptomycin solution for 72 h. Data were analyzed by two-way ANOVA after arcscine transformation and protected by Bonferroni post hoc test. The effects of cysteine and cysteamine on canine IVM were varied depending on the reproductive stage of oocyte donor bitches. In the follicular stage, significantly more oocytes reached the metaphase II (M II) stage when cultured with 0.5 or 1.0 mM cysteine (16.7% and 16.9%, respectively) compared to the control (6.2%). In the follicular stage, cysteamine increased oocyte maturation rate upto the M II stage (15.1% to 17.0%) compared to the control (4.4%). Both the 0.5 mM cysteine and 100 µM cysteamine, alone or together, increased the intracellular GSH level of canine oocytes compared to the control. Irrespective of reproductive stage, no further beneficial effects on nuclear or cytoplasmic maturation were observed when 0.5 mM cysteine and 100 µM cysteamine were supplemented together. In conclusion, addition of 0.5 mM cysteine and 100 µM cysteamine to the maturation medium improved IVM of canine oocytes. Mol. Reprod. Dev. 74: 1213–1220, 2007. © 2007 Wiley-Liss, Inc.</P>

Influence of ovarian hyperstimulation and ovulation induction on the cytoskeletal dynamics and developmental competence of oocytes

Lee, Seung Tae,Han, Ho Jae,Oh, Seo Jin,Lee, Eun Ju,Han, Jae Yong,Lim, Jeong M. JOHN WILEY & SONS LTD 2006 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.73 No.8

<P>This study was undertaken to determine the effects of gonadotrophin on cytoskeletal dynamics and embryo development and its role in improving the retrieval of developmentally competent oocytes. Female golden hamsters were injected with human chorionic gonadotrophin (hCG; 5-, 7.5- or 15-IU) on the day 4 of estrus, pregnant mare serum gonadotrophin (PMSG; 5-, 7.5- or 15-IU) on the day 1 of estrus, or 15-IU hCG at 56 hr post-15-IU PMSG injection in any cycle except estrus. Increasing the hCG dose decreased not only retrieval rate of 2-cell embryo but development to blastocyst after subsequent in vitro culture. Whereas, although increasing the PMSG dose induced increasing the number of 2-cell embryo and blastocyst, 15-IU PMSG injection caused retardation of development to blastocyst. No 2-cell embryos were retrieved by injecting both PMSG and hCG. The injections of 15-IU hCG and 7.5- or 15-IU PMSG inhibited the proliferation of trophectodermal and inner cell mass cells, respectively. Gonadotrophin injection didn't influence microtubular spindle formation, but 5- or 15-IU hCG, 15-IU PMSG, or PMSG and hCG injections induced aberrant cortical granule (CG) and microfilament distribution. After 15-IU hCG or PMSG and hCG injections, fewer oocytes had enriched cortical actin domains, and the expression of α-, β- and γ-actin genes was greatly increased. In conclusion, a high dose of gonadotrophins alters the microfilament and CG distribution, which in turn reduces the developmental competence of oocytes. Injecting a reduced dose of PMSG to initiate ovarian hyperstimulation without triggering ovulation contributes to the efficient retrieval of developmentally competent oocytes. Mol. Reprod. Dev. 1022–1033, 2006. © 2006 Wiley-Liss, Inc.</P>

Ectopic expression of Tollo/Toll-8 antagonizes Dpp signaling and induces cell sorting in the Drosophila wing

Kim, Sangjoon,Chung, SeYeon,Yoon, Jeongsook,Choi, Kwang-Wook,Yim, Jeongbin John Wiley & Sons 2006 Genesis Vol.44 No.11

<P>The wing imaginal disc of Drosophila consists of the primordia for the adult wing and the body wall. The zinc-finger transcription factor Teashirt (Tsh) is expressed in the region proximal to the wing primordium and regulates the formation of the wing-body wall boundary. Here, we report that Tollo/Toll-8, a member of Toll family transmembrane proteins, is also expressed proximal to the wing domain. Ectopic expression of Decapentaplegic (Dpp), a morphogen for wing development, represses tollo expression in the proximal domain. Likewise, misexpression of Tollo in the presumptive wing strongly antagonizes the effects of Dpp signaling. The extracellular domain of Tollo containing the Leucine-Rich Repeats (LRR) is required for the inhibition of Dpp signaling in the wing. Furthermore, clones of cells with Tollo overexpression are sorted out from the surrounding wild-type cells, resulting in the formation of epithelial folds around the clone boundaries. Tsh is ectopically induced at the border of Tollo-expressing clones. Despite the strong effects of Tollo overexpression on Dpp signaling and cell sorting, loss-of-function tollo mutants are viable with normal external morphology. Our data suggest that Tollo function might be redundant but is sufficient to antagonize Dpp signaling and induce sorting of Tollo expressing cells from the wing cells to develop proximal cell fate. genesis 44:541–549, 2006. © 2006 Wiley-Liss, Inc.</P>

Effects of calcitonin and parathyroid hormone on the regulation of cabindin-D_9k in the uterus, placenta, and fetal membrane of rats related to blood calcium level during late gestation

Hong, Eui-Ju,Choi, Kyung-Chul,Hyun, Sang-Hwan,Jeung, Eui-Bae JOHN WILEY & SONS LTD 2007 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.74 No.9

<P>Calbindin-D<SUB>9k</SUB> (CaBP-9k) gene is expressed in the uterus of pregnant rats, which is regulated by steroid hormones during estrous cycle or gestation. We hypothesized that there is a positive correlation between altered CaBP-9k expression and change in one or more of the hormones to provide a clue to the mechanism responsible for the altered calcium levels in the uterus, placenta, and fetal membrane during late gestation. Thus, in the present study, we investigated the effects of the hormones including estradiol (E2), calcitonin (CT), and parathyroid hormone (PTH) on the regulation of CaBP-9k in these tissues. There was an increase in the level of CaBP-9k in the uterus, placenta, and extra-embryonic membrane at late gestation, as blood calcium level increased. The protein level of CaBP-9k remained lower in the uterus at two-thirds of pregnancy, and then it rebounded abruptly during late pregnancy. During late gestation, E2 is postulated to be a dominant factor in the regulation of uterine CaBP-9k gene expression. Furthermore, we assumed that there is a positive correlation between altered expression of CaBP-9k and blood calcium level during pregnancy. The present study demonstrated the regulation of CaBP-9k mRNA in the uterus, placenta, and fetal membrane of rats, implying a role for CaBP-9k gene in the control of blood calcium in placenta and the calcium passing from maternal blood to fetal circulation. Taken together, these results suggest that major alterations in calcium metabolism caused by maternal thyroparathyroidectomy (TPTX), are sufficient to affect the changes in reproductive tissues during late pregnancy. In addition, an increase of blood calcium level is one of the most significant factors in the regulation of CaBP-9k at the transcriptional and/or translational levels in the reproductive tissues during late pregnancy. Mol. Reprod. Dev. 74: 1188–1197, 2007. © 2007 Wiley-Liss, Inc.</P>

Resident microglia die and infiltrated neutrophils and monocytes become major inflammatory cells in lipopolysaccharide-injected brain

Ji, Kyung-Ae,Yang, Myung-Soon,Jeong, Hey-Kyeong,Min, Kyoung-Jin,Kang, Seung-Hee,Jou, Ilo,Joe, Eun-Hye John Wiley & Sons, Inc. 2007 Glia Vol.55 No.15

<P>Generally, it has been accepted that microglia play important roles in brain inflammation. However, recently several studies suggested possible infiltration of blood neutrophils and monocytes into the brain. To understand contribution of microglia and blood inflammatory cells to brain inflammation, the behavior of microglia, neutrophils, and monocytes was investigated in LPS (lipopolysaccharide)-injected substantia nigra pars compacta, cortex, and hippocampus of normal and/or leukopenic rats using specific markers of neutrophils (myeloperoxidase, MPO), and microglia and monocytes (ionized calcium binding adaptor molecule-1, Iba-1), as well as a general marker for these inflammatory cells (CD11b). CD11b-immunopositive (CD11b<SUP>+</SUP>) cells and Iba-1<SUP>+</SUP> cells displayed similar behavior in intact and LPS-injected brain at 6 h after the injection. Interestingly, however, CD11b<SUP>+</SUP> cells and Iba-1<SUP>+</SUP> cells displayed significantly different behavior at 12 h: Iba-1<SUP>+</SUP> cells disappeared while CD11b<SUP>+</SUP> cells became round in shape. We found that CD11b/Iba-1-double positive (CD11b<SUP>+</SUP>/Iba-1<SUP>+</SUP>) ramified microglia died within 6 h after LPS injection. The round CD11b<SUP>+</SUP> cells detected at 12 h were MPO<SUP>+</SUP>. These CD11b<SUP>+</SUP>/MPO<SUP>+</SUP> cells were not found in leukopenic rats, suggestive of neutrophil infiltration. MPO<SUP>+</SUP> neutrophils expressed inducible nitric oxide synthase, interleukin-1β, cyclooxygenase-2, and monocyte chemoattractant protein-1, but died within 18 h. CD11b<SUP>+</SUP> cells detected at 24 h appeared to be infiltrated monocytes, since these cells were once labeled with Iba-1 and were not found in leukopenic rats. Furthermore, transplanted monocytes were detectable in LPS-injected brain. These results suggest that at least a part of neutrophils and monocytes could have been misinterpreted as activated microglia in inflamed brain. © 2007 Wiley-Liss, Inc.</P>

Development and calcium level changes in pre-implantation porcine nuclear transfer embryos activated with 6-DMAP after fusion

Im, Gi-Sun,Samuel, Melissa,Lai, Liangxue,Hao, Yanhong,Prather, Randall S. JOHN WILEY & SONS LTD 2007 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.74 No.9

<P>This study investigated the effect of treatment with 6-dimethylaminopurine (6-DMAP) following fusion on in vitro development of porcine nuclear transfer (NT) embryos. Frozen thawed ear skin cells were transferred into the perivitelline space of enucleated oocytes. Reconstructed oocytes were fused and activated with electric pulse in 0.3 M mannitol supplemented with either 0.1 or 1.0 mM CaCl<SUB>2</SUB>. In each calcium concentration, activated oocytes were divided into three groups. Two groups of them were exposed to either ionomycin (I + 6-DMAP or 6-DMAP alone. In experiment 2, fused NT embryos in 0.3 M mannitol containing 1.0 mM CaCl<SUB>2</SUB> were exposed to 6-DMAP either immediately or 20 min after fusion/activation. For 0.1 mM CaCl<SUB>2</SUB>, oocytes activated with either I + 6-DMAP or 6-DMAP alone showed a higher (P < 0.05) developmental rate to the blastocyst stage than those activated with an electric pulse alone (26.7 and 22.5 vs. 12.5%). For 1.0 mM CaCl<SUB>2</SUB>, oocytes activated with either I + 6-DMAP or 6-DMAP alone showed significantly higher (P < 0.05) developmental rate to the blastocyst stage (35.6 and 28.3 vs. 19.8%). Developmental rate to the blastocyst stage was (P < 0.05) increased in NT embryos activated with 6-DMAP 20 min after fusion. 6-DMAP made a higher and wider Ca<SUP>2+</SUP> transient compared to that induced by electric pulses (Fig. 3). The fluctuation lasted during the time that oocytes were cultured in 6-DMAP. Regardless of Ca<SUP>2+</SUP> concentration in fusion medium, activation with 6-DMAP following electric pulses supported more development of porcine NT embryos. Activation of NT embryos with 6-DMAP after fusion in the presence of 1.0 mM CaCl<SUB>2</SUB> could support better developmental rate to the blastocyst stage. Mol. Reprod. Dev. 74: 1158–1164, 2007. © 2007 Wiley-Liss, Inc.</P>