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Zygote: the Biology of Gametes and Early Embryos

Shogo Higaki, Masao Kishi, Keisuke Koyama, Masashi Nagano, Seiji Katagiri, Tatsuyuki Takada, Yoshiyuki Takahashi
The preselection of highly developmentally competent oocytes for in vitro maturation (IVM) is crucial for improving assisted reproductive technology. Although several intrinsic markers of oocyte quality are known to be closely related to the onset of nuclear maturation (germinal vesicle break down, GVBD), a direct comparison between GVBD timing and oocyte quality has never been reported. In this study, we established a non-invasive oocyte evaluation method based on GVBD timing for preselecting more developmental competent oocytes in mice...
November 22, 2016: Zygote: the Biology of Gametes and Early Embryos
Camila Marques, Francine Faustino, Bruno Bertolucci, Maria do Carmo Faria Paes, Regiane Cristina da Silva, Laura Satiko Okada Nakaghi
The aim of this study was to characterize the embryonic development of Zungaro jahu, a fresh water teleostei commonly known as 'jaú'. Samples were collected at pre-determined times from oocyte release to larval hatching and analysed under light microscopy, transmission electron microscopy and scanning electron microscopy. At the first collection times, the oocytes and eggs were spherical and yellowish, with an evident micropyle. Embryo development took place at 29.4 ± 1.5°C and was divided into seven stages: zygote, cleavage, morula, blastula, gastrula, organogenesis, and hatching...
November 22, 2016: Zygote: the Biology of Gametes and Early Embryos
J Zapata-Martínez, G Sánchez-Toranzo, F Chaín, C A N Catalán, M I Bühler
Sesquiterpene lactones (STLs) are a large and structurally diverse group of plant metabolites generally found in the Asteraceae family. STLs exhibit a wide spectrum of biological activities and it is generally accepted that their major mechanism of action is the alkylation of the thiol groups of biological molecules. The guaianolides is one of various groups of STLs. Anti-tumour and anti-migraine effects, an allergenic agent, an inhibitor of smooth muscle cells and of meristematic cell proliferation are only a few of the most commonly reported activities of STLs...
November 3, 2016: Zygote: the Biology of Gametes and Early Embryos
F M C Caixeta, R V Sousa, A L Guimarães, L O Leme, J F W Sprícigo, S B Senna Netto, I Pivato, M A N Dode
This study aimed to evaluate the effect of meiotic arrest using phosphodiesterase type 3A (PDE 3A) inhibitors, cilostamide and C-type natriuretic peptide (NPPC), on pre-maturation (PM) of oocytes to be used in the production of cloned embryos. Nuclear maturation, in vitro embryo production (IVP), somatic cell nuclear transfer (SCNT) and parthenogenetic activation (PA), and total cells number of cloned embryos were evaluated. The results were analysed by chi-squared and Kruskal-Wallis test with a P-value 0.05) between control and PM, both for cleavage (78...
October 26, 2016: Zygote: the Biology of Gametes and Early Embryos
A L S Guimarães, S A Pereira, M N Diógenes, M A N Dode
The aim of this study was to evaluate the effect of adding a combination of insulin, transferrin and selenium (ITS) and l-ascorbic acid (AA) during in vitro maturation (IVM) and in vitro culture (IVC) on in vitro embryo production. To verify the effect of the supplements, cleavage and blastocyst rates, embryo size and total cell number were performed. Embryonic development data, embryo size categorization and kinetics of maturation were analyzed by chi-squared test, while the total cell number was analyzed by a Kruskal-Wallis test (P < 0...
October 17, 2016: Zygote: the Biology of Gametes and Early Embryos
Yukou Sugano, Manami Yazawa, Sachio Takino, Sueo Niimura, Hideaki Yamashiro
The objective of this study was to classify spindle and first polar body (PB1) chromosome images in ovulated mouse oocytes over time to predict the developmental competence of metaphase II (MII) oocytes. Oocytes were collected at 12, 15, 20, and 25 h after human chorionic gonadotropin (hCG) injection, and stained for spindle tubulin, chromosomes, and PB1 chromosomes. MII spindle morphology was classified as tapered type or barrel type and PB1 chromosomes were categorized as aggregated, separated, dot, or collapsed...
October 13, 2016: Zygote: the Biology of Gametes and Early Embryos
Ching Man Chan, Jacqueline T M Aw, Sarah E Webb, Andrew L Miller
In zebrafish embryos, distinct Ca2+ transients are localized to the early cleavage furrows during the first few cell division cycles. These transients are generated mainly by release via IP3Rs in the endoplasmic reticulum, and they are necessary for furrow positioning, propagation, deepening and apposition. We previously showed, via the use of inhibitors, that store-operated Ca2+ entry (SOCE) also appears to be essential for maintaining the IP3R-mediated elevated levels of [Ca2+]i for the extended periods required for the completion of successful furrow deepening and daughter cell apposition in these large embryonic cells...
October 5, 2016: Zygote: the Biology of Gametes and Early Embryos
Sylvia J Bedford-Guaus, François Chauvigné, Eva Mejía-Ramírez, Mercè Martí, Antoni Ventura-Rubio, Ángel Raya, Joan Cerdà, Anna Veiga
While vitrification has become the method of choice for preservation of human oocytes and embryos, cryopreservation of complex tissues and of large yolk-containing cells, remains largely unsuccessful. One critical step in such instances is appropriate permeation while avoiding potentially toxic concentrations of cryoprotectants. Permeation of water and small non-charged solutes, such as those used as cryoprotectants, occurs largely through membrane channel proteins termed aquaporins (AQPs). Substitution of a Thr by an Ala residue in the pore-forming motif of the zebrafish (Dario rerio) Aqp3b paralog resulted in a mutant (DrAqp3b-T85A) that when expressed in Xenopus or porcine oocytes increased their permeability to ethylene glycol at pH 7...
October 5, 2016: Zygote: the Biology of Gametes and Early Embryos
Dong-Kyung Lee, Chi-Hun Park, Kwang-Hwan Choi, Yeon-Ik Jeong, Kyung-Jun Uh, Jae Yeon Hwang, Sang-Goo Lee, Chang-Kyu Lee
The development of embryonic stem cells (ESCs) from large animal species has become an important model for therapeutic cloning using ESCs derived by somatic cell nuclear transfer (SCNT). However, poor embryo quality and blastocyst formation have been major limitations for derivation of cloned ESCs (ntESCs). In this study, we have tried to overcome these problems by treating these cells with histone deacetylase inhibitors (HDACi) and aggregating porcine embryos. First, cloned embryos were treated with Scriptaid to confirm the effect of HDACi on cloned embryo quality...
October 3, 2016: Zygote: the Biology of Gametes and Early Embryos
Isao Takahashi, Keiichiro Kyozuka
An important step for successful fertilization and further development is the increase in intracellular Ca2+ in the activated oocyte. It has been known that starfish oocytes become increasingly sensitive to inositol 1,4,5-trisphosphate (IP3) during meiotic maturation to exhibit highly efficient IP3-induced Ca2+ release (IICR) by the time of germinal vesicle breakdown (GVBD). However, we noted that the peak level of intracellular Ca2+ increase after insemination is already high in the maturing oocytes before GVBD...
October 3, 2016: Zygote: the Biology of Gametes and Early Embryos
Miyako Sugiyama, Mei Sumiya, Koumei Shirasuna, Takehito Kuwayama, Hisataka Iwata
The main aim of the present study was to examine the hypothesis that an increase in the number of granulosa cells surrounding developing bovine oocytes results in both high ATP levels and an increase in the acetylation level of H4K12 in oocytes grown in vitro. Oocyte-granulosa cell complexes (OGCs) were collected from early antral follicles (EAFs, 0.4-0.7 mm in diameter), and individually cultured on 96-well plates with or without additional granulosa cell mass that had been prepared from other OGCs. After 16 days of culture, we examined: (i) the rate of antrum formation of the OGCs; (ii) the diameter, maturation, and fertilization rate of the oocytes; and (iii) the ATP content and acetylation level of H4K12 in the oocytes grown in vitro...
October 3, 2016: Zygote: the Biology of Gametes and Early Embryos
Maria Agnello, Roberto Chiarelli, Chiara Martino, Liana Bosco, Maria Carmela Roccheri
Autophagy is a major intracellular pathway for the degradation and recycling of cytosolic components. Emerging evidence has demonstrated its crucial role during the embryo development of invertebrates and vertebrates. We recently demonstrated a massive activation of autophagy in Paracentrotus lividus embryos under cadmium stress conditions, and the existence of a temporal relationship between induced autophagy and apoptosis. Although there have been numerous studies on the role of autophagy in the development of different organisms, information on the autophagic process during oogenesis or at the start of development in marine invertebrates is very limited...
December 2016: Zygote: the Biology of Gametes and Early Embryos
Maria Celina Abraham, Anders Johannisson, Jane M Morrell
Sperm preparation is an important step in the in vitro production of embryos. Centrifugation through colloids has been used to select normal sperm for assisted reproduction in several species. Animal models can sometimes be used as a preliminary step to investigate sperm preparation methods that are potentially of use for human fertility treatments. In this study bovine semen was prepared using three variants of the single-layer centrifugation sperm selection technique (Small, Mini, Mini-EP) with Bovicoll (Androcoll-B)...
December 2016: Zygote: the Biology of Gametes and Early Embryos
D E Rosa, J M Anchordoquy, J P Anchordoquy, M A Sirini, J A Testa, G A Mattioli, C C Furnus
The aim of this study was to investigate the influence of copper (Cu) during in vitro maturation (IVM) on apoptosis and DNA integrity of cumulus cells (CC); and oocyte viability. Also, the role of CC in the transport of Cu during IVM was evaluated on oocyte developmental capacity. Damage of DNA was higher in CC matured without Cu (0 µg/dl Cu, P < 0.01) with respect to cells treated with Cu for cumulus-oocyte complexes (COCs) exposed to 0, 20, 40, or 60 µg/dl Cu). The percentage of apoptotic cells was higher in CC matured without Cu than in CC matured with Cu...
December 2016: Zygote: the Biology of Gametes and Early Embryos
Xue Wang, Jingran Zhen, Zhengyi Sun, Qi Yu, Chengyan Deng, Yuanzheng Zhou, Hanbi Wang, Fangfang He
This study aimed to compare the neonatal outcomes of transplanted fifth day (D5) or sixth day (D6) frozen-thawed blastocysts, aiming to provide guidance when choosing blastocyst recovery methods. The clinical data of 1109 patients that were performed for recovered blastocyst transplantation, as well as the data of 515 patients who had already delivered were analyzed retrospectively. The patients were divided into single- or twins-birth groups according to blastocyst formation time (D5 or D6) and the number of fetus(es)...
October 2016: Zygote: the Biology of Gametes and Early Embryos
Nathália L M Lara, Ivan C Santos, Guilherme M J Costa, Dirceu A Cordeiro-Junior, Antônio C G Almeida, Ana P Madureira, Marcos S Zanini, Luiz R França
The spiny rat (Proechimys guyannensis) is a neotropical rodent that is used in biomedical research, particularly research related to chronic resistance to epilepsy and infectious diseases. To our knowledge, there are few reports concerning the reproductive biology of this species. Therefore, besides providing basic biometric and morphometric data, in the present study we investigated testis function and spermatogenesis in adult spiny rats. The mean testis weight and gonadosomatic index obtained were 1.63 ± 0...
October 2016: Zygote: the Biology of Gametes and Early Embryos
Zuowu Cao, Chuncheng Nie, Yan Xie, Dongqin Cai
In order to understand the role of the protein zona pellucida 2 in fertilization, an antibody against a central segment of the zona pellucida 2 peptide, segment 190-505 (Z2eH), was prepared. The influence of the antibody on sperm-zona interaction was tested using the sperm-egg binding assay. The effect of the antibody on fertility was evaluated by passive immunization with anti-Z2eH antibody. Immunohistochemical assay showed that an antibody from rabbit reacted specifically with the natural zona pellucida on mouse ovarian sections...
October 2016: Zygote: the Biology of Gametes and Early Embryos
Heghush Aleksanyan, Jing Liang, Stan Metzenberg, Steven B Oppenheimer
The sea urchin embryo is a United States National Institutes of Health (NIH) designated model system to study mechanisms that may be involved in human health and disease. In order to examine the importance of high-mannose glycans and polysaccharides in gastrulation, Lytechinus pictus embryos were incubated with Jack bean α-mannosidase (EC, an enzyme that cleaves terminal mannose residues that have α1-2-, α1-3-, or α1-6-glycosidic linkages. The enzyme treatment caused a variety of morphological deformations in living embryos, even with α-mannosidase activities as low as 0...
October 2016: Zygote: the Biology of Gametes and Early Embryos
K Kishida, H Harayama, F Kimura, T Murakami
The aims of this study were to show the existence of individual differences in the distribution of sperm acrosome-associated 1 (SPACA1) among male patients of infertile couples and to examine their possible impact on the outcomes of conventional in vitro fertilization (IVF). The spermatozoa were collected from male patients of infertile couples, washed by centrifugation, collected by the swim-up method, and then used for clinical treatments of conventional IVF. The surplus sperm samples were fixed and stained with an anti-SPACA1 polyclonal antibody for the immunocytochemistry...
October 2016: Zygote: the Biology of Gametes and Early Embryos
M A Filatov, Y V Khramova, M V Kiseleva, I V Malinova, E V Komarova, M L Semenova
In the present review, the main strategies of female fertility preservation are covered. Procedures of fertility preservation are necessary for women who suffer from diseases whose treatment requires the use of aggressive therapies, such as chemotherapy and radiotherapy. These kinds of therapy negatively influence the health of gametes and their progenitors. The most commonly used method of female fertility preservation is ovarian tissue cryopreservation, followed by the retransplantation of thawed tissue. Another approach to female fertility preservation that has been actively developed lately is the ovarian tissue in vitro culture...
October 2016: Zygote: the Biology of Gametes and Early Embryos
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