著者

Fernando LÓPEZ-GATIUS

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-119, (Released:2021-12-30)

被引用文献数

2

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Prostaglandin F2α (PGF2α) and its analogs are used to induce luteolysis in estrus synchronization programs to terminate unwanted pregnancies or to promote ovulation in certain cow subpopulations. In the past few decades, the luteolytic dose of PGF2α has remained unchanged. This review explores the clinical implications of increasing the standard dose for these applications in high-producing dairy cows. Ultrasonography may assist in selecting the most appropriate PGF2α dose and improve the results. A reference has been used for PGF2α for promoting ovulation in herds showing poor reproductive performance.

著者

Yasuhisa MATSUI Yohei HAYASHI

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-137, (Released:2021-12-25)

被引用文献数

3

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Metabolism is an important cellular process necessary not only for producing energy and building blocks for cells, but also for regulating various cell functions, including intracellular signaling, epigenomic effects, and transcription. The regulatory roles of metabolism have been extensively studied in somatic cells, including stem cells and cancer cells, but data regarding germ cells are limited. Because germ cells produce individuals of subsequent generations, understanding the role of metabolism and its regulatory functions in germ cells is important. Although limited information concerning the specific role of metabolism in germ cells is available, recent advances in related research have revealed specific metabolic states of undifferentiated germ cells in embryos as well as in germ cells undergoing oogenesis and spermatogenesis. Studies have also elucidated the functions of some metabolic pathways associated with germ cell development and the non-genomic heritable machinery of germ cells. In this review, we summarized all the available knowledge on the characteristic metabolic pathways in germ cells, focusing on their regulatory functions, while discussing the issues that need to be addressed to enhance the understanding of germ cell metabolism.

著者

Hiroshi SUZUKI Hiroyuki WATANABE Yasuyuki ABE

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-111, (Released:2021-11-29)

被引用文献数

6

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Assisted reproductive techniques (ARTs), such as artificial insemination, in vitro fertilization, and cryopreservation of gametes/zygotes, have been developed to improve breeding and reproduction of livestock and for the treatment of human infertility. Their widespread use has contributed to improvements in human health and welfare. However, in dogs, only artificial insemination using frozen semen is readily available as an ART to improve breeding and control genetic diversity. A recent priority in sperm cryopreservation is the development of alternatives to egg yolk, which is widely used as a component of the sperm extender. Egg yolk can vary in composition among batches and is prone to contamination by animal pathogens. The latter can be a problem for international exchange of cryopreserved semen. Low-density lipoprotein and skim milk are promising candidates for use as extenders, to ensure fertility after artificial insemination. Although not tested for its effects on fertility following artificial insemination, polyvinyl alcohol may also be a useful alternative to egg yolk as an extender. The development of cryopreservation techniques for canine embryos lags behind that for other mammals, including humans. However, given the success of non-surgical embryo transfer in 2011, studies have sought to refine this approach for practical use. Research on sperm cryopreservation has yielded satisfactory results. However, investigation of other approaches, such as cryopreservation of oocytes and gonadal tissues, remains insufficient. Techniques for the efficient induction of estrus may aid in the development of successful canine ARTs.

著者

Ryosuke SAKUMOTO Ken-Go HAYASHI Kosuke IGA

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-107, (Released:2021-11-20)

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The aim of the present study was to evaluate the effects of continuous administration of linoleic acid or linolenic acid into the intra-uterine horn, ipsilateral to the corpus luteum, on the duration of the estrous cycle and plasma progesterone (P4) concentration. The effects of linoleic and linolenic acids on bovine uterine and luteal functions were also studied using a tissue culture system. Intra-uterine administration of linoleic or linolenic acid (5 mg/10 ml of each per day) in cows, between days 12 and 21, resulted in a prolonged estrous cycle compared to the average duration of the last one to three estrous cycles before administration in each group (P < 0.05). Moreover, plasma P4 concentration in cows treated with linoleic or linolenic acid was high between days 19 and 21 (linoleic acid), or on day 20 (linolenic acid), compared to that of the control cows (saline administration; P < 0.05 or lower). Both linoleic (500 µg/ml) and linolenic (5 and 500 µg/ml) acids stimulated prostaglandin (PG) E2 but inhibited PGF2α production by cultured endometrial tissue (P < 0.01), while P4 production by cultured luteal tissue was not affected. These findings suggest that both linoleic and linolenic acids support luteal P4 production by regulating endometrial PG production and, subsequently, prolonging the duration of the estrous cycle in cows.

著者

Tomoko ITAHASHI Toshinori OIKAWA Takashi NUMABE

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-070, (Released:2021-11-05)

被引用文献数

2

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This study was conducted to examine the effects of adding glutathione (1 mM) to media used for sperm washing and in vitro fertilization (IVF) on the improvement of early development of embryos produced using cryopreserved spermatozoa of the less IVF-competent bull (the one considered unqualified as spermatozoa supplier for the production of bovine blastocysts using IVF). The cryopreserved spermatozoa of this bull were characterized by normal motility and lower ATP content and blastocyst productivity than those of IVF-competent bulls. The addition of glutathione to the sperm washing medium was more effective in improving the productivity of blastocysts and ATP content than the addition of glutathione to the IVF medium or no glutathione addition at all (control). These results suggest that this simple method may be used to improve the potential of cryopreserved spermatozoa of less IVF-competent bulls to fertilize oocytes in vitro and to induce normal embryonic development after fertilization.

著者

Ryo INABA Ryouka KAWAHARA-MIKI Akihisa SHINOZAWA Taichi YASUHARA Takashi FUJII Keisuke KOYAMA Michiko MURATA-OKUBO Kousaku SOUMA Hiroki HIRAYAMA

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-094, (Released:2021-10-31)

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Although hormonal induction of parturition in cattle results in the successful delivery of healthy calves, the risk of retained fetal membrane is significantly increased. In a previous study, a combination of the long-acting glucocorticoid, triamcinolone acetonide, with a high dose of betamethasone partially normalized the placentomal gene expression during parturition; however, the incidence of retained fetal membrane remained high. This study further explored placentomal dysfunction and aimed to elucidate the mechanism of retained fetal membrane in parturition-induced cows. In this study, transcriptome analysis revealed that enhanced glucocorticoid exposure normalized the expression of a substantial fraction of genes in the cotyledons. In contrast, a significant reduction in the multiple signaling pathway activities, including interferon signaling, was found in the caruncles during induced parturition. Real-time PCR showed that the expression of interferon-tau in the caruncles, but not interferon-alpha or interferon-gamma, was significantly lower in induced parturition than spontaneous parturition. Interferon-stimulated gene expression was also significantly decreased in the caruncles during induced parturition. These results indicate that interferon signaling could be important for immunological control in placentomes during parturition. Additionally, this suggests that interferon-tau might be a pivotal ligand for interferon receptors in the caruncles. This study revealed that peripheral blood leukocytes in prepartum cows transcribed interferon-tau. Macrophage infiltration in the placentome is known to participate in the detachment of the fetal membrane from the caruncle. Thus, this study raised the possibility that immune cells migrating into the caruncles at parturition may act as a source of ligands that activate interferon signaling.

著者

Yue SU Qianru LI Qiaochu ZHANG Zhiming LI Xinxin YAO Yong GUO Longfei XIAO Xiangguo WANG Hemin NI

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-077, (Released:2021-10-22)

被引用文献数

11

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Inadequate fetomaternal interactions could directly lead to pregnancy failure in dairy cows. Exosomes are widely involved in endometrial matrix remodeling, immune function changes, placental development, and other processes of embryo implantation and pregnancy in dairy cows. However, the role of exosomes derived from placental trophoblast cells in regulating the receptivity of endometrial cells and facilitating fetomaternal interaction remains unclear. In this study, bovine trophoblast cells (BTCs) were obtained from bovine placenta and immortalized by transfection with telomerase reverse transcriptase (TERT). Immortalized BTCs still possess the basic and key properties of primary BTCs without exhibiting any neoplastic transformation signs. Subsequently, the effect of trophoblast-derived exosomes (TDEs) on endometrial receptivity in endometrial epithelial cells (EECs) was determined, and the mechanism whereby TDEs and their proteins participate in the fetomaternal interaction during bovine pregnancy were explored. EECs were co-cultured with the exosomes derived from BTCs treated with progesterone (P4). Such treatment enhanced the expression of the endometrial receptivity factors, integrin αv, β3, Wnt7a, and MUC1 by changing the extracellular environment, metabolism, and redox balance in EECs via proteome alignment, compared with no treatment according to the DIA quantitation analysis. Our study demonstrated that trophoblast-derived exosome proteins are one of the most critical elements in fetomaternal interaction, and their changes may act as a key signal in altering endometrial receptivity and provide a potential target for improving fertility.

著者

David MARTÍN-HIDALGO Beatriz MACÍAS-GARCÍA Lauro GONZÁLEZ-FERNÁNDEZ

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-075, (Released:2021-10-24)

被引用文献数

6

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We aimed to analyze the influence of different cellular concentrations of boar sperm suspensions on the induction of capacitation and acrosome reaction. When spermatozoa were incubated at 100 or 200 mill/ml, significant increases in protein tyrosine phosphorylation in the p32 protein were observed, compared to those at 50 mill/ml. In addition, sperm concentration-dependent increases were observed in plasma membrane lipid disorganization (50 mill/ml vs. 200 mill/ml), induction of the acrosome reaction (50 mill/ml vs. 100 mill/ml and 200 mill/ml), and sperm viability (50 mill/ml vs. 100 mill/ml and 200 mill/ml). Our data indicate that an increase in sperm concentration stimulates the induction of capacitation and acrosome reaction in boars.

著者

Xiaoyu CHEN Fuxian YU Zhiwei ZHU Jing HUANG Liang ZHANG Jianzhi PAN

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-060, (Released:2021-10-16)

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Hormonal products have been developed for fixed-time artificial insemination (FTAI) to improve the efficiency of swine production. Here, we evaluated the effect of an FTAI protocol initiated during different phases of the estrous cycle on follicle development and ovulation in gilts. A total of 36 gilts were equally divided into three groups designated as the luteal (L), follicular (F), and post-ovulation (O) groups and fed with 20 mg of altrenogest for 18 days, followed by intramuscular injection of 1000 IU PMSG at 42 h after withdrawal of altrenogest, and 100 μg of GnRH after an 80-h interval. The L group had the highest number of follicles 4–6 mm in diameter, as well as corpora hemorrhagica. The mRNA expression of caspase-9 in the L group were significantly lower than those in the O and F groups (P < 0.05), while CYP11A1 and VEGF mRNA expression levels were significantly higher (P < 0.05). Moreover, FSHR mRNA levels were significantly higher in the O group than in the L, F, and control groups (P < 0.05). LHCGR and CYP19A1 mRNA levels were the highest in the F group (P < 0.05). Thus, the changes in the expression of genes associated with follicular development, maturation, and ovulation identified in this study indicated that initiation of the FTAI protocol during the luteal phase induced a better environment for follicle development and ovulation in gilts.

著者

Kaiyu KUBOTA Masafumi MIWA Ken-Go HAYASHI Misa HOSOE Miki SAKATANI

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-087, (Released:2021-10-14)

被引用文献数

3

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In cow herd management, inadequate embryo implantation leads to pregnancy loss and causes severe economic losses. Thus, it is crucial to understand the molecular mechanisms underlying endometrial receptivity and subsequent embryo implantation. Transmembrane glycocalyx mucin 1 (MUC1) has a large and highly glycosylated extracellular domain known to inhibit embryo implantation via steric hindrance. The role of MUC1 in the bovine endometrium remains to be explored. Herein, we used simple but reliable in vivo and in vitro experiments to investigate the expression and regulation of MUC1 in the bovine endometrium. MUC1 gene expression was analyzed in endometrial epithelial cells collected by the cytobrush technique using reverse transcription-quantitative polymerase chain reaction. MUC1 protein expression was evaluated by immunohistochemical analysis of endometrial samples collected from slaughtered cows. We used an in vitro cell culture model to study the regulation of MUC1 expression by treating cells with sex steroidal hormones or co-culturing cells with a blastocyst. The results revealed that MUC1 was expressed and localized to the apical surface of luminal epithelial cells in the bovine endometrium. MUC1 expression disappeared during the luteal phase of the estrous cycle and during pregnancy. 17β-estradiol induced MUC1 expression, whereas progesterone inhibited its increase and co-culturing with blastocysts did not affect the expression. A long postpartum interval is a known risk factor for reduced fertility, and MUC1 expression was higher in this compromised condition. Our results demonstrated the MUC1 regulation by steroid hormones in bovine endometrium for embryo implantation, and we observed a negative correlation between MUC1 expression and fertility.

著者

Taiga YAMAZAKI Satoru KOBAYAKAWA Kazuo YAMAGATA Kuniya ABE Tadashi BABA

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

vol.53, no.5, pp.1035-1041, 2007 (Released:2007-10-31)

参考文献数

24

被引用文献数

11 13

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To elucidate the molecular dynamics of HP1β in mouse preimplantation embryos, we examined the localization, dynamics, and mobility of HP1β in the (pro)nucleus by live cell imaging. Time-lapse observation revealed that the chromatin association of HP1β is regulated in a cell cycle-dependent manner. HP1β was localized in the interphase nucleus and was dynamically dissociated from the nucleus during the metaphase stage. The HP1β assembly and clustered heterochromatin structure were both found in the nuclei of 2-cell and later-stage embryos. Moreover, fluorescent recovery after photobleaching analysis implied that HP1β is more freely mobile in the pronucleus of the 1-cell embryo than in the 4-cell nucleus. These results suggest that the chromatin configuration may be regulated by the stability and mobility of chromatin-associated proteins including HP1β during early embryonic stages.

著者

小泉 稔 堀口 幸太郎 冨田 陽子 KATO Yukio HARIGAYA Toshio

出版者

日本繁殖生物学会

雑誌

家畜繁殖研究會誌 (ISSN:09168818)

巻号頁・発行日

vol.49, no.6, pp.465-472, 2003

被引用文献数

1 7

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In this study, we attempted to examine the presence of prolactin (PRL) messenger ribonucleic acid (mRNA) and protein in the mouse nipple and mammary gland in pregnancy and lactation. PRL-like substances were found by immunohistochemistry using an antibody against the mouse PRL (mPRL) in the sebaceous gland cells of the nipple during late pregnancy and lactation, and the cistern of alveoli in mammary glands during lactation. Western blot analysis of proteins extracted from the nipple and the mammary gland showed immunoreactive bands corresponding to molecular weights of approximate 16 kDa and 32 kDa, respectively. The expression of mRNA for mPRL in the nipple and mammary gland during late pregnancy and lactation was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR), Southern blotting, and nucleotide sequence analyses. These results suggest that mPRL mRNA and its translation product are synthesized in the mouse nipple.

著者

Kenji NARUSE Yan-Shi QUAN Su-Min CHOI Chang-Sik PARK Dong-Il JIN

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

vol.53, no.3, pp.679-684, 2007 (Released:2007-07-07)

参考文献数

19

被引用文献数

8 8

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This study was carried out to investigate the effects of minimum essential medium (MEM) vitamins during in vitro maturation (IVM)/in vitro culture (IVC) of porcine nuclear transfer (NT) embryos on subsequent developmental capacity in vitro. Porcine cumulus-oocyte complexes (COCs) were divided into five groups, matured for 44 h in maturation medium with various concentrations of MEM vitamins (0, 0.05, 0.1, 0.2 and 0.4%), and observed for maturation rate. Also, COCs were matured in NUSU-23 media without MEM vitamins for 44 h and cultured in PZM-3 media with various concentrations of MEM vitamins (0, 0.05, 0.4 and 1.0%) for 6 days following nuclear transfer. Factorial (IVM/IVC) experiments were also performed in NCSU-23 medium with or without 0.05% MEM vitamins and PZM-3 medium with or without 0.4% MEM vitamins. They were then tested by examining in vitro development of the porcine reconstructed embryos. The maturation rates of the COCs treated with the MEM vitamins did not differ significantly among the MEM vitamin-treated groups. Addition of vitamins to culture medium did not affect development of porcine reconstructed embryos in vitro. However, addition of low concentrations of MEM vitamins only to maturation medium increased (P<0.05) the proportion of NT embryos developing into blastocysts compared with the control group. Addition of MEM vitamins to IVC medium did not enhance the developmental rate compared with the control group. Thus, addition of MEM vitamins to IVM medium could improve subsequent blastocyst development of porcine NT embryos.

著者

Fernando LÓPEZ-GATIUS Irina GARCIA-ISPIERTO Ronald H.F. HUNTER

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-022, (Released:2021-05-30)

被引用文献数

3

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This study sought to establish whether temperature gradients between the cervix, vagina, and rectum at and 7 days post-artificial insemination (AI) were associated with the incidence of pregnancy in lactating dairy cows (Experiment I; n = 90 ovulating cows) and to evaluate temperature gradient dynamics from the time of insemination to 7 days post-AI under heat stress conditions (Experiment II; n = 16 ovulating and 4 non-ovulating cows). In Experiment I, 39 cows (43.3%) became pregnant. The odds ratio for pregnancy was 2.5 for each one-tenth of a degree drop in cervical temperature with reference to the control rectal temperature at the time of AI (P = 0.01), whereas the same decrease in the cervix–rectum temperature differential 7 days post-AI resulted in ana odds ratio of 0.44 (P = 0.02). In Experiment II, 5 of the ovulating cows (31.3%) became pregnant. The mean values of the vagina–rectum, vagina–cervix, and cervix–rectum temperature differentials at AI (day 0), 8 h, 24 h, and 7 days post-AI changed significantly from day 0 to day 7 (within-subject effect; P < 0.02) in ovulating cows but not in non-ovulating cows. Temperature differentials on days 0 and 7 were similar between ovulating cows and cows of Experiment I. Overall, our findings support the notion that a temperature differential between the caudal cervical canal and rectum at AI may be an indicator of the likelihood of pregnancy. Possible prospects of confirming estrus at the herd-level are also suggested.

著者

Ken SAWAI

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2021-031, (Released:2021-04-27)

被引用文献数

3

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In mammalian embryos, the first visible differentiation event is the segregation of the inner cell mass (ICM) and trophectoderm (TE) during the transition from the morula to the blastocyst stage. The ICM, which is attached to the inside of the TE, develop into the fetus and extraembryonic tissues, while the TE, which is a single layer surrounding the fluid-filled cavity called the blastocoel, will provide extraembryonic structures such as the placenta. ICM/TE differentiation is regulated by the interaction between various transcriptional factors. However, little information is available on the segregation of the ICM and TE lineages in preimplantation embryos of domestic animals, such as cattle and pigs. This review focuses on the roles of cell differentiation factors that regulate the ICM/TE segregation of preimplantation bovine and porcine embryos. Understanding the mechanism of cell differentiation in early embryos is necessary to improve the in vitro production systems for bovine and porcine embryos.

著者

武内 歩 加藤 めぐみ 伊藤 和美 木村 建 花田 章 平林 真澄 保地 眞一

出版者

日本繁殖生物学会

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.48, no.3, pp.243-248, 2002-06-01

参考文献数

28

被引用文献数

2 9

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The aim of this study was to investigate the effect of Ca²⁺- and Mg²⁺-free culture conditions on induction of spontaneous first cleavage in rat oocytes. Oocytes recovered from superovulated Wistar females 17 h after hCG injection were exposed for 1.5 h to Ca²⁺/Mg²⁺-free, Ca²⁺-free, Mg²⁺-free, or control mKRB medium supplemented with 5 &mu;g/ml cytochalasin-B (CB). The oocytes were then cultured for 4.5 h in control medium containing CB and for 28 h in CB-free control medium. The oocytes exposed to the Ca²⁺/Mg²⁺-free medium (23%) cleaved better than those exposed to Ca²⁺-free (8%), Mg²⁺-free (0%), or control (0%) media. The cleavage rates of oocytes recovered 12, 17 and 22 h after hCG injection and exposed to the Ca²⁺/Mg²⁺-free medium were 4, 17 and 22%, respectively. The efficiency of oocyte activation in 1.25 mM Sr²⁺ treatment for 6 h was not influenced by the culture background of bivalent cations (cleavage rates: both 49% in Ca²⁺/Mg²⁺-free and Ca²⁺-free medium). These results indicate that Ca²⁺/Mg²⁺-free culture condition induced the spontaneous first cleavage of rat oocytes in an age dependent manner, but had no additional effect on Sr²⁺-induced oocyte activation.

著者

Shuai SUN Shota YANO Momo O NAKANISHI Michiko HIROSE Kazuhiko NAKABAYASHI Kenichiro HATA Atsuo OGURA Satoshi TANAKA

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.2020-119, (Released:2021-03-20)

被引用文献数

4

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Mouse trophoblast stem cells (TSCs) can differentiate into trophoblast cells, which constitute the placenta. Under conventional culture conditions, in a medium supplemented with 20% fetal bovine serum (FBS), fibroblast growth factor 4 (FGF4), and heparin and in the presence of mouse embryonic fibroblast cells (MEFs) as feeder cells, TSCs maintain their undifferentiated, proliferative status. MEFs can be replaced by a 70% MEF-conditioned medium (MEF-CM) or by TGF-ß/activin A. To find out if KnockOutTM Serum Replacement (KSR) can replace FBS for TSC maintenance, we cultured mouse TSCs in KSR-based, FBS-free medium and investigated their proliferation capacity, stemness, and differentiation potential. The results indicated that fibronectin, vitronectin, or laminin coating was necessary for adhesion of TSCs under KSR-based conditions but not for their survival or proliferation. While the presence of FGF4, heparin, and activin A was not sufficient to support the proliferation of TSCs, the addition of a pan-retinoic acid receptor inverse agonist and a ROCK-inhibitor yielded a proliferation rate comparable to that obtained under the conventional FBS-based conditions. TSCs cultured under the KSR-based conditions had a gene expression and DNA methylation profile characteristic of TSCs and exhibited a differentiation potential. Moreover, under KSR-based conditions, we could obtain a suspension culture of TSCs using extracellular matrix (ECM) coating-free dishes. Thus, we have established here, KSR-based culture conditions for the maintenance of TSCs, which should be useful for future studies.

著者

Anders JOHANNISSON Essraa M. AL-ESSAWE Anas Kh. AL-SAFFAR Saeid KARKEHABADI Isabel LIMA-VERDE Manuela WULF Christine AURICH Jane M. MORRELL

出版者

The Society for Reproduction and Development

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

vol.66, no.3, pp.215-221, 2020 (Released:2020-06-12)

参考文献数

30

被引用文献数

3 7

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The mechanism by which the content of the major groups of seminal plasma proteins in stallion semen changes between the breeding and non-breeding seasons remains unknown. Here, we investigated the proportions of non-heparin-binding, phosphorylcholine-binding, and heparin-binding proteins in seminal plasma with the aim of relating them to sperm quality and testosterone levels in good and bad freezer stallions. Only minor variations in the major protein groups were found between the breeding and non-breeding seasons. In the non-breeding season, a higher content of a subset of non-heparin binding proteins as well as of heparin-binding proteins was found. Analysis of semen characteristics revealed a somewhat contrasting picture. While only minor variations in sperm kinematics and sperm morphology were found between seasons, the flow-cytometric measurements of mitochondrial membrane potential and also, to some extent, reactive oxygen species production indicated lower sperm quality in the breeding season. Chromatin integrity and testosterone levels were unchanged between seasons. The results suggest that stallion ejaculates could be used year-round for freezing, since only minor differences in protein composition exist between the breeding and non-breeding seasons, as well as between good and bad freezers. In addition, sperm quality is not impaired during the non-breeding season.

著者

Jason E. SWAIN

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

vol.57, no.4, pp.551-555, 2011 (Released:2011-09-06)

参考文献数

29

被引用文献数

3 8

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Elevated CO2 is required for in vitro embryo culture to maintain proper media pH and to supply embryo metabolic pathways. As an alternative to current approaches using gas cylinders, we examined use of a chemical reaction to supply CO2. A closed culture system was constructed and chemicals added to generate CO2, which was then supplied to developing embryos. This system was shown to provide a stable pH (7.2-7.4) over 4 days of use. One-cell mouse embryos were cultured in the device and no difference in blastocyst formation or cell number was apparent between embryos grown in a closed system with CO2 supplied by a chemical reaction or positive controls grown in a an open system in a CO2 incubator. This approach provides a highly purified, inexpensive, and easily obtainable gas source and offers potential for development of new, self-contained culture platforms.

著者

樋口 広芳

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

vol.41, no.6, pp.j127-j133, 1995 (Released:2010-10-20)

被引用文献数

1 2

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鳥類には,他の鳥の巣に卵を産みこみ,その後の抱卵や育雛をその巣の主にまかせてしまう托卵習性をもつものがいる.そうした鳥の代表,カッコウ属(Cuculus)のカッコウ類の托卵習性について調べてみると,この類のメスは,托卵相手の産卵期の巣にやってきて,巣内の卵を1個抜きとったあと,自分の卵を1個産みこむ.1羽のメスが1巣に托卵するのは1卵だけである.産卵に費やす時間は,数秒から10秒前後と非常に短い.産み込む卵は,托卵相手の卵より少し大きく,色や模様がよく似ている傾向がある.孵化したヒナは,孵化後数時間以上経つと,巣内の卵あるいはヒナを1つずつ背中にのせてすべて巣外に押し出す.これらの特徴はどれも,托卵を成功に導くこと,あるいはより効率よいものにすることにかかわっている.カッコウ類の1羽のメスが1繁殖期に産む,あるいは産卵可能な卵の数は,数個から25個と一般鳥類に比べて多い.これは,巣づくりや育雛から解放されることによって,その分のエネルギーを卵形成にふり向けることができるからだと思われる.