Epigenetic states of donor cells significantly affect the development of somatic cell nuclear transfer (SCNT) embryos in pigs

The type and pattern of epigenetic modification in donor cells can significantly affect the developmental competency of somatic cell nuclear transfer (SCNT) embryos. Here, we investigated the developmental capacity, gene expression, and epigenetic modifications of SCNT embryos derived from porcine bone marrow‐derived mesenchymal stem cells (BMSCs) and fetal fibroblasts (FFs) donor cells compared to embryos obtained from in vitro fertilization (IVF). Compared to FFs, the donor BMSCs had more active epigenetic markers (Histone H3 modifications: H3K9Ac, H3K4me3, and H3K4me2) and fewer repressive epigenetic markers (H3K9me3, H3K9me2, and DNA methyltransferase 1). Embryos derived from BMSC nuclear‐transfer (BMSC‐NT embryos) and IVF embryos had significantly higher cleavage and blastocyst rates (BMSC‐NT: 71.3 ± 3.4%, 29.1 ± 2.3%; IVF: 69.2 ± 2.2%, 30.2 ± 3.3%; respectively) than FF‐NT embryos (58.1 ± 3.4%, 15.1 ± 1.5%, respectively). Bisulfite sequencing revealed that DNA methylation at the promoter regions of NANOG and POU5F1 was lower in BMSC‐NT embryos (30.0%, 9.8%, respectively) than those in FF‐NT embryos (34.2%, 28.0%, respectively). We also found that BMSC‐NT embryos had more H3K9Ac and less H3K9me3 and 5‐methylcytosine than FF‐NT embryos. In conclusion, our finding comparing BMSCs versus FFs as donors for nuclear transfer revealed that differences in the initial epigenetic state of donor cells have a remarkable effect on overall nuclear reprogramming of SCNT embryos, wherein donor cells possessing a more open chromatin state are more conducive to nuclear reprogramming.     

钙调素一级结构保守性和变异性的数量分析──Ⅰ全序列主要免疫反应位点和靶酶结合位点保守性和变异性的数量分析

用计算机为工具对３２种生物钙调素（ＣａＭ）一级结构的保守性和变异性进行了数量分析,结果表明ＣａＭ分子高度保守,其保守性强于同类生物的细胞色素ｃ,脊椎动物ＣａＭ间的同源性在９８％以上,被子植物ＣａＭ间以及被子植物与脊椎动物ＣａＭ间的同源性高于８８％;脊椎动物与单细胞藻类ＣａＭ间的同源性也在８０％以上。对亲源关系较近的物种,它们的ＣａＭ主要免疫反应位点和靶酶结合位点间的同源性大于全序列间的同源性;对亲源关系较远的物种,它们的ＣａＭ主要免疫反应位点和靶酶结合位点间的差异大于它们全序列间的差异。     

Myometrial immune cells contribute to term parturition,preterm labour and post‐partum involution in mice

This study aimed to determine the mechanism of uterine activation during labour, both term (TL) and preterm (PTL). We hypothesized that the peripheral leucocytes are recruited to uterine tissues by locally produced cytokines where they contribute to the initiation of parturition. Mouse uteri were collected (i) during gestation, TL and post‐partum (PP), (ii) during PTL initiated by intrauterine infusion of LPS (125 μg) or (iii) injection of the progesterone receptor antagonist RU486 and analysed for multiple cytokine expression levels by real‐time polymerase chain reaction (RT‐PCR) and 23‐plex Cytokine assay or enzymatically dispersed for assessment of immune cell populations. Markers of myeloid cell differentiation (Gr1, Neu7/4 and F4/80) were evaluated by FACS to define tissue macrophages (Macs), monocytes (M) and neutrophils (N) and by immunohistochemistry to detect tissue Macs and N. Our results indicate that: (1) Macs were elevated in mouse myometrium before TL (P < 0.05) followed by an increase in M and N; these changes were accompanied by an increase in multiple pro‐inflammatory cytokines/chemokines genes. The expression of corresponding proteins increased PP. (2) TL and RU486‐PTL models showed similar gene/protein expression profiles, (3) LPS‐PTL was characterized by strong pro‐inflammatory response and massive influx of N in myometrial tissues showing a pattern different from TL and RU486‐PTL, (4) The PP period appears similar in all three models, with elevated myometrial cytokine levels and high infiltration of immune cells. We concluded that leucocytes infiltrate myometrium around the time of parturition implicating their potential role in labour activation (both term and preterm) and major role in PP uterine involution.     

不同饲料饲养家蚕其肠道微生态优势菌群类型的组成及差异性

为探讨鳞翅目昆虫的生长发育及抗病性与肠道微生态状况的关系,以不同的桑科植物柘叶与桑叶分别饲养家蚕,采用纯培养分离检测技术、16S rDNA序列测定和系统发育分析方法,对4、5龄家蚕肠道优势菌群的类型进行了鉴定和差异性分析。结果表明:柘叶与桑叶饲养家蚕共有的优势菌群有短波单胞杆菌属(Brevundimonas)、寡养单胞菌属(Stenotrophomonas)、肠杆菌属(Enterobacter)和葡萄球菌属(Staphylococcus)4个类群。从桑叶饲养家蚕肠道中检索到的优势菌群还有气单胞菌属(Aeromonas)、短杆菌属(Brevibacterium)、柠檬酸杆菌属(Citrobacter)、埃希氏菌属(Escherichia)和克雷伯氏菌属(Klebsiella)5个类群,而从柘叶饲养家蚕肠道中检索到的优势菌群仅有假单胞菌属(Pseudomonas)和土壤杆菌属(Agrobacterium)2个类群。饲料的改变导致家蚕肠道微生态细菌种群组成的变化,从柘叶饲养家蚕肠道中分离出的优势菌群与桑叶饲养的家蚕相比,出现较大差异且不如桑叶饲养家蚕的菌群丰富。推测这种改变可能与柘叶饲养家蚕生长发育不良、容易患病具有相关性。     

1998-2014年艾比湖湿地自然保护区生态系统服务价值及其时空变异

湿地的生态系统服务价值是生态学研究的热点之一。以艾比湖湿地自然保护区为研究区,以1998年的TM影像、2006年的Landsat ETM+影像及2014年的Landsat OLI影像为数据源,采用Costanza生态系统服务价值公式进行生态系统服务价值评估,结合空间自相关模型,定量探讨了艾比湖湿地自然保护区生态系统服务价值时空分异特征。结果表明：（1）近20年来,研究区的土地利用/覆被变化显著,除了水体和裸地面积减少,其它土地覆被类型面积都有不同比例的增加。（2）在生态系统服务价值方面,近20年来ESV（Ecosystem Services Values）整体变化不大,但近年ESV有所降低,生态环境出现恶化趋势。（3）在生态系统服务的时空变异方面,研究区ESV空间正相关显著,空间集聚程度高值区主要集中在艾比湖水域和湿地,并且高值区有增加向减少转变的趋势,低值聚集区在湖区四周,且逐年增加。（4）近20年来,影响研究区生态系统服务价值时空变化的驱动力因素主要包括自然因素和人为因素,人为因素是研究区生态系统服务价值时空变化的主要驱动因素。     

MicroRNA‐29b regulates DNA methylation by targeting Dnmt3a/3b and Tet1/2/3 in porcine early embryo development

MicroRNA‐29b (miR‐29b) is a member of the miR‐29 family, which targets DNA methyltransferases (DNMTs) and ten eleven translocation enzymes (TETs), thereby regulating DNA methylation. However, the role of miR‐29b in porcine early embryo development has not been reported. In this study, we examined the effects of miR‐29b in porcine in vitro fertilization (IVF) embryos to investigate the mechanism by which miR‐29b regulated DNA methylation. The interference of miR‐29b by its special miRNA inhibitor significantly up‐regulated Dnmt3a/b and Tet1 but downregulated Tet2/3; meanwhile it increased DNA methylation levels of the global genome and Nanog promoter region but decreased global DNA demethylation levels. The inhibition of miR‐29b also resulted in a decrease in the development rate and quality of blastocysts. In addition, the pluripotency genes Nanog and Sox2 were significantly downregulated, and the apoptosis genes Bax and Casp3 were upregulated, but anti‐apoptosis gene Bcl‐2 was downregulated in blastocysts. Our study indicated that miR‐29b could regulate DNA methylation mediated by miR29b‐ Dnmt3a/b – Tet1/2/3 signaling during porcine early embryo development.     

CCL229细胞经诱导后蛋白激酶C及抑制剂活性的变化

检测以维甲酸(RA), 1, 25－二羟基维生素D₃(1,25(OH)₂VD₃)诱导2d、佛波酯（PMA）诱导6h的人大肠癌细胞CCL₂₂₉的蛋白激酶C（PKC）及其抑制剂活性．结果显示：诱导后PKC总活性升高(P<0.05); RA, 1, 25(OH)₂VD诱导引起细胞质PKC活性增加,PMA诱导后细胞膜PKC比率（细胞膜活性／总活性）显著升高(P<0.01);诱导后PKC抑制剂活性均降低,其中1, 25 (OH)₂VD₃组与对照组有显著差异(P<0.05);提示PMA引起PKC从细胞质向细胞膜转移,不同药物诱导后PKC及其抑制剂活性出现不同的相对均衡关系．     

Induction of priming by cold stress via inducible volatile cues in neighboring tea plants

Plants have evolved sophisticated defense mechanisms to overcome their sessile nature. However, if and how volatiles from cold‐stressed plants can trigger interplant communication is still unknown. Here, we provide the first evidence for interplant communication via inducible volatiles in cold stress. The volatiles, including nerolidol, geraniol, linalool, and methyl salicylate, emitted from cold‐stressed tea plants play key role(s) in priming cold tolerance of their neighbors via a C‐repeat‐binding factors‐dependent pathway. The knowledge will help us to understand how plants respond to volatile cues in cold stress and agricultural ecosystems.