排序方式: 共有81条查询结果,搜索用时 15 毫秒
71.
采用RT-PCR技术对我国海南、云南、广西和广东等不同番木瓜生产区的7个番木瓜环斑病毒外壳蛋白基因(PRSV-CP)进行克隆和鉴定分析。PRSV-CP编码区在864~873核苷酸之间,编码288~291氨基酸。对分离的7个PRSV-CP的核苷酸及氨基酸序列的比较结果表明大部分序列差异都处于N端,而各产区番木瓜PRSV-CP基因的3′端586~864bp区段,即278bpDNA片断的同源率最高,达到98.5%。这一同源序列的获得为利用植物基因工程培育广谱抗病性的番木瓜新品系奠定了基础。 相似文献
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73.
Haruyama J Ohtake M Matsunaga T Morota T Honda C Yokota Y Abe M Ogawa Y Miyamoto H Iwasaki A Pieters CM Asada N Demura H Hirata N Terazono J Sasaki S Saiki K Yamaji A Torii M Josset JL 《Science (New York, N.Y.)》2009,323(5916):905-908
We determined model ages of mare deposits on the farside of the Moon on the basis of the crater frequency distributions in 10-meter-resolution images obtained by the Terrain Camera on SELENE (Selenological and Engineering Explorer) (Kaguya). Most mare volcanism that formed mare deposits on the lunar farside ceased at approximately 3.0 billion years ago, suggesting that mare volcanism on the Moon was markedly reduced globally during this period. However, several mare deposits at various locations on the lunar farside also show a much younger age, clustering at approximately 2.5 billion years ago. These young ages indicate that mare volcanism on the lunar farside lasted longer than was previously considered and may have occurred episodically. 相似文献
74.
为了分析UCP3基因SNPs与中国西门塔尔牛生长及育肥性状的相关性。以118头中国西门塔尔育肥牛为研究材料,通过DNA测序和PCR-RFLP技术检测UCP3基因BglI酶切位点SNPs,并进行相关分析。UCP3-BglI酶切位点表现多态,且处于Hardy-Weinberg平衡状态。与部分育肥性状的相关分析表明,该位点与饲料转化率性状和平均日增重性状表现显著相关(P<0.05),其中AA基因型个体均值显著优于AB和BB基因型个体,料肉比较低,日增重较高;与部分生长性状的相关分析发现在15月龄体高、体长和胸围性状,12月龄体高性状,8月龄体长性状中UCP3-BglI多态位点差异显著,AA基因型个体表型值显著高于其他或其中一个基因型值(P<0.05);在宰后体尺性状测量性状中,UCP3-BglI多态位点对胴体长、胴体胸深和后腿宽和背膘厚性状影响显著。其中AA和AB基因型个体胴体长、胴体胸深和背膘厚性状的表型值显著高于BB基因型个体(P<0.05);在后腿宽性状中,AB个体表型值显著高于AA和BB个体(P<0.05)。初步认为,AA基因型与优良的生长育肥性状显著相关,对A等位基因的选择有利于优良性状的改良。 相似文献
75.
河南部分地区H9亚型禽流感病毒的分离鉴定及交叉免疫攻毒保护试验 总被引:2,自引:1,他引:1
为了分离鉴定河南漯河、郑州H9亚型禽流感病毒及交叉免疫攻毒保护试验。于2011年用SPF鸡胚从河南漯河、郑州疑似感染H9亚型禽流感病毒的病料中分离出2株病毒,通过血凝及血凝抑制试验和RT-PCR方法进行鉴定,确定为AIV H9亚型;用河南省动物性食品安全重点实验室于2001年分离的2株H9亚型禽流感病毒分别制成油乳剂灭活疫苗免疫SPF鸡,然后再用上述4株病毒对免疫鸡群进行交叉攻毒,进行交叉免疫保护试验,测定其交叉免疫保护作用。结果表明:成功分离出2株H9亚型禽流感病毒;用2001年分离毒株所制备出的灭活疫苗免疫鸡后,试验鸡体内抗H9亚型禽流感HI抗体效价均明显上升,平均HI效价均大于11log2,不同毒株所诱导产生的HI抗体效价存在一定的差异;不同时期及地点分离的H9亚型禽流感流行毒株间均产生了较好的交叉保护,且同一地区的保护率更高,2001年的分离株对目前的流行毒株仍有很好的保护作用。 相似文献
76.
SEM observations on larval shell morphology of Manila clam Ruditapes philippinarum and their utility
Nariaki Inoue Ryogen Nanbu Natsuki Hasegawa Junya Higano Hisami Kuwahara Hideo Sekiguchi 《Fisheries Science》2012,78(6):1237-1243
Manila clam Ruditapes philippinarum is common and abundant on Japanese tidal flats, forming a commercially important clam fishery. However, annual catches of Manila clam have decreased drastically since 1975?C1985. To study larval recruitment processes of Manila clam, we carried out scanning electron microscopy (SEM) observations on larval and juvenile shells of clams reared at 20 and 24?°C. There was no significant difference in final shell length of trochophores between 20 and 24?°C. However, the larval duration was much longer and the shell length of settled size of pediveligers was much larger for clams reared at 20?°C than those reared at 24?°C. These findings suggest that larval duration and growth, as well as settlement size, may vary markedly depending on temperature (and probably on season). The larval shell morphology of Manila clam can provide essential information about larval recruitment processes. 相似文献
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Suto A Asano S Goto Y Murata J Mori T Adachi M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(5):547-549
A survey of proliferative enteritis (PE) in pigs at a meat processing plant was conducted using polymerase chain reaction (PCR) testing methods. During the investigation period, 227 of 83,717 pigs brought to the meat processing plant from Iwate, Fukushima, Miyagi, Niigata, and Yamagata Prefectures displayed characteristic general pathological features in terminal ileum, including mucosal hypertrophy and reticulation of serosal surface. Of these, 179 cases were further examined in the laboratory. All cases displayed characteristic histopathological features, and the specific band of the Lawsonia intracellularis (Li) causative agent of PE in pigs was detected in 155 cases by PCR testing methods. These results suggested a general infiltration of Li in the Tohoku district. 相似文献
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Kana Sato Takuya Wakai Yasunari Seita Akiko Takizawa Rafael A. Fissore Junya Ito Naomi Kashiwazaki 《Animal Science Journal》2013,84(4):359-368
A sperm‐specific phospholipase C (PLC), PLCzeta (PLCζ), is thought to underlie the initiation of calcium ([Ca2+]i) oscillations that induce egg activation in mammals. In large domestic species, only bovine, porcine and recently equine PLCζ have been cloned, and the physiological functions of these molecules have not been fully characterized. Here, we evaluated the physiological functions of equine PLCζ (ePLCζ) in mouse oocytes. ePLCζ was cloned from testis using RT‐PCR. The expression of ePLCζ messenger RNA was confirmed in testis but not in other tissues. Microinjection of ePLCζ complementary RNA (cRNA) into mouse oocytes induced long‐lasting [Ca2+]i oscillations, and most of the injected oocytes formed pronuclei (PN). The injection of cRNAs encoding horse, mouse, human and cow PLCζ into mouse oocytes showed that ePLCζ had the highest [Ca2+]i oscillation‐inducing activity among the species tested. Mutation of D202R, which renders the protein inactive, abrogated the activity of ePLCζ. The nuclear translocation ability of ePLCζ was defective when expressed in mouse oocytes. Taken together, our findings show for the first time that ePLCζ has highest activity of the mammalian species studied to date. Our findings will be useful for the improvement of reproductive technologies in the horse. 相似文献
79.
Takafumi Namiki Maki Kamoshita Atsuko Kageyama Jumpei Terakawa Junya Ito Naomi Kashiwazaki 《Animal Science Journal》2021,92(1):e13615
In mice, the conditional knockout strategy using the Cre-loxP system is useful for various types of research. The Cre mouse line with progesterone receptor promoter (PgrCre) has been widely used to produce specific uterine gene-deficient mice, but in the Cre line, endogenous Pgr gene is replaced by Cre recombinase gene, which makes the breeding of homozygous mice (PgrCre/Cre) difficult because they are infertile. Yang et al. (2013, https://10.1016/j.cell.2013.04.017 ) reported the generation of another PgriresCre mouse line that still has endogenous Pgr gene, and they inserted Cre recombinase downstream of the Pgr gene via an internal ribosome entry site (IRES). It is possible that this new PgriresCre line would be useful for uterine research as the mice can be bred as homozygotes (PgriresCre/iresCre). Herein, we confirmed the PgriresCre mice effectively directed recombination in the female reproductive tract and was capable of genetic alteration in the endometrium that enables the studies of its uterine function. Our findings demonstrate that the new PgriresCre mouse line is also useful for the generation of uterine-specific knockout mice. The findings using PgriresCre mouse will contribute to the understanding of reproductive systems and diseases in humans and domestic animals. 相似文献
80.
Michiko NAKAI Manabu OZAWA Naoki MAEDOMARI Junko NOGUCHI Hiroyuki KANEKO Junya ITO Akira ONISHI Naomi KASHIWAZAKI Kazuhiro KIKUCHI 《The Journal of reproduction and development》2014,60(3):256-259
In pigs, the embryonic developmental ability after intracytoplasmic sperm injection (ICSI) is inferior to that resulting from
in vitro fertilization (IVF). We evaluated the timing of cell division up to blastocyst formation on
embryonic development after ICSI using either whole sperm (w-ICSI) or the sperm head alone (h-ICSI) and IVF as a control. At
10 h after ICSI or IVF, we selected only zygotes, and each of the zygotes/embryos was evaluated for cleavage every 24 h until
168 h. We then observed a delay in the 1st and 2nd cleavages of h-ICSI embryos and also in blastocoele formation by w-ICSI
embryos in comparison with IVF embryos. The rate of blastocyst formation and the quality of blastocysts in both ICSI groups
were inferior to those in the IVF group. In conclusion, the delay in cleavage of porcine ICSI embryos shows poorer embryonic
development. 相似文献