Effects of Ovarian Preservation Time on in vitro Maturation and in vitro Fertilization of Oocytes from Slaughtered Sheep

[Objectives] The aim was to study the effects of ovarian preservation time on in vitro fertilization of oocytes from slaughtered sheep. [Methods] The collected ovaries were randomly and evenly divided into four groups. They were preserved in physiological saline containing penicillin( 100 IU/ml) and streptomycin( 100 μg/ml) at 15-20 ℃ for 0( Control),6,12 and 18 h,respectively. Then,the oocytes were subjected to in vitro fertilization. [Results]The maturation rates,cleavage rates and blastocyst rates of the oocytes preserved for 6 and 12 h showed no significant differences compared with those of the oocytes preserved for0 h( 72. 03%,70. 87% vs. 73. 68%; 74. 12%,72. 60% vs. 74. 49%; 22. 22%,20. 75% vs. 23. 29%)( P > 0. 05). There were also no significant differences in maturation rate,cleavage rate or blastocyst rate between the oocytes preserved for 18 and 0 h( P > 0. 05). [Conclusions] Within a certain rage( 0-18 h),storage time of ovary at 15-20 ℃ does not affect the continued development of oocytes from slaughtered sheep.

实时荧光PCR法检测肺癌细胞系中吉西他滨耐药相关基因的表达(英文)

Objective: To explore the molecular mechanism of gemcitabine-resistance, the relative mRNA expression of five genes related to gemcitabine-resistance was detected in six lung cancer cell lines. Methods: The total RNA was extracted from six lung cancer cell lines GLC-82, NCI-H460, A549, 95-C, 95-D and QG56. Then the cDNA was amplified by real-time quantitative PCR method to quantify the gene expression of RRM1, PTEN, ERCC1, dCK and CDA. The cytotoxicity of gem- citabine to cell lines was tested by MTT method. Results: Among the detected six lung cancer cell lines, the mRNA level of RRM1, PTEN and ERCC1 in lung squamous cell line QG56 was highest, and the IC50 of gemcitabine to QG56 cell line was also highest. Conclusion: The mRNA expression of RRM1, PTEN and ERCC1 was correlated, and the high expression of RRM1 was related to gemcitabine resistance of lung cancer.

Effects of Bovine Embryos at Different Developmental Stages on Bisection Effect

[Objectives]This study was conducted to explore the effects of embryos at different developmental stages on the bisection effect of embryos,improve the efficiency of bovine embryo bisection,and facilitate the application of embryo bisection technology in cattle breeding.[Methods]The effects of two different bisection solutions on the bisection of morulae and blastocysts in vitro were explored.The morulae and blastocysts produced in vitro from cattle that developed to the 6th to 8th d were bisected by hands,and demi-embryos were cultured in vitro.Their development was observed.[Results]Morulae were bisected in PBS solution and PBS+0.2 mol/L sucrose,and the success rates of bisection were 50%and 95.2%,respectively.The success rate of bisecting morulae in PBS+0.2 mol/L sucrose was significantly higher than that in PBS(P<0.05),while the development rate of the bisected demi-embryos had no significant difference between the two(53.3%,52.4%)(P>0.05).The success rates of blastocyst bisection in PBS solution and PBS+0.2 mol/L sucrose were 51.6%and 95.1%,respectively.The success rate of blastocyst bisection in PBS+0.2 mol/L sucrose was significantly higher than that in PBS(P<0.05),while the development rate of the bisected demi-embryos had no significant difference between the two(50.0%,56.4%)(P>0.05).[Conclusions]There were no significant differences between the success rates of bisecting bovine morulae and blastocysts in PBS+0.2 mol/L sucrose,which were both significantly better than those in pure PBS bisection solution,proving that PBS+0.2 mol/L sucrose bisection solution is suitable for bovine embryo bisection.

Molecular Markers of Fat and Inosinic Acid Content in Sheep Muscle and Application

This study was conducted to speed up the process of improving the quality of lamb breeds in China,and to solve the problems that restrict the development of lamb breeds in China,such as low quality of lamb breeds,low meat production rate,and poor meat quality.By studying molecular markers of fat content in sheep muscles,we searched for polymorphic loci related to fat content in sheep muscles on the ANGPTL4 gene.Among the 9 polymorphic loci retrieved,ANGPTL4 was found.Two polymorphic sites,C724 A and A601 G,were significantly associated with intramuscular fat in mutton.In summary,these two molecular markers can be used as a molecular marker reference when breeding high-quality meat or hair and meat using German Merino sheep breeds.

Study on the Relationship Between CAPN Gene Peptide and Fat Content in Sheep Muscle

[Objectives] This study was conducted to speed up the process of improving the quality of lamb breeds in China,and to solve the problems that restrict the development of lamb breeds in China,such as low quality of lamb breeds,low meat production rate,and poor meat quality. [Methods]By studying molecular markers of fat content in sheep muscle,the CAPN gene was used to find polymorphic sites related to fat content in sheep muscle,and the correlation between two polymorphic sites C724 A and A601G on CAPN1 and CAPN2 and fat content in sheep muscle was analyzed. [Results] The two polymorphic sites,C724 A on CAPN1 and A601G on CAPN2 were significantly related to intramuscular fat in mutton. [Conclusions] These two molecular markers can be used as a molecular marker reference when breeding high-quality meat or hair and meat using German Merino sheep breeds.

Research on Key Technology of Efficient Production of Bovine Embryos

[Objectives]This study was conducted to explore the effects of three different splitting fluids on the bisection effects of bovine morulae and blastocysts.[Methods]With the help of a micromanipulator,the morulae and blastocysts that were routinely produced in the body from the 6 th to the 8 th d were divided into half-embryos in vitro to observe their development,and the half-embryos with a restored morphology and a blastocyst trophoblast were selected.[Results]The success rates of bisection of morulae in PBS+0.2 mol/L sucrose and PBS+5%PVP were significantly higher than that in PBS(P<0.05),and the values in the three liquids were 95.7%,97.2% and 50%,respectively,while the blastocyst development rates and of half-embryos and the pregnancy rates of transplantation were not significantly different(P>0.05).When blastocysts were bisected in PBS+0.2 mol/L sucrose and PBS+5% PVP,the success rates of bisection were significantly higher than that of PBS(P<0.05),and the values in the three liquids were 96.8%,95.5% and 50.0%,respectively,while the development rates of half-embryos and the pregnancy rates of transplantation were not significantly different(P>0.05).The development rate of half-embryos bisected from blastocysts was significantly higher than that of morulae.[Conclusions]This study improves the efficiency of bovine embryo bisection,which is beneficial to the application of embryo bisection technology in cattle breeding.

多肽靶向嵌合体通过促进tau蛋白特异性去磷酸化治疗阿尔茨海默病和其他tau蛋白病

Abnormal hyperphosphorylation and accumulation of tau protein play a pivotal role in neurodegeneration in Alzheimer’s disease(AD)and many other tauopathies.Selective elimination of hyperphosphorylated tau is promising for the therapy of these diseases.We have conceptualized a strategy,named dephosphorylation-targeting chimeras(DEPTACs),for specifically hijacking phosphatases to tau to debilitate its hyperphosphorylation.Here,we conducted the step-by-step optimization of each constituent motif to generate DEPTACs with reasonable effectiveness in facilitating the dephosphorylation and subsequent clearance of pathological tau.Specifically,for one of the selected chimeras,D16,we demonstrated its significant efficiency in rescuing the neurodegeneration caused by neurotoxic K18-tau seeds in vitro.Moreover,intravenous administration of D16 also alleviated tau pathologies in the brain and improved memory deficits in AD mice.These results suggested DEPTACs as targeted modulators of tau phosphorylation,which hold therapeutic potential for AD and other tauopathies.

Polydimethylsiloxane assisted supercritical CO2 foaming behavior of high melt strength polypropylene grafted with styrene

可起泡沫的高度融化力量聚丙烯(HMSPP ) 被 grafting 苯乙烯(圣) 通过一出一步舞准备到聚丙烯(PP ) 和同时介绍的 polydimethylsiloxane (PDMS ) 上融化挤出过程。HMSPP 的起泡沫的行为上的 PDMS 粘性的效果系统地作为起泡沫的代理人用 supercritical 公司 2 被调查。结果证明 PDMS 的增加在圣的 grafting 反应上有小效果， HMSPP 展出提高的有弹性的反应和明显的紧张变硬效果。尽管没有 PDMS，有 PDMS (PDMS-HMSPP ) 的 HMSPP 的 CO 2 溶解度是比 HMSPP 的低的，特别为有低粘性的 PDMS， PDMS-HMSPP 泡沫展出狭窄的房间尺寸分发和高房间密度。PDMS-HMSPP 的破裂形态学证明有低粘性的 PDMS 在 HMSPP 矩阵更容易并且一致地分散，导致小领域在挤出期间处理的形式。这些小域充当水泡成核地点并且可能因此为 HMSPP 的改进起泡沫的性能负责。

Versatile functions of RNA m6A machinery on chromatin

m6A,a conserved and abundant modification on RNA,regulates RNA processing and function.RNA m6A machinery,including writers,erasers,and readers of m6A,is indispensable for m6A installation and function.Intriguingly,recent studies have revealed that m6A machinery can be recruited to chromatin by pleiotropic factors,including nascent RNA,transcription factors,regulatory RNA,histone modifications,and epigenetic machinery.Consequently,recruitment of m6A machinery can directly regulate chromatin biology,such as transcription,DNA damage repair,and DNA recombination beyond installation of m6A on nascent mRNA.Here,we discuss recent evidence showing that m6A machinery is targeted to chromatin and the direct biological consequences along with the underlying mechanisms.

The Tianlai Cylinder Pathfinder array: System functions and basic performance analysis

The Tianlai Cylinder Pathfinder is a radio interferometer array designed to test techniques for 21 cm intensity mapping in the post-reionization Universe,with the ultimate aim of mapping the large scale structure and measuring cosmological parameters such as the dark energy equation of state.Each of its three parallel cylinder reflectors is oriented in the north-south direction,and the array has a large field of view.As the Earth rotates,the northern sky is observed by drift scanning.The array is located in Hongliuxia,a radio-quiet site in Xinjiang,and saw its first light in September 2016.In this first data analysis paper for the Tianlai cylinder array,we discuss the sub-system qualification tests,and present basic system performance obtained from preliminary analysis of the commissioning observations during 2016-2018.We show typical interferometric visibility data,from which we derive the actual beam profile in the east-west direction and the frequency band-pass response.We describe also the calibration process to determine the complex gains for the array elements,either using bright astronomical point sources,or an artificial on site calibrator source,and discuss the instrument response stability,crucial for transit interferometry.Based on this analysis,we find a system temperature of about 90 K,and we also estimate the sensitivity of the array.