完整的供体细胞膜及供体胞质对小鼠体细胞克隆胚发育的影响

利用显微注射和电融合的方法都可以成功地获得体细胞克隆小鼠, 由于电融合法操作耗时, 融合率低, 因而大多数克隆小鼠是采用注射方法。而注射法需要将供体细胞核从细胞中分离出来, 此分离操作有可能导致对DNA的损伤, 曾有人使用直径较粗的注射管进行完整的供体细胞注射, 这种方法操作相对简单而且对供体核没有损伤。为了研究这种方法在小鼠核移植中是否适用, 本实验使用完整的小鼠卵丘细胞作供体, 进行显微注射, 结果显示, 完整的卵丘细胞注入卵母细胞后, 无论在1小时或者6小时激活, 大部分的重构胚在2细胞期碎裂, 而去掉细胞膜的供体体细胞核注入卵母细胞后, 重构胚可以卵裂并进一步发育。卵母细胞去核后不注射供体也发生碎裂, 大部分的孤雌胚(不去核)在完整的卵丘细胞被注入后同样发生碎裂。在供体卵丘细胞刚破膜后即被注入卵胞质和供核被充分剥离后注入两种情况下获得的重构胚的体外发育中, 前者发育各期的比率显著低于后者。这些结果说明完整的卵丘细胞膜阻碍了卵胞质对体细胞核的重编程作用, 造成碎裂; 注入卵胞质的供体质膜和胞质成分影响了克隆胚的体外发育。     

家猪减数分裂粗线期二价体与有丝分裂中期染色体的比较研究

以性成熟公猪睾丸和外周血为材料,采用长低渗、高氯仿卡诺固定液固定和外周血细胞培养制备减数分裂粗线期二价体和有丝分裂中期染色体,通过对二价体和有丝分裂中期染色体分裂指数和长度的比较研究,发现二价体的分裂指数和长度分别是有丝分裂中期染色体的5倍和3.42倍(1.87～5.98);同时以12号染色体为例, 比较了二价体上的染色粒结构带与有丝分裂中期染色体G-带,表明染色粒结构带比中期染色体G-带带纹丰富,而与早中期G-带带纹吻合。 Abstract:Meiotic pachytene bivalents were obtained from porcine testes using prolonged hypotonic treatment combined with high chloroform Carnory's fixative solution. Mitotic metaphase chromosomes were prepared from blood cell culture. Comparative studies on division index and length of pachytene bivalents and mitosis metaphase chromosomes showed that those of the former are 5 times higher and 3.42(1.87～5.98) times longer than the latter, respectively. Chromomere maps of bivalents are more abundant than mitotic metaphase G-bands, while they are correspondent with mitotic early-metaphase G-bands. The result was found by using the chromosome 12 as a sample.     

Nesting season,nest age,and disturbance,but not habitat characteristics,affect nest survival of Chinese grouse

Nest survival is a vital component of breeding success,and affects population dynamics,as the loss of nests is the main cause of reproductive failure in birds.To identify key factors for the conservation of Chinese grouse Tetrastes sewerzowi,we tested the effects of nest concealment,nest age,nesting season,and habitat edge on nest daily survival rate(DSR)of Chinese grouse using 54 nests found at Lianhuashan Nature Reserve,Gansu,China,2009-2012.Moreover,we controlled for the effect of research activity by testing the effect of nest checks on DSR.Overall,mammal predation caused 93%of nest failures.DSR was 0.986±0.0038 in the constant model and the probability of a nest with a full clutch of 6 eggs surviving the entire 40-day nesting period was 0.526±0.090.DSR decreased with nest age and nesting season(from 19 May to 3 July).Mammals instead of avian predators being responsible for most nest failures suggest that nest sites might be selected to avoid visual avian predators,but not olfactory mammalian predators,and the decreasing trend of DSR with nest age and nesting season could attribute to an additive exposure effect.Moreover,nest checks conducted by investigators significantly lowered nest DSR,especially during the late period of nesting season and for older nests.Mammalian predators might locate the nest site by following the investigator's odor.Based on our results,we suggest that the late incubation stage is a particularly vulnerable period for nest survival of Chinese grouse and those researchers should adjust their activities around nests to balance the need of acquiring accurate data and decreasing nest predation risk.     

The group size effect and synchronization of vigilance in the Tibetan wild ass

Vigilance behavior is considered as an effective strategy for prey species to detect predators.An individual benefits from living in a group by reducing the time spent being vigilant without affecting the probability of detecting a predator.However,the mechanism producing a decrease in vigilance with increasing group size is unclear.Many models of vigilance assume that group members scan independently of one another.Yet in recent studies,the other 2 patterns of vigilance,coordination and synchronization,were reported in some species.In 2 summers(2018 and 2019),we studied the group-size effect on vigilance and foraging of Tibetan wild ass in Chang Tang Nature Reserve of Tibet.We also tested whether individuals scan the environment independently,tend to coordinate their scans,or tend to synchronize their vigilance.The results showed that individuals decreased the time spent on vigilance with increasing group size,while increased the time spent foraging.Group members scanned the environment at the same time more frequently and there was a positive correlation between group members'behaviors,indicating that Tibetan wild asses tend to synchronize their vigilance.     

SRB-生物硫铁复合材料对废弃煤矿地下水的修复研究

酸性矿山废水（AMD）中含有高浓度的硫酸盐和金属离子，对矿山生态环境造成了严重的危害。硫酸盐还原菌（SRB）可以将SO42-还原为S2-，沉淀金属离子，并生成生物硫铁，其处理效率较高。文章利用农业废弃物秸秆制备SRB的缓释碳源，考察了不同形式的碳源条件下SRB对酸性矿山废水特征污染组分的处理效果，并结合SRB原位生成的生物硫铁包覆颗粒，制备得到SRB-生物硫铁复合材料，通过批量实验和动态柱实验考查SRB-生物硫铁复合材料对高浓度模拟废水和实际矿井水的处理效果。结果显示：在pH为5.5时，将秸秆渣作为游离SRB的碳源是可行的，但与秸秆渣相比，秸秆生物炭的处理效率明显更高，将秸秆生物炭与乳酸钠结合制备的SRB碳源，激活SRB的时间更短，12 h内对SO42-和Fe2+的去除率分别达到了59.25%和79.56%。在此实验范围内，随着生物炭投加量的增大，去除效率逐渐提高，在p H为4.5～6.5的范围内，体系初始p H对SRB反应体系的处理效果影响不大。SRB-碳源与生物硫铁包覆颗粒结合后对高浓度的SO42-和Fe2+模拟废水能保持高效且持久的反应活性。动态柱实验表明SRB-生物炭-生物硫铁...     

Zacopride selectively activates the Kir2.1 channel via a PKA signaling pathway in rat cardiomyocytes

We recently reported that zacopride is a selective inward rectifier potassium current (IK1 ) channel agonist, suppressing ventricular arrhythmias without affecting atrial arrhythmias. The present study aimed to investigate the unique pharmacological properties of zacopride. The whole-cell patch-clamp technique was used to study IK1 currents in rat atrial myocytes and Kir2.x currents in human embryonic kidney (HEK)-293 cells transfected with inward rectifier potassium channel (Kir)2.1, Kir2.2, Kir2.3, or mutated Kir2.1 (at phosphorylation site S425L). Western immunoblots were performed to estimate the relative protein expression levels of Kir2.x in rat atria and ventricles. Results showed that zacopride did not affect the IK1 and transmembrane potential of atrial myocytes. In HEK293 cells, zacopride increased Kir2.1 homomeric channels by 40.7%±9.7% at 50 mV, but did not affect Kir2.2 and Kir2.3 homomeric channels, and Kir2.1-Kir2.2, Kir2.1-Kir2.3 and Kir2.2-Kir2.3 heteromeric channels. Western immunoblots showed that similar levels of Kir2.3 protein were expressed in rat atria and ventricles, but atrial Kir2.1 protein level was only 25% of that measured in the ventricle. In addition, 5-hydroxytryptamine (5-HT) 3 receptor was undetectable, whereas 5-HT 4 receptor was weakly expressed in HEK293 cells. The Kir2.1-activating effect of zacopride in these cells was abolished by inhibition of protein kinase A (PKA), but not PKC or PKG. Furthermore, zacopride did not activate the mutant Kir2.1 channel in HEK293 cells but selectively activated the Kir2.1 homomeric channel via a PKA-dependent pathway, independent to that of the 5-HT receptor.     

Research Progress of Microbial Diversity in Recent Three Years

The general situation and latest research trends in the research field of microbial diversity were summarized in this article, including the number of articles in different years, in different databases, in and different research objects which the researchers prefer to select. The papers are categorized into different research emphasis and detailed the corresponding research content in recent 3 years. This review provides us insights into the broader framework of microbial diversity in recent years and represents the research emphasis in this field. The purpose of this article is to provide a research basis for scholars to choose research direction and determine their research content.     

Oral delivery of dsHvlwr is a feasible method for managing the pest Henosepilachna vigintioctopunctata(Coleoptera:Coccinellidae)

RNA interference(RNAi)techniques have emerged as powerful tools that facilitate development of novel management strategies for insect pests,such as Henosepilachna vigintioctopunctata(Coleoptera:Coccinellidae),which is a major pest of solanaceous plants in Asia.In this study,the potential of oral delivery of in vvYro-synthesized and bacterially expressed double-stranded H.vigintioctopunctata lesswright(Iwr)gene(dsHvlwr)to manage of H.vigintioctopunctata was investigated.Our results showed that the gene Hvlwr had a 480-bp open reading frame and encoded a 160-amino acid protein.Hvlwr expression levels were greater in the fat body than other tissue types.Hvlwr silencing led to greater H.vigintioctopunctata mortality rates and appeared to be time-and partially dose-dependent,likely as a result of the number of hemocytes increasing with dsRNA concentration,but decreasing with time.Bacterially expressed dsHvlwr that was applied to leaf discs caused 88%,66%,and 36%mortality in 1st instars,3rd instars,and adults after 10,10,and 14 d,respectively;when applied to living plants,there was greater mortality in 1 st and 3rd instars,but there was no effect on adults.Furthermore,dsHvlwr led to improved plant protection against H.vigintioctopunctata.Our study shows an effective dietary RNAi response in H.vigintioctopunctata and that Hvlwr is a promising RNAi target gene for control of this pest species.     

Sinoalaria,a name to replace Alaria （Araneae,Theridiosomatidae）

Sinoalaria nom. nov.
= Alaria Zhao ＆ Li, 2012. ZooKeys 255： 7.
Type species. Alaria chengguanensis Zhao ＆ Li, 2012
Etymology. The generic epithet is a combination of Latin Sino （=China） and Latin alaria （=of wings）, referring to the distribution of the genus and the shape of projection of the copulatory ducts. Gender is feminine.