Tissue expression, association analysis between three novel SNPs of the RXRα gene and growth traits in Chinese indigenous cattle

Retinoid X receptor(RXR) α is a member of the nuclear hormone receptor superfamily that mediates the biological effects on several hormones,vitamins,and regulates lipid,glucose and energy metabolism.In this study,the tissue expression profiles of the bovine RXRαgene and association analysis of single nucleotide polymorphisms(SNPs) with growth traits were carried out in 413 Chinese native cattle.The expression profile was analysed in ten Jiaxian cattle tissues by real-time PCR,and the results showed that RXRαgene was abundantly expressed in adipose tissue and spleen,moderately expressed in heart,liver,lung,kidney,muscle and testis.Meanwhile,three SNPs(T27919A,T28139C and G28142A) and five haplotypes were identified.Haplotype with TTG was dominant with frequency of 69.1%.Chi-square test showed all populations were in Hardy-Weinberg equilibrium(P>0.05) at the three sites except Jiaxian cattle at G28142A site and Qinchuan cattle at T27919A site.Statistical analysis of combined sites showed that the individuals with TTGA genotype had significantly higher heart girth than those with TAGG genotype(P<0.05) and the animals with AAGA genotype had higher body weight than those with TAGG genotype(P<0.05) in T27919A-G28142A site.Heart girth,abdominal circumference and body weight of individuals with TCAG genotype were exceedingly higher than those with TTGG(P<0.01),TTGA and TCGG(P<0.05) in T28139C-G28142A site.For T27919A-T28139C site,the individuals of TCTA and TCTT genotype had significantly higher heart girth and lower height at hip cross than those with TTTA(P<0.05),and the body weight of TCAA and TCTT genotype individuals was higher than those with TTTA(P<0.05).In conclusion,these results provided evidence that the polymorphisms of RXRαgene were associated with growth traits and might apply to Chinese indigenous yellow cattle breeding program as a possible candidate for marker-assisted selection(MAS).     

Effects of cadmium, 17β-estradiol and their interaction in the male Chinese loach （Misgurnus anguillicaudatus）

To assess the interaction effect between cadmium (Cd) and 17-estradiol (E2),male Chinese loaches (Misgurnus anguillicaudatus) were exposed to E2 (1 g/L) and Cd (50 or 500 g/L) alone and in combination using a semi-static waterborne exposure system.The effects of E2 on the accumulation and distribution of Cd,as well as the effects of Cd on vitellogenin (Vtg) synthesis induced by E2,were investigated.Cd mainly accumulated in the kidneys,liver,intestines,and gills,with little amounts in muscles,bones,and gonads.Co-exposure with E2 did not change the main targets for Cd.E2 could induce Vtg synthesis in male Chinese loaches,and co-exposure with 50 or 500 g/L Cd could inhibit the Vtg induced by 1 g/L E2.Compared with the results reported in the literature,it can be concluded that factors such as fish species,Cd dosage,and manner of exposure might make contributions to the interaction between Cd and E2.Our results also suggested that male Chinese loaches are susceptible to Cd,and can be recommended as a potential sentinel species to study the ecotoxicology of heavy metals.     

Two neuropeptides from synganglia of the hard tick, Ixodes sinensis （Acari： Ixodidae）

Two neuropeptides were isolated from synganglia (central nervous system) of the hard tick, Ixodes sinensis. Their primary sequences were established as Leu-Val-Val-Tyr-Pro-Trp-Thr-Lys and Trp-Glu-Lys-Leu-Gly-Ser-Met-Glu-Thr-Leu. By hot plate bioassay, neuropeptide a displayed strong antino-ciceptive effect in mice by a dose-dependent behavior, while neuropeptide b had some relaxant effects on the isolated rat strip. These neuropeptides might be involved in down-regulating the host's defensive reaction.     

Phenotypic and genetic variation between two populations of the Chinese yellow pond turtle, Mauremys mutica （Cantor, 1842）

Mauremys mutica (Cantor, 1842) is an endangered species in China. Main phenotypic variations in body color, body weight, body shape, clutch size, egg size, and hatchling size were revealed between the southern and northern populations. Both populations have the phenomenon of "larger male" sexual size dimorphism (SSD), especially in the southern population. Furthermore, genetic variations between the two populations were analyzed by RAPD band patterns of 30 random individuals in each population. The average genetic distance was 0.299±0.108 among the samples of two populations. The average genetic distance between southern and northern populations was 0.305±0.046. Cluster analysis indicated that all the individuals from the southern and northern populations were clustered among themselves to form two distinct clades. A total of 20 population-specific RAPD fragments were scored from 16 primers, and could be used as RAPD markers for distinguishing the southern and the northern population. Based on the nucleotide sequences of two RAPD markers, two pairs of SCAR primers (SC1-S and SC2-S) were designed, which could be used as SCAR markers for the southern population. According to the significant phenotypic and genetic variations, we suggested that the northern population and southern population might be considered as two separate taxa, the "northern taxon" and the "southern taxon", and the conservation should be respectively conducted on the two taxa.     

Seasonal variation of gut Cyanophyta contents and liver GST expression of mud carp （Cirrhina molitorella） and Nile tilapia （Oreochromis niloticus） in the tropical Xiangang Reservoir （Huizhou, China）

Liver glutathione S-transferase(GST) plays a major role in the detoxification of microcystins(MCs) via conjugation to glutathione(GSH).We evaluated the relationship between seasonal variation in fish gut contents and the expression of GST isoforms in mud carp(Cirrhina molitorella) and Nile tilapia(Oreochromis niloticus).We quantified the abundance and diversity of plankton in the water column and foregut of mud carp and Nile tilapia in the tropical Xiangang Reservoir between October 2007 and July 2008.The mRNA expression of 7 liver GST isoforms was determined by real-time RT-PCR.The gut contents of both species were dependent on the amount and type of phytoplankton and zooplankton in the water.The expression of liver GST genes in Nile tilapia and mud carp was positively and negatively correlated,respectively,with the abundance of toxic cyanobacteria in the fore-gut.The expression of liver GST mRNA was correlated to the abundance of toxic cyanobacteria in the gut contents of both species,suggesting that mRNA expression of GST isoforms could be used as a biomarker in Nile tilapia and mud carp to monitor cyanobacteria blooms in reservoirs.     

cDNA cloning and expression of erythropoietin in the plateau zokor （Myospalax baileyi） from the Qinghai-Tibet Plateau

All organisms respond to variation in their environments and manage environmental stress through metabolic adjustments.The plateau zokor(Myospalax baileyi) is an endemic and keystone subterranean rodent species that inhabits the Qinghai-Tibet Plateau between 2800 and 4200 m above sea level.It is a hypoxic-tolerant mammal with a high ratio of oxygen utilization that enables it to cope with its harsh surroundings.To explore the molecular mechanism of altitude acclimatization of the plateau zokor,we cloned the zokor erythropoietin(Epo) gene and used real-time PCR to compare Epo mRNA levels in zokors inhabiting 16 different altitudes.The full-length zokor Epo open reading frame was 579 bp that encoded a precursor peptide of 192 amino acids with a signal peptide of 26 residues.The Epo gene of the plateau zokor was 81%-95% homologous to that of human,mouse,rat,root vole and the Golan Heights blind mole rat,with the highest homology(95%) to species of the genus Spalax.Epo mRNA was detected mainly in the zokor kidney and spleen among 8 selected tissues.The level of Epo mRNA increased in the liver and kidney with increases in altitude.The increase in the kidney was 5 times that in the liver.Remarkably,expression of Epo mRNA in the kidney of zokors living at the highest altitude(4268 m) was 12-fold higher than that of zokors living at the lowest(2492 m) altitude.These findings provide essential information for understanding the possible role of Epo in adaptation to hypoxia in the plateau zokor.     

New primitive ichthyosaurian （Reptilia,Diapsida） from the Middle Triassic of Panxian,Guizhou, southwestern China and its position in the Triassic biotic recovery

A new primitive ichthyopterygian Xinminosaurus catactes gen. et. sp. nov. is erected based on a complete skeleton from the Middle Triassic Upper Member of the Guanling Formation at Panxian, Guizhou, southwestern China. It has a suite of uniquely derived char- acters in its dentition, ulna, carpals and tarsals. It is similar to primitive ichthyopterygians in retaining elongated limb bones. The new taxon and a diversity of marine reptiles in Panxian Fauna are the physical markers of the Middle Triassic Biotic radiation. Detailed studies of this fauna will supply essential knowledge on the diversity, migration and paleobiogeographic affinity of Middle Triassic ichthyopterygians.     

Molecular dissection of plant height QTLs using recombinant inbred lines from hybrids between common wheat （Triticum aestivum L.） and spelt wheat （Triticum spelta L.）

In wheat, plant height is an important agronomic trait, and a number of quantitative trait loci (QTLs) controlling plant height have been located. In this study, using the conditional and unconditional QTL mapping methods, combined with data from five different growth stages over two years of field trials, the developmental behavior for plant height in wheat was dissected. Nine unconditional QTLs and 8 conditional QTLs were identified, of which 6 were detected by both methods. None of the 11 QTLs was detected at all of the 5 investigated developmental stages, but 7 QTLs were detected at certain stages in both years. Further analysis identified 9 unconditional QTLs at different stages, which could explain the phenotypic variation from 4.81% to 17.35%. It was noteworthy that one major QTL designated QHt-4B-2, which was located on chromosome 4B, was detected on May 18 and 25 in both years, and its genetic contributions to plant height ranged from 13.42% to 16.13%. Moreover, of the 8 conditional QTLs identified, six were detected in both years, in the order of QHt-3B→QHt-4B-1→QHt-4B-2→QHt-4D→QHt-5A and QHt-2B expressed at the same developmental stage. The results indicate that QTL expression during plant height development is selective and in a temporal order.     

Primary investisation of the pollution status of polycyclic aromatic hydrocarbons （PAHs） in water and soil of Xuanwei and Fuyuan,Yunnan Province,China

Lung cancer incidence in Xuanwei and Fuyuan is extremely high. The air pollution, especially indoor airborne PAHs generated by burning smoky coals, has been considered as the most probable reason. The air pollution may affect drinking water and soil through dry and wet deposition. In this study, the concentrations of PAHs in water and soil samples from Xuanwei and Fuyuan were monitored to investigate the influence of atmospheric PAHs pollution on water and soil. No obvious PAHs pollution in water was found in these two areas, indicating that airborne PAHs have no apparent effect on the drinking water （well water）. The smoky coal combustion from household and industry, such as the activities related to power plants, coking plants and chemical industries, is responsible for the soil PAHs pollution in these two areas. The soil pollution might be the reemission source and would pose long-term threat to the local environment and health of residents.     

红豆杉胚源细胞株的培养和紫杉醇的生产

研究了建立适用于紫杉醇生物合成的红豆杉 ( Taxus chinensis)胚源细胞株的方法 .红豆杉成熟种子 ,用自来水冲洗 9d,培养 1 0 d,萌发率可达 1 0 0 %.已萌发的种胚在诱导培养基中培养 6d,愈伤组织的诱导率达 1 0 0 %,使用红豆杉茎源细胞株看护培养诱导出的愈伤组织使愈伤组织的继代成活率提高一倍 .红豆杉茎源细胞株生长 1 5d的条件培养液也能使愈伤组织继代成活率提高 60 %.对建立的胚源细胞株进行了筛选和培养 ,其中细胞株 E2和 E3生长快 ,紫杉醇含量也较高     

植物种质资源的保存--离体保存

植物种质资源的保存研究对于生物多样性保护和植物生物技术均具有十分重要的意义．文章综述了利用组培技术对不同植物组织器官进行限制生长与低温保存、超低温保存(玻璃化法、包埋脱水法、干燥法、预冻法、两步法)等离体保存技术．同时，列述了对保存种质存活率的鉴定及遗传稳定性分析的主要方法。     

人参组织和细胞培养研究进展

回顾人参组织和细胞培养研究的历史，介绍了人参组织和器官的离体培养、胚状体的诱导、毛状根的培养、花药的培养、原生质体培养、细胞培养、细胞的工业化生产的最新进展。     

人工饲养幼鳄出现卵黄硬结原因的探讨

本文报导扬子鳄幼鳄卵黄硬结形成的原困和防止的方法。人工饲养扬子鳄幼鳄卵黄硬结形成原因是过早喂食,野生幼鳄从孵出到第二年冬眠苏醒是不吃食的。孵出7—9天开始喂食将导致幼鳄卵黄消化困难并形成硬结,死亡率很高,饲养一年后死亡率达40%。幼鳄死亡的主要原因为卵黄变性,胃扩张,接近卵黄囊附近的小肠彼此粘连长合在一起。1987年初孵幼鳄饲养于31—32℃的幼鳄饲养室内,以提高卵黄吸收速率,同时,孵出后18天触摸幼鳄腹部,当卵黄完全吸收时立刻开始喂食,死亡率很低,饲养一年后幼鳄成活率为97.9%。少数幼鳄死亡原因多种多样,但无一例死于卵黄变性。     

扬子鳄幼鳄身体量度间的回归参数分析

扬子鳄头部和躯干随年龄增加按一定比速增长.据目前研究,躯干和头部长度之间具有较显著的相关性.扬子鳄幼体的4个身体量度数据和14个头部形态学参数被测量和记录下来.头部量度与身体量度间的数学关系通过回归分析提取出来.体重值采取log转化,再与体长进行回归分析,得到了直线方程.回归方程为由头部参数来估计出扬子鳄幼体体长与体重等数据提供了可行的途径.     

微重力细胞培养与组织工程

组织工程主要致力于组织和器官的形成和再生,其核心就是建立细胞与生物材料的三维复合体,形成具有生命力的活体组织,用于对病损组织进行形态结构和功能的重建并达到永久性替代。目前有关微重力和模拟微重力条件下细胞体外生长的研究提示微重力培养环境有利于细胞体外增生,维持有功能的细胞长期生长,并且有助于形成组织样结构,使培养得到的组织更接近于活体组织。因此微重力细胞培养为组织工程的研究开辟了新的前景。     

濒危药用植物新疆雪莲资源的研究进展

新疆雪莲分布于我国西部高寒山地的雪线附近,为我国特有的名贵中药材,具有多种化学成分和广泛的药理活性.本文概述了新疆雪莲的生物学特征和民间用途,总结了新疆雪莲的开发利用和资源现状,从原地保护和人工栽培、组织培养与细胞工程、遗传转化三方面阐述了雪莲资源的保护研究进展.根据已有的研究成果,本文提出了未来的研究方向,以期为今后新疆雪莲资源的合理利用与保护研究提供参考.     

离体保存技术在植物种质资源保存中的应用

植物种质资源的保存研究对于生物多样性保护和新品种选育均具有十分重要的意义。文章介绍了利用组培技术和低温生物技术对不同植物组织器官进行组织培养保存、超低温保存的研究现状和应用前景,并提出了有待继续研究的相关问题。     

鳙鱼Aristichthys nobilis吻端细胞系BHS的建立及特性观察

以鳙鱼吻端组织为材料,建立了鳙鱼吻端细胞系,定命为 BHS。7个月期间细胞已传25代,选用培养基为 TC-199加20%或10%小牛血清。该细胞生长温度范围为14℃—35℃,最适温度28℃—30℃,形态主要为纤维样细胞,染色体数从55—82(2n=48)为异倍体细胞,克隆形成率较低为4.4%。     

韭菜花序培养及植株再生

韭菜花序外植体在附加不同种类和浓度的ＭＳ培养基上脱分化形成愈伤组织。愈伤组织在分化培养基中分化成苗或者不经继代直接分化成苗。在含有ＮＡＡ的培养基中分化生根，开成再生完整植株。２，４－Ｄ或ＮＡＡ与６－ＢＡ配合使用，对愈伤组织的诱导效果最好。ＮＡＡ与ＺＴ组合地培养基中，苗的分化率最高。