Molecular characterization and expression analysis of a KIFC1-like kinesin gene in the testis of Eumeces chinensis

The member of the kinesin-14 subfamily, KIFC1, is a carboxyl-terminal motor protein that plays an important role in the elongation of nucleus and acrosome biogenesis during the spermiogenesis of mammals. Here, we had cloned and sequenced the cDNA of a mammalian KIFC1 homologue (termed ec-KIFC1) from the total RNA of the testis of the reptile Eumeces chinensis. The full-length sequence was 2,339 bp that contained a 216 bp 5′-untranslated region (5′UTR), a 194 bp 3′-untranslated region (3′UTR) and a 1,929 bp open reading frame that encoded a special protein of 643 amino acids (aa). The calculated molecular weight of the putative ec-KIFC1 was 71 kDa and its estimated isoelectric point was 9.47. The putative ec-KIFC1 protein owns a tail domain from 1 to 116 aa, a stalk domain from 117 to 291 aa and a conserved carboxyl motor domain from 292 to 642 aa. Protein alignment demonstrated that ec-KIFC1 had 45.6, 42.8, 44.6, 36.9, 43.7, 46.4, 45.1, 55.6 and 49.8 % identity with its homologues in Mus musculus, Salmo salar, Danio rerio, Eriocheir sinensis, Rattus norvegicus, Homo sapiens, Bos taurus, Gallus gallus and Xenopus laevis, respectively. Tissue expression analysis showed the presence of ovary, heart, liver, intestine, oviduct, testis and muscle. The phylogenetic tree revealed that ec-KIFC1 was more closely related to vertebrate KIFC1 than to invertebrate KIFC1. In situ hybridization showed that the ec-KIFC1 mRNA was localized in the periphery of the nuclear membrane and the center of the nucleus in early spermatids. In mid spermatids, the ec-KIFC1 had abundant expression in the center of nucleus, and was expressed in the tail and the anterior part of spermatids. In the late spermatid, the nucleus gradually became elongated, and the ec-KIFC1 mRNA signal was still centralized in the nucleus. In mature spermatids, the signal of the ec-KIFC1 gradually became weak, and was mainly located at the tail of spermatids. Therefore, the ec-KIFC1 probably plays a critical role in the spermatogenesis of E. chinensis.     

改良三倍体鲫鱼的生物学特性研究

利用鱼类远缘杂交和雌核发育相结合的方法培育出改良四倍体鲫鲤和改良二倍体红鲫,两者交配制备出一种改良三倍体鲫鱼（湘云鲫2号）.对改良三倍体鲫鱼的染色体数目和组型、性腺和垂体结构、外形特征、生长速度等方面进行了系统的研究.结果表明,改良三倍体鲫鱼的染色体数目为3n=150,核型公式为33m＋51sm＋33st＋33t;其精巢和卵巢在繁殖季节不能产生成熟配子,垂体超微结构显示,GTH细胞内的分泌颗粒和分泌小球在繁殖季节没有大量排出,该特征从内分泌的角度证明了它们的不育性;改良三倍体鲫鱼具有体背高、尾柄短和头部小的优良外形特征.与三倍体湘云鲫相比,改良三倍体鲫鱼不但保留了三倍体鱼生长速度快、不育等特点,而且在体形方面表现出明显的改良特征,是一种新型改良三倍体鲫鱼.     

雷氏大疣蛛毒素—Ⅱ的纯化与初步毒性研究

雷氏大疣蛛是我国最近鉴定的蜘蛛新种。雷氏大疣蛛毒素－Ⅱ就是以其粗毒为材料,利用阴、阳离子交换层析和反相HPLC分离得到并命名的一种新型神经毒素肽,根据质谱分析得知它的相对分子质量为3021．56;通过初步毒性研究,证明它是一个神经毒素。     

Nitrogen economy of alpine plants on the north Tibetan Plateau: Nitrogen conservation by resorption rather than open sources through biological symbiotic fixation

Nitrogen (N) is one of the most important factors limiting plant productivity, and N fixation by legume species is an important source of N input into ecosystems. Meanwhile, N resorption from senescent plant tissues conserves nutrients taken up in the current season, which may alleviate ecosystem N limitation. N fixation was assessed by the ¹⁵N dilution technique in four types of alpine grasslands along the precipitation and soil nutrient gradients. The N resorption efficiency (NRE) was also measured in these alpine grasslands. The aboveground biomass in the alpine meadow was 4–6 times higher than in the alpine meadow steppe, alpine steppe, and alpine desert steppe. However, the proportion of legume species to community biomass in the alpine steppe and the alpine desert steppe was significantly higher than the proportion in the alpine meadow. N fixation by the legume plants in the alpine meadow was 0.236 g N/m², which was significantly higher than N fixation in other alpine grasslands (0.041 to 0.089 g N/m²). The NRE in the alpine meadows was lower than in the other three alpine grasslands. Both the aboveground biomass and N fixation of the legume plants showed decreasing trends with the decline of precipitation and soil N gradients from east to west, while the NRE of alpine plants showed increasing trends along the gradients, which indicates that alpine plants enhance the NRE to adapt to the increasing droughts and nutrient‐poor environments. The opposite trends of N fixation and NRE along the precipitation and soil nutrient gradients indicate that alpine plants adapt to precipitation and soil nutrient limitation by promoting NRE (conservative nutrient use by alpine plants) rather than biological N fixation (open sources by legume plants) on the north Tibetan Plateau.     

基因治疗与人类健康

随着分子生物学及基因工程技术的迅猛发展 ,基因治疗已经成为治疗人类疾病的重要方法之一 ,同时也是维护人类健康最有发展前景的手段之一。诸如遗传病、肿瘤、和传染病与心血管病的基因治疗。遗传免疫方面 ,病毒性疾病和肿瘤的基因治疗 ,如将病毒抗原基因 (HBsAg)及一些肿瘤抗原基因 (CEA)直接注入人体内而产生抗体 ;人类亚健康状态 ,如肥胖、秃顶、疲劳、衰老等的基因治疗。然而基因治疗目前仍面临着许多困扰 ,如基因治疗的有效性、安全性、及社会伦理等诸多问题 ,因此在临床实际应用中要慎之又慎。只有对基因治疗合理规范和正确引导并遵循伦理原则 ,才能最终推动现代医学的发展。     

Global gene expression analysis to identify molecular markers of uterine receptivity and embryo implantation

Infertility and spontaneous pregnancy losses are an enduring problem to women's health. The establishment of pregnancy depends on successful implantation, where a complex series of interactions occurs between the heterogeneous cell types of the uterus and blastocyst. Although a number of genes are implicated in embryo-uterine interactions during implantation, genetic evidence suggests that only a small number of them are critical to this process. To obtain a global view and identify novel pathways of implantation, we used a dual screening strategy to analyze the expression of nearly 10,000 mouse genes by microarray analysis. Comparison of implantation and interimplantation sites by a conservative statistical approach revealed 36 up-regulated genes and 27 down-regulated genes at the implantation site. We also compared the uterine gene expression profile of progesterone-treated, delayed implanting mice to that of mice in which delayed implantation was terminated by estrogen. The results show up-regulation of 128 genes and down-regulation of 101 genes after termination of the delayed implantation. A combined analysis of these experiments showed specific up-regulation of 27 genes both at the implantation site and during uterine activation, representing a broad diversity of molecular functions. In contrast, the majority of genes that were decreased in the combined analysis were related to host immunity or the immune response, suggesting the importance of these genes in regulating the uterine environment for the implanting blastocyst. Collectively, we identified genes with recognized roles in implantation, genes with potential roles in this process, and genes whose functions have yet to be defined in this event. The identification of unique genetic markers for the onset of implantation signifies that genome-wide analysis coupled with functional assays is a promising approach to resolve the molecular pathways required for successful implantation.     

CO2浓度升高对不同品种水稻镉吸收和根形态的影响

为了探讨CO2浓度升高下不同水稻品种荣优398 (RY)和粤杂889(YZ)吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明:低Cd处理(5、10、20 μmol·L-1)显著增加水稻生物量;当Cd浓度高于50 μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5～200 μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一.     

含铬重组液激活部分缺失金属原子簇的钼铁蛋白的研究

棕色固氮菌（Ａｚｏｔｏｂａｃｔｅｒ ｖｉｎｅｌａｎｄｉｉ）固氮酶钼铁蛋白经邻菲口罗啉和Ｏ２ 处理后,变为部分缺失ＦｅＭｏｃｏ 和Ｐ－ｃｌｕｓｔｅｒ的失活蛋白。与由Ｋ２ＣｒＯ４、高柠檬酸铁、Ｎａ２Ｓ和二硫苏糖醇组成的重组液保温后,处理蛋白对乙炔和质子还原的活性都得以显著恢复;然而,它的吸收光谱和圆二色谱虽有明显恢复,但仍与还原钼铁蛋白有所不同。这表明,激活蛋白中也许存在功能与钼铁蛋白相似,而结构则有所差异的含铬（ＣｒＦｅ）蛋白     

Production and selected fuel properties of biodiesel from promising non-edible oils: Euphorbia lathyris L., Sapium sebiferum L. and Jatropha curcas L

A comparative study on the composition, biodiesel production and fuel properties of non-edible oils from Euphorbia lathyris L. (EL), Sapium sebiferum L. (SS), and Jatropha curcas L. (JC) was conducted. Under optimal conditions, the FAME content and yield of the three oils were greater than 97.5 wt.% and 84.0%, respectively. The best biodiesel was produced from EL due to its high monounsaturation (82.66 wt.%, Cn: 1), low polyunsaturation (6.49 wt.%, Cn: 2, 3) and appropriate proportion of saturated components (8.78 wt.%, Cn: 0). Namely, EL biodiesel possessed a cetane number of 59.6, an oxidation stability of 10.4 h and a cold filter plug point of -11 °C. However, the cetane number (40.2) and oxidative stability (0.8 h) of dewaxed SS kernel oil (DSSK) biodiesel were low due to the high polyunsaturation (72.79 wt.%). In general, the results suggest that E. lathyris L. is a promising species for biodiesel feedstock.