酿酒酵母Sfi1p的结构及生物学功能

纺锤体极体(spindle pole body,SPB)是酵母细胞的微管组织中心,它在细胞分裂及细胞遗传稳定性的维持过程中起着极其重要的作用,是细胞生物学领域热门的研究方向.Sfi1p是酿酒酵母SPB的必需蛋白并且横跨整个半桥,该蛋白与SPB的复制有关,它的缺失或突变会导致SPB复制失败,在哺乳动物的中心体也存在酵母Sfi1p的同源蛋白.本文系统的介绍了酵母Sfi1p及其在人类中心体中的同源蛋白hSfi1p的结构特征,并且阐明了Sfi1p在SPB复制与分离、核配及生孢等细胞周期过程中的作用.对Sfi1p的功能研究,将有助于解决SPB研究过程中重要的科学问题,同时为中心体中Sfi1p同源蛋白的功能研究提供良好的借鉴.     

产DHA菌株的诱变育种

以海水中分离得到产DHA的酒香酵母(编号为7-3)作为出发菌株,对其进行单一及复合诱变处理,初筛采用分光光度法确定菌体中油脂的相对含量,选择吸光度相对较高的菌株进行复筛,复筛采用有机溶剂萃取法测定油脂含量、气相色谱法测定DHA含量。单一诱变的菌株H-1的脂肪含量达到43.8%,为对照的4倍,经复合诱变后得到1株编号为H-Z-6-3的菌株其油脂含量达50.4%,诱变后油脂中DHA的含量提高较少。     

Comparison of sampling methods for alate aphids and observations on epidemiology of soybean mosaic virus in Nanjing, China

Using standard diversity indices, samples of aphids collected on a vertical net were found to be more diverse than collections from green pan traps in experiments conducted in Nanjing, China in 1981. Some species, notably Myzuspersicae, Aphis citricola, and Eriosoma (Schizoneura) japonicum, were collected in greater relative numbers in the pan traps. Several species, including the Macrosiphoniella spp., were under-represented in the green pan traps presumably because they were not attracted to the green colour of the traps. Yellow pan traps, used concurrently to monitor landing rates of economic species, caught relatively more Aphis craccivora and M. persicae and relatively fewer Aphis gossypii than green ones. In the Nanjing area soybean mosaic virus (SMV) usually spreads in spring planted soybeans during the latter half of May, causing damage. The predominant aphid species trapped at that time were M. persicae, Lipaphis erysimi, A. gossypii, A. craccivora and E. japonicum, of which the first four are known vectors. Summer planted soybeans are usually affected during a second period of virus spread occurring in mid-August when various Aphis spp. are abundant. The predominant vector of SMV at that time was thought to be Aphis glycines which colonises the crop; in 1981, however, A. citricola and A. gossypii, which do not colonise soybean and A. craccivora. which rarely colonises soybean, were much more abundant in mid-August than A. glycines. A. citricola, A. gossypii and A. craccivora are all able to transmit SMV, and thus should be considered as potentially important vectors. In infectivity assays, only four of 1040 aphids transmitted SMV. These included an A. craccivora, two Toxoptera citricidus and one Aphis sp.     

Functional evaluation of iodoacetic acid induced photoreceptor degeneration in the cat

Iodoacetic acid(IAA) has been applied to different species to acutely induce photoreceptor degeneration.The purpose of the present study was to use this toxin to thoroughly eliminate photoreceptors and induce complete blindness in the cat.IAA was delivered by single ear vein injection(20 mgkg-1).Six months after the IAA treatment,functional evaluations including pupillary light reflex(PLR),electroretinogram(ERG),visual behavior tests were performed.Morphological examinations were carried out after the functional evaluation.The present result shows that,six months after the IAA application,animals lost visual functions and became completely blind.High dose IAA application via ear vein delivery created an acute and reliable complete photoreceptor degeneration model in the cat.This model can be applied to genetic and cellular therapies for visual function restoration.     

Melanopsin-expressing retinal ganglion cell loss and behavioral analysis in the Thy1-CFP-DBA/2J mouse model of glaucoma

In this study,the role of melanopsin-expressing retinal ganglion cells(mRGCs) in the glaucoma-induced depressive behavioral response pattern was investigated.The CFP-D2 transgenic glaucoma animal model from five age groups was used in this study.Immunohistochemical labeling,quantitative analysis of mRGC morphology,open field test(OFT),and statistical analysis were used.In comparison with C57 BL/6 mice,the age-matched CFP-D2 mice had significantly elevated intraocular pressure(IOP).We observed parallel morphological changes in the retina,including a reduction in the density of cyan fluorescent protein(CFP) expressing cells(cells mm 2 at 2 months of age,1309±26;14 months,878±30,P<0.001),mRGCs(2 months,48±3;14 months,19±4,P<0.001),Brn3b-expressing RGCs(2 months,1283±80;14 months,950±31,P<0.001),Brn-3b expressing mRGCs(5 months,50.17%±5.5%;14 months,12.61%±3.8%,P<0.001),and reduction in the dendritic field size of mRGCs(mm2 at 2 months,0.077±0.015;14 months,0.065±0.015,P<0.05).CFP-D2 mice had hyperactive locomotor activity patterns based on OFT findings of the total distance traveled,number of entries into the center,and time spent in the center of the testing apparatus.The glaucoma induced hyperactive response pattern could be associated with dysfunctional mRGCs,most likely Brn-3b-positive mRGCs in CFP-D2 mice.