从线粒体Cyt b���因探讨红瘰疣螈物种地位的有效性

疣螈属的红瘰疣螈(Tylototriton shanjing)和棕黑疣螈(T.verrucosus)的物种界限一直不清楚.测定了来自中国西南地区14个地点的T.shanjing和T.verrucosus共40只标本的线粒体DNA Cyt b���因(753 bp).结果表明:(1)用邻接法、最大简约法和贝叶斯法等3种系统发育分析法分别重建棕黑疣螈种组系统发育树的拓扑结构不支持T.shanjing是单系群;(2)T.shanjing与T.verrucsus的mtDNA Cyt b���列差异平均值仅为1.2%.未达到种级水平.因此,全部T.shanjing样品都属于同一个物种,即T.verrucosus,不支持T.shanjing的物种地位,T.shanjing为T.verrucosus的同物异名,并建议恢复T.verrucosus的中文名红瘰疣螈.根据基于40个样品Cvt b���因序列的系统发育树和遗传变异以及地理分布,这些红瘰疣螈(T.verrucosus)样品聚为3支,即中国西南地区的红瘰疣螈可分为片马、滇中滇西和滇东南3个地理居群.

Molecular phylogeny and taxonomy of wood mice (genus Apodemus Kaup, 1829) based on complete mtDNA cytochrome b sequences, with emphasis on Chinese species

Phylogenetic relationships among 15 species of wood mice (genus Apodemus) were reconstructed to explore some long-standing taxonomic problems. The results provided support for the monophyly of the genus Apodemus, but could not reject the hypothesis of paraphyly for this genus. Our data divided the 15 species into four major groups: (1) the Sylvaemus group (A. sylvaticus, A. flavicollis, A. alpicola, and A. uralensis), (2) the Apodemus group (A. peninsulae, A. chevreri, A. agrarius, A. speciosus, A. draco, A. ilex, A. semotus, A. latronum, and A. mystacinus), (3) A. argenteus, and (4) A. gurkha. Our results also suggested that orestes should be a valid subspecies of A. draco rather than an independent species; in contrast, A. ilex from Yunnan may be regarded as a separate species rather than a synonym of orestes or draco. The species level status of A. latronum, tscherga as synonyms of A. uralensis, and A. chevrieri as a valid species and the closest sibling species of A. agrarius were further corroborated by our data. Applying a molecular clock with the divergences of Mus and Rattus set at 12 million years ago (Mya) as a calibration point, it was estimated that five old lineages (A. mystacinus and four major groups above) diverged in the late Miocene (7.82-12.74 Mya). Then the Apodemus group (excluding A. mystacinus) split into two subgroups: agrarius and draco, at about 7.17-9.95 Mya. Four species of the Sylvaemus group were estimated to diverge at about 2.92-5.21 Mya. The Hengduan Mountains Region was hypothesized to have played important roles in Apodemus evolutionary histories since the Pleistocene. (C) 2004 Elsevier Inc. All rights reserved.

HIV-1感染对T和B���胞核内UNG2 mRNA表达的影响

目的:探讨HIV-1感染是否影响细胞中UNG2的表达.方法:采用四步法SYBR green Ⅰ实时定量RT-PCR,对HIV-1感染者的T和B���巴细胞,以及HIV-1感染的C8166细胞核内UNG2 mRNA的表达进行测定.结果:UNG2 mRNA的表达在HIV-1感染者的T细胞和HIV-1感染的C8166细胞中被明显上调,分别是对照的8.76倍和8.14倍,而在HIV-1感染者的B���胞中却没有被上调.结论:HIV-1感染导致的UNG2表达上调,可能通过减少TCR的多样性削弱Th的功能,另一方面可能有利于病毒对UNG2的包装.

与植物多糖硫酸酯结合的HIV-1ⅢB���活病毒免疫小鼠的研究

目的：为了探讨植物多糖硫酸酯（’&&(）与)*+%$ 结合后，能否诱导,-./+#0 的)*+%$ 暴露出中和抗体的表 位，用它作为灭活疫苗以便诱导产生中和抗体。方法：用’&&( 结合的灭活,-./+#0 作为免疫原，与佐剂混和后，免疫 0(102 3 小鼠，制备出免疫血浆。用41-5( 检测血浆内抗,-./+ 特异性-)6 抗体的滴度，用改良的活细胞染色法中和试验检测 免疫血浆的抗,-./+#0 的中和活性。结果：从与’&&( 结合的,-./+#0 免疫组的动物获得的免疫血浆内抗,-./+ 抗体的滴 度（7 组：+8 # 9 +$" ；: 组：+8 # 9 +$" ）比未结合’&&( 的,-./+#0 免疫组（;8 < 9 +$# ）高，雌性小鼠的免疫血浆的特异性抗体滴 度比雄性的高& 倍。所有免疫组获得的免疫血浆均没有抗,-./+ 中和活性。结论：’&&( 与)*+%$ 相互作用不能诱导暴露出 )*+%$ 的中和抗体表位，但’&&( 可以增强机体免疫原的抗体反应强度，提示它可以作为免疫增强剂用于疫苗研究。

Subdivision-stabilised immersed b-spline finite elements for moving boundary flows

An immersed finite element method is presented to compute flows with complex moving boundaries on a fixed Cartesian grid. The viscous, incompressible fluid flow equations are discretized with b-spline basis functions. The two-scale relation for b-splines is used to implement an elegant and efficient technique to satisfy the LBB condition. On non-grid-aligned fluid domains and at moving boundaries, the boundary conditions are enforced with a consistent penalty method as originally proposed by Nitsche. In addition, a special extrapolation technique is employed to prevent the loss of numerical stability in presence of arbitrarily small cut-cells. The versatility and accuracy of the proposed approach is demonstrated by means of convergence studies and comparisons with previous experimental and computational investigations.

银额果蝇的B���色体研究 1: 昆明群体的Bs数目和频率

银额果蝇昆明群体有丝分裂中期核型中存在B���色体, 出现频率为69.1%在已 研究过的来自各个地区的银额果蝇中, 昆明群体的B���色体频率最高。B���色体 数目为1—6条。该群体内单雌系间的B���色体数目不同, 个体间和细胞间的B���色 体数目也不同。在核型中, B���色体最小, 形态稳定, 点状, C-带和G-带呈阳性 。 图版1图2表1参12

银额果蝇的B���色体研究2: 昆明群体的生活力和B���色体的关系

银额果蝇的B���色体在其生长和发育过程中具双重性调节作用。一方面, B���色体以单一的形式存在于单雌系核型中, 即1B���2Bs可刺激生长发育,增强生活力。另一方面, 在单雌系的细胞中存在多条B���色体, 并形成核型多态性, 似乎对生长发育有一定的抑制作用而减弱其生活力。图1表1参5