Endangered Pinzgauer cattle subtype Jochberger Hummel are genetically distinct

Autochthonous cattle breeds are an important part of cultural heritage and reservoir of genetic diversity. Usually, such breeds have been selected over centuries and reflect adaptation to a specific local environment and human demands. However, owing to low effective population size in conjunction with increased inbreeding and genetic drift, many of these lineages are threatened with extinction. The Jochberger Hummel (‘Jochberger Bumblebee’) is such an endangered subtype of the Pinzgauer cattle originating from a single polled female calf. To evaluate the suspected uniqueness of this subtype and to assess whether it should be kept separate or managed together with the Pinzgauer cattle as one population, I examined the genetic diversity in a set of 844 cattle (Angus, Charolais, Holstein, Jochberger Hummel, Pinzgauer, Uckermaerker and Tux-Zillertaler) using principal component and biogeographical ancestry analysis. The analysis showed that the Jochberger Hummel is still a distinct subtype of Pinzgauer cattle with less than 5% admixture and a low inbreeding coefficient.     

Characterizations of the murine mesenchymal cell line expressing GFP

We established and characterized a murine mesenchymal stem cell line from the bone marrow of a transgenic C57BL mouse that ubiquitously expressed green fluorescent protein (GFP). Immunostaining revealed the presence of several markers common for mesenchymal stem cells (MSCs). The cells expressed specific fibroblast proteins, such as smooth muscle actin, which is localized in stress fibrils, and vimentin, a major protein of intermediate filaments in connective tissue cells. These proteins are responsible for the ability to differentiate into adipocytes or osteoblasts under appropriate conditions. The MSC karyotype was unstable. At the 6th passage cells, were aneuploid and genetically heterogeneous. The number of chromosomes ranged from near 2n to 8n. 80% of cells had chromosome numbers between 50 and 85 without a well-defined modal class. Differential G-staining of metaphase spreads showed variability in the copy numbers of individual chromosomes and presence of random chromosome rearrangements, such as ectopic associations of nonhomologous chromosomes. All cells analyzed contained a single dicentric marker chromosome. Some cells also had mini-chromosomes regarded as indicators of gene amplification. We suppose that the karyotypic instability of MSCs that express GFP is provoked by the insertion of foreign GFP transgenes into the murine genome. These cells could be useful for the study of genomic alterations during the spontaneous oncogenic transformation of stem cells.     

新疆艾比湖湿地自然保护区植物的生态分组

应用列联表的χ~2检验和Spearman相关系数研究了艾比湖湿地自然保护区植物的种间联结性和相关性.依据测定结果,将艾比湖湿地自然保护区的植物划分为4个生态种组:梭梭+盐节木+白麻+盐爪爪+琵琶柴+碱蓬+花花柴+骆驼刺+绢蒿+白刺+芦苇、小獐茅+多枝柽柳+滨藜+小叶碱蓬+盐豆木+鹅绒藤+盐穗木、胡杨+白梭梭、奶浆草+甘草+西北天门冬+赖草+罗布麻.各生态种组内,物种间具备最大的种问联结性和相关性.长期的演替过程使各生态种组对生境有最大的适应能力,各自分别生活于过渡带的盐化平原低地、湖滨盐沼地、荒漠和荒漠优势种间的阳斑.今后在艾比湖湿地自然保护区植物的保护和恢复中,以整个生态种组的角度出发较单个植物的保护和恢复更为有效.     

余甘子种子的抗逆生理特性及其对天然更新的影响

余甘子（Phylanthus emblica）是干热河谷植被的重要特征种和建群树种。本文通过模拟金沙江干热河谷典型地区元谋盆地4月气候条件下,研究了余甘子种子的活力散失机制及其有关生理生化变化情况,并对余甘子天然群落的自然更新状况进行了调查。结果表明: 随着高温干旱处理时间延长,种子活力不断降低,相对电导率、Pro含量和MDA含量呈持续上升趋势;呼吸强度、SOD活性、POD活性、CAT活性、可溶性糖含量呈单峰曲线变化;膜保护酶系统活力降低和保护性物质含量减少是造成种子活力下降的主要因素;实验处理的第18天至第24天是余甘子种子抵御逆境的临界期;每年3月下旬至4月上、中旬,应采取人工辅助措施来提高其种子的天然更新能力。     

不同居群白木香的染色体研究

采用常规压片法和改良BSG法对3个居群白木香的染色体核型及Giemsa C-带带型进行研究。结果表明:3个居群白木香的核型均属2B类型,其中广西居群白木香的核型公式为2n=16=4m+8sm+4st;其他两个居群白木香的核型公式为2n=16=6m+6sm+4st,居群间核型变异不明显。白木香的C带带型为CIT型,具有着丝粒带、中间带、端带和全带。3个居群白木香C带的分布、数目和类型不完全一样,出现了带型的多态性。     

三种紫金牛属植物的核型研究

对紫金牛属三种植物进行了核型分析,其中朱砂根染色体数目2n=46、核型2n=46=42m+2sm+2st和紫金牛核型2n=92=58m+24sm+10st为首次报道;虎舌红核型公式为2n=44=40m+2sm+2st。核型分析结果显示,紫金牛属植物存在染色体数目非整倍体变异及多倍化的进化方式。     

拟鹅观草属3种植物的核型研究

对禾本科小麦族拟鹅观草属物种Pseudoroegneria geniculata、P.geniculata ssp.scythica和P.geniculata ssp.pruinifera的核型进行了研究.结果显示:P.geniculata和P.geniculata ssp.scythica为四倍体物种,P.geniculata ssp.pruinifera为六倍体物种;P.geniculata、P.geniculata ssp.scythica和P.geniculata ssp.pruinifera的核型公式分别为2n=4x=28=18m(2sat)+10sm(2sat)、2n=4x=28=28m(2sat)和2n=6x=42=36m(6sat)+6sm(2sat);P.geniculata和P.geniculata ssp.pruinifera为2A核型,而P.geniculata ssp.scythica为1A核型.研究表明:3种植物的核型存在差异;P.geniculata ssp.pruinifera的核型为首次报道,其核型明显不同于P.geniculata和P.geniculata ssp.scythica.     

黑龙江省产两种草蜥染色体组型研究

采用常规骨髓细胞制片法,对黑龙江省产黑龙江草蜥和白条草蜥的染色体组型进行分析.结果表明,两种草蜥二倍体染色体的数目均是38,由18对常染色体和1对性染色体组成.常染色体中17对为端部着丝点染色体,1对为点状染色体;性染色体为ZW 型,从核型特征看来,二者都为蜥蜴目较原始的类型.