大鼠前列腺上皮细胞角蛋白8mRNA表达调节的定位研究

本文应用反义RNA探针原位杂交法,研究雄激素对大鼠腹侧前列腺(VP)上皮细胞角蛋白(CK)8 mRNA表达的影响。发现1.在任何VP组织切片中,CK 8探针专一、大量定位于VP腺上皮细胞中,CK 8 mRNA是前列腺上皮细胞特异而灵敏的标志。2.去睾大鼠VP CK 8 mRNA染色增强,提示CK 8mRNA有过度表达,注射雄激素又可抑制其过度表达。3.与已知受雄激素抑制性基因不同,即使大鼠VP完全萎缩之后达2个月之久,其存留腺上皮细胞CK 8 mRNA表达仍持续增高。4.前列腺发育早期,迅速增殖的幼稚腺上皮细胞高度表达CK 8 mRNA,以后随着体内雄激素水平升高,VP上皮CK 8 mRNA表达下降,分布转移。以上结果进一步支持前列腺CK 8基因是新的一类受雄激素抑制性基因的推测,同时表明前列腺CK 8基因的表达与前列腺干细胞的增殖分化有密切联系,CK 8 mRNA高度表达是前列腺干细胞一个重要特征。     

小麦－黑麦－中间偃麦草三属杂种F_1及其花粉植株的细胞遗传学研究

２个小麦－黑麦－中间偃麦草三属杂种Ｆ１的减数分裂方为复杂,中期Ⅰ染色体平均每细胞构型为１９．５３Ⅰ＋１３．４７Ⅱ＋０．７０Ⅲ＋０．０６Ⅳ和１９．９９Ⅰ＋１３．４２Ⅱ＋０．６５Ⅲ＋０．０４Ⅳ＋０．０１Ⅴ,后期Ⅰ染色体分配不平衡,单价体并不一定排列在赤道板上,产生各种类型的异常四分体。１８株花粉植株染色体组成类型多样,在２个花粉植株中分别观察到端体和等臂染色体。单倍体花粉植株中期Ⅰ染色体配对频率较高,交叉值为１．５１－３．８５。本文还讨论了三属杂种和花药培养的结合应用。     

Correlation and path-coefficient analyses of seed-yield components in pearl millet x elephantgrass hybrids

Correlation and path-coefficient analyses have been successful tools in developing selection criteria. Since increased seed yield is an important goal in our pearl millet x elephantgrass [Pennisetum glaucum (L.) R.Br. x P. purpureum Schum.] hexaploid breeding program, we used correlation and path-coefficient analyses on seed data. This study was conducted to develop appropriate selection criteria by determining the direct and indirect effects of seed-yield components on seed yield plant^-1. Number of tillers plant^-1, panicles tiller^-1, seeds panicle^-1, 100-seed weight, and seed yield plant^-1, were estimated for individual plants in seven families. Phenotypic (r_p) and genetic correlations (r_g) were calculated, and path analyses (phenotypic and genetic) were carried out according to predetermined causal relationships. Phenotypic and genetic correlations differed in several cases due to large environmental variance and covariance. Phenotypically, all components were positively and significantly associated with seed yield plant^-1. Genotypically, only seeds panicle^-1 and 100-seed weight were significantly correlated. These two components were also positively correlated (r _p=0.55, r _g=0.63), so simultaneous improvement for both components would be feasible. Panicles tiller^-1 and seeds panicle^-1 were negatively correlated (r _g=-0.97). In the path analyses, all direct effects of the components on seed yield plant^-1 were positive. Phenotypic indirect effects were not as important as genetic indirect effects. The components seeds panicle^-1 and 100-seed weight influenced seed yield plant^-1 the greatest, both directly and indirectly.Florida Agricultural Experimental Station Journal Series No. R-03339     

新基因BM390716、BI274487和AA963863与大鼠再生肝8种细胞的细胞外基质代谢

为了解新基因BM390716、BI274487、AA963863在细胞外基质代谢中的作用及其与大鼠肝再生的相关性,文章用Percoll密度梯度离心结合免疫磁珠分选分离大鼠再生肝的8种细胞,用Rat Genome 230 2.0芯片检测它们的基因表达变化,用Microsoft Excel、BLAST等软件分析基因的共表达关系、序列同源性及参与的代谢活动。结果表明,BM390716与pparα同源和共表达,BI274487与timp2同源和共表达,AA963863与csgalnact1同源和共表达。根据上述基因的同源性和共表达推测,新基因BM390716、BI274487和AA963863参与大鼠再生肝8种细胞的细胞外基质代谢。     

Outbreeding Depression Caused by Intraspecific Hybridization Between Local and Nonlocal Genotypes in Abies sachalinensis

To evaluate the effects of intraspecific hybridization of local and nonlocal genotypes on growth traits of progeny in Abies sachalinensis, we performed reciprocal crossing between nonlocal trees in a high‐elevation zone (1,100–1,200 m asl) and local trees in a low‐elevation zone (530 m asl) in Hokkaido, northern Japan, in 1979 and established a common garden experiment using local × local (female × male ), local × nonlocal , nonlocal × local , and nonlocal × nonlocal progeny in the low‐elevation zone in 1986. Survival, height, diameter at breast height (dbh), needle nitrogen content, specific leaf area (SLA), and needle area per shoot diameter (NA) of 25‐year‐old progeny were measured in 2005. The survival rate was consistently high (>85% on average). Reductions in height and dbh were apparent in F1 hybrids compared with local × local progeny. Furthermore, outbreeding depression was significant in height growth of nonlocal × local F1 hybrids and in dbh of both F1 hybrids. Reductions in growth traits may be related to morphological needle traits, such as the low values of SLA and NA. Elevation guidelines for A. sachalinensis seed zones are discussed to ensure the long‐term viability of both restored and native populations.     

Trigenomic Bridges for Brassica Improvement

We introduce and review Brassica crop improvement via trigenomic bridges. Six economically important Brassica species share three major genomes (A, B, and C), which are arranged in diploid (AA, BB, and CC) and allotetraploid (AABB, AACC, and BBCC) species in the classical triangle of U. Trigenomic bridges are Brassica interspecific hybrid plants that contain the three genomes in various combinations, either triploid (ABC), unbalanced tetraploid (e.g., AABC), pentaploid (e.g., AABCC) or hexaploid (AABBCC). Through trigenomic bridges, Brassica breeders can access all the genetic resources in the triangle of U for genetic improvement of existing species and development of new agricultural species. Each of the three Brassica genomes occurs in several species, where they are distinguished as subgenomes with a tag to identify the species of origin. For example, the A subgenome in B. juncea (2n = AABB) is denoted as A^j and the A subgenome in B. napus (2n = AACC) as Aⁿ. Trigenomic bridges have been used to increase genetic diversity in allopolyploid Brassica crop species, such as a new-type B. napus with subgenomes from B. rapa (A^r) and B. carinata (C^c). Recently, trigenomic bridges from several sources have been crossed together as the ‘founders’ of a potentially new allohexaploid Brassica species (AABBCC). During meiosis in a trigenomic bridge, crossovers are expected to form between homologous chromosomes of related subgenomes (for example A^r and Aⁿ), but cross-overs may also occur between non-homologous chromosomes (for example between A and C genome chromosomes). Irregular meiosis is a common feature of new polyploids, and any new allotetraploid or allohexaploid Brassica genotypes derived from a trigenomic bridge must achieve meiotic stability through a process of diploidisation. New sequencing technologies, at the genomic and epigenomic level, may reveal the genetic and molecular basis of diploidization, and accelerate selection of stable allotetraploids or allohexaploids. Armed with new genetic resources from trigenomic bridges, Brassica breeders will be able to improve yield and broaden adaptation of Brassica crops to meet human demands for food and biofuel, particularly in the face of abiotic constraints caused by climate change.     

Cultural isolation is greater than genetic isolation across an avian hybrid zone

Elucidating the relationship between genetic and cultural evolution is important in understanding speciation, as learned premating barriers might be involved in maintaining species differences. Here, we test this relationship by examining a widely recognized premating barrier, bird song, in a hybrid zone between black‐throated green (Setophaga virens) and Townsend's warblers (S. townsendi). We use song analysis, genomic techniques and playback experiments to characterize the cultural and genetic backgrounds of individuals in this region, expecting that if song is an important reproductive barrier between these species, there should be a strong relationship between song and genotype. We show that songs in the hybrid zone correspond to the distinctly different songs found in allopatry but that song and genotype are not tightly coupled in sympatry. Allopatric individuals responded only to local songs, indicating that individuals may have learned to respond to songs they commonly hear. We observed discordance between song and genotype clines; a narrower cline suggests that cultural selection on song is stronger than natural selection on genotype. These findings indicate that song is unlikely to play a role in reproductive isolation between these species, and we suggest that spatial variation in song may nonetheless be maintained by frequency‐dependent cultural selection. This decoupling of genes and culture may contribute to hybridization in this region.     

Morphological differentiation among closely related species with disjunct distributions: a case study of Mediterranean Cyclamen L. subgen. Psilanthum Schwarz (Primulaceae)

In Cyclamen subgenus Psilanthum , previous authors have recognized three species ( C. repandum, C. balearicum and C. creticum ), with C. repandum subdivided into three subspecies (ssp. repandum , ssp. peloponnesiacum and ssp. rhodense ), and two varieties (var. vividum and var. peloponnesiacum ) within C. repandum ssp. peloponnesiacum . To examine the validity of this classification and the degree of morphological differentiation among closely related endemic taxa with disjunct distributions, we undertook analyses of three quantitative and eight qualitative morphological traits of flowers and leaves, most of which have previously been used without statistical comparison in the classification of the different taxa. Cyclamen balearicum showed high levels of morphological differentiation from all other taxa in subgenus Psilanthum consistent with its specific status. In contrast, morphological differentiation between C. creticum and subspecies of C. repandum was similar to that among the three subspecies of C. repandum . When compared with a recent molecular phylogeny of this subgenus, our results suggest that C. creticum may best be described as a geographical subspecies of C. repandum . The two varieties of C. repandum ssp. peloponnesiacum showed few significant differences for individual traits and their overall morphology is very similar to each other. The morphology of plants at three sites on Corsica strongly suggest, consistent with molecular data, the occurrence of hybrid populations between C. balearicum (outside of its previously recognized distribution) and local C. repandum .  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 133–144.     

HCV 5′NCR转基因细胞HepG2.9706的特性分析

丙型肝炎是由丙型肝炎病毒(hepatitis C virus,HCV)引起的威胁人类健康的重要传染病,迄今尚无有效的疫苗及特异性抗病毒治疗药物.抗HCV药物的研究和开发面临的关键问题是缺乏合适的HCV感染细胞及动物评价模型.转基因细胞模型是研究人类疾病常用的有效手段,因此,在HCV分子生物学进展的基础上,我们以对HCV翻译与复制有明显调控功能的HCV 5′NCR及部分翻译起始区序列为靶标,构建了HCV 5′NCR及部分多聚蛋白起始区序列与荧光素酶基因的融合基因,插入真核表达载体,转染HepG2细胞,获得了HCV 5′NCR转基因细胞HepG2.9706细胞株[1].本文对该细胞的某些特性进行了分析,以便更好地利用该细胞模型进行药物评价.