Development of EST‐SSRs from the Alpine Lady‐fern,Athyrium distentifolium

The utility of EST‐simple sequence repeats (EST‐SSRs) was evaluated in the fern Athyrium distentifolium. From 1152 frond cDNA clones, 165 microsatellites, including di‐, tri‐, tetra and penta‐nucleotide repeat motifs, were identified. Primer design was possible for 74 of the SSRs; subsequent screening of 10 loci on 186 individuals from six natural populations revealed between two and seven alleles per locus and expected heterozygosity (H_E) estimates ranging from 0.027 to 0.809. Eight of these loci were further examined for cross‐species and cross‐generic amplification in other Woodsiaceae species, and polymorphic products were detected. EST‐derived SSRs provide robust, informative and potentially transferable polymorphic markers suitable for biodiversity research.     

Microsatellite loci isolated from the scleractinian coral, Acropora nobilis

We report the isolation and characterization of eight microsatellite loci from the scleractinian coral, Acropora nobilis. The microsatellite loci were obtained using compound SSR primers or an enrichment protocol. All the loci were polymorphic with four to eight alleles per locus and observed heterozygosities ranging from 0.22 to 0.76. Some of the primers developed for the two congeners, Acropora palmata and Acropora millepora were applicable to A. nobilis. These loci are useful for studying the connectivity among A. nobilis populations in Okinawa, southern Japan.     

随机扩增杂交微卫星方法在大仓鼠种群遗传多态性研究中的应用

随机扩增杂交微卫星(Random amplified hybridization microsatellites,RAHM)是一种复合RAPD扩增和寡核苷酸扫描的方法。该方法能够从RAPD产物凝胶上获得更多的信息,具有分析方法快速,高敏感性,能检测到高水平的多态性等优点。RAHM方法通过对RAPD扩增的DNA片段进行微卫星杂交来替代限制性内切酶对基因组DNA的消化,有助于揭示微卫星基因组克隆,进行微卫星引物的筛选。本文采用随机扩增杂交微卫星方法来检测小型哺乳动物大仓鼠(Techerskia triton)种群的遗传多态性,结果表明RAHM方法能够检测到大仓鼠种群中较高的多态性以及种群间的差异,这些条带模式可能代表真核基因组中另一种多态性标记的来源,可用于检测小型哺乳动物种群的遗传多态性。     

Isolation and Characterization of Polymorphic Microsatellite Markers for the Masked Palm Civet (Paguma larvata)

The masked palm civet (Paguma larvata) has been suspected to be the host of a SARS-like CoV virus that causes severe acute respiratory syndrome in humans. In China, the palm civet lives wild and is farmed, but even though the species is a potential carrier of the virus, its geographic distribution and genetic diversity have never been studied. We report the isolation and characterization of six polymorphic microsatellite markers for P. larvata. To characterize each locus, two farmed masked palm civet populations from Shanxi and Guangxi provinces in China were genotyped. The number of alleles per locus ranged from 3 to 15, and the observed heterozygosity for these populations was 47.1 and 68.7%, respectively.     

Isolation and Characterization of Highly Polymorphic Microsatellites from the Polychaete Pectinaria koreni

We report on the isolation of dinucleotide microsatellites from the polychaete Pectinaria koreni using (GT)₁₀ and (CT)₁₀ olignonucleotide probes. Compound and particularly imperfect microsatellites are predominant in this species. In most cases the associated element is (AT)_n leading to AT microsatellites being the most frequent class after GT repeats. Obtaining single-copy polymerase chain reaction products in the expected size range proved to be difficult, and only 24% of the primer pairs tested produced polymorphic single-locus markers. We obtained five highly variable loci with 16 to 41 alleles and an observed heterozygosity ranging from 0.29 to 0.81. Amplifications have also been obtained from the earliest postlarval stage. These highly informative markers will allow studies of the population structure of P. koreni at fine spatial and temporal scales. Received March 19, 1999; accepted September 10, 1999.     

Development of Novel Microsatellite DNA Markers from the Pacific Oyster Crassostrea gigas

We document the potential of novel microsatellites as a genetic tool in furthering our understanding of the Crassostrea gigas genetic structure. From the microsatellite-enriched libraries we constructed, 123 repeat regions that had sufficient sequence information to design polymerase chain reaction primer sets were isolated. From these, 9 primer pairs were screened in a C. gigas population of 67 individuals to evaluate the genetic variability. All but 1 of the 9 loci showed allelic variation (number of alleles, 2–20; observed heterozygosity, 0.119–0.925; unbiased expected heterozygosity, 0.139–0.914). Considerable discrepancy of genotypic proportions from the Hardy-Weinberg equilibrium was observed at 1 locus with an apparent heterozygote deficiency. Several loci were successfully amplified in 3 other related species with the appropriate allele size: 6 loci in C. sikamea, 4 loci in C. ariakensis, and 5 loci in C. nippona.     

Isolation and characterization of microsatellite loci from Eidothea hardeniana,an early Proteaceae

Eidothea hardeniana is a recently discovered rainforest species representing a basal Proteoid genus. It is known from a single location in New South Wales (Australia) with the only other member of the genus, Eidothea zoexylocarya, found in northern Queensland. We developed six microsatellite loci (five cross‐transferable) from an (AG) enriched library. The loci produced relatively high levels of diversity within 30 individuals of such a rare species. These microsatellites are now being used to provide new and useful information on the management of the species and on the processes shaping the evolution and persistence of ancient rainforest taxa.     

水稻组蛋白H_3基因的分离和组织结构分析

用噬菌斑原位杂交法,从一个水稻新品系的EMBL,基因文库中筛选到了两个组蛋白H,基因克隆,并制作了它们的限制性内切酶图谱,分析了它们的组织结构。其中λRH_3-1克隆包含2个组蛋白H_3基因区(分别为0.5kb和0.8kb的BamHI-EcoRI片段,两基因区距离5.8kb)。而λRH_3-2克隆只带有1个结构特异的H_3基因区(5.2kb的EcoRI-HindⅢ片段)。本文还就水稻组蛋白H_3基因在整个基因组中的组织结构特点进行了讨论。     

中国特有单种属血水草的微卫星分子标记开发与评价

血水草(Eomecon chionantha Hance)是中国亚热带地区特有的单种属植物。本研究采用(AG)15、(AC)15两种生物素探针及磁珠富集法从血水草基因组中开发并筛选出13个微卫星位点,且在该物种中能进行稳定的PCR扩增并表现出多态性。利用筛选出的13个SSR多态性标记对血水草4个野生居群24个个体进行PCR扩增,结果显示每个微卫星位点的等位基因数为2~7个,观测杂合度(HO)和期望杂合度(HE)分别为0.125~0.792和0.299~0.691。说明这些SSR标记可用于血水草遗传多样性的后续研究,并揭示该物种地理分布格局形成的原因,有助于保护和利用中国亚热带地区的血水草野生资源。     

Microsatellite markers for the tambaqui (Colossoma macropomum, Serrasalmidae, Characiformes), an economically important keystone species of the Amazon River floodplain

Colossoma macropomum is a keystone species of the Amazon floodplain, and is an important but severely overexploited commercial species. To provide tools for addressing ecological and conservation questions, we developed 14 highly polymorphic microsatellite markers that had between four and 21 alleles per locus in the 25 tested individuals. With the exception of comparisons involving the locus Cm1F5 that also showed heterozygosity deficiency, no pairs of loci were at linkage disequilibrium. Many of the microsatellite loci were also variable in three other serrasalmid species which span the phylogenetic depth of the Serrasalmidae.     

中国特有种爆杖花的微卫星分子标记开发与评价

爆杖花（Rhododendron spinuliferum）是中国西南地区特有的观赏和药用植物。为了研究爆杖花和碎米花之间的杂交物种形成过程,本研究利用FIASCO方法对爆杖花进行微卫星引物开发,从100对引物中筛选出28个微卫星标记,其中22个为多态。利用爆杖花两个居群共24个个体对22个多态性位点进行分析,结果显示：每个位点具有2~5个等位基因,平均为34个,其观测杂合度和期望杂合度分别为0083~0792和0153~0744。对筛出的28个微卫星标记在碎米花的两个自然居群中也做了检测,结果显示：有22个微卫星标记成功扩增,其中20个有多态性;每个多态位点有2~6个等位基因,平均为32个,其观测杂合度和期望杂合度分别为0000~0833和0117~0736。开发的微卫星标记可用于爆杖花及其近缘物种的居群遗传学分析和杂交物种形成研究。     

Microsatellite loci from the trematode Lecithochirium fusiforme,a parasite of the European conger eel

Seven polymorphic loci containing dinucleotide repeats and one trinucleotide microsatellite were developed for the hemiurid fluke Lecithochirium fusiforme, a parasite of the European conger eel Conger conger. All parasites that were collected from a single individual host (a total of 54 specimens) were genotyped. The number of alleles ranged from two to eight. The observed and expected heterozygosities ranged from 0.057 to 0.736 and from 0.091 to 0.794, respectively. Hardy–Weinberg deviations were statistically significant for two loci. These markers will be useful for study of parasite transmission patterns and population genetic structure.     

Isolation and Characterization of Nine Microsatellite Loci from the Hawaiian Grouper <Emphasis Type="Italic">Epinephelus Quernus</Emphasis> (Serranidae) for Population Genetic Analyses

The availability of variable genetic markers for groupers (Serranidae) has generally been limited to mitochondrial DNA. For studies of population genetic structure, more loci are usually required; particularly useful are those that are nuclear in origin such as microsatellites. Here, we isolated and characterized 9 microsatellite loci from the endemic Hawaiian grouper Epinephelus quernus using a biotin-labeled oligonucleotide-streptavidin–coated magnetic bead approach. Of the 20 repeat-containing fragments isolated, 15 had sufficient flanking region in which to design primers. Among these, 9 produced consistent polymerase chain reaction product, and 6 were highly variable. These 6 loci were all composed of dinucleotide repeats, with the number of alleles ranging from 6 to 18, and heterozygosities from 33.3% to 91.7%. The high levels of variability observed should make these markers useful for population genetic studies of E. quernus, and potentially other epinephelines.     

Isolation and characterization of microsatellite loci in Epidendrum puniceoluteum, an endemic orchid from the Atlantic Rainforest

Epidendrum puniceoluteum is an endemic orchid of Atlantic Rainforest, restricted to few populations only due to the destruction and fragmentation of its native habitat. Here, we report on the development of 10 microsatellite markers isolated from this orchid species. Genetic variability was characterized in two distant populations from Brazil coast. The number of alleles observed for each locus ranged from two to 12 and with an average of 6.4 alleles per locus. These microsatellites should be valuable tools for studying both fine-scale genetic structure of scattered E. puniceoluteum population and patterns will be useful genetic markers for other closely related taxa.     

Microsatellite markers for the cardinal tetra Paracheirodon axelrodi,a commercially important fish from central Amazonia

The cardinal tetra Paracheirodon axelrodi is a very popular aquarium fish and the most important ornamental fishery resource for riverine communities inhabiting the Rio Negro floodplain in central Amazonia. Here we describe the isolation and characterization of 14 microsatellite DNA loci for cardinal tetras. Number of alleles and heterozygosity per locus in a sample of 30 fish ranged from 2 to 22 and from 0.49 to 0.92, respectively. These markers provide powerful tools for studies on conservation and management of cardinal tetra resources and for investigating evolutionary processes underlying population diversification in Amazonian flooded forest fishes.     

Isolation of polymorphic microsatellite markers for the tetraploid Dipteryx odorata, an intensely exploited Amazonian tree species

Dipteryx odorata is an intensely exploited Amazonian tree legume. Microsatellite markers were developed to study the genetic structure, gene flow and reproductive biology of D. odorata. Eight highly polymorphic microsatellite markers were isolated from enriched repeat libraries screened for microsatellite repeats. An average of 16 alleles and 0.964 phenotype diversity per locus were found in 76 individuals from the Tapajos National Forest, in the state of Pará in the Brazilian Amazon.