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1.
The maize b-32 protein is a functional ribosome-inactivating protein (RIP), inhibiting in vitro translation in the cell-free reticulocyte-derived system and having specific N-glycosidase activity on 28S rRNA. Previous results indicated that opaque-2 (o2) mutant kernels, lacking b-32, show an increased susceptibility to fungal attack and insect feeding and that ectopic expression in plants of a barley and a pokeweed RIP leads to increased tolerance to fungal and viral infection. This prompted us to test whether b-32 might functi on as a protectant against pathogens. The b32.66 cDNA clone under the control of the potato wun1 gene promoter was introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Out of 23 kanamycin resistant regenerated shoots, 16 contained a PCR fragment of the corrrect size spanning the boundary between the promoter used and the coding region of the b-32 gene. Eight independently transformed tobacco lines were randomly chosen for protein analysis: all of them expressed b-32 protein. The data presented indicate that transgenic tobacco plants expressing b-32 show an increased tolerance against infection by the soil-borne fungal pathogen Rhizoctonia solani Kuhn  相似文献   
2.
We identified 11 polymorphic microsatellite markers for Alouatta caraya. Three markers were isolated from an enriched genomic library of A. caraya (AC14, AC17, AC45), five were previously described in Homo sapiens (TGMS1, TGMS2, D5S117, D8S165, D17S804), and three were identified for Lagothix lagotricha (1110, 1118, 157). Forty‐eight individuals from one Argentinean population were genotyped, yielding heterozygosity values between 0.146 and 0.792. These markers provide an exclusion power of 0.922 when neither parent is known (0.992 when one parent is known) and are suitable for parentage analysis, population genetics and phylogeographical studies of A. caraya, the southernmost primate in the New World.  相似文献   
3.
Microsatellite markers for Schistosoma mansoni were developed using four genomic microsatellite‐enriched libraries. Microsatellites were observed in 65.4% of all sequences. Primer pairs were designed and tested for 23 loci. Eighteen loci produced amplification products, out of which 11 were polymorphic and were further characterized on 100 individuals of S. mansoni. Two to 19 alleles per locus were detected. The average values of expected and observed heterozygosities among the 11 loci were 0.79 and 0.59, respectively.  相似文献   
4.
A new species of Daptonema is described based upon morphological characters and 18S rRNA sequence. Daptonema matrona sp. nov. was collected in Pina Basin (north‐eastern Brazil). It differs from all other species of the genus by the presence of reduced cephalic setae and straight spicules. These features require an adaptation of the generic diagnosis. Moreover, the females are characterized by intra‐uterine development of the offspring, considered herein as their major autapomorphic feature. Molecular systematic analyses supported Daptonema matrona sp. nov. as a distinct genetic and evolutionary lineage. The data also indicate hypotheses of taxonomic synonymies amongst some related taxa from Xyalidae as well as the paraphyly of Daptonema. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 1–15.  相似文献   
5.
The four living genera of Ctenodactylidae (Rodentia) are the only survivors of a flourishing Tertiary group. In this paper, we describe a new Oligocene species from Ulantatal (Chinese Mongolia) that highlights the origins of crown ctenodactylids. This species, Helanshania deserta gen. et sp. nov. , is lophodont and displays semi‐hypsodont teeth, a dental pattern that is somewhat transitional between that of primitive Oligocene ctenodactylids and the later hypsodont genera. We perform here a cladistic assessment of the dental evidence for species produced by the successive radiations of the group. In order to get new data, to decipher homologies for the dental pattern of modern ctenodactylids, and to specify their dental replacement, we describe additional dental material of Ctenodactylus, Massoutiera, and Felovia. The phylogenetic analysis (using PAUP) considered 45 characters (mainly dental) and 31 species. The performed heuristic searches yielded 596 equally most parsimonious trees. Protataromys and Karakoromys are stem ctenodactylids and appear as the earliest offshoots of the Ctenodactylidae clade, which represents a well‐supported family rank. Within this family, the Tataromyinae appear paraphyletic, whereas the Ctenodactylinae sensu lato are a clade including the new taxon Helanshania. As such, a revision of the Tataromyinae is envisaged and a new subfamily is erected (Yindirtemyinae). Amongst the Ctenodactylinae, a tribe Ctenodactylini encompassing the crown ctenodactylines is proposed. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 531–550.  相似文献   
6.
Five microsatellite loci were isolated and characterized within the woolly mouse opossum (Micoureus paraguayanus), a Neotropical marsupial, using an enrichment cloning procedure. Between four and seven alleles were detected per locus, with expected heterozygosity ranging from 0.358 to 0.560. These microsatellites should provide useful markers in a variety of genetic analyses to examine parentage, inbreeding, population structure and population dynamics in fragmented forest habitats.  相似文献   
7.
Caesalpinia echinata and C. ferrea var. ferrea have different seed behaviours and seed and fruit types. Comparison of the seed ontogeny and anatomy partly explained the differences in seed behaviour between these two species of Brazilian legumes; some differences were also related to fruit development. The seed coat in C. ferrea consisted of two layers of osteosclereids, as well as macrosclereids and fibres, to form a typical legume seed coat, whereas C. echinata had only macrosclereids and fibres. In C. echinata , the developing seed coat had paracytic stomata, a feature rarely found in legume seeds. These seed coat features may account for the low longevity of C. echinata seeds. The embryogeny was similar in both species, with no differences in the relationship between embryo growth and seed growth. The seeds of both species behaved as typical endospermic seeds, despite their different morphological classification (exendospermic orthodox seeds were described for C. echinata and endospermic orthodox seeds for C. ferrea ). Embryo growth in C. ferrea accelerated when the sclerenchyma of the pericarp was developing, whereas embryonic growth in C. echinata was associated with the conclusion of spine and secretory reservoir development in the pericarp. Other features observed included an endothelial layer that secreted mucilage in both species, a nucellar summit, which grew up into the micropyle, and a placental obturator that connected the ovarian tissue to the ovule in C. ferrea . © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 57–70.  相似文献   
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9.
Dendrobatid frogs have undergone an extensive systematic reorganization based on recent molecular findings. The present work describes karyotypes of the Brazilian species Adelphobates castaneoticus, A. quinquevittatus, Ameerega picta, A. galactonotus and Dendrobates tinctorius which were compared to each other and with previously described related species. All karyotypes consisted of 2n = 18 chromosomes, except for A. picta which had 2n = 24. The karyotypes of the Adelphobates and D. tinctorius species were highly similar to each other and to the other 2n = 18 previously studied species, revealing conserved karyotypic characteristics in both genera. In recent phylogenetic studies, all Adelphobates species were grouped in a clade separated from the Dendrobates species. Thus, we hypothesized that their common karyotypic traits may have a distinct origin by chromosome rearrangements and mutations. In A. picta, with 2n = 24, chromosome features of pairs from 1 to 8 are shared with other previously karyotyped species within this genus. Hence, the A. picta data reinforced that the C-banding pattern and the NOR location are species-specific traits in the genus Ameerega. Moreover, the Ameerega monophyletism proposed by previous phylogenetic studies indicates that the karyotypic differences among species in this genus result from a long divergence time.  相似文献   
10.
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