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41.
Eight pregnant Soay ewes were made anosmic by ablation of the olfactory bulbs before their lambs were born. They were observed during parturition and in the following few days. Four out of five ewes seen during parturition did not show pre-natal lip licking which is normally seen in Soays. Four ewes did not lick their lambs properly after birth, and in six there was a lack of specific response to their own lambs, so that strange lambs were often fed. Post-mortem examination showed that olfactory tracts were absent in all except one of the ewes examined. It is suggested that the importance of olfaction in maternal care is concerned with identification of the lamb at close quarters and in forming the ewe-lamb relationship.  相似文献   
42.
Direct gene transfer to cells of a graminaceous monocot   总被引:3,自引:0,他引:3  
Summary Definitive evidence is presented for the first time for stable gene transfer to cultured cells in a plant of the family Gramineae, Lolium multiflorum (Italian Ryegrass), using DNA transformation of protoplasts from a non-morphogenic cell culture. A construction consisting of expression signals from gene VI of Cauliflower Mosaic virus joined to the aminoglycoside (neomycin) phosphotransferase gene (APH(3)II) from transposon Tn5 conferred resistance to the antibiotic G-418 to cell colonies arising from transformed protoplasts. By demonstrating a tight correlation between the resistant phenotype, the physical presence of the foreign gene and the presence of the active gene product we have shown that these colonies are true transformants and that a gene which is expressed well in dicotyle-denous plants is also expressed in cells of graminaceous monocots.Dedicated to professor Georg Melchers to celebrate his 50-year association with the journal  相似文献   
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Rapid progress in genome research creates a wealth of information on the functional annotation of mammalian genome sequences. However, as we accumulate large amounts of scientific information we are facing problems of how to integrate and relate the data produced by various genomic approaches. Here, we propose the novel concept of an organ atlas where diverse data from expression maps to histological findings to mutant phenotypes can be queried, compared and visualized in the context of a three-dimensional reconstruction of the organ. We will seek proof of concept for the organ atlas by elucidating genetic pathways involved in development and pathophysiology of the kidney. Such a kidney atlas may provide a paradigm for a new systems-biology approach in functional genome research aimed at understanding the genetic bases of organ development, physiology and disease.Key Words: EuReGene, kidney, genome, development, pathophysiology, genetics  相似文献   
45.
Summary A hybrid Cauliflower Mosaic Virus (CaMV) genome containing a selectable marker gene was constructed by replacing the gene VI coding region with the aminoglycoside (neomycin) phosphotransferase type II [APH(3)II] gene from Tn5. This modified viral genome was tested for its infectivity both in planta and in a protoplast transformation system of Brassica campestris var. rapa. Stable, genetically transformed cell lines of B. campestris var. rapa were obtained after transformation. DNA of the hybrid CaMV genome was found to be integrated into high molecular weight plant genomic DNA. Transformation was achieved only when the hybrid genome was supplied together with wild type viral DNA. A possible complementation of the modified CaMV genome with the wild type viral DNA as a helper molecule in planta and in the protoplast system is discussed.  相似文献   
46.

Background

Forming a new species through the merger of two or more divergent parent species is increasingly seen as a key phenomenon in the evolution of many biological systems. However, little is known about how expression of parental gene copies (homeologs) responds following genome merger. High throughput RNA sequencing now makes this analysis technically feasible, but tools to determine homeolog expression are still in their infancy.

Results

Here we present HyLiTE – a single-step analysis to obtain tables of homeolog expression in a hybrid or allopolyploid and its parent species directly from raw mRNA sequence files. By implementing on-the-fly detection of diagnostic parental polymorphisms, HyLiTE can perform SNP calling and read classification simultaneously, thus allowing HyLiTE to be run as parallelized code. HyLiTE accommodates any number of parent species, multiple data sources (including genomic DNA reads to improve SNP detection), and implements a statistical framework optimized for genes with low to moderate expression.

Conclusions

HyLiTE is a flexible and easy-to-use program designed for bench biologists to explore patterns of gene expression following genome merger. HyLiTE offers practical advantages over manual methods and existing programs, has been designed to accommodate a wide range of genome merger systems, can identify SNPs that arose following genome merger, and offers accurate performance on non-model organisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-014-0433-8) contains supplementary material, which is available to authorized users.  相似文献   
47.
Microorganisms colonizing the exoskeletons of the tube worm Riftia pachyptila are described at the ultrastructural level. The prokaryotic cells from the worm tube wall differ from those colonizing the exoskeleton outer surface in the presence of an electron dense granule. The morphology and distribution of these bacteria-like cells are described. Prokaryotic organisms are assembled in nodules which increased in size in the oldest part of the exoskeleton. The aspect, location and elemental composition of the intracellular granules are determined. Most of them (100 nm in diameter) are located close to the cell membrane and exhibit a homogeneous and amorphous content. EDX and EFTEM microanalyses show that these structures contain phosphorus, oxygen and iron. All together these data suggest that these granules are iron polyphosphates. These structures may act as energy sources for making ATP during anoxic conditions as existing in hydrothermal environments.  相似文献   
48.

Background  

S. meliloti forms indeterminate nodules on the roots of its host plant alfalfa (Medicago sativa). Bacteroids of indeterminate nodules are terminally differentiated and, unlike their non-terminally differentiated counterparts in determinate nodules, do not accumulate large quantities of Poly-3-hydroxybutyrate (PHB) during symbiosis. PhaZ is in intracellular PHB depolymerase; it represents the first enzyme in the degradative arm of the PHB cycle in S. meliloti and is the only enzyme in this half of the PHB cycle that remains uncharacterized.  相似文献   
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Microsatellites were identified by screening 2294 GenBank entries available for Atlantic cod (Gadus morhua L.), mainly representing expressed sequence tags and cDNA sequences. Ninety‐two novel microsatellite loci (tetra‐, tri‐ and dinucleotides) were characterized on 96 individuals. This strategy yielded 25 gene‐associated polymorphic microsatellite markers (11 tri‐ and 14 dinucleotides) with two to 20 alleles and an average heterozygosity of 0.48 in the population studied (range 0.02–0.89). One marker exhibited significant homozygote excess, and one of the primer pairs amplified two linked markers. The gene identity was determined at nine of the loci, confirming the associated microsatellites as type I markers.  相似文献   
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