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Genome Structure (genome + structure)
Selected AbstractsGenetic processes in arbuscular mycorrhizal fungiFEMS MICROBIOLOGY LETTERS, Issue 2 2005Teresa E. Pawlowska Abstract Arbuscular mycorrhizal (AM) fungi (Glomeromycota) colonize roots of the majority of land plants and facilitate their mineral nutrient uptake. Consequently, AM fungi play an important role in terrestrial ecosystems and are becoming a component of sustainable land management practices. The absence of sexual reproductive structures in modern Glomeromycota combined with their long evolutionary history suggest that these fungi may represent an ancient asexual lineage of great potential interest to evolutionary biology. However, many aspects of basic AM fungal biology, including genome structure, within-individual genetic variation, and reproductive mode are poorly understood. These knowledge gaps hinder research on the mechanisms of AM fungal interactions with individual plants and plant communities, and utilization of AM fungi in agricultural practices. I present here the current state of research on the reproduction in AM fungi and indicate what new findings can be expected in the future. [source] Social behavior and comparative genomics: new genes or new gene regulation?GENES, BRAIN AND BEHAVIOR, Issue 4 2002G. E. Robinson Molecular analyses of social behavior are distinguished by the use of an unusually broad array of animal models. This is advantageous for a number of reasons, including the opportunity for comparative genomic analyses that address fundamental issues in the molecular biology of social behavior. One issue relates to the kinds of changes in genome structure and function that occur to give rise to social behavior. This paper considers one aspect of this issue, whether social evolution involves new genes, new gene regulation, or both. This is accomplished by briefly reviewing findings from studies of the fish Haplochromis burtoni, the vole Microtus ochrogaster, and the honey bee Apis mellifera, with a more detailed and prospective consideration of the honey bee. [source] Hairpin telomeres and genome plasticity in Borrelia: all mixed up in the endMOLECULAR MICROBIOLOGY, Issue 3 2005George Chaconas Summary Spirochetes of the genus Borrelia have a highly unusual genome structure composed of over 20 replicons. Most of these replicons are linear and terminated by covalently closed hairpin ends or telomeres. Moreover, the linear replicons are affected by extensive DNA rearrangements, including telomere exchanges, DNA duplications, and harbour a large number of pseudogenes. The mechanism for the unusual genome plasticity in the linear replicons has remained elusive. The enzymatic machinery (the telomere resolvase ResT) responsible for generating the hairpin ends from replicative intermediates has recently been shown to also perform a reverse reaction that fuses telomeres on unrelated replicons. Infrequent stabilization of such fusion events over evolutionary time provides the first proposed biochemical mechanism for the DNA rearrangements that are so prominent in the linear replicons of B. burgdorferi. [source] Complete mutation analysis panel of the 39 human HOX genesBIRTH DEFECTS RESEARCH, Issue 2 2002Kenjiro Kosaki Background The HOX gene family consists of highly conserved transcription factors that specify the identity of the body segments along the anteroposterior axis of the embryo. Because the phenotypes of mice with targeted disruptions of Hox genes resemble some patterns of human malformations, mutations in HOX genes have been expected to be associated with a significant number of human malformations. Thus far, however, mutations have been documented in only three of the 39 human HOX genes (HOXD13, HOXA13, and HOXA11) partly because current knowledge on the complete coding sequence and genome structure is limited to only 20 of the 39 human HOX genes. Methods Taking advantage of the human and mouse draft genome sequences, we attempted to characterize the remaining 19 human HOX genes by bioinformatic analysis including phylogenetic footprinting, the probabilistic prediction method, and comparison of genomic sequences with the complete set of the human anonymous cDNA sequences. Results We were able to determine the full coding sequences of 19 HOX genes and their genome structure and successfully designed a complete set of PCR primers to amplify the entire coding region of each of the 39 HOX genes from genomic DNA. Conclusions Our results indicate the usefulness of bioinformatic analysis of the draft genome sequences for clinically oriented research projects. It is hoped that the mutation panel provided here will serve as a launchpad for a new discourse on the genetic basis of human malformations. Teratology 65:50,62, 2002. © 2002 Wiley-Liss, Inc. [source] | ||||||||||