Recent Advances in Plant Organelle Dynamics

<正>Organelles are eukaryotic subcellular structures each possessing a specific set of functions.The morphology,abundance,and content of the organelles also undergo constant changes for optimal function     

Emergent Properties of Balinese Water Temple Networks: Coadaptation on a Rugged Fitness Landscape

For over a thousand years, generations of Balinese farmers have gradually transformed the landscape of their island, clearing forests, digging irrigation canals, and terracing hillsides to enable themselves and their descendants to grow irrigated rice. Paralleling the physical system of terraces and irrigation works, the Balinese have also constructed intricate networks of shrines and temples dedicated to agricultural deities. Ecological modeling shows that water temple networks can have macroscopic effects on the topography of the adaptive landscape, and may be representative of a class of complex adaptive systems that have evolved to manage agroecosystems.     

Molecular mechanisms and genetics of hyaluronan biosynthesis

Hyaluronan is an extremely important polysaccharide from both the biological and commercial points of view. This review summarizes the present state of the art concerning the polymer and our understanding of the molecular mechanisms of its synthesis with emphasis on the implications of this understanding for polysaccharide engineering of hyaluronan.     

Two novel gene orders and the role of light-strand replication in rearrangement of the vertebrate mitochondrial genome

Two novel mitochondrial gene arrangements are identified in an agamid lizard and a ranid frog. Statistical tests incorporating phylogeny indicate a link between novel vertebrate mitochondrial gene orders and movement of the origin of light-strand replication. A mechanism involving errors in light-strand replication and tandem duplication of genes is proposed for rearrangement of vertebrate mitochondrial genes. A second mechanism involving small direct repeats also is identified. These mechanisms implicate gene order as a reliable phylogenetic character. Shifts in gene order define major lineages without evidence of parallelism or reversal. The loss of the origin of light-strand replication from its typical vertebrate position evolves in parallel and, therefore, is a less reliable phylogenetic character. Gene junctions also evolve in parallel. Sequencing across multigenic regions, in particular transfer RNA genes, should be a major focus of future systematic studies to locate novel gene orders and to provide a better understanding of the evolution of the vertebrate mitochondrial genome.      

Evolutionary relationships among the male and female mitochondrial DNA lineages in the Mytilus edulis species complex

A novel form of mitochondrial DNA (mtDNA) inheritance has previously been documented for the blue mussel (Mytilus edulis). Female mussels inherit their mtDNA solely from their mother while males inherit mtDNA from both their mother and their father. In males, the paternal mtDNA is preferentially amplified so that the male gonad is highly enriched for the paternal mtDNA that is then transmitted from fathers to sons. We demonstrate that this mode of mtDNA inheritance also operates in the closely related species M. galloprovincialis and M. trossulus. The evolutionary relationship between the male and female mtDNA lineages is estimated by phylogenetic analysis of 455 nucleotides from the large subunit ribosomal RNA gene. We have found that the male and female lineages are highly divergent; the divergence of these lineages began prior to the speciation of the three species of blue mussels. Further, the separation between the male and female lineages is estimated to have occurred between 5.3 and 5.7 MYA.