Emergence Of Angiosperms Research Articles

Mitogenome-based phylogeny of mosquitoes (Diptera: Culicidae).

Mosquitoes are of great medical significance as vectors of many deadly diseases. Mitogenomes have been widely used in phylogenetic studies, but mitogenome knowledge within the family Culicidae is limited, and Culicidae phylogeny is far from resolved. In this study, we surveyed the mitogenomes of 149 Culicidae species, including 7 newly sequenced species. Comparative analysis of 149 mosquito mitogenomes shows gene composition and order to be identical to that of an ancestral insect, and the AT bias, length variation, and codon usage are all consistent with that of other reported Dipteran mitogenomes. Phylogenetic analyses based on the DNA sequences of the 13 protein-coding genes from the 149 species robustly support the monophyly of the subfamily Anophelinae and the tribes Aedini, Culicini, Mansoniini, Sabethini, and Toxorhynchitini. To resolve ambiguous relationships between clades within the subfamily Culicinae, we performed topological tests and show that Aedini is a sister to Culicini and that Uranotaeniini is a sister to (Mansoniini+(Toxorhynchitini+Sabethini)). In addition, we estimated divergence times using a Bayesian relaxation clock based on the sequence data and 3 fossil calibration points. The results show mosquitoes diverged during the Early Jurassic with massive Culicinae radiations during the Cretaceous, coincident with the emergence of angiosperms and the burst of mammals and birds. Overall, this study, which uses the largest number of Culicidae mitogenomes sequenced to date, comprehensively reveals the mitogenome characteristics and mitogenome-based phylogeny and divergence times of Culicidae, providing information for further studies on the mitogenome, phylogeny, evolution, and taxonomic revision of Culicidae.

Phylogeny and temporal diversification of mosquitoes (Diptera: Culicidae) with an emphasis on the Neotropical fauna

AbstractUnderstanding phylogenetic relationships within the family Culicidae informs mosquito evolution and may have public health implications as this family includes numerous species of medical and veterinary importance. We investigated the mitochondrial genomes of 102 mosquitoes, including six newly sequenced species, representing 21 genera with an emphasis on the Neotropical region. We estimated divergence times based on sequence data and three fossil calibration points, using Bayesian relaxed clock methods. Bayesian and maximum‐likelihood phylogenetic analyses based on the DNA sequences of 13 PCGs of the 102 species provided robust support for the monophyly of the subfamily Anophelinae and the tribes Aedini, Culicini, Mansoniini and Sabethini. Despite the current genera of Anophelinae being consistently recovered as monophyletic, relationships among them proved to be quite variable depending on the method used (concatenated or partitioned) and the number of taxa sampled. Molecular divergence time estimates revealed that the two mosquito subfamilies, Anophelinae and Culicinae, diverged in the early Jurassic (approximately 197.5 Mya). However, most major lineages of these groups arose after the Cretaceous, coincident with the emergence of angiosperms and the expansion of mammals and birds. The diversification and worldwide distribution of Culicidae may also be determined in part by geographic isolation as a result of continental drift during the Cretaceous.

Ecology of the Podocarpaceae in Tropical Forests

The emergence of angiosperms in tropical forests at the expense of the gymnosperms, their ancestral relatives, was one of the most important events in the evolutionary history of terrestrial plants. Gymnosperms were nearly eliminated from the tropics after the evolution of angiosperms in the early Cretaceous, yet conifers of the Podocarpaceae are among the few gymnosperm families that persist in tropical forests worldwide. Podocarps are often considered to be restricted to montane sites in the tropics, a feature of their biogeography that is used by paleoecologists to reconstruct past forest communities. However, podocarps also occur in the lowland tropics, where they can be the dominant component of forest canopies. Podocarps have proved to be remarkably adaptable in many cases: members of the family have a semi-aquatic lifestyle, exhibit drought tolerance and resprouting, and include the only known parasitic gymnosperm. Other intriguing aspects of podocarp physiology include the mechanism of water transport in the leaves and the conspicuous root nodules, which are not involved in nitrogen fixation but instead house arbuscular mycorrhizal fungi. Perhaps most surprising, paleobotanical evidence indicates that far from being 'relict' members of tropical forest communities, podocarps have been dispersing into the tropics since the late Eocene epoch more than 30 million years ago. These and other aspects of the Podocarpaceae explored in this volume have far-reaching implications for understanding the ecology and evolution of tropical rain forests.

Cucumber, melon, pumpkin, and squash: Are rules of editing in flowering plants chloroplast genes so well known indeed?

The similarities and differences in the chloroplast genes editing patterns of four species from one family (and two genera), which is the first-ever attempt at comparison of such data in closely related species, is discussed. The effective use of the chloroplast genes editing patterns in evolutionary studies, especially in evaluating the kinship between closely related species, is thereby proved. The results indicate that differences in editing patterns between different genera (Cucumis and Cucurbita) exist, and some novel editing sites can be identified even now. However, surprising is the fact of finding editing in the codon for Arg (in flowering plants detected before only in Cuscuta reflexa chloroplast genome, Funk et al.,[Funk H.T., Berg S., Krupinska K., Maier U.G. and Krause K., 2007. Complete DNA sequences of the plastid genomes of two parasitic flowering plants species, Cuscuta reflexa and Cuscuta gronovi. BMC Plant Biol. 7:45, doi: 10.1186/1471-2229-7-45.]), which was believed to have been lost during evolution before the emergence of angiosperms. In addition, the existence of silent editing in plant chloroplasts has been confirmed, and some probable reasons for its presence are pointed out herein.