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Articles 1 - 4 of 4
Full-Text Articles in Comparative and Evolutionary Physiology
Duplication And Remolding Of Trna Genes In The Mitochondrial Genome Of Reduvius Tenebrosus (Hemiptera: Reduviidae), Pei Jiang, Hu Li, Fan Song, Yao Cai, Jianyun Wang, Jinpeng Liu, Wanzhi Cai
Duplication And Remolding Of Trna Genes In The Mitochondrial Genome Of Reduvius Tenebrosus (Hemiptera: Reduviidae), Pei Jiang, Hu Li, Fan Song, Yao Cai, Jianyun Wang, Jinpeng Liu, Wanzhi Cai
Markey Cancer Center Faculty Publications
Most assassin bugs are predators that act as important natural enemies of insect pests. Mitochondrial (mt) genomes of these insects are double-strand circular DNAs that encode 37 genes. In the present study, we explore the duplication and rearrangement of tRNA genes in the mt genome of Reduvius tenebrosus, the first mt genome from the subfamily Reduviinae. The gene order rearranges from CR (control region)-trnI-trnQ-trnM-ND2 to CR-trnQ-trnI2-trnI1-trnM-ND2. We identified 23 tRNA genes, including 22 tRNAs commonly found in insects and an additional trnI (trnI2), which has high sequence similarity to trnM. We found several …
Euryhalinity In An Evolutionary Context, Eric T. Schultz, Stephen D. Mccormick
Euryhalinity In An Evolutionary Context, Eric T. Schultz, Stephen D. Mccormick
EEB Articles
This chapter focuses on the evolutionary importance and taxonomic distribution of euryhalinity. Euryhalinity refers to broad halotolerance and broad halohabitat distribution. Salinity exposure experiments have demonstrated that species vary tenfold in their range of tolerable salinity levels, primarily because of differences in upper limits. Halotolerance breadth varies with the species’ evolutionary history, as represented by its ordinal classification, and with the species’ halohabitat. Freshwater and seawater species tolerate brackish water; their empirically-determined fundamental haloniche is broader than their realized haloniche, as revealed by the halohabitats they occupy. With respect to halohabitat distribution, a minority of species (<10%) are euryhaline. Habitat-euryhalinity is prevalent among basal actinopterygian fishes, is largely absent from orders arising from intermediate nodes, and reappears in the most derived taxa. There is pronounced family-level variability in the tendency to be halohabitat-euryhaline, which may have arisen during a burst of diversification following the Cretaceous-Palaeogene extinction. Low prevalence notwithstanding, euryhaline species are potent sources of evolutionary diversity. Euryhalinity is regarded as a key innovation trait whose evolution enables exploitation of new adaptive zone, triggering cladogenesis. We review phylogenetically-informed studies that demonstrate freshwater species diversifying from euryhaline ancestors through processes such as landlocking. These studies indicate that some euryhaline taxa are particularly susceptible to changes in halohabitat and subsequent diversification, and some geographic regions have been hotspots for transitions to freshwater. Comparative studies on mechanisms among multiple taxa and at multiple levels of biological integration are needed to clarify evolutionary pathways to, and from, euryhalinity.
Phylogeny Of Panthera, Including P. Atrox, Based On Cranialmandibular Characters, Leigha M. King
Phylogeny Of Panthera, Including P. Atrox, Based On Cranialmandibular Characters, Leigha M. King
Electronic Theses and Dissertations
Over the past 20 years both morphological and molecular phylogenies have been proposed for extant and extinct members of the family Felidae. However, there remain several discrepancies, particularly within the genus Panthera and the position of Panthera atrox. Consequently, morphologic characters from the skull and dentary were analyzed within Panthera (including all extant and one extinct taxa) to gain a better understanding of pantherine phylogeny. Multiple specimens of each taxon were analyzed, including: P. leo, P. tigris, P. onca, P. pardus , Uncia uncia, and Neofelis nebulosa. Four outgroups were used; Crocuta crocuta, Metailurus ssp., Proailurus lemanensis …
Molecular Phylogenetic Evidence For An Extracellular Cu Zn Superoxide Dismutase Gene In Insects, Joel D. Parker
Molecular Phylogenetic Evidence For An Extracellular Cu Zn Superoxide Dismutase Gene In Insects, Joel D. Parker
Joel D Parker
Representatives of three ancient gene families of the antioxidant enzyme superoxide dismutase (SOD) can be found in most metazoans. In mammals and Caenorhabditis elegans , there is at least one gene each of the cytoplasmic, mitochondrial and extracellular lineages of SOD genes. The cytoplasmic SOD was one of the first enzymes to be implicated in ageing due to its protection against damaging oxygen free radicals. In contrast to other metazoans, insects were thought to lack a gene for the extracellular SOD. We have cloned and sequenced an SOD mRNA in the ant Lasius niger that appears to belong to this …