Evolution and phylogeny of birds - Taxonomic consequences

Nucleotidsequenzen von mitochondrialen und nucleären Markergenen eignen sich hervorragend, um die Phylogenie und Evolution der Vögel zu untersuchen. Eine kürzlich publizierte Analyse mit 19 Kerngenen (Hackett et al. 2008) erlaubte erstmalig die Rekonstruktion einer verlässlichen Phylogenie der Vögel auf Familienebene. Auch für die Systematik der Singvögel erbrachten DNA-Daten bedeutsame Fortschritte. Die von diesen Phylogenien ableitbaren Klassifikationen unterscheiden sich signifikant von der bisher akzeptierten Systematik. Die molekularen Phylogenien erlauben es außerdem, para- und polyphyletische Gruppierungen zu erkennen. Da die Kladistik nur monophyletische Gruppen zulässt, sollten mindestens 22 Gattungsnamen palaearktischer Vogelarten geändert werden. Die DNA-Analysen unterstützen eine Trennung (Splits) von mindestens 44 bestehenden Arten in neue Arten. Insgesamt 4 Vogeltaxa von den Kanarischen Inseln und den Azoren konnten in den letzten 10 Jahren mittels DNAUntersuchungen als neu identifiziert werden. Dieses Review gibt eine Übersicht über die taxonomischen und systematischen Änderungen, die zwischen 1990 und 2010 für die Palaearktis publiziert wurden.Nucleotide sequences of mitochondrial and nuclear marker genes are well suited to elucidate the evolution and phylogeny of birds. A recent study with 19 nuclear genes (Hackett et al. 2008) has provided a reliable framework of avian phylogeny at the family level which allows to build up a new systematics of birds. This scheme differs substantially from previous checklists and classification systems. A large number of DNA papers give evidence for a new systematics of song birds, too. DNA based phylogenies have indicated a number of paraphyletic and polyphyletic taxa. In order to avoid such conflicts about 22 genus names had to be changed for birds of the Palaearctic. DNA sequence data suggest a split of at least 44 existing species into new species. Furthermore, about 4 new taxa, mostly living on Macaronesian islands, could be identified during the last 10 years by DNA sequence data. This review is focused on taxonomic and classification changes of bird taxa of the Western Palearctic that have been reported between 1990 and 2010

Hippopotamyrus ansorgii species complex in the Upper Zambezi River System with a description of a new species, H. szaboi (Mormyridae)

Specimens referable to Hippopotamyrus ansorgii sampled from the Upper Zambezi River System within Caprivi (Namibia) represent a complex of three species, two of which coexist in the Upper Zambezi River, and a third that inhabits a nearby river, the Kwando, with which the Zambezi has been connected during periods of flooding. All three are indistinguishable in terms of their general appearance, but differ consistently in electric organ discharges (EOD), morphology, and molecular genetic characters. All phenotypes display a monopolar, headpositive EOD pulse with specific post- or prepotentials. For H. ansorgii from the Zambezi River (HaZ), pulse duration is less than 0.5 ms (down to 0.205 ms; N = 34); for the syntopic H. szaboi sp. n., it is greater than 0.6 ms (up to 1.8 ms at 10% peak amplitude; N = 19). The parapatric phenotype of H. ansorgii from the Kwando River (HaK) has pulses shorter than 0.215 ms (down to 0.105 ms; N = 36). All three members of the species complex may be distinguished from each other by 7 − 9 anatomical characters, analysed by MANOVA. Based on 22 enzymes and proteins studied, the moderate to high Wright’s fixation index and the significant (P < 0.05) allele differentiation between EOD phenotypes provide additional evidence for incipient speciation. Pairwise analyses of the three different phenotypes showed the two parapatric species of H. ansorgii grouped together, and distinguishable from individuals of H. szaboi . Analyses of the mitochondrial cytochrome b gene revealed that all specimens which were attributed to H. szaboi form a well-supported monophyletic basal clade (bootstrap support 73% or 82%). The genetic distances (uncorrected p distances) between H. szaboi and the two species of H. ansorgii are between 0.6% and 1.7%. Within the derived H. ansorgii clade some phylogeographical differentiation can be seen for fishes from the Zambezi and Kwando Rivers, but the respective groups are not consistent or supported by significant bootstrap values. The question of which of the two parapatric morphological and EOD phenotypes of H. ansorgii recognized in the present paper represents H. ansorgii (Boulenger, 1905) cannot be resolved at present because of the paucity and unclear origin of the historical type material

Allopatric differentiation in the Marcusenius macrolepidotus species complex in southern and eastern Africa: the resurrection of M. pongolensis and M. angolensis, and the description of two new species (Mormyridae, Teleostei)

We critically compared local populations of the bulldog fish, Marcusenius macrolepidotus (Peters 1852), from different watersheds, from the furthest south (28° South, South Africa) to the Equator in Kenya. We ascertained allopatric differentiation from topotypical M. macrolepidotus from the Lower Zambezi River (Mozambique) in morphology, electric organ discharges, and molecular genetics for: (1) samples from the Okavango and Upper Zambezi Systems (Botswana and Namibia), (2) samples from South Africa's rivers draining into the Indian Ocean, and (3) samples from the East African Tana River (Kenya). Significant genetic distances in the mitochondrial cytochrome b gene and differing ISSR-PCR profiles corroborate differentiation between the four taxa. We resurrect M. pongolensis (Fowler, 1934) for South Africa (sample 2), and M. angolensis (Boulenger, 1905) for the Quanza River/Angola. We recognize M. altisambesi sp. n. for the Upper Zambezi/Okavango specimens (sample 1), and M. devosi sp. n. for those from Kenya (sample 3)

East–west differentiation in the Marcusenius macrolepidotus species complex in Southern Africa: the description of a new species for the lower Cunene River, Namibia (Teleostei: Mormyridae)

This paper critically compares the Southern African bulldog fish species Marcusenius macrolepidotus (Peters, 1852), inhabiting the eastern Lower Zambezi River, and Marcusenius altisambesi Kramer et al., 2007, inhabiting the central Upper Zambezi River, with bulldog fish samples from the western lower Cunene River, a 2600-km range from the Indian Ocean to the Atlantic. The three species or forms are well differentiated in morphology and molecular genetics, and differentiation is also present in electric organ discharges. Marcusenius altisambesi and the Cunene sample, which we recognize as Marcusenius multisquamatus sp. nov., are closely related and form a sister taxon to M. macrolepidotus. This result is based on the analysis of mitochondrial cytochrome b sequences and genomic Inter-simple-sequence-repeat fingerprinting. Morphological adaptations to life in a torrential escarpment river seem to be present in M. multisquamatus sp. nov. when compared with M. altisambesi, which lives in a reservoir river that periodically floods the savannah. http://www.zoobank.org/urn:lsid:zoobank.org:pub:8FE68494-9ED9-428E-B181-E814D25493F

The phorbol ester fraction from Jatropha curcas seed oil: Potential and limits for crop protection against insect pests

The physic nut shrub, Jatropha curcas (Euphorbiaceae), has been considered as a "miracle tree", particularly as a source of alternate fuel. Various extracts of the plant have been reported to have insecticidal/acaricidal or molluscicidal/anthelminthic activities on vectors of medical or veterinary interest or on agricultural or non-agricultural pests. Among those extracts, the phorbol ester fraction from seed oil has been reported as a promising candidate for use as a plant-derived protectant of a variety of crops, from a range of pre-harvest and post-harvest insect pests. However, such extracts have not been widely used, despite the "boom" in the development of the crop in the tropics during recent years, and societal concerns about overuse of systemic chemical pesticides. There are many potential explanations to such a lack of use of Jatropha insecticidal extracts. On the one hand, the application of extracts potentially harmful to human health on stored food grain, might not be relevant. The problem of decomposition of phorbol esters and other compounds toxic to crop pests in the field needing further evaluation before such extracts can be widely used, may also be a partial explanation. High variability of phorbol ester content and hence of insecticidal activity among physic nut cultivars/ecotypes may be another. Phytotoxicity to crops may be further limitation. Apparent obstacles to a wider application of such extracts are the costs and problems involved with registration and legal approval. On the other hand, more studies should be conducted on molluscicidal activity on slugs and land snails which are major pests of crops, particularly in conservation agriculture systems. Further evaluation of toxicity to natural enemies of insect pests and studies on other beneficial insects such as pollinators are also needed. (Résumé d'auteur

α-Hexylcinnamaldehyde synergistically increases doxorubicin cytotoxicity towards human cancer cell lines

α-Hexylcinnamaldehyde (HCA), a compound derived from cinnamaldehyde, was evaluated for its potential chemosensitizing properties

DNA Analyses Have Revolutionized Studies on the Taxonomy and Evolution in Birds

Whereas Linné aimed to classify all species of our planet by a unique binomial Latin name, later generations of taxonomists and systematicists intended to place the taxa in a natural system according to their phylogeny. This also happened in ornithology and still scientists are on the way to find the ultimate “Avian Tree of Life”. Formerly, systematic relationships were studied by comparing morphological characters. Since adaptive character evolution occurred frequently, convergences could lead to misleading conclusions. An alternative to morphological characters are biochemical markers, especially nucleotide sequences of marker genes or of complete genomes. They are less prone to convergent evolution. The use of DNA sequences of marker genes for bird systematics started around 1990. The introduction of Next Generation Sequencing (NGS) facilitated the sequence analysis of large parts of bird genomes and to reconstruct the Avian Tree of Life. The genetic analyses allowed the reconstruction of phylogenetic trees and the detection of monophyletic clades, which should be the base for a phylogenetic classification. In consequence, several orders, families and genera of birds had to be rearranged. In addition, a number of species was split into several new species because DNA data could point out hidden lineages in cryptic species or in species complexes

Marked differentiation in a new species of dwarf stonebasher, Pollimyrus cuandoensis sp. nov. (Mormyridae: Teleostei), from a contact zone with two sibling species of the Okavango and Zambezi rivers

We studied the systematic status of a form of Pollimyrus of the lower Kwando River that is flanked by the Okavango River, inhabited by Pollimyrus castelnaui (Boulenger, 1911), and the Zambezi River, inhabited by Pollimyrus marianne Kramer et al., 2003. In morphology and electric organ discharges (EODs), the Kwando phenotype proved well differentiated from both P. castelnaui and P. marianne. Sequence analysis of the cyt b gene confirmed that the three forms or species form a monophyletic clade, with P. castelnaui sister to the other two species. Genomic fingerprinting with ISSR-PCR confirmed differentiation of the Kwando form, that we recognize as a different species, P. cuandoensis sp. nov., from its sister species, P. marianne. A considerable amount of EOD and morphological variation was revealed among samples of P. cuandoensis sp. nov. from four different locations on the lower Kwando River, possibly due to hybrid introgression. This seems an ideal system for testing theories of parapatric speciation. http://www.zoobank.org/urn:lsid:zoobank.org:pub:FB644B21-04F6-44F8-AEB6-8DC09268C17

NARINGIN AND RUTIN PREVENT D-GALACTOSAMINE-INDUCED HEPATIC INJURY IN RATS VIA ATTENUATION OF THE INFLAMMATORY CASCADE AND OXIDATIVE STRESS

The dried stems and leaves of Citrus jambhiri Lush. (Rutaceae) were extracted with aqueous methanol and the extracts were fractionated using light petroleum, chloroform and ethyl acetate. Column chromatography of the ethyl acetate fractions resulted in the isolation of naringin, rutin, hesperidin, and neohesperidin. Their structures were identified by MS and different NMR techniques. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) of these fractions allowed the identification 7 flavonoid glycosides. Hepatoprotective properties of naringin and rutin were evaluated in d-galactosamine (d-GalN)-induced hepatic injury in rats. d-GalN increased serum aminotransferase activity, total bilirubin, liver tumor necrosis factor-α level (TNF-α), hepatic lipid peroxidation, nuclear factor κB and decreased hepatic glutathione content, IL-10 levels and the IL-10/TNF-α ratio. These changes were attenuated in rats pretreated with rutin and naringin (40 mg/kg body weight). They increased liver IL-10 levels and the IL-10/TNF-α ratio. Rutin but not naringin down-regulated NF-κB gene expression and decreased gamma-glutamyltransferase (GGT) activity

Understanding extra-pair mating behaviour: A case study of socially monogamous european pied flycatcher (Ficedula hypoleuca) in Western Siberia

Extra-pair copulation (EPC) occurred in most socially monogamous bird species. The mechanisms leading to the frequent occurrence of extra-pair offspring (EPO, EPY) in socially monogamous couples, as well as the ‘function’ of EPC, are the subjects of strong debates and raise many unan-swered questions. We studied the relationship between extra-pair paternity (EPP) and the different characteristics of males and females in the European pied flycatcher in Western Siberia (Russia). The analysis was based on the genotyping of 232 males, 250 females, 1485 nestlings (250 nests). The European pied flycatchers were predominantly socially and genetically monogamous, but about 20% of birds could be involved in EPP. Loss of paternity tended to be more frequent in one-year-old males. EPCs could be multiple: one individual may have up to three extra-pair partners. The EPP rate was independent of the breeding time. The extra-pair mates of an individual were mainly its near neighbours. The EPC status of an individual was unrelated to most of its morpho-physiological traits. The occurrence of EPP was almost twice as high in females nesting in good quality territories. The fitness of within-pair offspring, EPO, paternal half-sibs of EPO and maternal half-sibs of EPO did not differ statistically significantly. Assuming very low heritability of extra-pair mating, we argued that EPCs could be incidental side effects (by-product) of selection. We believe that the evolution and maintenance of extra-pair mating are the episelective processes in the case of the European pied flycatcher