A phylogenetic analysis of Pseudonaja (Hydrophiinae, Elapidae, Serpentes) based on mitochondrial DNA sequences

A phylogenetic analysis of mitochondrial ND4 and adjacent tRNA sequences for a geographically extensive series of specimens reveals nine major clades within Pseudonaja, of which six are largely coincident with nominal taxa (P. affinis, P. guttata, P. inframacula, P. ingrami, P. modesta, and P. textilis). The remaining three clades are composed of specimens presently referred to P. nuchalis. Two of these clades correspond with the "Darwin" and "Southern" morphs of previous authors, while the third clade incorporates the "Orange with black head" and "Pale head, grey nape" morphs. We are unable to confirm the presence of consistent karyotypic differences between "Orange with black head" and "Pale head, grey nape" specimens, however, P. inframacula, P. textilis, and P. nuchalis "Darwin" are found to exhibit distinctive karyotypes, as previously reported. These results, in conjunction with additional observations of karyotpic and morphological variation, are consistent with nine historically-independent lineages (i.e., species) within Pseudonaja. There is strong support for a clade composed of P. affinis, P. inframacula, P. ingrami, P. textilis, and the three P. nuchalis lineages, and for the relationships (P. inframacula, P. nuchalis "Southern") and (P. nuchalis "Darwin", P. nuchalis "Orange with black head"--"Pale head, grey nape" ).     

Defining the cost of the Egyptian lymphatic filariasis elimination programme

BACKGROUND: Ultrasonography (USG) is known to be a suitable tool for diagnosis in lymphatic filariasis as the adult filarial nematode Wuchereria bancrofti in scrotal lymphatic vessels of infected men can be detected by the characteristic pattern of movement, the Filaria Dance Sign. In onchocerciasis, moving adult worms have not yet been demonstrated by USG. In addition the verification of drug effects on living adult Onchocerca volvulus filariae in trials is hampered by the lack of tools for longitudinal observation of alterations induced by potentially macrofilaricidal drugs in vivo. The present study was carried out to determine the frequency of detection of moving adult filariae of O. volvulus by USG. METHODS: In an endemic region for onchocerciasis in Ghana, 61 patients infected with onchocerciasis were recruited by palpation and onchocercomas examined by USG using an ultrasound system equipped with a 7.5 - 10 MHz linear transducer. Onchocercomas were recorded on videotape and evaluated with regard to location, number and size, as well as to movements of adult filariae. RESULTS: In the 61 patients 303 onchocercomas were found by palpation and 401 onchocercomas were detected by USG. In 18 out of 61 patients (29.5%), altogether 22 nodules with moving adult O. volvulus filariae were detected and are presented in animated ultrasound images as mp-4 videos. CONCLUSION: Ultrasonographical examinations of onchocercomas where living adult filariae can be displayed may serve as a new tool for the longitudinal observation in vivo of patients with onchocerciasis undergoing treatment and as an adjunct to histological evaluation.     

Molecular evidence for an Asian origin of monitor lizards followed by Tertiary dispersals to Africa and Australasia

Monitor lizards are emblematic reptiles that are widely distributed in the Old World. Although relatively well studied in vertebrate research, their biogeographic history is still controversial. We constructed a molecular dataset for 54 anguimorph species, including representatives of all families with detailed sampling of the Varanidae (38 species). Our results are consistent with an Asian origin of the Varanidae followed by a dispersal to Africa 41 (49-33) Ma, possibly via an Iranian route. Another major event was the dispersal of monitors to Australia in the Late Eocene-Oligocene 32 (39-26) Ma. This divergence estimate adds to the suggestion that Australia was colonized by several squamate lineages prior to the collision of the Australian plate with the Asian plate starting 25 Ma.     

Evidence for an early evolutionary emergence of γ-type carbonic anhydrases as components of mitochondrial respiratory complex I

Background  

The complexity of mitochondrial complex I (CI; NADH:ubiquinone oxidoreductase) has increased considerably relative to the homologous complex in bacteria. Comparative analyses of CI composition in animals, fungi and land plants/green algae suggest that novel components of mitochondrial CI include a set of 18 proteins common to all eukaryotes and a variable number of lineage-specific subunits. In plants and green algae, several purportedly plant-specific proteins homologous to γ-type carbonic anhydrases (γCA) have been identified as components of CI. However, relatively little is known about CI composition in the unicellular protists, the characterizations of which are essential to our understanding of CI evolution.