Comparative Analysis of Hair Melanins by Chemical and Electron Spin Resonance Methods

Eighteen hair samples from Karakul newborn lambs with various colors were estimated for eumelanin and pheomelanin contents (C_e and C_p, respectively) by electron spin resonance (ESR) spectrometry and by high-performance liquid chromatography (HPLC). Correlation coefficients between the values estimated by the ESR and HPLC methods were 0.96, 0.93, and 0.99 for C_e, C_p, and C_e/C_p, respectively. The high correlation coefficients show that both methods fit well for estimation of relative values of these parameters. The absolute values of C_e and C_e/C_p coincide rather well when C_e is high, but considerable discrepancies appear when C_e is low. The reasons for these discrepancies are discussed. The HPLC method appears to be more sensitive for detection of low concentrations of pheomelanin, while the ESR method fits well for mass selection purposes.     

Revision of the genus Australimyza Harrison (Diptera: Australimyzidae)

Abstract.  The species of Australimyza Harrison are revised and the saprophagous larvae are described for the first time. The phylogenetic analysis revealed two species groups and one ungrouped species. One species group is distributed in New Zealand and associated subantarctic islands; all other species occur in Australia. Four new species, A. glandulifera , A. kaikoura , A. mcalpinei and A. victoria , are described, A. anisotomae is synonymized with A. australensis and a neotype is designated for the latter species. A lectotype is designated for A. macquariensis .     

The petrosal and inner ear of the Late Jurassic cladotherian mammal Dryolestes leiriensis and implications for ear evolution in therian mammals

Dryolestes leiriensis is a Late Jurassic fossil mammal of the dryolestoid superfamily in the cladotherian clade that includes the extant marsupials and placentals. We used high resolution micro‐computed tomography (µCT) scanning and digital reconstruction of the virtual endocast of the inner ear to show that its cochlear canal is coiled through 270°, and has a cribriform plate with the spiral cochlear nerve foramina between the internal acoustic meatus and the cochlear bony labyrinth. The cochlear canal has the primary bony lamina for the basilar membrane with a partially formed (or partially preserved) canal for the cochlear spiral ganglion. These structures, in their fully developed condition, form the modiolus (the bony spiral structure) of the fully coiled cochlea in extant marsupial and placental mammals. The CT data show that the secondary bony lamina is present, although less developed than in another dryolestoid Henkelotherium and in the prototribosphenidan Vincelestes. The presence of the primary bony lamina with spiral ganglion canal suggests a dense and finely distributed cochlear nerve innervation of the hair cells for improved resolution of sound frequencies. The primary, and very probably also the secondary, bony laminae are correlated with a more rigid support for the basilar membrane and a narrower width of this membrane, both of which are key soft‐tissue characteristics for more sensitive hearing for higher frequency sound. All these cochlear features originated prior to the full coiling of the therian mammal cochlea beyond one full turn, suggesting that the adaptation to hearing a wider range of sound frequencies, especially higher frequencies with refined resolution, has an ancient evolutionary origin no later than the Late Jurassic in therian evolution. The petrosal of Dryolestes has added several features that are not preserved in the petrosal of Henkelotherium. The petrosal characters of dryolestoid mammals are essentially the same as those of Vincelestes, helping to corroborate the synapomorphies of the cladotherian clade in neural, vascular, and other petrosal characteristics. The petrosal characteristics of Dryolestes and Henkelotherium together represent the ancestral morphotype of the cladotherian clade (Dryolestoidea + Vincelestes + extant Theria) from which the extant therian mammals evolved their ear region characteristics. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 433–463.     

Tests for adaptive RAPD variation in population genetic structure of wild barley, Hordeum spontaneum Koch.

We examined the adaptive importance of RAPD variation in the population genetic structure of wild barley, Hordeu m spontaneum. The test involved (1) a nested sampling design with four population groups representing four distinct environments; and (2) a comparison of observed variation with that expected as a result of natural selection. Analyses of selection on fitness-related traits by reciprocal introductions served as guidelines for the expected pattern of RAPD variation. We found no concordance between the observed pattern of population genetic structure and that expected under the null hypothesis of environment-specific natural selection. There was no relationship between genetic distance and environmental similarity; none of 54 putative loci exhibited an allele distribution in accordance with that expected and no favoured epistatic allele combinations were detected across the four environments. The fact that environmentally induced adaptation, detected by fitness-related traits, was not reflected in inter-population RAPD structure (1) strongly enhances the neutralist viewpoint and (2) casts doubt on the notion that significant correlations between some environmental parameters and allele frequencies in one or more loci are evidence of selection on the latter.     

The Microaerophilic Flagellate, Trichomonas vaginalis, Contains Unusual Acyl Lipids but no Detectable Cardiolipin

ABSTRACT. Previous lipid analysis of trichomonads has led to controversy as to whether these hydrogenosome-containing organisms contain cardiolipin (CL), which is a characteristic component of mitochondria. Here we report a careful lipid analysis of the sexually transmitted protist Trichomonas vaginalis . Major lipids were phosphatidylethanolamine (42%) and phosphatidylcholine (20%) with lesser amounts of phosphatidylglycerol (PG) (12%) and non-polar components. Two unusual lipids, acyl-PG (8%) and ceramide phosphorylethanolamine (2%), were also significant components. The structures of these lipids were confirmed by tandem mass spectrometry following reverse-phase high-performance liquid chromatography. This is the first time ceramide phosphorylethanolamine has been reported in a trichomonad. In contrast, CL (diphosphatidylglycerol) could not be detected either by two-dimensional thin-layer chromatography or by mass spectrometry. These data are discussed in relation to the organism's phylogenetic origin as a parasite showing secondary adaptation to microaerobic conditions.