The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed

The Arctic Warbler Phylloscopus borealis breeds across the northern Palaearctic and northwestern‐most Nearctic, from northern Scandinavia to Alaska, extending south to southern Japan, and winters in Southeast Asia, the Philippines and Indonesia. Several subspecies have been described based on subtle morphological characteristics, although the taxonomy varies considerably among different authors. A recent study (T. Saitoh et al. (2010) BMC Evol. Biol. 10 : 35) identified three main mitochondrial DNA clades, corresponding to: (1) continental Eurasia and Alaska, (2) south Kamchatka, Sakhalin and northeast Hokkaido, and (3) most of Japan (Honshu, Shikoku, Kyushu). These three clades were estimated to have diverged during the late Pliocene to early Pleistocene (border at c. 2.6 million years ago). Differences in morphometrics have also been reported among members of the three clades (T. Saitoh et al. (2008) Ornithol. Sci. 7 : 135–142). Here we analyse songs and calls from throughout the range of the Arctic Warbler, and conclude that these differ markedly and consistently among the populations representing the three mitochondrial clades. Kurile populations, for which no sequence data are available, are shown to belong to the second clade. To determine the correct application of available scientific names, mitochondrial DNA was sequenced from three name‐bearing type specimens collected on migration or in the winter quarters. Based on the congruent variation in mitochondrial DNA, morphology and vocalizations, we propose that three species be recognized: Arctic Warbler Phylloscopus borealis (sensu stricto) (continental Eurasia and Alaska), Kamchatka Leaf Warbler Phylloscopus examinandus (Kamchatka (at least the southern part), Sakhalin, Hokkaido and Kurile Islands), and Japanese Leaf Warbler Phylloscopus xanthodryas (Japan except Hokkaido).     

Breakdown of middle lamella pectin by ●OH during rapid abscission in Azolla

Azolla, a small water fern, abscises its roots and branches within 30 min upon treatment with various stresses. This study was conducted to test whether, in the rapid abscission that occurs in Azolla, breakdown of wall components of abscission zone cells by ^●OH is involved. Experimentally generated ^●OH caused the rapid separation of abscission zone cells from detached roots and the rapid shedding of roots from whole plants. Electron microscopic observations revealed that ^●OH rapidly and selectively dissolved a well‐developed middle lamella between abscission zone cells and resultantly caused rapid cell separation and shedding. Treatment of abscission zones of Impatiens leaf petiole with ^●OH also accelerated the separation of abscission zone cells. However, compared with that of Azolla roots, accelerative effects in Impatiens were weak. A large amount of ^●OH was cytochemically detected in abscission zone cells both of Azolla roots and of Impatiens leaf petioles. These results suggest that ^●OH is involved in the cell separation process not only in the rapid abscission in Azolla but also in the abscission of Impatiens. However, for rapid abscission to occur, a well‐developed middle lamella, a unique structure, which is sensitive to the attack of ^●OH, might be needed.     

Spontaneous Infarction of an Intraductal Papilloma of the Breast: Cytological Presentation On Fine Needle Aspiration

A relatively rare case of spontaneous infarction of an intraductal papilloma of the breast is presented which was considered to be suspicious for malignancy on fine needle aspiration (FNA) cytology. The aspirate revealed several groups of atypical cells featuring a high nuclear-cytoplasmic ratio, coarsely granular chromatin, and somewhat prominent nucleoli. There was abundant necrotic cellular debris in the background. These cellular features were considered evidence of ductal carcinoma of the breast. The correct diagnosis was made by open biopsy which revealed necrosis involving the breast due to infarction of an intraductal papilloma.     

Division of Chloroplasts in a Green Alga, Trebouxia potteri

The division of chloroplasts in Trebouxia potteri was studiedby electron microscopy. At the beginning of chloroplast division,vesicles with fine fibrils (FVs) and ER attach to the isthmusof the chloroplast. Then, filaments appear around the isthmusparallel to the direction of constriction and seem to contractin order to decrease the diameter of the isthmus. It is suggestedthat the FVs are involved in the formation of the filamentsand that the ER is involved in the contraction of the filaments.At the final stages of the division of the chloroplast, thefilaments decompose. FVs are partially surrounded and decomposedby lysosomal sheets. For the next cycle of division of the chloroplast,the recovery of substances from decomposed filaments by functionalFVs seems a realistic possibility. chloroplast division, division apparatus, division cycle, transmission electron microscopy, Trebouxia potteri     

Difference in the Manner of Association of Acrosome-Intact and Acrosome-Reacted Hamster Spermatozoa with Egg Microvilli as revealed by Scanning Electron Microscopy

Scanning electron microscopy was employed to examine the manner of association between in vitro capacitated spermatozoa and zona-free eggs of the hamster. Spermatozoa with intact acrosomes, which were unable to fuse with eggs, were seen in general associated with egg microvilli in the region of the acrosomal cap. Acrosome-reacting spermatozoa were seen associated with egg microvilli with the dissociating acrosomal caps. Acrosome-reacted spermatozoa, which were able to fuse with eggs, generally associated with egg microvilli by the equatorial segment and the anterior portion of the postacrosomal region. It is inferred that the completion of the acrosome reaction signals changes in the plasma membrane over the equatorial segment of the acrosome and the anterior area of the postacrosomal region which give it a greater affinity to and fusibility with the oolemma.     

Cytologic evaluation of conjunctival epithelium using Cytobrush-S: value of slide preparation by ThinPrep technique

Cytologic evaluation of conjunctival epithelium using Cytobrush-S: value of slide preparation by ThinPrep technique
Recent clinical trials have indicated that an automated smear apparatus (ThinPrep process) of sample preparation has great diagnostic sensitivity. In this study, conjunctival brush cytology prepared using the ThinPrep method was applied in ocular surface disorders especially for dry eye status. To assess its diagnostic value in cellular samples, 17 patients with keratoconjunctivitis sicca (KCS) and 10 normal volunteer patients were examined using this technique. Conjunctival cells from normal controls revealed fine chromatin and polyhedral cytoplasm without having keratinized cytoplasm. On the other hand, the cellular samples from KCS revealed increased keratinized cells with pyknotic nuclei. They also contained extremely elongated cells. In KCS patients, the mean number of keratinized cells was significantly higher (34.1 cells/300 cells) than that of the normal control group (0.2 cells/300 cells). In patients with KCS, inflammatory cell counts were also higher than those of normal controls. Conjunctival cytology by means of the ThinPrep method obviously deserves additional trials as an adjunct in the cytology of dry eye states, especially in quantitative ocular evaluation for various ocular lesions.