Assessment of cytogenetic response to folic acid deprivation in rat lymphocytes

Summary Rat lymphocyte cultures were initiated in minimal essential medium containing 0, 0.01, 1.0, or 10 mg/l of folic acid to investigate the influence of folic acid on cell kinetics, chromosome aberration, and sister chromatid exchange (SCE) frequencies. No significant difference was observed between cultures with and without folic acid in mitotic index or cell cycle kinetics as judged by the numbers of average lymphocyte divisions. However, a sequential reduction in the number of chromatid gaps occurred as the concentration of folic acid increased. On the other hand, addition of folic acid did not significantly affect the SCE frequency. Although folic acid does not seem to alter SCE formation, its significant influence in the reduction of chromatid gaps suggests that caution should be exercised in selecting a medium regarding folic acid content especially because gaps alone are produced by certain dose levels of some chemical clastogens.     

Mycobiota of Eucommia ulmoides bark: Diversity,rare biosphere and core taxa

Bark represents a unique microbial habitat. Revealing the interactions among bark-associated microbes is important for understanding their diversity, stability, and function, and how core microbiome influences the health and production of the host plant. We used amplicon sequencing of bark from the medicinal plant Eucommia ulmoides collected across nine distinct biogeographical regions in China, and comprehensively analyzed the diversity, rare biosphere and core taxa of bark fungi. The co-occurrence network results showed significant differences in the compositions of core mycobiota in E. ulmoides bark between the nine regions. Ecological factors (e.g., temperature and rainfall) were crucial determinants of differences in the unique core mycobiota of E. ulmoides from different regions. The metacommunity-scale network indicated that Cladosporium, Alternaria, and Teratosphaeria were core fungal taxa of E. ulmoides bark. Moreover, some core fungal taxa included rare taxa in particular local communities which, despite their relatively low abundance, may play a significant role in the community structure of E. ulmoides bark.     

The genus Williamia in the western Pacific (Mollusca: Siphonariidae)

Abstract

The taxonomic status and synonymy of Williamia Monterosato, 1884 are discussed. Williamia is retained in preference to Allerya Mörch, 1877 and Brondelia Bourguignat, 1862, both of which have priority. Roya Iredale, 1912 is transferred from Trochidae to Siphonariidae as a synonym of Williamia. Roya kermadecensis Iredale, 1912 is synonymised with Capulus nutatus Hedley, 1908, which in turn is placed as a geographic subspecies of W. radiata Pease, 1861. Allerya japonica Habe, 1962 is considered a probable synonym of W. radiata. W. maxwelli n.sp. is described from the Upper Oligocene to Lower Miocene of New Zealand. Roya spongotheras Bertsch, 1980 is transferred to an undescribed genus of the Tylodinidae.     

Book review

Fauna of New Zealand (Ko te Aitanga Pepeke o Aotearoa) No. 60. Carabidae (Insecta: Coleoptera): synopsis of supraspecific taxa. By André Larochelle and Marie‐Claude Larivière. Published in 2007 by Landcare Research, Manaaki Whenua Press. Online price: NZ$54.00. ISBN: 9780478093940. 188 p.     

Clavaptera ornata n.gen. et sp., a new genus and species of Carventinae (Hemiptera: Heteroptera: Aradidae) from Northland,New Zealand

Abstract

Clavaptera ornata gen. et sp. n. from leaf-litter from North Cape, Northland, New Zealand, is described and figured. This new genus falls within Group 1 of the Carventinae as proposed by Usinger & Matsuda (1959), and shares some characteristics of Carventaptera and Neocarventus, but it is readily distinguished from these genera by the medial fusion of the mesothorax and metathorax and the presence of a large hexagonal median prominence in the region of fusion. The holotype male was collected in leaf-litter near Serpentine access road, 4 miles from Spirits Bay road and the allotype from the Tapotupotu Stream area, at the base of Cape Reinga.     

The morphology and ecology of a new large agglutinated Antarctic foraminifer (Textulariina: Notodendrodidae nov.)

A now genus and species of large (up to 38 mm) arborescent foraminifer was found in abundance (100/m²) in an ice-covered embayment of the Ross Sea, Antarctica. In contrast to highly productive adjacent areas, this oligotrophic embayment is bathed with water coming from beneath the extensive Ross Ice Shelf. Analyses demonstrate no primary productivity and very low bacterial populations in the water column: however, benthic diatom productivity and bacterial populations are substantial. This arborescent foraminifer is well adapted to these unusual conditions. It is of complex construction with a subcentral double-walled bulb, a dendritic root system, and a stem which gives rise to branches. The bulb and root system reside in the sediment. The stem extends from the top of the bulb through from I to 3 mm of sediment into the overlying water, where it terminates in branches. Laboratory and in situ observations have demonstrated that the organism captures bottom sediments, which are brought into suspension by the activities of larger benthic invertebrates, in cytoplasm extending from the branches and stem. Examination of cytoplasmic composition and arrangement indicates that feeding lakes place infrequently.     

Macroevolution of hoverflies (Diptera: Syrphidae): the effect of using higher‐level taxa in studies of biodiversity,and correlates of species richness

We test a near‐complete genus level phylogeny of hoverflies (Diptera: Syrphidae) for consistency with a null model of clade growth having uniform probabilities of speciation and extinction among contemporaneous species. The phylogeny is too unbalanced for this null model. Importantly, the degree of imbalance in the phylogeny depends on whether the phylogeny is analysed at the genus level or species level, suggesting that genera ought not to be used uncritically as surrogates for species in large‐scale evolutionary analyses. Tests for a range of morphological, life‐history and ecological correlates of diversity give equivocal results, but suggest that high species‐richness may be associated with sexual selection and diet breadth. We find no correlation between species‐richness and either body size or reproductive rate.