A national survey of airborne pollen and grass flowering in New Zealand,with implications for respiratory disorder

Airborne pollen and spore levels were monitored at seven sites in New Zealand using the Intermittent Cycling Rotorod sampler during the summer of 1988/1989. Grasses formed the major component of atmospheric pollen levels during spring and summer at every locality. Peak levels of grass and total pollen occurred during December or late November, with a slight latitudinal lag apparent at the more southern sites. Highest levels were recorded at the smaller rural centres of Gore and Kaikohe and the lowest at the larger urban centres of Auckland, Christchurch and Wellington. We make a first approximation of the likely risk to hayfever and allergic asthma patients at each of the seven centres. For example, significantly higher grass pollen levels were experienced at Kaikohe on 44% and 65% of days during November and December, compared with just 15% and 8% at Auckland. By recording the flowering seasons of the principal allergenic grass species at each locality, we determined the potentially allergenic grasses contributing to peak pollen levels, the most ubiquitous being tall fescue (Festuca arundinacea Schreb.), ryegrass (Lolium perenne L.,L. multiflorum Lam.), cocksfoot (Dactylis glomerata L.), Yorkshire fog (Holcus lanatus L.) and sweet vernal (Anthoxanthum odoratum L.). Corresponding author. Deceased.     

Serratia marcescens forms a new type of cytolysin

Most Serratia marcescens strains produce a new type of cytolysin (hemolysin) which is also found in other Serratia species. The hemolytic polypeptide ShlA (M(r) 162 101) is secreted across the outer membrane through the help of the ShlB protein which also involves conversion of an inactive precursor in an hemolytically active form. Both proteins are synthesized with signal sequences which are released during export across the cytoplasmic membrane. Mutants expressing inactive ShlB derivatives are impaired in activation and secretion suggesting a tight coupling between both processes. The region of ShlA for activation and secretion is confined to the N-terminal 16% of the polypeptide which contains the sequence NPNG which is also found in the Proteus hemolysin, the Bordetella pertussis filamentous hemagglutinin and two highly expressed outer membrane proteins of Haemophilus influenzae. Substitution of the first asparagine (N) residue by isoleucine converts the Serratia hemolysin into an inactive secretion incompetent form. It is concluded that this region is recognized by ShlB for activation and secretion of ShlA. The Serratia hemolysin forms defined pores in erythrocyte membranes.     

Experiments with artificial nests provide evidence for ant community stratification and nest site limitation in a tropical forest

Ants are dominant in tropical forests and many species nest in hollow cavities. The manner in which species are vertically stratified in these complex habitats is not known, with lack of nest sites being proposed to limit ant populations. Here, we assess ant community stratification and nest site limitation in a lowland rainforest in New Guinea using experimental addition of artificial bamboo nests of two cavity sizes (small: ~12 mm large: ~32 mm diameter) placed at ground level, in the understorey, and in the canopy. We also conducted a pilot experiment to test the utility of nest translocation. Nests were checked for occupancy after 10 weeks and half of the occupied nests were then translocated between forest plots, while keeping same vertical position. Occupancy of small nests was much higher in the understorey and canopy than at ground level (~75% vs. ~25%). Translocation was successful, as a majority of nests was inhabited by the same species before and after translocation and there was no impact of translocation to a different plot compared to the control, except for a reduction in colony size at ground level. Our experiment demonstrates a vertical stratification in community composition of ants nesting in hollow dead cavities and shows that these ants are more nest site limited in the higher strata than at ground level. Use of small artificial cavities has great potential for future experimental studies, especially for those focused on arboreal ants, as occupancy is high and translocation does not negatively affect their colony size. Abstract in Tok Pisin is available with online material.     

Cultured circular smooth muscle from the rabbit colon

Summary Although cultured vascular smooth muscle cells have been extensively characterized and investigated, there are very few studies of cultured intestinal smooth muscle cells. The aim of this study was to culture colonic smooth muscle (CSM) cells from the rabbit colon. Freshly isolated CSM cells from the circular muscle layer of the distal colon were prepared by collagenase digestion. In primary culture, CSM cells attached to the culture vessels by 48 to 72 h, proliferated by 3 to 7 d, and reached confluency by 14 to 17 d with a “hill-and-valley” pattern. Spontaneous contractions were not observed at any time at 21° or 37° C. Confluent primary cultures were greater than 95% CSM cells, as identified by intensely positive immunofluorescent staining to smooth muscle actin-specific CGA7 and muscle-specific HHF-35 monoclonal antibodies. Transmission electron microscopy of freshly isolated and proliferating CSM cells revealed ultrastructural features consistent with smooth muscle cells. We successfully cultured CSM cells of the rabbit from freshly isolated cells and validated these CSM cells by electron microscopy and immunocytochemical staining. These highly pure primary cultures may be used to investigate numerous aspects of CSM cell metabolism and physiology. These studies were supported by the National Institutes of Health grant to the Inflammatory Bowel Disease Center (Bethesda, MD) P30-AM-32200 and R01-DK-31147. Dr. Kao is the recipient of a Research Career Development Award from the National Foundation for Ileitis and Colitis, Inc. A preliminary report of this work was presented at the American Motility Society Meeting, Houston, TX, in October 1986, and appeared in abstract form inGastroenterology 91: 1057; 1986.     

In vitro fertilization and seed development inTrifolium

Summary Pistils ofTrifolium repens L. andT. ambiguum Bieb. were cultured on an agar-based modified Murashige-Skoog medium. Pistils with and without accessory floral parts were removed from flowers of selected clones ofT. repens, hand-pollinated under aseptic conditions, and planted on the medium. Pistils cultured without accessory floral parts showed no evidence of fertilization after 2 weeks. However, 52% of thoseT. repens pistils cultured with calyx lobes and pedicels contained ovules with maturing embryos 12 days after in vitro cross-pollination. Pistils fromT. ambiguum intraspecific cross-pollinations could not be cultured successfully under the same conditions; however, addition of various combinations of auxin, cytokinin, and gibberellic acid enhanced embryo growth. Fertilization and partial embryo development occurred in interspecific crosses betweenT. ambiguum andT. repens orT. hybridum only whenT. ambiguum was used as the pistillate parent. These results indicate that embryological development under in vitro conditions closely parallels in situ development although growth regulator requirements may vary among species. This work is Technical Contribution 1785 from the South Carolina Agricultural Experiment Station and was supported by SCAES-USDA Cooperative State Research Agreement No. 616-15-65.     

Chromosome evolution in the owl monkey,Aotus

We have reported nine distinct karyotypes for Aotus, of four pelagic phenotypes, and suggest that this single species has undergone extensive subspeciation. We reconstruct the mechanism of chromosomal evolution and propose a hypothesis about the events of subspeciation in Aotus. We speculate that isolated groups of ancestral individuals living in several confined areas have separately accumulated a fusion or inversion pair as a result of inbreeding. A subsequent reassociation of descendants from these individuals led to the formation of offspring with mixtures of fusion or inversion pairs in their complements. They, in turn, radiated into different ecological niches accompanied by adaptive genetic changes and eventually gave rise to the present forms of Aotus distinguishable by their karyotypes, but not easily recognizable by ordinary taxonomic criteria.     

Interaction of cobalt(II) bovine carbonic anhydrase with pyridine-2,6-dicarboxylate ion and other chelating ligands

The removal of cobalt from cobalt(II) bovine carbonic anhydrase by pyridine-2-carboxylate, pyridine-2,6-dicarboxylate and 5-methyl-1,10-phenanthroline occurs via formation of an intermediate. This is presumed to be a ternary adduct of cobalt(II) enzyme with the ligand. In this, metal-protein bonds are loosened, probably via distortion of the normal geometry, resulting in accelerated breakdown of the adduct to apoprotein, compared with the behavior of the cobalt(II) enzyme alone. With 2-carboxy-1,10-phenanthroline, removal of metal is very rapid but no adduct is observed. Values of stability constants of the adducts and rate constants for their decomposition to apoprotein and their formation from apoprotein and cobalt(II) complex were measured at pH 5.5 and 25°C. Formation and dissociation rate constants for the adduct of cobalt carbonic anhydrase with pyridine-2,6-dicarboxylate could be measured from pH 5 to 7 and 10° to 25°C by stopped flow. Values of thermodynamic parameters for the various reactions agreed well with those estimated from the kinetic data.     

New Mesozoic and early Cenozoic spicular Nassellaria and Nassellaria-like Radiolaria

This paper continues a former study (Rev. Española Micropaleontol. 14 (1982b) 401), where the author described spicular nassellarian and entactinarian Radiolaria found in the Middle Triassic samples available at that time. Based on the study of new samples bearing well preserved radiolarians collected during the 20 years that followed the former publication, samples coming from Triassic, Jurassic, Cretaceous, and Paleogene deposits, the author found that spicular Nassellaria are extremely rare in the post-Fassanian radiolarian faunas. Their fossil record is punctuated, their occurrences being separated by very long gaps. And even so, when they occur their number is usually reduced to one, two, or several specimens of a single species. Spicular Nassellaria are rare or very rare in the upper Spathian and Anisian, frequent in the upper Anisian-lower Ladinian, practically absent in the upper Ladinian and the whole upper Triassic and pre-Toarcian Lower Jurassic, rare in lower Toarcian, very rare in the Bajocian, rare in the lower Tithonian. No specimens were recorded in the other stages of the middle and upper Jurassic and in the whole Cretaceous, except for one in the Coniacian. In the Paleogene only five species belonging to four genera have been recorded in the upper Paleocene-middle Eocene. In the Neogene the only genus known so far is Neosemantis that occurs sporadically since the lower Miocene. A wider diversity is recorded in the living plankton or Recent sediments that comprise all genera and species described in the literature before 1970. It is suggested that this scarcity reflects their real scarcity in the tropical or subtropical seas of the past, but this scarcity was probably magnified by selective preservation. The idea of origination of spicular Nassellaria once or several times from shell-bearing Nassellaria by the reduction of shell during some environmental crises of the Mesozoic and Cenozoic or by hybridization is rejected because the group is rather unitary in its spicular structure and it shows a certain evolution from taxa with massive spines to taxa with three-bladed spines. Nassellarian-like spicular Radiolaria range within the boundaries of the Triassic; they seem to have disappeared by the end on the Norian.In order to give a complete inventory of these radiolarians all taxa known in the Mesozoic and lower Cenozoic are described, discussed, or just mentioned. They comprise 44 species of which 20 are new, 14 genera of which six are new (Palaeosemantis, Molzaxis, Daniplagia, Verticiplagia, Jeanpierria and Nandartia), three subfamilies of which one (Zaldacriinae) is new, and two families (Plagiacanthidae and Archaeosemantidae).     

Life history in culture of the obligate epiphyte Porphyra subtumens (Bangiales, Rhodophyta) endemic to New Zealand

This is the first report of the growth in culture of Porphyra subtumens J. Agardh ex Laing (Bangiales, Rhodophyta), an obligate epiphyte of Durvillaea species and endemic to New Zealand waters. Archeospores, previously observed on field material, develop directly into the blade phase. Spores released from field collected blades form conchocelis. Conchospores develop into new blades, completing the life history in culture. Earlier reports of reproduction in P. subtumens gave conflicting accounts with some authors citing this species as having an asexual, monophasic life history with an unusual form of spore production, while others described spermatangia and carposporangia on the blade phase.