Temperature influences on root growth for Encelia farinosa (Asteraceae), Pleuraphis rigida (Poaceae), and Agave deserti (Agavaceae) under current and doubled CO2 concentrations

To help evaluate root distribution patterns, elongation rates of individual roots were measured as a function of soil temperature for Encelia farinosa (a C₃ species), Pleuraphis rigida (C₄), and Agave deserti (CAM), sympatric codominants in the northwestern Sonoran Desert. Measurements were made at current and doubled CO₂ concentrations under winter and summer conditions of air temperature (day/night temperatures of 17 C/10 C and 33 C/22 C, respectively). The three species had different optimal temperatures for root elongation (T_opt) under winter conditions (25 C for E. farinosa, 35 C for P. rigida, and 30 C for A. deserti); T_opt increased by 2-3 C under summer conditions for all three species. The limiting temperatures for elongation also acclimated from winter to summer conditions. The rate of root elongation at T_opt was higher under summer than winter conditions for E. farinosa (9 vs. 6 mm d⁻¹) and P. rigida (20 vs. 14 mm d⁻¹), reflecting conditions for maximum photosynthesis; no difference occurred for A. deserti (9 vs. 10 mm d⁻¹). Decreased elongation rates at extreme temperatures were associated with less cell division and reduced cell extension. The doubled CO₂ concentration increased average daily root elongation rates for A. deserti under both winter (7%) and summer (12%) conditions, reflecting increased cell extension, but had no effect for the other two species. Simulations of root elongation as a function of soil temperatures showed that maximum elongation would occur at different depths (16-20 cm for E. farinosa, 4-8 cm for P. rigida, and 0-4 cm for A. deserti) and during different seasons (winter to spring for E. farinosa, spring to summer for P. rigida, and all year for A. deserti), contributing to their niche separation. Shading of the soil surface moderated daily variations in soil temperature, reducing seasonal root elongation for winter and spring and increasing elongation for summer. Shading also altered root distribution patterns, e.g., optimal rooting depth for A. deserti and especially P. rigida increased for a hot summer day.     

Field release,establishment and initial dispersal of Irish <Emphasis Type="Italic">Microctonus aethiopoides</Emphasis> in <Emphasis Type="Italic">Sitona lepidus</Emphasis> populations in northern New Zealand pastures

The clover root weevil Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) became an economically important pasture pest in New Zealand shortly after it was discovered in the Waikato region in 1996. A classical biological programme was initiated and an Irish biotype of Microctonus aethiopoides Loan (Hymenoptera: Braconidae) was released at four sites in the North Island in late summer 2006. These sites in Waikato, Hawke’s Bay and Manawatu (two sites) regions were monitored monthly and parasitoid establishment confirmed at all sites within four months. In the winter of 2007, parasitism exceeded 70%. A widespread North Island drought in summer 2008 had a severe impact on S. lepidus populations at the Waikato and the two Manawatu release sites, resulting in parasitism below detection levels in the following summer. However, populations recovered by autumn. Within three years at the Hawke’s Bay site, M. aethiopoides appears to be suppressing S. lepidus populations and has dispersed naturally over 60 km.     

Fishing in Macaca fascicularis: A Rarely Observed Innovative Behavior

Observations of fishing behavior in nonhuman primates are rare and isolated, and there is no prior published observation on the behavior in long-tailed macaques (Macaca fascicularis). We observed fishing behavior in 3 groups of long-tailed macaques from 2 separate study sites in North Sumatra and East Kalimantan, Indonesia. We propose that the behavior is rare and fulfills the requirements for classification as innovation. Further, all of the fishing individuals were watched by other members of their group, with their actions inciting attempts at fishing by them. We consider the possibility that the behavior has the potential to become cultural within the populations.     

Proceedings of the 11th Oamaru Penguin Symposium 2018

This paper records the abstracts of the presentations given at the 11th Oamaru Penguin Symposium, held at the Opera House, Oamaru, New Zealand, 3 and 4 May, 2018.     

Behavioral fingerprints predict insecticide and anthelmintic mode of action

Novel invertebrate‐killing compounds are required in agriculture and medicine to overcome resistance to existing treatments. Because insecticides and anthelmintics are discovered in phenotypic screens, a crucial step in the discovery process is determining the mode of action of hits. Visible whole‐organism symptoms are combined with molecular and physiological data to determine mode of action. However, manual symptomology is laborious and requires symptoms that are strong enough to see by eye. Here, we use high‐throughput imaging and quantitative phenotyping to measure Caenorhabditis elegans behavioral responses to compounds and train a classifier that predicts mode of action with an accuracy of 88% for a set of ten common modes of action. We also classify compounds within each mode of action to discover substructure that is not captured in broad mode‐of‐action labels. High‐throughput imaging and automated phenotyping could therefore accelerate mode‐of‐action discovery in invertebrate‐targeting compound development and help to refine mode‐of‐action categories.     

The SARS-CoV-2 Spike protein has a broad tropism for mammalian ACE2 proteins

SARS Coronavirus 2 (SARS-CoV-2) emerged in late 2019, leading to the Coronavirus Disease 2019 (COVID-19) pandemic that continues to cause significant global mortality in human populations. Given its sequence similarity to SARS-CoV, as well as related coronaviruses circulating in bats, SARS-CoV-2 is thought to have originated in Chiroptera species in China. However, whether the virus spread directly to humans or through an intermediate host is currently unclear, as is the potential for this virus to infect companion animals, livestock, and wildlife that could act as viral reservoirs. Using a combination of surrogate entry assays and live virus, we demonstrate that, in addition to human angiotensin-converting enzyme 2 (ACE2), the Spike glycoprotein of SARS-CoV-2 has a broad host tropism for mammalian ACE2 receptors, despite divergence in the amino acids at the Spike receptor binding site on these proteins. Of the 22 different hosts we investigated, ACE2 proteins from dog, cat, and cattle were the most permissive to SARS-CoV-2, while bat and bird ACE2 proteins were the least efficiently used receptors. The absence of a significant tropism for any of the 3 genetically distinct bat ACE2 proteins we examined indicates that SARS-CoV-2 receptor usage likely shifted during zoonotic transmission from bats into people, possibly in an intermediate reservoir. Comparison of SARS-CoV-2 receptor usage to the related coronaviruses SARS-CoV and RaTG13 identified distinct tropisms, with the 2 human viruses being more closely aligned. Finally, using bioinformatics, structural data, and targeted mutagenesis, we identified amino acid residues within the Spike–ACE2 interface, which may have played a pivotal role in the emergence of SARS-CoV-2 in humans. The apparently broad tropism of SARS-CoV-2 at the point of viral entry confirms the potential risk of infection to a wide range of companion animals, livestock, and wildlife.

A study using a combination of surrogate entry assays and live virus suggests that SARS-CoV-2 may have a broad host-range, revealing that the virus''s spike protein can use a broad range of host ACE2 receptors to enter cells and that the sequence of this protein might have changed during the zoonotic jump into humans.     

Expression of the androgen-dependent MMTV-specific orf gene in Shionogi 115 mouse mammary tumor cells

The Shionogi 115 (S115) mouse mammary tumor cells express the MMTV-specific 1.7 kb mRNA (orf) at a high level in the presence of androgens. In lymphoid cells the orf-gene encodes a superantigen which has an important role in establishing self-tolerance but in mammary and breast cancer cells the function of the orf gene is unclear. In the present work we studied the expression of the S115 mammary tumor cell orf sequence and its role in the androgen regulated growth of S115 cells. The cloning and sequencing of the cDNA specific for the 1.7 kb mRNA from the S115 mouse mammary tumor cells revealed a 990 bp DNA sequence with a 99.8% homology to the Mtv-17 proviral strain. There was a difference of only one amino acid (isoleu-tyr) in the coding region. A peptide was synthesized according to the hypervariable C-terminal part of the predicted protein and used to raise a rabbit antiserum. The anti-S115-orf antiserum immunoprecipitated an approximately 45 kDa protein from the metabolically labeled S115 cell lysates. In order to analyze the putative functions of the protein, the orf-sequence was linked to MoMLV-LTR and to the human ß-actin promoter in the mammalian expression vectors pLTRpoly and pHßAPr-1-neo, respectively, and transfected into NIH3T3 and S115 cells. NIH3T3 transfectants expressing orf mRNA did not show a transformed phenotype in vitro. The S115 orf transfectants proliferated somewhat more slowly than the vector transfected control cells in cell culture, both in the presence or absence of androgen, but there was no obvious change in the phenotype of S115 cells or in expression of the fibroblast growth factor 8 (FGF-8). This factor is activated by Mtv-6 integration and mediates androgen effects in these cells. Unexpectedly, however, the formation of tumors by S115 orf cells in nude mice was considerably prolonged and tumor growth retarded when compared with vector transfected control or parent S115 cells. The results suggest that MMTV-orf can be functional in breast cancer cells but the mechanism of the growth repressive effect in mammary tumor remains to be analyzed.