The effects of fire on the frillneck lizard (Chlamydosaurus kingii) in northern Australia

Abstract A population of frillneck lizards, Chlamydosaurus kingii, was monitored by radio telemetry and mark-recapture techniques between April 1991 and April 1994, as part of a landscape-scale fire experiment, in Kakadu National Park, Northern Territory. The study aimed to investigate both the short- and longer-term effects of fire on a lizard species in a tropical savanna where fires are frequent and often annual. Frillneck lizards are able to survive fires that occur in the first few months of the dry season by remaining perched in trees. A high level of mortality (29%) occurred during late dry-season fires, along with changes in their behavioural response to fire: sheltering in either larger trees or hollow termite mounds. Food is more accessible after fires due to the removal of ground vegetation. This is reflected in greater volume and diversity of prey in stomach contents after fires. This increase is more pronounced after late dry-season fires, possibly due to increased accessibility of prey caused by more complete vegetation removal. Frillneck lizards show an overall preference for trees with a dense canopy cover located in an area with a low density of grass. Fire has an effect on this relationship. Frillneck lizards in habitat unburnt for a number of years tend to perch in trees with a smaller canopy, whereas lizards in annually burnt habitat perch in trees with a dense canopy. Volume and composition of lizard stomach contents was broadly similar among fire treatments over a 2 year period, although termites were more predominant in stomach contents of lizards in unburnt habitat. Wet-season body condition is lower in lizards from unburnt habitat, although the reason for this is unclear. These results demonstrate the importance of different fire intensities and regimes on the ecology of a lizard species in a tropical savanna.     

Association mapping for chilling tolerance in elite flint and dent maize inbred lines evaluated in growth chamber and field experiments

Chilling sensitivity of maize is a strong limitation for its cultivation in the cooler areas of the northern and southern hemisphere because reduced growth in early stages impairs on later biomass accumulation. Efficient breeding for chilling tolerance is hampered by both the complex physiological response of maize to chilling temperatures and the difficulty to accurately measure chilling tolerance in the field under fluctuating climatic conditions. For this research, we used genome‐wide association (GWA) mapping to identify genes underlying chilling tolerance under both controlled and field conditions in a broad germplasm collection of 375 maize inbred lines genotyped with 56 110 single nucleotide polymorphism (SNP). We identified 19 highly significant association signals explaining between 5.7 and 52.5% of the phenotypic variance observed for early growth and chlorophyll fluorescence parameters. The allelic effect of several SNPs identified for early growth was associated with temperature and incident radiation. Candidate genes involved in ethylene signalling, brassinolide, and lignin biosynthesis were found in their vicinity. The frequent involvement of candidate genes into signalling or gene expression regulation underlines the complex response of photosynthetic performance and early growth to climatic conditions, and supports pleiotropism as a major cause of co‐locations of quantitative trait loci for these highly polygenic traits.     

Opsin Oligomerization in a Heterologous Cell System

Using bioluminescence resonance energy transfer (BRET) we studied opsin oligomerization in heterologous expression systems and quantitatively assessed its oligomerization state. BRET² saturation and competition experiments were performed with live COS-7 cells expressing Rluc-and GFP²-tagged receptor constructs. BRET² saturation curves obtained were hyperbolic, and the calculated oligomerization state (N = 1 for dimers) suggested that opsin (N = 1.34 ± 0.25) forms higher oligomers. Very high BRET² values obtained for the opsin homo-dimer pair indicated a large energy transfer efficiency (E) and for cases where E ? 0.1 a modified saturation curve was proposed. The existence of homo-dimer complexes was additionally supported by competition assay results and was also observed in HEK-293 cells. Furthermore, evidence was provided for homo-and hetero-dimerization of family A (β₂-adrenergic) and B (gastric inhibitory polypeptide, GIP) receptors. In summary, these experiments demonstrate homo-and hetero-dimerization for opsin, β ₂-adrenergic, and GIP receptors.     

What’s in a frog stomach? Solving a 150‐year‐old mystery (Diptera: Calliphoridae)

Abstract.  The nominal taxon Acanthosoma chrysalis Mayer, 1844 is revised, and a lectotype is designated. The species, which was described from Germany from a number of alleged parasites encysted in the peritoneal wall of the stomach of edible frogs, is shown to be based on first instar larvae of blow flies (Calliphoridae). Argued from the shape and configuration of mouthhooks and abdominal cuticular spines, Acanthosoma Mayer, 1844 is shown to be a junior synonym of Onesia Robineau-Desvoidy, 1830 , syn.n. , and A. chrysalis is shown to be a junior synonym of O. floralis Robineau-Desvoidy, 1830 , syn.n. This species is an obligate parasitoid of earthworms, and it is hypothesized that first instar larvae enter the frogs through infected earthworms.     

Hidden Wolbachia diversity in field populations of the European cherry fruit fly, Rhagoletis cerasi (Diptera, Tephritidae)

The European cherry fruit fly Rhagoletis cerasi has been a field model for cytoplasmic incompatibility since the mid 1970s. Two Wolbachia strains were detected in this tephritid species and w Cer2 was described as the CI inducing agent dividing European populations into two unidirectional incompatible groups, i.e. southern females produce viable offspring with northern males, whereas the reciprocal cross results in incompatibility. We detected three new Wolbachia strains by sequencing a multitude of plasmids derived from Wolbachia surface protein gene ( wsp ) polymerase chain reaction (PCR) products. Strain-specific primers were developed allowing individual diagnosis without need for cloning. Hybridization of specific PCR products with a wsp oligonucleotide enhanced the detection limit significantly and revealed the presence of low-titre infections in some strains, in different ontogenetic stages and in adults of different age. We then performed a survey of strain prevalence and infection frequency in eight European regions. w Cer1 was fixed in all populations, whereas w Cer2 was detected only in the South. w Cer3 frequency was the lowest without a clear distribution pattern. The abundance of w Cer4 was homogenous across Europe. Like w Cer2, w Cer5 showed significant differences in spatial distribution. Our new findings of previously undetected and recombinant Wolbachia strains in R. cerasi reveal a major caveat to the research community not to overlook hidden Wolbachia diversity in field populations. Low-titres and geographical variability in Wolbachia diversity are expected to influence the outcome of Wolbachia population dynamics and Wolbachia- based insect population control and may create invasion barriers for expanding and artificially introduced Wolbachia strains.     

Carmine cochineal killers: the flower fly genus Eosalpingogaster Hull (Diptera: Syrphidae) revised

The flower fly genus Eosalpingogaster Hull, predator of the carminic acid producer cochineal (Dactylopiidae), is revised. Two new species are described (knutsoni sp.n. and umbra sp.n. ) and an identification key is provided for all known species. Diagnoses, illustrations, synonymies and distributional and biological data are given. Three new synonyms are proposed [texana Curran as jun.syn. of cochenillivora (Guérin‐Méneville); liposeta Fluke and dactylopianus Blanchard as jun.syn. of nigriventris (Bigot)] and two lectotypes are designated for cochenillivora (Guérin‐Méneville) and nigriventris (Bigot). Eosalpingogaster is elevated to full generic status based on adult morphological characters, biological data and a new phylogenetic analysis of molecular characters with genes 28S, 18S and cytochrome c oxidase subunit I. All data, images and drawings are available online as an example of the utility of international standards for biodiversity informatics.