How does a transforming landscape influence bird breeding success?

Context

The conversion of agricultural landscapes to tree plantations is a major form of landscape transformation worldwide, but its effects on biodiversity, particularly key population processes like reproductive success, are poorly understood.

Objectives

We compared bird breeding success between woodland remnants surrounded by maturing stands of plantation Radiata Pine and a matched set of woodland remnants in semi-cleared grazing land.

Methods

Our study was conducted in the Nanangroe region in south-eastern New South Wales, Australia. Using repeated field measurements, we quantified bird breeding success in 23 woodland remnants; 13 surrounded by Radiata Pine plantations and 10 on farms where remnants were surrounded by semi-cleared grazing land. We matched the attributes of native remnant patches between two types of matrix.

Results

We found that: (1) rates of nesting success of smaller-bodied birds in woodland remnants surrounded by grazing land were significantly higher than in woodland remnants surrounded by pine plantations; and (2) taxa with domed nests were more successful at nesting than species that constructed open cup/bowl nests in woodland remnants within farmlands.

Conclusions

Our findings suggest that bird breeding success in remnant woodland patches is significantly diminished as a result of the conversion of semi-cleared grazing land to pine plantations.

     

Chromosome-level de novo genome assemblies of over 100 plant species

Genome sequence analysis in higher plants began with the whole-genome sequencing of Arabidopsis thaliana. Owing to the great advances in sequencing technologies, also known as next-generation sequencing (NGS) technologies, genomes of more than 400 plant species have been sequenced to date. Long-read sequencing technologies, together with sequence scaffolding methods, have enabled the synthesis of chromosome-level de novo genome sequence assemblies, which has further allowed comparative analysis of the structural features of multiple plant genomes, thus elucidating the evolutionary history of plants. However, the quality of the assembled chromosome-level sequences varies among plant species. In this review, we summarize the status of chromosome-level assemblies of 114 plant species, with genome sizes ranging from 125 Mb to 16.9 Gb. While the average genome coverage of the assembled sequences reached up to 89.1%, the average coverage of chromosome-level pseudomolecules was 73.3%. Thus, further improvements in sequencing technologies and scaffolding, and data analysis methods, are required to establish gap-free telomere-to-telomere genome sequence assemblies. With the forthcoming new technologies, we are going to enter into a new genomics era where pan-genomics and the >1,000 or >1 million genomes’ project will be routine in higher plants.     

New Cytotoxic and Antibacterial Compounds Isolated from the Sea Hare,Aplysia kurodai

The extract of the sea hare, Aplysia kurodai, showed cytotoxicity against HeLa cells and antibacterial activity against Staphylococcus aureus. Bioassay-guided purification afforded four active compounds, which were identified to be laurinterol, laurinterol acetate, debromolaurinterol, and debromolaurinterol acetate by spectroscopic analysis. Although the acetates were derived from laurinterol and debromolaurinterol before, this is the first isolation of the acetates from natural sources.     

Extinct technetium in silicon carbide stardust grains: implications for stellar nucleosynthesis

The isotopic composition of ruthenium (Ru) in individual presolar silicon carbide (SiC) stardust grains bears the signature of s-process nucleosynthesis in asymptotic giant branch stars, plus an anomaly in 99Ru that is explained by the in situ decay of technetium isotope 99Tc in the grains. This finding, coupled with the observation of Tc spectral lines in certain stars, shows that the majority of presolar SiC grains come from low-mass asymptotic giant branch stars, and that the amount of 99Tc produced in such stars is insufficient to have left a detectable 99Ru anomaly in early solar system materials.     

Endosperm starch properties in several wheat cultivars preferred for Japanese noodles

To characterize superior genotypes for the white Japanese noodle, endosperm starch properties including amylose content, flour peak viscosity and starch-granule bound Waxy (Wx) proteins were compared using several cultivars preferred for noodle manufacture. Amylose contents from three seasons trials and flour peak viscosity from two seasons trials varied among cultivars. Low amylose content was a common property in the noodle cultivars, whereas a high peak viscosity was not always the case. When the Wx proteins were analyzed by sodium dodecylsulfate polyacrylamide gel electrophoresis, a clear reduction in the amount of low molecular weight protein or a lack of the high molecular weight protein occurred in the noodle cultivars. Segregation of Wx proteins was detectable in a B₁F₁ population, indicating that the Wx protein analysis has a potential as a surrogate of selecting low amylose genotypes in early generations.     

Application of a real-time PCR assay for the detection of Ascaris suum DNA in the liver of experimentally infected chickens

This study aimed to evaluate the sampling method for the detection of Ascaris suum larval DNA in chicken livers using real-time PCR. Chickens were inoculated with A. suum eggs of a single dose (Group A) or repeatedly low doses (Group B). White spots (WSs) were continuously observed on liver from day 3 after the last infection in Group B and day 14 in Group A. In Group A, larval DNA was detected in WS lesions (78.6%) at a significantly higher rate than in the remaining tissue samples (31.3%). In conclusion, applying WS lesions to the assay improved the detection rate of A. suum DNA in chicken livers, especially in the case of a single infection.