Biology subjects

Werner, S. J.

Publications and source records attributed to Werner, S. J..

4 recordsLinked to original sources

bioRxiv2025

Enzymatic Glycosylation of Anthranilates for Enhanced Functionality

Anthranilate (ANT) is a precursor for the synthesis of valuable compounds, including its alkyl esters (AEANTs), such as methyl anthranilate (MANT). These derivatives are industrial petrochemical products used as flavouring agents and bird repellents. Due to the mandatory green transition, their biological industrial production must be considered. However, their antimicrobial activity and physicochemical properties inhibit efficient microbial production and challenge their practical use. To overcome this, we explored enzymatic glycosylation using UDP-dependent glycosyltransferases (UGTs). Screening identified three UGTs with activity on a selected AEANT panel, with UGT72B68 from Solanum lycopersicum showing the highest efficiency (840 s-1 M-1) for MANT. Rational engineering produced a mutant (F145M) with improved activity for bulkier AEANTs. We scaled up enzymatic synthesis, producing 9.3 g of MANT-N-glucose (>99% purity, 74% yield). With this in hand, we observed that MANT-N-glucose has a significantly lower impact on the growth of E. coli and P. putida, supporting microbial production. Furthermore, we found that MANT-N-glucose completely inhibited sunflower seed consumption, compared to a 70% reduction observed in a previous study using MANT, when tested on captured red-winged blackbirds. Finally, a preliminary life-cycle assessment demonstrated that microbially produced MANT-N-glucose is a viable alternative to chemically synthesised MANT as a bird repellent.

biochemistry↗

bioRxiv2021

Concurrent invasions by European starlings (Sturnus vulgaris) suggest selection on shared genomic regions even after genetic bottlenecks

A species success during the invasion of new areas hinges on an interplay between demographic processes and the outcome of localized selection. Invasive European Starlings (Sturnus vulgaris) established populations in Australia and North America in the 19th century. Here, we compare whole-genome sequences among native and independently introduced European Starling populations from three continents to determine how demographic processes interact with rapid adaptive evolution to generate similar genetic patterns in these recent and replicated invasions. Our results confirm that a post-bottleneck expansion may in fact support local adaptation. We find that specific genomic regions have differentiated even on this short evolutionary timescale, and suggest that selection best explains differentiation in at least two of these regions. This infamous and highly mobile invader adapted to novel selection (e.g., extrinsic factors), perhaps in part due to the demographic boom intrinsic to many invasions.

evolutionary biology↗

bioRxiv2021

Transcript- and annotation-guided genome assembly of the European starling

The European starling, Sturnus vulgaris, is an ecologically significant, globally invasive avian species that is also suffering from a major decline in its native range. Here, we present the genome assembly and long-read transcriptome of an Australian-sourced European starling (S. vulgaris vAU), and a second North American genome (S. vulgaris vNA), as complementary reference genomes for population genetic and evolutionary characterisation. S. vulgaris vAU combined 10x Genomics linked-reads, low-coverage Nanopore sequencing, and PacBio Iso-Seq full-length transcript scaffolding to generate a 1050 Mb assembly on 1,628 scaffolds (72.5 Mb scaffold N50). Species-specific transcript mapping and gene annotation revealed high structural and functional completeness (94.6% BUSCO completeness). Further scaffolding against the high-quality zebra finch (Taeniopygia guttata) genome assigned 98.6% of the assembly to 32 putative nuclear chromosome scaffolds. Rapid, recent advances in sequencing technologies and bioinformatics software have highlighted the need for evidence-based assessment of assembly decisions on a case-by-case basis. Using S. vulgaris vAU, we demonstrate how the multifunctional use of PacBio Iso-Seq transcript data and complementary homology-based annotation of sequential assembly steps (assessed using a new tool, SAAGA) can be used to assess, inform, and validate assembly workflow decisions. We also highlight some counter-intuitive behaviour in traditional BUSCO metrics, and present BO_SCPLOWUSCOMPC_SCPLOW, a complementary tool for assembly comparison designed to be robust to differences in assembly size and base-calling quality. Finally, we present a second starling assembly, S. vulgaris vNA, to facilitate comparative analysis and global genomic research on this ecologically important species.

genomics↗

bioRxiv2019

Environment but not geography explains genetic variation in the invasive and largely panmictic European starling in North America

Populations of invasive species that colonize and spread in novel environments may differentiate both through demographic processes and local selection. European starlings (Sturnus vulgaris) were introduced to New York in 1890 and subsequently spread throughout North America, becoming one of the most widespread and numerous bird species on the continent. Genome-wide comparisons across starling individuals and populations can identify demographic and/or selective factors that facilitated this rapid and successful expansion. We investigated patterns of genomic diversity and differentiation using reduced-representation genome sequencing (ddRADseq) of 17 winter-season starling populations. Consistent with this species high dispersal rate and rapid expansion history, we found low geographic differentiation and few FST outliers even at a continental scale. Despite starting from a founding population of approximately 180 individuals, North American starlings show only a moderate genetic bottleneck, and models suggest a dramatic increase in effective population size since introduction. In genotype-environment associations we found that [~]200 single-nucleotide polymorphisms are correlated with temperature and/or precipitation against a background of negligible genome- and range-wide divergence. Local adaptation in North American starlings may have evolved rapidly even in this wide-ranging and evolutionarily young population. This survey of genomic signatures of expansion in North American starlings is the most comprehensive to date and complements ongoing studies of world-wide local adaptation in these highly dispersive and invasive birds.

evolutionary biology↗