Comparative analysis of annotation pipelines using the first Japanese white-eye (Zosterops japonicus) genome

Introduced into Hawaii in the early 1900s, the Japanese white-eye or warbling white-eye (Zosterops japonicus) is now the most abundant land bird in the archipelago. Here, we present the first Z. japonicus genome, sequenced from an individual in its invasive range. This genome provides an important resource for future studies in invasion genomics. We annotated the genome using two workflows – standalone AUGUSTUS and BRAKER2. We found that AUGUSTUS was more conservative with gene predictions when compared to BRAKER2. The final number of annotated gene models was similar between the two workflows, but standalone AUGUSTUS had over 70% of gene predictions with Blast2GO annotations versus under 30% using BRAKER2. Additionally, we tested whether using RNA-seq data from 47 samples had a significant impact on annotation quality when compared to data from a single sample, as generating RNA-seq data for genome annotation can be expensive and requires well preserved tissue. We found that more data did not significantly change the number of annotated genes using AUGUSTUS but using BRAKER2 the number increased substantially. The results presented here will aid researchers in annotating draft genomes of non-model species as well as those studying invasion success.

Cordia subcordata (Boraginaceae), a distylous species on oceanic coral islands, is self-compatible and pollinated by a passerine bird

Background and aims – Distyly is usually rare on oceanic islands, which is probably due to the difficulty for distylous plants to colonize those islands. However, Cordia subcordata was observed to be distylous with short- and long-styled morphs on the Xisha Islands in the South China Sea. To characterize the reproduction system of Cordia subcordata and to understand how this distylous species maintains itself on these islands, we studied its reproductive and pollination biology.Methods – Seed set and pollen tube growth under manipulated intermorph, intramorph, and self-pollination were examined to investigate self-incompatibility in the species. The number of pollen grains deposited on the stigmas after a single pollinator visit were counted to investigate the pollination efficiency of different visitors. Key results – Our study indicated that Cordia subcordata shows reciprocal herkogamy as is typical in distylous species. Pollen tubes could reach the base of the style and move into the ovules under all the manipulated pollination treatments in both morphs. Seed set resulting from four hand-pollination experiments did not show any differences between both morphs, suggesting that Cordia subcordata lacks heterostylous self-incompatibility. The most frequent flower visitors, Zosterops japonicus and Apis cerana, were observed foraging on the large volumes of nectar and pollen grains, respectively, with Zosterops japonicus being the most effective pollinator, depositing large number of pollen grains on the stigmas during their visits.Conclusions – Our findings show that Cordia subcordata established itself and persists in the archipelago by producing fruits through a combination of self-compatibility and pollination by the most common passerine bird on the oceanic islands.

Warbling White-eye (Zosterops japonicus Temminck & Schlegel 1845).

This chapter describes the common terminologies, taxonomy, morphology, geographical distribution, physiology, diet, behaviour, reproduction, habitats, ecology, invasion pathways, environmental impact, control and human use of the warbling white-eye (Zosterops japonicus).

Becoming Endemic

This chapter examines the Japanese White-eye, Zosterops japonicus, and the confounding nature of introduced species, some of which have been here long enough to have evolved into something unique to the islands. The White-eye, also known by its Japanese name Mejiro, has been a fixture in the islands since it was introduced on Oʻahu by the Hawaiʻi Board of Commissioners of Agriculture and Forestry (BCAF) in 1929, which was interested in birds primarily as a form of insect control. The White-eye's introduction was then continued by the Hui Manu, a private group founded in 1930 as an acclimatization society that introduced birds from around the world for aesthetic reasons.