Biology subjects

Araujo, N. d. S.

Publications and source records attributed to Araujo, N. d. S..

3 recordsLinked to original sources

bioRxiv2023

Insights from Melipona bicolor hybrid genome assembly: A stingless bee genome with chromosome-level scaffold

BackgroundThe highly eusocial stingless bees are crucial pollinators of native and agricultural ecosystems. Nevertheless, genomic studies within this bee tribe remain scarce. We present the genome assembly of the stingless bee Melipona bicolor. This bee is a remarkable exception to the typical single-queen colony structure, since in this species, multiple queens may coexist and share reproductive duties, resulting in genetically diverse colonies with weak kinship connections. As the only known genuinely polygynous bee, M. bicolors genome provides a valuable resource for investigating sociality beyond kin selection. ResultsThe genome was assembled employing a hybrid approach combining short and long reads, resulting in 241 contigs spanning 259 Mb (N50 of 6.2 Mb and 97.5% complete BUSCOs). Comparative analyses shed light on some evolutionary aspects of stingless bee genomics, including multiple chromosomal rearrangements in Melipona. Additionally, we explored the evolution of venom genes in M. bicolor and other stingless bees, revealing that, apart from two genes, the conserved repertoire of venom components remains under purifying selection in this clade. ConclusionThis study advances our understanding of stingless bee genomics, contributing to the conservation efforts of these vital pollinators and offering insights into the evolutionary mechanisms driving their unique adaptations.

genomics↗

bioRxiv2022

Facing lethal temperatures: heat shock response in desert and temperate ants

Several genera of desert ants have adapted to endure prolonged exposure to high temperatures. The study of these ants is essential to unravel how species respond and adapt to thermal stress. We investigated the thermal tolerance and the transcriptomic heat stress response of three desert ant genera (Cataglyphis, Melophorus and Ocymyrmex) and two temperate genera (Formica and Myrmica) to explore convergent and specific adaptations. We found a variable transcriptomic response among desert species exposed to similar levels of physiological heat-stress: Cataglyphis holgerseni and Melophorus bagoti differentially regulated very few transcripts, 0.12% (54/44,525) and 0.14% (53/38,726) respectively, while Cataglyphis bombycina and Ocymyrmex robustior showed greater expression alterations affecting 0.6% (253/41,912) and 1.53% (698/45,701) of their transcriptomes, respectively. These two responsive mechanisms - reactive and constitutive - were related to desert species thermal tolerance survival pattern and convergently evolved in distinct desert ant genera. By comparison, the two temperate species differentially expressed thousands of transcripts more than desert ants in response to heat stress (affecting 8% and 12,71% of F. fusca and Myr. sabuleti transcriptomes), suggesting that keeping restrained gene expression is an important adaptation in heat adapted species. Finally, we found a significant overlap of the molecular pathways activated in response to heat-stress in temperate and desert species, and our data revealed that larger gene expression responses also affected a greater number of taxonomically restricted genes. These results suggest that the molecular processes involved in heat-stress response are mostly evolutionary conserved in ants, but new genes may also play a role.

molecular biology↗

bioRxiv2020

Multiple lineages, same molecular basis: task specialization is commonly regulated across all eusocial bee groups

A striking feature of advanced insect societies is the existence of workers that forgo reproduction. Two broad types of workers exist in eusocial bees: nurses which care for their young siblings and the queen, and foragers who guard the nest and forage for food. Comparisons between this two worker subcastes have been performed in honeybees, but data from other bees are scarce. To understand whether similar molecular mechanisms are involved in nurse-forager differences across distinct species, we compared gene expression and DNA methylation profiles between nurses and foragers of the buff-tailed bumblebee Bombus terrestris and of the stingless bee Tetragonisca angustula. These datasets were then discussed comparatively to previous findings on honeybees. Our analyses revealed that although the expression pattern of genes is often species-specific, many of the biological processes and molecular pathways involved are common. Moreover, DNA methylation and gene expression correlation were dependent on the nucleotide context.

evolutionary biology↗