Biology subjects

Barros, M.

Publications and source records attributed to Barros, M..

2 recordsLinked to original sources

bioRxiv2023

Evolution of threat response-related polymorphisms at the SLC6A4 locus in callitrichid primates

Variation in an upstream repetitive region at the SLC6A4 locus, which encodes a serotonin transporter, is associated with anxiety-related behaviour in a few primate species, including humans and rhesus macaques. In this study we investigate evolution of SLC6A4 polymorphisms associated with anxiety-related behaviour in common marmosets (Callithrix jacchus). Assaying variation in the SLC6A4 repeat region across 14 species in 8 genera of callitrichid primates (marmosets and tamarins) we find large interspecific variation in the number of repeats present (24-43). The black tufted-ear marmoset (C. penicillata) has sequence polymorphisms similar to those found in the common marmoset, which is its sister species, and no other species has intraspecific variation at these sites. We conclude that, similar to humans and rhesus macaques, the functional polymorphism at SLC6A4 in common marmosets has a recent evolutionary origin, and that the anxiety-related allele is evolutionarily derived. Common/black tufted-ear marmosets and rhesus macaques share high ecological adaptability and behavioural flexibility that we propose may be related to the maintenance of the polymorphism.

evolutionary biology↗

bioRxiv2022

HMGN5, an RNA or Nucleosome binding protein - potentially switching between the substrates to regulate gene expression

The packaging of DNA into chromatin and its compaction within cells renders the underlying DNA template un-accessible for processes like transcription, replication and repair. Active mechanisms as chromatin modifying activities or the association with non-coding RNAs can de-condense chromatin, rendering it accessible for the DNA dependent processes. High mobility group proteins (HMG) are small architectural chromatin proteins that were shown to contribute to the regulation of chromatin accessibility and condensation. Here we show that HMGN5, a member of the HMGN family that is capable to de-compact chromatin exhibits a novel RNA binding domain that overlaps with its nucleosome binding domain (NBD). HMGN5 binds exclusively to nucleosomes or RNA, suggesting that molecular function relies on switching between these two substrates. We show the specific binding of HMGN5 to regulatory regions and at the same time to bind the RNA of the genes it tends to activate. Furthermore, HMGN5 co-localizes and directly interacts with CTCF, suggesting a cooperative role of both proteins in organizing higher order structures of chromatin and active chromatin domains.

molecular biology↗