Biology subjects

Brito, L. A.

Publications and source records attributed to Brito, L. A..

3 recordsLinked to original sources

bioRxiv2024

The "abominable mystery" of Schenck: the polymorphism of Serjania piscatoria and its implications for the evolution of vascular variants in Paullinieae (Sapindaceae)

Serjania is the only genus of Paullinieae that exhibits all types of vascular variants in stems and includes S. piscatoria with a complex vascular structure that has intrigued botanists for centuries. Here, we analyzed the stem development of S. piscatoria in an evolutionary context and determined its phylogenetic position within the genus. We studied four individuals using standardized anatomical techniques and employed DNA sequencing and phylogenetic analysis to determine the species phylogenetic position. Additionally, we employed ancestral state reconstruction to explore the pattern of evolution of vascular variants. We find that the stem development in S. piscatoria is determined by various ontogenetic processes that result in vascular variants that occur through modifications during primary and/or secondary growth, or ectopic cambia formation. These various patterns are classified into distinct categories of vascular variants, highlighting the lability of vascular meristems and the polymorphism within the species, which manifests across different individuals. Serjania piscatoria belongs to a clade composed of species with compound stems, from which the fissured stems observed in the species would have evolved. The findings provide evidence for the diverse stem vasculature in Serjania, and the importance of studying vascular variant diversity from a developmental and evolutionary perspective.

plant biology↗

bioRxiv2023

The ribonucleoprotein-mediated CRISPR-Cas9 system induces recurrent Aire gene mutations in contrast to the nickase expression vector in murine in vitro or in vivo models

Although in vitro mTEC cultures can help determine the role of the autoimmune regulator (Aire) gene, the mechanisms of Aire mutations were identified using Aire mutant mice. Nevertheless, long-term cultures of mTECs from mice are difficult to establish. To overcome this, we used a CRISPR-Cas9 system to edit Aire in a murine mTEC line in vitro and mouse embryos. Two ribonucleoprotein (RNP) complexes were designed to separately target Aire exons 6 and 8. NHEJ-derived indels or HDR-derived mutations were obtained. Recurrent NHEJ-derived mutations were observed among editions, one in exon 6 (del 3554G) and the other in exon 8 (del 5676_5677TG), i.e., the exon 6 mutation was kept in an mTEC clone edited in vitro and in vivo in a mouse, and the exon 8 mutation was kept in mTECs in vitro. None of the mutations obtained with the nickase system were recurrent, indicating the participation of the RNP complex.

molecular biology↗

bioRxiv2019

"mir152 hypomethylation, potentially triggered by embryonic hypoxia, as a mechanism for non-syndromic cleft lip/palate"

Non-syndromic cleft lip/palate (NSCLP), the most common human craniofacial malformations, is a complex disorder given its genetic heterogeneity and multifactorial component revealed by genetic, epidemiological and epigenetic findings. Association of epigenetic variations with NSCLP has been made, however still of little functional investigation. Here we combined a reanalysis of NSCLP methylome data with genetic analysis and used both in vitro and in vivo approaches to dissect the functional effects of epigenetic changes. We found a frequent differentially methylated region in mir152, hypomethylated in NSCLP cohorts (21-26%), leading to mir152 overexpression. In vivo analysis using zebrafish embryos revealed that mir152 upregulation leads to craniofacial impairment analogue to palatal defects. Also, we demonstrated that zebrafish embryonic hypoxia leads to mir152 upregulation combined with mir152 hypomethylation and also analogue palatal alterations. We therefore suggest mir152 hypomethylation, potentially induced by hypoxia in early development, as a novel and frequent predisposing factor to NSCLP.

developmental biology↗