Search results for "Lineage"

ceRNA Network Regulation of TGF-β, WNT, FOXO, Hedgehog Pathways in the Pharynx of Ciona robusta

2021

The transforming growth factor-β (TGF-β) family of cytokines performs a multifunctional signaling, which is integrated and coordinated in a signaling network that involves other pathways, such as Wintless, Forkhead box-O (FOXO) and Hedgehog and regulates pivotal functions related to cell fate in all tissues. In the hematopoietic system, TGF-β signaling controls a wide spectrum of biological processes, from immune system homeostasis to the quiescence and self-renewal of hematopoietic stem cells (HSCs). Recently an important role in post-transcription regulation has been attributed to two type of ncRNAs: microRNAs and pseudogenes. Ciona robusta, due to its philogenetic position close to verte…

Temporal frames of 45S rDNA site-number variation in diploid plant lineages: lessons from the rock rose genus Cistus (Cistaceae)

2016

The perception that the turnover of 45S rDNA site number in plants is highly dynamic pervades the literature on rDNA evolution. However, most reported evidences come from the study of polyploid systems and from crop species subjected to intense agronomic selection. In sharp contrast with polyploids, the evolutionary patterns of rDNA loci number in predominantly diploid lineages have received less attention. Most studies on rDNA loci changes lack explicit temporal frames, and hence their dynamics could not be assessed. Here, we assess the temporal patterns of rDNA site evolution in Cistus, an entirely diploid lineage. We assessed the number and chromosomal position of 45S rDNA loci in Cistus…

Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses

2016

Lau et al. show that the FLT3-ITD mutation directly affects dendritic cell development in preleukemic mice, indirectly modulating T cell homeostasis and supporting the expansion of regulatory T cells.

Stage-specific control of oligodendrocyte survival and morphogenesis by TDP-43

2021

AbstractGeneration of oligodendrocytes in the adult brain enables both adaptive changes in neural circuits and regeneration of myelin sheaths destroyed by injury, disease, and normal aging. This transformation of oligodendrocyte precursor cells (OPCs) into myelinating oligodendrocytes requires processing of distinct mRNAs at different stages of cell maturation. Although mislocalization and aggregation of the RNA binding protein TDP-43 occur in both neurons and glia in neurodegenerative diseases, the consequences of TDP-43 loss within different stages of the oligodendrocyte lineage are not well understood. By performing stage-specific genetic inactivation of Tardbp in vivo, we show that olig…

Ancient bacterial genomes reveal a formerly unknown diversity ofTreponema pallidumstrains in early modern Europe

2020

SummarySexually transmitted (venereal) syphilis marked European history with a devastating epidemic at the end of the 15thcentury, and is currently re-emerging globally. Together with non-venereal treponemal diseases, like bejel and yaws, found in subtropical and tropical regions, it poses a prevailing health threat worldwide. The origins and spread of treponemal diseases remain unresolved, including syphilis’ potential introduction into Europe from the Americas. Here, we present the first genetic data from archaeological human remains reflecting a previously unknown diversity ofTreponema pallidumin historical Europe. Our study demonstrates that a variety of strains related to both venereal…

Estimating the dwarfing rate of an extinct Sicilian elephant.

2021

Summary Evolution on islands, together with the often extreme phenotypic changes associated with it, has attracted much interest from evolutionary biologists. However, measuring the rate of change of phenotypic traits of extinct animals can be challenging, in part due to the incompleteness of the fossil record. Here, we use combined molecular and fossil evidence to define the minimum and maximum rate of dwarfing in an extinct Mediterranean dwarf elephant from Puntali Cave (Sicily). 1 Despite the challenges associated with recovering ancient DNA from warm climates, 2 we successfully retrieved a mitogenome from a sample with an estimated age between 175,500 and 50,000 years. Our results sugge…

Editorial overview: Fluidity of cell fates – from reprogramming to repair

2021

Evolutionary and phenotypic characterization of spike mutations in a new SARS-CoV-2 Lineage reveals two Variants of Interest

2021

Molecular epidemiology of SARS-CoV-2 aims to monitor the appearance of new variants with the potential to change the virulence or transmissibility of the virus. During the first year of SARS-CoV-2 evolution, numerous variants with possible public health impact have emerged. We have detected two mutations in the Spike protein at amino acid positions 1163 and 1167 that have appeared independently multiple times in different genetic backgrounds, indicating they may increase viral fitness. Interestingly, the majority of these sequences appear in transmission clusters, with the genotype encoding mutations at both positions increasing in frequency more than single-site mutants. This genetic outco…

A conspectus of Tephroseris (Asteraceae: Senecioneae) in Europe outside Russia and notes on the decline of the genus

2021

Tephroseris is generally considered a difficult genus. Based on the examination of extensive herbarium material and considering the existing literature, we recognize seven species in Europe outside Russia. These are T. palustris, T. integrifolia with subsp. integrifolia, subsp. aurantiaca, subsp. capitata, subsp. maritima, subsp. serpentini and subsp. “tundricola”, T. balbisiana, T. crispa, T. helenitis, T. longifolia and T. papposa. Phylogenetic analysis of ITS and ETS sequences showed that these species fall into three lineages. These are: (1) T. palustris, clearly related to Arctic species of the genus; (2) T. integrifolia; and (3) the remaining species. Molecular dating of the T. integr…

A broader model for C 4 photosynthesis evolution in plants inferred from the goosefoot family (Chenopodiaceae s.s.)

2012

C 4 photosynthesis is a fascinating example of parallel evolution of a complex trait involving multiple genetic, biochemical and anatomical changes. It is seen as an adaptation to deleteriously high levels of photorespiration. The current scenario for C 4 evolution inferred from grasses is that it originated subsequent to the Oligocene decline in CO 2 levels, is promoted in open habitats, acts as a pre-adaptation to drought resistance, and, once gained, is not subsequently lost. We test the generality of these hypotheses using a dated phylogeny of Amaranthaceae s.l. (including Chenopodiaceae), which includes the largest number of C 4 lineages in eudicots. The oldest chenopod C 4 lineage da…