TY - JOUR T1 - The story of rRNA expansion segments: Finding functionality amidst diversity. JF - Wiley Interdiscip Rev RNA Y1 - 2022 A1 - Hariharan, Nivedita A1 - Ghosh, Sumana A1 - Palakodeti, Dasaradhi AB -

Expansion segments (ESs) are multinucleotide insertions present across phyla at specific conserved positions in eukaryotic rRNAs. ESs are generally absent in bacterial rRNAs with some exceptions, while the archaeal rRNAs have microexpansions at regions that coincide with those of eukaryotic ESs. Although there is an increasing prominence of ribosomes, especially the ribosomal proteins, in fine-tuning gene expression through translation regulation, the role of rRNA ESs is relatively underexplored. While rRNAs have been established as the major catalytic hub in ribosome function, the presence of ESs widens their scope as a species-specific regulatory hub of protein synthesis. In this comprehensive review, we have elaborately discussed the current understanding of the functional aspects of rRNA ESs of cytoplasmic eukaryotic ribosomes and discuss their past, present, and future. This article is categorized under: RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems Translation > Ribosome Structure/Function Translation > Regulation.

ER - TY - JOUR T1 - Temporal specificity and heterogeneity of Drosophila immune cells. JF - EMBO J Y1 - 2020 A1 - Cattenoz, Pierre B A1 - Sakr, Rosy A1 - Pavlidaki, Alexia A1 - Delaporte, Claude A1 - Riba, Andrea A1 - Molina, Nacho A1 - Hariharan, Nivedita A1 - Mukherjee, Tina A1 - Giangrande, Angela AB -

Immune cells provide defense against non-self and have recently been shown to also play key roles in diverse processes such as development, metabolism, and tumor progression. The heterogeneity of Drosophila immune cells (hemocytes) remains an open question. Using bulk RNA sequencing, we find that the hemocytes display distinct features in the embryo, a closed and rapidly developing system, compared to the larva, which is exposed to environmental and metabolic challenges. Through single-cell RNA sequencing, we identify fourteen hemocyte clusters present in unchallenged larvae and associated with distinct processes, e.g., proliferation, phagocytosis, metabolic homeostasis, and humoral response. Finally, we characterize the changes occurring in the hemocyte clusters upon wasp infestation, which triggers the differentiation of a novel hemocyte type, the lamellocyte. This first molecular atlas of hemocytes provides insights and paves the way to study the biology of the Drosophila immune cells in physiological and pathological conditions.

ER - TY - JOUR T1 - Temporal specificity and heterogeneity of the fly immune cells’ transcriptional landscape JF - The EMBO Journal (in press) Y1 - 2020 A1 - Cattenoz, Pierre B. A1 - Sakr, Rosy A1 - Pavlidaki, Alexia A1 - Delaporte, Claude A1 - Riba, Andrea A1 - Molina, Nacho A1 - Hariharan, Nivedita A1 - Mukherjee, Tina A1 - Giangrande, Angela AB -

Immune cells provide defense against the non-self, however recent data suggest roles well beyond innate immunity, in processes as diverse as development, metabolism and tumor progression. Nevertheless, the heterogeneity of these cells remains an open question. Using bulk RNA sequencing we find that the Drosophila immune cells (hemocytes) display distinct features in the embryo, a closed and rapidly developing system, compared to the larva, which is exposed to environmental and metabolic challenges. Through single cell RNA sequencing we identify fourteen hemocyte clusters present in unchallenged larvae and associated with distinct cellular processes e.g. proliferation, phagocytosis, metabolic homeostasis and humoral response. Finally, we characterize the changes occurring in the hemocyte clusters upon wasp infestation that triggers the differentiation of a novel cell type, the lamellocyte. This first molecular atlas provides precious insights and paves the way to study the biology of the Drosophila immune cells in physiological and pathological conditions.

ER -