Biology subjects

Boskovic, A.

Publications and source records attributed to Boskovic, A..

6 recordsLinked to original sources

bioRxiv2026

Cross-generational characterization of paternal Low Protein Diet effects in mice

The impact of diet on the physiology of organisms and their progeny has been well documented across phyla. Using the established paternal Low Protein (LP) diet paradigm in mice, here we assess the robustness of the diet-induced intergenerational responses upon variation of genetic background and dietary history of tested animals. Protein restriction in FVB/NCrl resulted in mild, but specific hepatic responses in exposed animals, as well as their F1 progeny, affecting fatty acid metabolism and cholesterol biosynthesis, respectively. These phenotypes were qualitatively conserved between FVB/NCrl and C56BL/6J mice, suggesting the existence of shared molecular mechanisms underlying metabolic reprogramming, modulated in magnitude by genetic background. Unexpectedly, we uncover cumulative intergenerational inheritance effects that get reshaped at every generation, and a sex-specific priming of cholesterol metabolism of LP-sired F1 offspring, evident upon dietary challenge. Together, our data, spanning multigenerational physiology, transcriptomics and lipidomics, indicate that the phenotypic consequences of paternal LP consumption depend on the duration and/or on the interaction of dietary exposure across generations, leading to distinct trajectories in hepatic energy metabolism.

molecular biology↗

bioRxiv2024

Embryonic Signatures of Intergenerational Inheritance across Paternal Environments and Genetic Backgrounds

The paternal preconception environment has been implicated as a modulator of phenotypic traits and disease risk in F1 offspring. However, the prevalence and mechanisms of such intergenerational epigenetic inheritance (IEI) in mammals remain poorly defined. Moreover, the interplay between paternal exposure, genetics, and age on emergent offspring features is unexplored. Here, we measure the quantitative impact of three paternal environments on early embryogenesis across genetic backgrounds. Using in vitro fertilisation (IVF) at scale, we capture batch-robust transcriptomic signatures of IEI with single-blastocyst resolution. Amongst these, paternal gut microbiota dysbiosis is linked with aberrant expression of lineage regulators in blastocysts, particularly affecting extra-embryonic tissues. Conversely, paternal low-protein high-sugar diet associates with subtle preimplantation developmental delay. We further identify gene expression variability as a paternally-induced F1 phenotype, and highlight confounding issues for IEI such as batch-effects and under-sampling. Finally, paternal genetic background and age exert a dominant influence over the inherited environmental signature. This study systematically characterises how paternal conditioning programmes subtle but detectable molecular responses in early embryos, and suggests guiding principles to dissect intergenerational phenomenology.

genomics↗

bioRxiv2024

Perturbing nuclear glycosylation in the mouse preimplantation embryo slows down embryonic growth

The only known form of intracellular protein glycosylation (O-GlcNAc) is reversible and has been mapped on thousands of cytoplasmic and nuclear proteins, including RNA polymerase II, transcription factors and chromatin modifiers. The O-GlcNAc modification is catalyzed by a single enzyme known as O-GlcNAc Transferase (OGT), that is required for mammalian early development. Remarkably, the regulatory function of protein O-GlcNAcylation in the embryo as well as the embryonic O-GlcNAc proteome remain unknown. Here, we devised a new method to enzymatically remove O-GlcNAc from preimplantation embryonic nuclei, where it accumulates coincidently with embryonic genome activation (EGA). Unexpectedly, the depletion of nuclear O-GlcNAc to undetectable levels has no impact on EGA, but dampens the transcriptional activation of the translational machinery, and triggers a spindle checkpoint response. These molecular alterations were phenotypically associated with a developmental delay starting from early cleavage stages and persisting after embryo implantation, establishing a novel link between nuclear glycosylation and embryonic growth.

developmental biology↗

bioRxiv2020

Deficient spermiogenesis in mice lacking Rlim

The X-linked gene Rlim plays major roles in female mouse development and reproduction, where it is crucial for the maintenance of imprinted X chromosome inactivation in extraembryonic tissues of embryos. However, while females carrying a systemic Rlim knockout (KO) die around implantation, male Rlim KO mice appear healthy and are fertile, raising questions as to the pressures driving Rlim gene selection during evolution. Here we report an important role for Rlim in testis where it is highly expressed in post-meiotic round spermatids as well as in Sertoli cells. Systemic deletion of the Rlim gene leads to lower numbers of mature sperm that contains excess cytoplasm, leading to decreased sperm motility and in vitro fertilization rates. Targeting the conditional Rlim cKO specifically to the spermatogenic cell lineage largely recapitulates this phenotype. These results reveal functions of Rlim in male reproduction specifically in round spermatids during spermiogenesis with likely evolutionary implications.

developmental biology↗

bioRxiv2018

Control of noncoding RNA production and histone levels by a 5’ tRNA fragment

Small RNAs derived from mature tRNAs, referred to as tRNA fragments or \"tRFs\", are an emerging class of regulatory RNAs with poorly understood functions in cellular regulation. We recently identified a role for one specific tRF - 5 tRF-Gly-GCC, or tRFGG - in repression of genes associated with the endogenous retroelement MERVL, but the mechanistic basis for this regulation was unknown. Here, we show that tRF-GG plays a role in production of a wide variety of noncoding RNAs normally synthesized in Cajal bodies. Among these noncoding RNAs, tRF-GG regulation of the U7 snRNA modulates heterochromatin-mediated transcriptional repression of MERVL elements by supporting an adequate supply of histone proteins. Importantly, the effects of inhibiting tRF-GG on histone mRNA levels, activity of a histone 3 UTR reporter, and ultimately on MERVL regulation could all be suppressed by the U7 RNA. We show that the related RNA-binding proteins hnRNPF and H bind directly to tRF-GG, and are required for Cajal body biogenesis. Together, our data reveal a conserved mechanism for 5 tRNA fragment control of noncoding RNA biogenesis and, consequently, in global chromatin organization.

molecular biology↗

bioRxiv2018

Profiling of pluripotency factors in individual stem cells and early embryos

Major cell fate decisions are governed by sequence-specific transcription factors (TFs) that act in small cell populations within developing embryos. To understand how TFs regulate cell fate it is important to identify their genomic binding sites in these populations. However, current methods cannot profile TFs genome-wide at or near the single cell level. Here we adapt the CUT&RUN method to profile chromatin proteins in low cell numbers, mapping TF-DNA interactions in single cells and individual pre-implantation embryos for the first time. Using this method, we demonstrate that the pluripotency TF NANOG is significantly more dependent on the SWI/SNF family ATPase BRG1 for association with its genomic targets in vivo than in cultured cells--a finding that could not have been made using traditional approaches. Ultra-low input CUT&RUN (uliCUT&RUN) enables interrogation of TF binding from low cell numbers, with broad applicability to rare cell populations of importance in development or disease.

genomics↗