Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.08.14.744765

In vitro fertilisation and vitrification disrupt embryo mitochondrial function and redox balance that persists into adulthood in mice

Chen, Y.·Chukwuefe, H. N.·Zi, M.·Galli, G. J.
View original source ↗Export metadata ↓

Abstract

Background and aimsAssisted reproductive technologies (ART), including in vitro fertilisation (IVF), account for over 10 million births worldwide. ART-conceived young offspring show altered cardiovascular phenotypes, including cardiac remodelling and raised blood pressure, but the mechanisms remain unclear. Mitochondrial disturbance during preimplantation development may link early ART exposure to later cardiac dysfunction. However, to our knowledge, no one has assessed mitochondrial function in adult offspring from IVF pregnancies. In this study, investigated the effects of IVF and embryo vitrification on blastocyst mitochondrial redox balance and metabolism, and determined whether these effects persisted into the adult heart. Methods and ResultsIGS-CD1 mouse blastocysts from naturally mated donors or IVF were transferred fresh or after vitrification-warming. IVF reduced blastocyst total, trophectoderm and inner cell mass cell number, while vitrification lowered the inner cell mass proportion and increased apoptosis. Both exposures depolarised mitochondrial membrane potential and depleted glutathione; reactive oxygen species rose with an interaction, being highest in vitrified IVF embryos. IVF reduced live birth rate and litter size. In the adult offspring, high-resolution respirometry of isolated mitochondria from left ventricle revealed reduced oxidative phosphorylation capacity with an increased H2O2 production, altered OXPHOS subunit abundance and reduced complex I, III and IV activities. ConclusionsIVF and vitrification impose distinct disturbance on preimplantation embryo redox states and bioenergetics, and this early disturbance is followed into adulthood with a reduced mitochondrial aerobic capacity and increased basal ROS production. These results have important implications for IVF practices and suggest that mitochondria may be permanently programmed by this procedure. Graphical Summary O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/744765v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1cd1bd7org.highwire.dtl.DTLVardef@ded6b8org.highwire.dtl.DTLVardef@1e2ddf7org.highwire.dtl.DTLVardef@15abc84_HPS_FORMAT_FIGEXP M_FIG C_FIG IVF and vitrification impose distinct and partly independent effects on the preimplantation embryo that persist into the adult offspring heart. At the blastocyst stage, IVF reduced cell number and vitrification altered lineage allocation, while both exposures lowered mitochondrial membrane potential ({Delta}{Psi}m) and glutathione (GSH) and raised reactive oxygen species (ROS); vitrification additionally increased apoptosis. After embryo transfer, IVF reduced live birth rate and litter size, whereas vitrification altered postnatal growth trajectory. In adult offspring, ventricular mitochondria, vitrification reduced OXPHOS capacity and IVF reduced LEAK respiration, while both exposures increased H2O2/ O2 flux, reduced respiratory chain enzyme activities and altered OXPHOS subunit abundance.

Explore related subjects

developmental biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Chen, Y., Chukwuefe, H. N., Zi, M., Galli, G. J.. 2026-08-18. In vitro fertilisation and vitrification disrupt embryo mitochondrial function and redox balance that persists into adulthood in mice. https://doi.org/10.64898/2026.08.14.744765

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

A bicistronic Aldh1a3-P2A-TagBFP knock-in reporter mouse line for studying genitourinary tract development

Aldehyde dehydrogenase 1a3 (Aldh1a3) is an enzyme involved in retinoic acid synthesis with dynamic expression patterns during development, including in the urogenital system. Here, we generated a bicistronic Aldh1a3-P2A-TagBFP knock-in mouse using CRISPR/Cas9 genome editing, inserting TagBFP immediately upstream of the endogenous Aldh1a3 stop codon. Correct targeting was confirmed by Oxford Nanopore long-read sequencing, and heterozygous and homozygous mice were viable and fertile without overt morphological abnormalities. TagBFP fluorescence faithfully overlapped with endogenous Aldh1a3 immunoreactivity and reproduced established expression domains in the developing craniofacial region, intestine, kidney, and broader urogenital system. Extensive characterization of the urogenital system revealed dynamic, spatially restricted BFP reporter activity in Aldh1a3-expressing domains across several key structures, including the ureteric bud and collecting duct lineage, seminal vesicles, caput epididymis, and developing uterine horns. The Aldh1a3-P2A-TagBFP mouse provides a fluorescent resource for visualizing Aldh1a3 expression across development and in adult tissues, including for the characterization of Aldh1a3-expressing domains in the urogenital system. The relatively low fluorescence intensity of TagBFP should be considered when assessing low-level reporter expression.

developmental biology↗
bioRxiv2026

Translation of a small upstream open reading frame functions as a rheostat for the regulation of lin-41 by the Let-7 microRNA in Caenorhabditis elegans

MicroRNAs have been likened to the "dark matter" of eukaryotic genomes, reflecting their pervasive regulatory influence. MicroRNAs were first identified through genetic studies of developmental timing in the nematode Caenorhabditis elegans. Let-7 was the first microRNA recognized to be broadly conserved. The principal target of Let-7 in the developmental timing pathway is the TRIM-NHL RNA-binding protein LIN-41. During the L4 larval stage, Let-7 represses lin-41 translation by binding to two Let-7 complementary sites in the lin-41 3'UTR. Despite the importance of microRNA-based translational regulation, the underlying molecular mechanisms are incompletely understood. Through genetic analysis, we discovered an unrecognized feature of the mechanism by which Let-7 controls lin-41 translation. This mechanism requires a 5'-regulatory exon containing a seven-amino acid upstream open reading frame (uORF) and conserved sequence elements. Genome editing indicates that the specific uORF amino acid sequence itself is not important. Our data suggest that uORF translation and 5'UTR structure limit initiation at the downstream lin-41 start codon, enabling tight control by Let-7. Without this mechanism, the Let-7 microRNA is unable to properly regulate lin-41 to enable proper development.

developmental biology↗
bioRxiv2026

Ductal myofibroblasts reactivate contractile program to stabilize alveolar architecture during lung regeneration

The alveolar sac architecture is essential for efficient gas exchange and must be precisely maintained throughout life; however, how this delicate structure is preserved during adult regeneration remains poorly understood. Using a mouse pneumonectomy model, we found that Lgr6+ Hhip+ ductal myofibroblasts, a poorly characterized mesenchymal population, are indispensable for maintaining alveolar integrity during lung regrowth. Comprehensive characterization using single-cell transcriptomics, mouse genetics, and pharmacological assays demonstrated that these ductal myofibroblasts secrete myogenic factors, most notably CCN4, to reactivate a myogenic program that converts them into contractile PA-DMFs, thereby preserving alveolar architecture. Lineage-tracing further revealed that these ductal myofibroblasts originate from embryonic MCAM- SMA+ distal progenitors via subepithelial TGF-{beta} signaling, serving as a lifelong guardian of alveolar structural integrity. Notably, cross-species analysis identified an analogous population of LGR6+ fibromyocytes in human respiratory bronchioles. Together, these findings indicate ductal myofibroblasts as a developmentally programmed cell population that reactivate a contractile program to structurally support the regeneration of adult lungs.

developmental biology↗