oocyte

Overview

An oocyte is the female germ cell, or egg cell, produced in the ovary and capable of being fertilized by sperm to form a zygote. It is central to sexual reproduction and early embryonic development, and its biological quality strongly influences fertilization success, embryo viability, and reproductive lifespan. In biomedical research, oocytes are often studied as a model for female fertility, ovarian aging, mitochondrial function, oxidative stress, and the effects of metabolic or environmental insults on reproductive potential.

Oocytes are also important in experimental reproductive biology because they can be manipulated by assisted reproductive technologies, in vitro maturation, in vitro fertilization, embryo transfer, and gene-editing approaches such as CRISPR-Cas method and CRISPR-Cas12a. Recent studies have used oocytes to investigate how aging, diabetes, and oxidative stress affect developmental competence, and how interventions may preserve oocyte quality or enable precise genetic modification in embryos and germline cells.

Focus of Latest Publications

Recent publications on oocyte biology have focused on reproductive aging, metabolic stress, and experimental manipulation of germ cells. In a mouse study of ovarian aging, oocytes were examined alongside ovarian somatic cells across age groups, with reproductive function assessed by superovulation, in vitro fertilization, and embryo transfer. The work found that age-related p16 upregulation occurred prominently in cumulus, granulosa, and theca cells, but not in oocytes or blastocysts, suggesting that somatic cell senescence rather than direct p16 changes in oocytes correlated more closely with declining reproductive function and poorer post-implantation outcomes.

Another study addressed oocyte quality under diabetic conditions. In vitro matured oocytes from type 1 diabetic mice were supplemented with BGP-15 during maturation, which improved maturation rates and reduced oxidative stress, mitochondrial damage, and DNA damage. Transcriptome analysis linked the diabetic effect on oocytes mainly to dysregulated metabolism and mitochondrial-related pathways, and the authors reported that BGP-15 increased mitochondrial fatty acid β-oxidation, supporting a protective role for this compound in preserving oocyte competence under maternal diabetes-related stress.

Oocytes were also used as a target in a methodological study of genome editing in reptiles. Researchers developed a surgical approach in brown anole lizards that allowed access to unfertilized oocytes still maturing within the ovary, followed by microinjection of CRISPR-Cas9 ribonucleoprotein complexes. This enabled targeted mutagenesis despite the practical barriers posed by internal fertilization and difficulty identifying ovulation, demonstrating a route for routine gene-edited lizard production.

In addition, recent review literature has highlighted oocytes as a key experimental system in reproductive genome editing. A broader discussion of CRISPR/Cas9 in reproductive failure described the use of oocytes and zygotes for disease modeling and proof-of-concept editing studies, while emphasizing technical barriers such as off-target effects, embryo mosaicism, and low homology-directed repair efficiency. Together, these publications show oocytes being studied both as a biologically vulnerable cell type in aging and disease and as an important platform for reproductive biotechnology.

Key Publications

NEWJul Eliminating PD-L1 on Dendritic Cell Extracellular Vesicles for Immunotherapy Potentiates Immune-Mediated Tumour Rejection in Mice. (Journal of extracellular vesicles, 2026, PMID 42377985): "We generated and characterized ovalbumin (OVA)-loaded BMDC EVs from wild-type (WT) and PD-L1-/- C57BL/6 mice."
Jun TLR7 ligand-cyclodextrin conjugate is a promising adjuvant for intranasal influenza vaccine. (Vaccine, 2026, PMID 42202427): "enhanced both mucosal and systemic IgA and IgG responses against a model antigen, ovalbumin, recombinant hemagglutinin (rHA) from influenza virus strain A/Puerto Rico/8/1934 (H1N1), and a commercially available split influenza vaccine."
May From germline immortality to somatic rejuvenation: Unlocking the ovarian blueprint for longevity. (PLoS biology, 2026, PMID 42189781): "Despite residing within an aging organism and within a fast-aging ovarian tissue environment, oocytes give rise to embryos that begin life with restored developmental potential and youthful molecular organization."
May Age-related upregulation of p16 expression in mouse ovarian somatic cells correlated with reproductive function decline p16 expression and ovarian aging in mice. (PloS one, 2026, PMID 42101984): "Age-related upregulation of p16 in ovarian somatic cells, but not in oocytes, correlated with declining reproductive function, particularly affecting post-implantation development."
Jun On-site loading of powder-attached microneedles enables quantitative and reproducible intradermal vaccine delivery. (International journal of pharmaceutics, 2026, PMID 42035934): "Lyophilized OVA formulations stabilized with trehalose were prepared, milled, and size-controlled to obtain powders suitable for reproducible attachment."
May BGP-15 Mitigates Oxidative Stress and Mitochondrial Dysfunction in In Vitro Matured Oocytes From Type 1 Diabetic Mice. (FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2026, PMID 41961060): "BGP-15 supplementation can protect oocytes from maternal diabetes-related damage and provide a potential strategy to improve reproductive outcomes of women with diabetes."
Jun Investigating the stability and mechanism of a walnut protein isolate-ovalbumin dual-protein emulsion system: Insights from interfacial effects. (Food chemistry, 2026, PMID 41935481): "Ovalbumin (OVA)-stabilized emulsions often suffer from coalescence-prone nature due to the protein's rigid structure and insufficient surface hydrophobicity."
Mar Two dimensional layered double hydroxides augment antigen loading and release. (Biomaterials advances, 2026, PMID 41844084): "The LDHs were loaded with ovalbumin (OVA), and their performance was compared to that of the commercial adjuvant alum."
Apr CRISPR/Cas9 and reproductive failure: applications, ethical challenges, and future perspectives in human germline genome editing. (Clinica chimica acta; international journal of clinical chemistry, 2026, PMID 41620000): "This review critically examines current applications of CRISPR/Cas9 in reproductive biology, including disease modeling in animal systems, editing of spermatogonial stem cells (SSCs), manipulation of oocytes and zygotes, and proof-of-concept studies in human embryos."
Apr A Surgical Method for Oocyte Injection and CRISPR-Cas9 Mutagenesis in Anolis Lizards. (Cold Spring Harbor protocols, 2026, PMID 40744727): "microinject unfertilized oocytes with CRISPR-Cas9 ribonucleoprotein complexes to generate targeted mutations"