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oocyte

Real pictures of the oocyte delivered by gather.site, each with its paper.

14 pictures and 10 papers.

Galleries within: GV oocyte (1), MII oocyte (2)

Gallery

Representative bright-field (A-D) and birefringence (A1-D1) images of metaphase II spindle-positive oocytes captured using the Oosight Imaging System. Oocytes were qualitatively classified on the basis of birefringence morphology and signal intensity in both the spindle and zona pellucida (ZP). (human; Figure 1, panels A-D (bright-field) and A1-D1 (birefringence), four quality groups of human MII oocytes.)

Lee, Chen, Lo et al 2026, Frontiers in Endocrinology · CC BY 4.0

Cytoplasmic reorganisation of oocytes treated or not with metaphase II-follicular fluid extracellular vesicles (MII-ffEVs) during in vitro maturation. TEM images of oocytes. Scale bars (A-C) 20 µm, (D) 10 µm and (E-H) 5 µm. M-SER, mitochondria smooth endoplasmic reticulum (highlighted by white dotted line); MV, mitochondria vesicle; pvs, perivitelline space; mi, microvilli; ZP, zona pellucida. (human; Figure 5, panels A-C (whole-oocyte TEM at 20 µm scale; rows 0-707 of figure).)

Makieva, Saenz-de-Juano, Almiñana et al 2026, Human Reproduction Open · CC BY 4.0

Fluorescence images of human IVM-MII oocytes by laser confocal microscopy. Scale bar, 20 um. (A) Effect of NADH on CDK2 in IVM-MII oocytes. (C) Effect of NADH on GAS6 in IVM-MII oocytes. (E) Effect of NADH on C14orf36 in IVM-MII oocytes. (G) Effect of NADH on DCM1 in IVM-MII oocytes. (I) Effect of NADH on FIGN in IVM-MII oocytes. (K) Effect of NADH on FAM9B in IVM-MII oocytes. Each panel shows immunofluorescence channel, brightfield, and merged overlay for control and NADH-treated oocytes. Adapted: micrograph panels A, C, E, G, I and K rearranged side by side; bar chart panels removed. (human (IVM-MII oocytes); Figure 7, panels A, C, E, G, I, K (confocal IF micrographs only; bar chart panels B, D, F, H, J, L excluded; left group cols 5-257 and right group cols 420-664 of full figure, stitched).)

Zhang, Yang, Yang et al 2025, Frontiers in Endocrinology · CC BY 4.0

beta-tubulin isotype composition differentially affects meiotic spindle morphology. (A) Representative IF images of metaphase I-arrested spindles illustrating length differences for the indicated genotypes; scale bar = 2.0 um. (The tbb-2(E439K) strain is wild type at the tbb-1 locus). (B) Quantification of spindle length measurements. (C) Quantification of ASPM-1 pole-associated signal. (D) Quantification of pole widths, with schematic depicting how pole widths were measured. For Fig. 5, B-D, n = number of spindles analyzed, error bars indicate SD. Data were analyzed using two-tailed Mann-Whitney test; ns, not significant; *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. IF, immunofluorescence. (Figure 5..)

Nsamba, Villeneuve, Arribere et al 2026, The Journal of Cell Biology · CC BY 4.0

DNA damage causes metaphase arrest of the oocytes from COCs but not DOs. (A) Schematic of meiotic maturation in DOs and COCs treated with 10 ug/ml etoposide for 2 h at meiosis onset. Both groups were cultured in M16 medium with etoposide. After 2 h, cumulus cells in COCs group were removed and etoposide were washed out, followed by SiR-tubulin loading and 12 h time-lapse confocal imaging. Time is indicated as hh:mm post-GV release. (B) Representative gamma-H2AX and DNA labelling in DO and COC oocytes. Scale bars: 10 um. Oocytes were cultured in M16 medium with 10 ug/ml etoposide for 2 h, then fixed and stained with gamma-H2AX antibody and Hoechst. Dashed circles indicate the germinal vesicle location. n=4 independent experiments, with a total of 20 COC oocytes and 21 DO oocytes analysed. (C) gamma-H2AX foci per oocyte in COCs and DOs after 2 h etoposide treatment. Data are presented as box-and-whisker plots. n=4 independent experiments, with a total of 20 COC oocytes and 21 DO oocytes analysed. ns, not significant (two-tailed paired Student's t-test). (D) PBE rates of DO and COC oocytes after 2 h treatment with 10 ug/ml etoposide at maturation onset. Cumulus cells in COCs were removed after 2 h, then cultured in normal M16 for 12 h. Data are presented as box-and-whisker plots. n=4 independent experiments, with a total of 91 COC oocytes and 75 DO oocytes analysed. **P<0.01 (two-tailed paired Student's t-test). (Fig. 2.)

Zhou, McKinnon, Homer et al 2026, Journal of Cell Science · CC BY 4.0

MATR3 in growing oocyte regulates female reproduction in mice. (A) Immunofluorescence showing MATR3 levels in mouse oocytes. (B) Western blot results showing MATR3 expression in mouse oocytes. Total proteins from 200 oocytes were loaded in each lane. GAPDH served as a loading control. (C) Relative expression level of MATR3 to GAPDH. (D) Immunofluorescence showing MATR3 levels in human oocytes. n=11. (E) Representative image of follicles and oocytes from negative control (NC) and si-Matr3. (F) Immunohistochemistry results showing MATR3 expression in oocytes. (G) Cumulative number of pups from Ctrl (n=6) and cKO (n=3) female. (H) Percentage of antral follicles in E. n>=33 per group. (I) MII ratio of oocytes collected from E. n>=33 per group. Scale bars: 20 um in (A), (B), and (C), 40 um in (E) and (F). Data are represented as mean +/- SD. ***p<0.001, **p<0.01, *p<0.05, n.s., not significant. (Figure 1..)

Bao, Zuo, Wang et al 2026, eLife · CC BY 4.0

MIS12 is required for K-MT attachment in mouse oocytes. (A) Representative time-lapse images of control and Mis12-deleted oocytes expressing EGFP-MAP4 (microtubules, green) and H2B-mCherry (chromosomes, magenta), captured over 15 h with a frame interval of 10 min. Scale bar: 20 um. (B) MIS12 deletion disrupts chromosome alignment. Quantification of the maximal equatorial chromosome width in meiosis I shows significant widening in mutant oocytes (n = 23) compared with control oocytes (n = 30). Data are presented as mean +/- SEM. (C) Analysis of spindle bipolarity at metaphase I in control (n = 47) and Mis12-cKO (n = 63) mouse oocytes. (D) Analysis of spindle length at metaphase I in control (n = 39) and Mis12-cKO (n = 52) mouse oocytes. (E) Analysis of spindle width at metaphase I in control (n = 39) and Mis12-cKO (n = 52) mouse oocytes. (F) Analysis of the spindle length/width ratio at metaphase I in control (n = 39) and Mis12-cKO (n = 52) mouse oocytes. (G) Mis12 deletion accelerates meiosis I progression (control, n = 138; Mis12-cKO, n = 152). (mouse (control and Mis12-cKO mouse oocytes at meiosis I metaphase and progression); FIGURE 2.)

Li, Zhang, Wang et al 2026, Advanced Science · CC BY 4.0

MIS12 localizes to kinetochores in mouse oocytes. (A) Exogenous MIS12 robustly localizes to kinetochores during both meiosis I (n = 13) and meiosis II (n = 12). Oocytes were immunostained with anti-MYC and anti-ACA antibodies, DNA is counterstained with DAPI. Three independent experiments were conducted. (B) Endogenous MIS12 clearly localizes to kinetochores in meiosis I (n = 15) and meiosis II (n = 13), as validated using antibody from Abcam. Three independent experiments were conducted. (C) Endogenous MIS12 clearly localizes to kinetochores in meiosis I (n = 11) and meiosis II (n = 14), as validated using antibody from Bioss. Three independent experiments were conducted. (D) MIS12 signal is absent from kinetochores in Mis12-deleted oocytes. Oocytes after spreading were immunostained with anti-MIS12 (Abcam) and anti-ACA antibodies. DNA is counterstained with DAPI (Applies to A-D). Scale bars: 10 um (overview), 5 um (enlarged view) (Applies to A-D). (FIGURE 5.)

Li, Zhang, Wang et al 2026, Advanced Science · CC BY 4.0

Mos-/- eggs have defects in meiotic midbody formation. (A-D) Representative immunofluorescence images of wild-type (A) and Mos-/- eggs (B-D) showing localization of MKLP1 (magenta), tubulin (green), and DNA (white). Arrowheads indicate structure features of MKLP1. Wild-type and Mos-/- oocytes were fixed 9-11.5 h after prophase I release. Scale bars: 10 um. (E) Percentage of wild-type and Mos-/- eggs with normal or defective MKLP1 structure (n indicates the number of eggs imaged per condition; three or more independent experiments conducted per condition). (mouse (Mos+/+ wild-type and Mos-/- knockout mouse oocytes at telophase I); Fig. 6..)

Cairo, Haseeb, Boyce Joy et al 2026, Journal of Cell Science · CC BY 4.0

OTA induces GRP78-based ER stress in porcine oocytes. (A) Endoplasmic reticulum fluorescence staining showed that the fluorescence of treatment group was significantly decreased. Blue, endoplasmic reticulum. Bar = 50 um. (B) The results of statistical analysis showed that the intensity of endoplasmic reticulum in treatment group was significantly reduced. **p < 0.01. (C) GRP78 fluorescence staining results showed that the fluorescence of treatment group was obviously higher. Red, GRP78. Bar = 20 um. Statistical analysis results showed that the fluorescence of GRP78 in treatment group increased significantly. **p < 0.01. (D) Western Blot analysis of GRP78 protein expression in the control and treatment groups. *p < 0.05. (Figure 2.)

Hu, Yi, Ke et al 2026, Frontiers in Veterinary Science · CC BY 4.0

Defective spindle assembly caused by perturbed Ran-GTP pathway in TUBB8 D417N oocytes. (A) Representative immunofluorescence images of mouse oocytes at MTOC recruitment stages of meiosis. Green, microtubule (TUBB8-HA); red, active-Ran (Ran-GTP); blue, DNA (DAPI). The dashed line demarcates the oocyte. Right panels showing LUT colour grading according to intensity of the Ran-GTP. (B) Intensity profiles along the white lines are shown for oocytes at the MTOC recruitment stage. The shaded box represents the Ran-GTP gradient in WT oocyte. (C) Co-immunoprecipitation was performed to determine the decreased affinity between TUBB8 and Ran-GTP or TPX2 by the D417N missense variant. The immunoblots of protein precipitants were probed with Ran-GTP, TPX2, and streptavidin (TUBB8) antibodies. (D) Representative immunofluorescence images of mouse oocytes at the Pro-MI stage. Green, TPX2; red, microtubule (TUBB8-HA); blue, DNA (DAPI). Scale bars, 10 um. (E) Quantitative analysis of the mean intensity of TPX2 (*** p < .001 by Unpaired Student's t-test). Numbers indicate the individual oocytes quantified. (F) Representative immunofluorescence images of mouse oocytes at MI stage. Green, NuMA; blue, DNA (DAPI). Scale bars, 10 um. (G) Quantitative analysis of the percentage of oocytes with NuMA labelling at spindle poles (*** p < .001 by unpaired Student's t-test). (H) Co-immunoprecipitation was performed to determine the increased affinity between TUBB8 and RanGAP1 by the D417N missense variant. The immunoblots of protein precipitants were probed with RanGAP1 and streptavidin (TUBB8) antibodies. (I) Representative immunofluorescence images demonstrating spindle assembly in mouse metaphase I oocytes from WT and D417N. Green, microtubule (TUBB8-HA); red, RanGAP1; blue, DNA (DAPI). Scale bar, 10 um. (J) Quantitative analysis of the mean intensity of RanGAP1 (*** p < .001 by unpaired Student's t-test). Numbers indicate the individual oocytes. (K) Representative immunofluorescence images demonstrating spindle assembly in mouse metaphase I oocytes from WT and D417N females. Green, gamma-Tubulin; red, microtubule (TUBB8-HA); blue, DNA (DAPI). Scale bar, 10 um. The white arrow indicates the unfragmented MTOC. (L) Quantification of individual MTOC size (Unpaired Student's t-test, two-tailed, *** p < .001). Numbers indicate the individual oocytes quantified. (mouse (oocytes from wild-type and TUBB8-D417N conditional knockin mice at meiosis I stages); Figure 4.)

Luo, Chen, Li et al 2025, Clinical and Translational Medicine · CC BY 4.0

Papers

Bao Y, Zuo Z, Wang T, Lin L, Gao M, Qin S, et al. MATR3 is essential for oocyte growth and maturation quality through a dual molecular mechanism. Elife. 2026;15:RP110703. PMID: 42765984.
Hu LL, Yi Y, Ke XH, Ou MM, Nong LL, Qin LZ, et al. Exposure to ochratoxin a induces organelle damage during porcine oocyte maturation. Front Vet Sci. 2026;13:1912554. PMID: 42625677.
Nsamba ET, Villeneuve AM. Differential contributions of β-tubulin isotypes to acentrosomal oocyte meiosis in C. elegans. J Cell Biol. 2026;225:e202511199. PMID: 42573477.
Zhou C, McKinnon B, Homer H. Cumulus cells enhance oocyte genomic quality control by promoting DNA damage-induced meiotic arrest. J Cell Sci. 2026;139:jcs264929. PMID: 42339509.
Li J, Zhang CH, Wang Y, Li CY, Wen DR, Xia X, et al. MIS12 Is Required for Kinetochore-Microtubule Attachment in Oocyte Meiosis. Adv Sci (Weinh). 2026;13:e76171. PMID: 42338338.
Lee CI, Chen HH, Lo WC, Huang CC, Lee TH, Lin PY, et al. Spindle-to-oocyte light retardance ratio as a noninvasive biomarker for oocyte quality assessment: a prospective cohort study. Front Endocrinol (Lausanne). 2026;17:1803476. PMID: 42165024.
Makieva S, Saenz-de-Juano MD, Almiñana C, Bauersachs S, Bernal-Ulloa S, Xie M, et al. Treatment of human oocytes with extracellular vesicles from follicular fluid during rescue in vitro maturation enhances maturation rates and modulates oocyte proteome and ultrastructure. Hum Reprod Open. 2026;2026:hoag021. PMID: 41924634.
Cairo G, Haseeb MA, Boyce Joy Z, Schindler K, Lacefield S. MOS is a key regulator of meiotic midbody assembly and prevents abnormal divisions in mouse eggs and their polar bodies. J Cell Sci. 2026;139:jcs264411. PMID: 41664602.
Zhang Q, Yang H, Yang D, Lu H, Xiong M, Xie L, et al. NADH supplementation improves human oocyte maturation and developmental competence of resulting embryos in controlled ovarian hyperstimulation cycles: a pilot study implicating the CDK2/GAS6 signaling pathway. Front Endocrinol (Lausanne). 2025;16:1627679. PMID: 40969372.
Luo H, Chen J, Li C, Wu T, Yin S, Yang G, et al. Pathogenic variants of TUBB8 cause oocyte spindle defects by disrupting with EB1/CAKP5 interactions and potential treatment targeting microtubule acetylation through HDAC6 inhibition. Clin Transl Med. 2025;15:e70193. PMID: 39834092.