Figure 2. C-type natriuretic peptide (CNP) supplementation recovers cytoplasmic maturation events of maternally aged mouse oocytes.

(A) Representative images of the spindle morphology and chromosome alignment at metaphase II in young, aged, and aged + CNP mice. Scale bar, 10 μm. (B) The rate of aberrant spindles at metaphase II was recorded in young, aged, and aged + CNP mice. (C) Representative images of the Golgi apparatus distribution at metaphase II in young, aged, and aged + CNP mice. Scale bar, 10 μm. (D) The rate of aberrant Golgi apparatus distribution was recorded in young, aged, and aged + CNP mice. (E) Representative images of the endoplasmic reticulum distribution at metaphase II in young, aged, and aged + CNP mice. Scale bar, 10 μm. (F) The rate of aberrant endoplasmic reticulum distribution was recorded in young, aged, and aged + CNP mice. (G) Representative images of the cortical granules (CGs) distribution in young, aged, and aged + CNP mice. Scale bar, 10 μm. (H) The rate of mislocalized CGs was recorded in the young, aged, and aged + CNP mice. (I) The fluorescence intensity of CG signals was measured in the young, aged, and aged + CNP mice oocyte. (J) Representative images of mitochondrial distribution in the young, aged, and aged + CNP mice oocytes stained with MitoTracker Red. Scale bar, 10 μm. (K) The abnormal rate of mitochondrial distribution was recorded in the young, aged, and aged + CNP mice oocytes. (L) ATP levels were measured in the young, aged, and aged + CNP mice. (M) Mitochondrial membrane potential (ΔΨm) was detected by JC-1 staining in the young, aged, and aged + CNP mice oocytes. Scale bar, 10 μm. (N) The ratio of red to green fluorescence intensity was calculated in the young, aged, and aged + CNP mice oocytes.

Figure 2—figure supplement 1. Effects of C-type natriuretic peptide (CNP) on Golgi apparatus distribution in aged oocytes.

Representative images of Golgi apparatus distribution in the aged control and CNP treatment oocytes stained with Golgi-Tracker Red. Scale bar, 10 μm. (B) Abnormal distribution of Golgi apparatus in the aged control and CNP treatment oocytes. *Significant difference (p<0.05).

Figure 2—figure supplement 2. Effects of C-type natriuretic peptide (CNP) on endoplasmic reticulum distribution and function in aged oocytes.

(A) Representative images of endoplasmic reticulum (ER) distribution in the aged control and CNP treatment oocytes stained with ER-Tracker Red. Scale bar, 10 μm. (B) Abnormal distribution of ER in the aged control and CNP treatment oocytes. *Significant difference (p<0.05).

Figure 2—figure supplement 3. Effects of C-type natriuretic peptide (CNP) on the dynamics of cortical granules (CGs) in aged oocytes.

Representative images of CGs distribution in the aged control and CNP treatment oocytes stained with LCA-FITC and imaged by confocal microscope. Scale bar, 10 μm. (B) The rate of mislocalized CGs was recorded in the aged control and CNP treatment oocytes. *Significant difference (p<0.05). (C) The fluorescence intensity of CG signals was measured in the aged control and CNP treatment oocytes. ****Significant difference (p<0.0001).

Figure 2—figure supplement 4. Effects of C-type natriuretic peptide (CNP) on the mitochondrial distribution and function in aged oocytes.

(A) Representative images of mitochondrial distribution in aged control and CNP treatment oocytes stained with MitoTracker Red. Scale bar, 10 μm. (B) The abnormal rate of mitochondrial distribution was recorded in aged control and CNP treatment oocytes. **Significant difference (p<0.01). (C) ATP levels were measured in aged control and CNP treatment oocytes. *Significant difference (p<0.05). (D) Mitochondrial membrane potential (ΔΨm) was detected by JC-1 staining in control and CNP treatment oocytes. Scale bar, 20 μm. (E) The ratio of red to green fluorescence intensity was calculated in aged control and CNP treatment oocytes. ****Significant difference (p<0.0001).