Table 3. Fertility parameters in Six6Gnrh-cre mice.
The total number of GnRH neurons in the brain was counted using IHC for GnRH at embryonic day 13.5 (E13.5), E17.5 and in adult mice. Pubertal onset was evaluated by vaginal opening (VO) in females and preputial separation (PPS) in males. Gonadal weights were assessed in 12–20-week-old males and females. Circulating LH and FSH levels were measured in male and diestrus females. Fold change in circulating LH was evaluated in males after GnRH and kisspeptin ip injections. Statistical analysis by Student’s t-test. * p < 0.05; ** p < 0.01, *** p < 0.001.
| Six6flox/flox | Six6Gnrh-cre | P | |
|---|---|---|---|
| GnRH neurons (E13.5) | 1234 ± 32 n=3 | 375 ± 38, n=4 | 0.0001 (***) |
| GnRH neurons (E17.5) | 809 ± 44, n=4 | 85 ± 10, n=3 | 0.0001 (***) |
| GnRH neurons (adult) | 487.8 ± 47, n=6 | 340.5 ± 16, n=6 | 0.0001 (***) |
| Age at VO | 29.45 ± 0.34, n=11 | 43.40 ± 2.06, n=5 | 0.0001 (***) |
| Age at PPS | 30.18 ± 0.26, n=11 | 47.40 ± 1.28, n=5 | 0.0001 (***) |
| Ovary weight (g) | 0.014 ± 0.001, n=3 | 0.009 ± 0.001, n=3 | 0.0445 (*) |
| Uterus weight (g) | 0.090 ± 0.015, n=3 | 0.076 ± 0.009, n=3 | 0.454 |
| Testis weight (g) | 0.061 ± 0.004, n=3 | 0.014 ± 0.003, n=3 | 0.0007 (***) |
| FSH (ng/ml) male | 14.01 ± 1.23, n=7 | 4.33 ± 1.63, n=5 | 0.0007 (***) |
| LH (ng/ml) male | 0.15 ± 0.04, n=6 | 0.08 ± 0.04 n=5 | 0.2716 |
| FSH (ng/ml) female | 2.33 ± 1.18, n=4 | 0.87 ± 0.21, n=5 | 0.214 |
| LH (ng/ml) female | 0.04 ± 0.01, n=5 | 0.28 ± 0.11, n=4 | 0.0472 (*) |
| Fold change of LH in response to GnRH (male) | 4.34 ± 1.86, n=4 | 43.94 ± 20.94, n=5 | 0.1401 |
| Fold change of LH in response to kisspeptin (male) | 1.86 ± 0.17, n=4 | 3.70 ± 0.89, n=4 | 0.1154 |