赤腹松鼠血清性激素水平的季节差异

正季节性繁殖是动物适应环境的具体表现,也是动物维持其种群发展的重要策略。生殖激素和动物的繁殖活动关系密切,协调实现繁殖后代的机能(赖平等,2012),如配子的发生、成熟与排出及受精、妊娠、分娩与泌乳等性行为活动。例如雄性甘肃鼢鼠(Myospalax cansus)血清中睾酮(程志兴,2009)和黄山短尾猴(Macaca thibetana)血清中孕酮含量(夏东坡,2007)在交配期间显著升高,

Seasonal changes in serum reproductive steroids levels of red-bellied squirrels (Callosciurus erythraeus)

We examined variation of some hormones reflecting reproductive function in the blood plasma of red-bellied squirrels (Callosciurus erythraeus). 70 males and 74 females were captured from February to December 2015 from Yingjing County, Sichuan Province. We measured the levels of reproductive hormones (testosterone: T, estradiol: E₂, follicle-stimulating hormone: FSH, luteinizing hormone: LH, gonadotropin-releasing hormone: GnRH, progesterone: P₄) by ELISA, and analyzed the data from the different sexes and months. In addition, impacts of reproductive status were also analyzed. These indices were analyzed by two-way ANOVA or ANCOVA. If some indices showed significant sex differences, monthly variations of those indices for any gender were further examined by one-way ANOVA or ANCOVA. The results were as follows: （1）There were sex differences in the levels of serum reproductive hormones in female and male squirrels that changing with reproductive status (except GnRH), and were lowest in October. （2）The serum concentrations of FSH, LH, T, E₂ and P₄ in males peaked in February or March and July or August, shortly before mating. Concentrations of FSH, LH and E₂ in females and GnRH of both sexes peaked in February and July during the mating period, whereas T concentrations in females were low throughout the year, and serum P₄ was highest in May. （3）Compared with non-reproductive squirrels, the concentrations of all serum reproductive hormones were significantly higher in pregnancy, mating and lactating female squirrels, or mating males. These results indicate that the levels of serum reproductive hormones in female and male squirrels can vary with the seasons and the reproductive status, which is of great significance to understanding the reproductive characteristics of the red-bellied squirrels and control their damage to plantations.