THE giant panda is a kind of endangered rare animal,the number of which is less than onethousand at present,specially distributed in China.According to the protective scheme issuedby The International Association of N...THE giant panda is a kind of endangered rare animal,the number of which is less than onethousand at present,specially distributed in China.According to the protective scheme issuedby The International Association of Nature Protection,stock population in captivity must展开更多
Breeding coloration of females often signals aspects of their reproductive status,suggesting a link between color and sex steroid hormones.In this study,we examined the relationships between 2 sex steroid hormones(pro...Breeding coloration of females often signals aspects of their reproductive status,suggesting a link between color and sex steroid hormones.In this study,we examined the relationships between 2 sex steroid hormones(progesterone and p-estradiol)and reproductive coloration in female spinyfooted lizards Acanthodactylus erythrurus.We first explored natural variation in female plasma hormone levels and coloration during their reproductive cycle,p-estradiol was negatively related to brightness and positively related to red saturation,whereas progesterone was not significantly related to coloration.After identifying key relationships,plasma hormone concentrations were manipulated by creating 3 experimental female groups(p-estradiol-treated,progesterone-treated,and control),and the effects on coloration were monitored,p-estradiol-treated females,in which there was a rise in both p-estradiol and progesterone levels,lost their red coloration earlier than females in the other 2 experimental groups,whereas progesterone treatment had no significant effect on female coloration.Our results suggest that high levels of either p-estradiol alone or(3-estradiol together with progesterone trigger the loss of red coloration in female spiny-footed lizards,and that progesterone alone does not affect coloration.We hypothesize that changes in female breeding color might be regulated by(3-estradiol in species in which conspicuous coloration is displayed before ovulation,and by progesterone in species in which this color is displayed during gravidity.展开更多
文摘THE giant panda is a kind of endangered rare animal,the number of which is less than onethousand at present,specially distributed in China.According to the protective scheme issuedby The International Association of Nature Protection,stock population in captivity must
文摘Breeding coloration of females often signals aspects of their reproductive status,suggesting a link between color and sex steroid hormones.In this study,we examined the relationships between 2 sex steroid hormones(progesterone and p-estradiol)and reproductive coloration in female spinyfooted lizards Acanthodactylus erythrurus.We first explored natural variation in female plasma hormone levels and coloration during their reproductive cycle,p-estradiol was negatively related to brightness and positively related to red saturation,whereas progesterone was not significantly related to coloration.After identifying key relationships,plasma hormone concentrations were manipulated by creating 3 experimental female groups(p-estradiol-treated,progesterone-treated,and control),and the effects on coloration were monitored,p-estradiol-treated females,in which there was a rise in both p-estradiol and progesterone levels,lost their red coloration earlier than females in the other 2 experimental groups,whereas progesterone treatment had no significant effect on female coloration.Our results suggest that high levels of either p-estradiol alone or(3-estradiol together with progesterone trigger the loss of red coloration in female spiny-footed lizards,and that progesterone alone does not affect coloration.We hypothesize that changes in female breeding color might be regulated by(3-estradiol in species in which conspicuous coloration is displayed before ovulation,and by progesterone in species in which this color is displayed during gravidity.
