TY - JOUR
T1 - The annual ovarian cycle of Chrysemys picta
T2 - Correlated changes in plasma steroids and parameters of vitellogenesis
AU - Callard, Ian P.
AU - Lance, Valentine
AU - Salhanick, Adele R.
AU - Barad, David
N1 - Funding Information:
by NSF Grant No. BMS 75-18910 to
PY - 1978/7
Y1 - 1978/7
N2 - The annual ovarian cycle of the painted turtle, Chrysemys picta, is described and correlated with plasma changes in parameters of vitellogenesis (protein, calcium, and cholesterol) and steroids (progesterone, testosterone, and estradiol). Three major classes of ovarian follicles were identified at all times of the year, and ovarian growth was confined to two major phases. The first, in which vitellogenesis was most active, occurred in the fall, after a postovulatory period of follicular atresia. This was followed by a winter period of inactivity and the spring ovarian growth phase, in which the follicles rapidly reached ovulatory size. Ovulation occurs during mid-May to mid-June, and a period of follicular atresia follows oviposition. Marked changes in all three plasma steroids occur during the periovulatory period, increasing sharply prior to or around the time of ovulation, and falling sharply thereafter. Correlated with the fall period of ovarian recrudescence, smaller peaks of testosterone and estradiol, but not progesterone, occur. These data are discussed with regard to possible control of the chelonian ovarian cycle.
AB - The annual ovarian cycle of the painted turtle, Chrysemys picta, is described and correlated with plasma changes in parameters of vitellogenesis (protein, calcium, and cholesterol) and steroids (progesterone, testosterone, and estradiol). Three major classes of ovarian follicles were identified at all times of the year, and ovarian growth was confined to two major phases. The first, in which vitellogenesis was most active, occurred in the fall, after a postovulatory period of follicular atresia. This was followed by a winter period of inactivity and the spring ovarian growth phase, in which the follicles rapidly reached ovulatory size. Ovulation occurs during mid-May to mid-June, and a period of follicular atresia follows oviposition. Marked changes in all three plasma steroids occur during the periovulatory period, increasing sharply prior to or around the time of ovulation, and falling sharply thereafter. Correlated with the fall period of ovarian recrudescence, smaller peaks of testosterone and estradiol, but not progesterone, occur. These data are discussed with regard to possible control of the chelonian ovarian cycle.
UR - http://www.scopus.com/inward/record.url?scp=0018132522&partnerID=8YFLogxK
U2 - 10.1016/0016-6480(78)90069-2
DO - 10.1016/0016-6480(78)90069-2
M3 - Article
C2 - 689359
AN - SCOPUS:0018132522
SN - 0016-6480
VL - 35
SP - 245
EP - 257
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 3
ER -