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Formation and regression of the corpus luteum of the American alligator

January 1, 1995

Luteal morphology of the American alligator is unique when compared to other reptiles but is similar to that of its phylogenetic relatives, the birds. The theca is extensively hypertrophied, but the granulosa never fills the cavity formed following the ovulation of the ovum. The formation of the corpus luteum (CL) is correlated with elevated plasma progesterone concentrations, which decline dramatically after oviposition with the onset of luteolysis. Unlike those of most other reptiles, the central luteal cell mass is composed of two cell types; one presumably is derived from the granulosa, whereas the other is from the theca interna. Both cell types are present throughout gravidity but only one cell type is seen during mid to late luteolysis. A significant decline in luteal volume occurs following oviposition and continues throughout the post-oviposition period. The fastest decline in luteal volume occurs in the month immediately after oviposition; this rate then slows. Luteolysis appears to continue for a year or more following oviposition, as distinct structures of luteal origin can still be identified in animals 9 months after oviposition. The size of persistent CL can be used to determine whether a given female oviposited during the previous nesting season. Females with CL having volumes greater than 0.2 cm2 or CL diameters greater than 0.4 cm were active the previous season. 

Publication Year 1995
Title Formation and regression of the corpus luteum of the American alligator
DOI 10.1002/jmor.1052240111
Authors L. J. Guillette, A.R. Woodward, Q. You-Xiang, M.C. Cox, J.H. Matter, T. S. Gross
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Morphology
Index ID 1008432
Record Source USGS Publications Warehouse
USGS Organization Florida Integrated Science Center