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Development of an avascular region (the stigma) in ovarian follicles of lizards (Anolis)
Author(s) -
Jones Richard E.,
Lopez Kristin H.,
Summers Cliff H.,
Austin Harriet B.,
Rand Matt S.
Publication year - 1987
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051940310
Subject(s) - anolis , biology , follicular phase , stigma (botany) , theca , anatomy , follicle , ovulation , zoology , andrology , lizard , endocrinology , hormone , botany , medicine
Abstract The architecture of follicular blood vessels in the ovary of lizards ( Anolis equestris and Anolis carolinensis ) was studied by standard histology and also after vascular perfusion with an orange silicone‐rubber compound or with India ink. The theca of the follicular wall contains a netlike arrangement of anastomosing sinusoids, which increase in size as a follicle grows. An avascular stigma forms in very small, growing follicles when a portion of the follicular wall contacts the ovarian surface epithelium. Blood vessels then invade the theca except in the zone of contact. The diameter of the stigma is about 50% of follicular diameter, regardless of follicular size. Although the stigma of smaller follicles is avascular, that of vitellogenic follicles is hypovascular, i.e., a few vessels radiate into the stigma region. The antiangiogenic process involved in stigma formation may continue as the stigma enlarges. The development pattern of stigma formation found in Anolis is displayed by many other vertebrates.