1. Structural changes to the uterus of the dwarf ornate wobbegong shark ( <scp> Orectolobus ornatus </scp> ) during pregnancy
- Author
-
Michael B. Thompson, Camilla M. Whittington, Nicholas M. Otway, Samson N. Dowland, Colin A. Simpfendorfer, Alice L. Buddle, James U. Van Dyke, Megan T. Ellis, and Christopher R. Murphy
- Subjects
0106 biological sciences ,0301 basic medicine ,Placenta ,Uterus ,Connective tissue ,010603 evolutionary biology ,01 natural sciences ,Epithelium ,Morphological transformation ,Andrology ,03 medical and health sciences ,Pregnancy ,medicine ,Animals ,Wobbegong ,biology ,Embryo ,medicine.disease ,Orectolobus ornatus ,biology.organism_classification ,030104 developmental biology ,medicine.anatomical_structure ,Sharks ,Female ,Animal Science and Zoology ,Developmental Biology - Abstract
Embryos of the viviparous dwarf ornate wobbegong shark (Orectolobus ornatus) develop without a placenta, unattached to the uterine wall of their mother. Here, we present the first light microscopy study of the uterus of O. ornatus throughout pregnancy. At the beginning of pregnancy, the uterine luminal epithelium and underlying connective tissue become folded to form uterine ridges. By mid to late pregnancy, the luminal surface is extensively folded and long luminal uterine villi are abundant. Compared to the nonpregnant uterus, uterine vasculature is increased during pregnancy. Additionally, as pregnancy progresses the uterine epithelium is attenuated so that there is minimal uterine tissue separating large maternal blood vessels from the fluid that surrounds developing embryos. We conclude that the uterus of O. ornatus undergoes an extensive morphological transformation during pregnancy. These uterine modifications likely support developing embryos via embryonic respiratory gas exchange, waste removal, water balance, and mineral transfer.
- Published
- 2020
- Full Text
- View/download PDF