Seasonal Changes in the Morphology of the Uterus of the Oviparous Lizard <em>Saproscincus mustelinus</em> and the Reproductively Bimodal Lizard <em>Saiphos equalis</em>.

<p>Among vertebrates, oviparity, a condition in which young at least partially develop outside the mother's body and are supported by yolk, is the ancestral state to viviparity, the reproductive mode in which embryos are fully developed at birth. Viviparity in reptiles is found only in the squamates. Among the more than 100 origins of viviparity in squamates, many have occurred fairly recently and as a result some species contain populations of both reproductive modes, i.e., are reproductively bimodal. The evolution of viviparity is associated with many changes including an increase in oviductal egg retention times, a decrease in thickness of the eggshell and a decrease in secretion of the uterine shell glands that are responsible for eggshell secretion. The uterine morphology of the oviparous <em>Saproscincus mustelinus</em> and the reproductively bimodal <em>Saiphos equalis</em> were compared to study the uterine shell gland cycle.</p>

Name thesis:degree_name

MS (Master of Science)

Level thesis:degree_level

Thesis - restricted

Discipline thesis:degree_discipline

Biology

Year dc:date.issued

2009

Author dc:creator

• Mathieson, Ashley Nicole

• uterus
• shell glands
• reproductively bimodal
• viviparity
• Cell and Developmental Biology
• Developmental Biology
• Life Sciences

Statement dc:rights

• Copyright by the authors.

Repository record dc:identifier

https://dc.etsu.edu/etd/1816

OAI identifier oai:identifier

oai:dc.etsu.edu:etd-3168