An ovotestis is a gonad with both testicular and ovarian aspects. In humans, ovotestes are an anatomical abnormality associated with gonadal dysgenesis. In invertebrates that are normally hermaphroditic, such as most gastropods (snails and slugs) in the clade Eupulmonata, an ovotestis is a common feature of the reproductive anatomy.
In mice, ovotestes are structured such that the central region is testicular tissue while the poles both contain ovarian tissue. Experiments involving the Sox9 gene, which is initiated by the SRY region of the Y chromosome, have shown the gene’s requirement for testicular differentiation from the presence of ovotestis formation within XX Sox9 trangenic mice. (6) Ovotestis within B6-XYPOS mice allow for gonadal development research within the same tissue to take place in ways previously unavailable.  
An ovotestis or hermaphroditic gland (in Latin language: glandula hermaphroditica), is found as normal anatomical feature in the reproductive system of some gastropods including such species as the land snail Helix aspersa.
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