Coevolution of the male and female reproductive tracts in an old endemic murine rodent of Australia. (18th October 2012)

• Record Type: Journal Article
• Authors: Breed, W. G.; Leigh, C. M.; Speight, N.
• Is Part Of: Journal of zoology. Volume 289:Number 2(2013:Feb.)
• Page Start: 94
• Page End: 100
• Publication Date: 2012-10-18
• Subjects: Zoology -- Periodicals; Zoologie -- Périodiques; 590.5
• DOI: 10.1111/j.1469-7998.2012.00966.x
• Languages: English
• ISSNs: 0952-8369

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>The male reproductive tract of most Australian hopping mice in the genus <italic>Notomys</italic> has a suite of highly derived features that differ markedly from those of other Australian rodents. These include, among others, extremely small testes, a reduced complement of accessory sex glands and a spiny penis. Here we ask the question – what are the coevolved features of the female reproductive tract? To answer this question, we used histology and resin casts to compare the reproductive tract of the Australian plains mouse (<italic>Pseudomys australis</italic>) with that of the <italic>Spinifex</italic> hopping mouse (<italic>Notomys alexis</italic>). In <italic>P. australis</italic>, the cervix is highly fibrous and has two small canals whereas the vagina has prominent fornices, a large lumen and a folded epithelial lining. By contrast, in <italic>N. alexis</italic> the cervix is not prominent and is far more cellular. It has a very small, single lumen with the boundary between it and the vagina not being readily evident. The vagina has minute fornices and is surrounded by a comparatively thick muscle coat. Shortly after ejaculation, <italic>N. alexis</italic> had many uterine sperm that associated with coagulated material but, unlike in <italic>P.australis</italic>, no large vaginal plug occurs after ejaculation. These observations support the conclusion that <italic>N. alexis</italic> has a highly derived distal region of the female reproductive tract which has coevolved with that of the male. It appears to facilitate rapid sperm transport postcoitum without the need for a large copulatory plug.</p> </abstract>