Skip to main content Accessibility help
×
Home
Hostname: page-component-78dcdb465f-vddjc Total loading time: 0.318 Render date: 2021-04-19T07:51:10.173Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": false, "newCiteModal": false, "newCitedByModal": true }

Article contents

Novelties of conception in insectivorous mammals (Lipotyphla), particularly shrews

Published online by Cambridge University Press:  08 November 2004

J. Michael Bedford
Affiliation:
Center for Reproductive Medicine and Infertility, Weill Medical College, Cornell University, New York, N.Y., 10021, U.S.A.
Orin B. Mock
Affiliation:
Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, MO, 63501, U.S.A.
Steven M. Goodman
Affiliation:
Department of Zoology, The Field Museum of Natural History, Chicago, IL, 60605, U.S.A.
Get access

Abstract

In the order Lipotyphla (Insectivora), certain reproductive features differ quite distinctly from the eutherian norms, and are of interest with regard to the evolution of mammalian gamete function and perhaps for questions of lipotyphlan phylogeny. As seen in one or more members of five lipotyphlan families (shrews, moles, hedgehogs, golden moles, tenrecs), these features can involve the configuration of the male tract including the penis, the morphology of the sperm head, the anatomy of the oviduct and the patterns of sperm transport within it, the character of the cumulus oophorus, and the way in which fertilising spermatozoa interact with the eggs. However, the picture is by no means uniform within the order. Reproductive idiosyncrasies occur variously in the different lipotyphlan families, and appear consistently and strikingly in shrews – the group studied most extensively. Compared to the patterns in most Eutheria, the most interesting anomalies in soricids include (a) the regulation of sperm transport to the site of fertilisation by oviduct crypts, whose arrangement can vary even according to species, (b) a circumscribed matrix-free cumulus oophorus that appears essential for fertilisation as the inducer of the acrosome reaction, (c) barbs on the acrosome-reacted sperm head by which it may attach to the zona pellucida.

With regard to the bearing such reproductive traits might have on lipotyphlan systematics, the African mouse shrew (Myosorex varius) displays a mix of traits that characterize either crocidurine or soricine shrews, consistent with the proposal that it belongs in a more primitive tribe, Myosoricinae, or subfamily, the Crocidosoricinae, from which the crocidurine and soricine lines probably evolved. Moreover, although elephant shrews are assigned now to a separate order (Macroscelidea), they display several of the unusual reproductive features seen in lipotyphlans, particularly in chrysochlorids and tenrecs. On the other hand, if used as a phylogenetic yardstick, none of the reproductive features described serves to define the Lipotyphla as classically constituted within one order, nor necessarily all the relationships suggested by recent sequencing studies of nuclear and mitochondrial genes.

Type
Review Article
Copyright
2004 Cambridge Philosophical Society

Access options

Get access to the full version of this content by using one of the access options below.

Full text views

Full text views reflects PDF downloads, PDFs sent to Google Drive, Dropbox and Kindle and HTML full text views.

Total number of HTML views: 0
Total number of PDF views: 14 *
View data table for this chart

* Views captured on Cambridge Core between September 2016 - 19th April 2021. This data will be updated every 24 hours.

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Novelties of conception in insectivorous mammals (Lipotyphla), particularly shrews
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Novelties of conception in insectivorous mammals (Lipotyphla), particularly shrews
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Novelties of conception in insectivorous mammals (Lipotyphla), particularly shrews
Available formats
×
×

Reply to: Submit a response


Your details


Conflicting interests

Do you have any conflicting interests? *