Skip to main content

The effect of ploidy level on fitness in parthenogenetic flatworms

Buy Article:

$51.00 plus tax (Refund Policy)

Abstract:

Although polyploidy plays an important role in speciation, its impact on fitness is still debated. One problem is that its adaptive significance can only be inferred by comparing forms with different ploidy that are identical in all other traits. This situation is uncommon, presumably because ploidy types often differ in reproduction mode, genetic background or habitat. Here we compare fitness in a system of triploid and tetraploid karyotypes of the planarian flatworm Schmidtea polychroa. Both types have the same type of sperm-dependent parthenogenesis and share the same genetic background and habitat. Hence, fitness differences, if any, can be attributed to different ploidy levels only. Contrary to the general assumption of a positive correlation between fitness and ploidy level, we showed that triploids produced 58% more offspring than tetraploids. Within each ploidy type, we identified groups of highly related clones using microsatellites. Significant variation among clonal groups in body size, offspring and cocoon number and hatching time indicated a genetic basis for variance in these traits. A small model shows that despite low fitness of tetraploids, stable coexistence of triploids and tetraploids can be explained by the recurrent origin of triploids from tetraploids and vice versa. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85, 191–198.

Keywords: Schmidtea polychroa; clonal lineages; coexistence; interclonal variation; microsatellites; polyploidy; reproduction; tetraploid; triploid

Document Type: Research Article

DOI: http://dx.doi.org/10.1111/j.1095-8312.2005.00482.x

Affiliations: Westphalian Wilhelms-University, Institute for Animal Evolution and Ecology, Munster, Germany

Publication date: June 1, 2005

bsc/bij/2005/00000085/00000002/art00005
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more