Egg size and hybrid syndrome-dependent embryo mortality in Chironomus hybrids (Diptera: Chironomidae)

Title:

Egg size and hybrid syndrome-dependent embryo mortality in Chironomus hybrids (Diptera: Chironomidae)

Creator:

Hägele, Klaus and Kasper-Sonnenberg, Monika

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:f45c3264-8c87-4878-b032-8acb99a06d8d
uuid:f45c3264-8c87-4878-b032-8acb99a06d8d

Subject:

Chironominae, hybridy, mortalita, entomologie, hmyz, dvoukřídlí, Chironomus thummi, Chironomus thummi thummi, Chironomus thummi piger, kříženci, hybridní syndromy, Rud syndrom, velikost vajíček, mortalita embryí, postzygotická reprodukční izolace, hybrid syndromes, Rud, HLE, egg size, embryo mortality, postzygotic reproductive isolation, 595.2/.7, and 591.1

Type:

article, model:article, and TEXT

Format:

print, text, and regular print

Description:

Female hybrids of the cross Chironomus t. thummi female × Ch. t. piger male which are largely affected by the sterility inducing Rud syndrome were backcrossed with males of both parental strains. The aim of the study was to provide information about those egg volumes that are insufficient for a normal embryogenesis and to ascertain whether in the hybrids the lethally small egg size represents a new abnormal trait of the Rud syndrome. The egg masses obtained contain eggs of very different sizes with volumes ranging from 0.5 nl to 3.49 nl. Embryo mortality is unusually frequent in those eggs of the backcrosses and of the parental strains that have volumes smaller than 1.5 nl. An egg volume of 1.5 nl represents in Ch. thummi the lower limit for those volumes that are sufficient for a normal embryogenesis. Mortality increases with decreasing egg size, reaching 100% in backcross eggs with volumes of 0.99 nl and smaller. Small egg size is a new trait of the Rud syndrome affected thummi female × piger male hybrids. This trait is part of a postzygotic reproductive isolation barrier between thummi and piger and manifests first in the backcrosses. Most backcross eggs show volumes between 1.5 nl and 2.99 nl. Within this volume range the amount of mortality does not depend upon egg volume. Here, embryo death is great in the backcrosses but normal in the parental strains. The high frequency of embryo death in the backcrosses must be predominantly due to the action of the Rud syndrome and a second hybrid syndrome, called HLE syndrome. Since further characteristic traits of these syndromes could be detected in surviving backcross individuals, the study demonstrates the occurrence of the syndromes in this generation also. Therefore, the postzygotic reproductive isolation mechanism of both hybrid syndromes is effective in the hybrids and in their progeny as well., Klaus Hägele, Monika Kasper-Sonnenberg, 4 obrázky, 2 tab., and Lit.

Language:

English

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Source:

European Journal of Entomology | 2000 Volume:97 | Number:1

Harvested from:

CDK

Metadata only:

false