Translocation heterozygosity in southern African species of Viscum

Bothalia - African Biodiversity & Conservation

 
 
Field Value
 
Title Translocation heterozygosity in southern African species of Viscum
 
Creator Wiens, D. Barlow, B. A.
 
Subject — —
Description Sex-associated and floating translocation complexes are characteristic of dioecious species of  Viscum,  but are virtually absent in monoecious species. The majority of dioecious species has fixed sex-associated translocation complexes with the male being the heterozygous sex. The sex-associated multivalent is usually O4 (ring-of-four) or O6 , rarely O8 . Dioecious species without sex-associated translocations are much less common. Most of the dioecious species are also polymorphic for floating translocations, producing one or more additional multivalents ranging from O4 to O12. Floating translocations may be more frequent in species that do not have sex-associated translocations. Supernumerary chromosomes are also present in several species. Sex ratios are at unity in most dioecious species, but female-biased ratios may occur in some species. The high correlation between dioecy and translocation heterozygosity suggests that translocations are primarily associated with the origin and establishment of dioecy. Any róle in the maintenance of biased sex ratios through meiotic drive is probably secondary. Sex-associated translocations may serve to stabilize dioecy by bringing the sex factors into close linkage. Subsequent structural rearrangements within a sex-associated translocation complex may bring the sex factors together in one chromosome pair, releasing floating translocations. The high frequencies of floating translocation heterozygosity in some species indicate that such heterozygosity also has adaptive value.
 
Publisher AOSIS
 
Contributor
Date 1980-11-06
 
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — —
Format application/pdf
Identifier 10.4102/abc.v13i1/2.1306
 
Source Bothalia; Vol 13, No 1/2 (1980); 161-169 2311-9284 0006-8241
 
Language eng
 
Relation
The following web links (URLs) may trigger a file download or direct you to an alternative webpage to gain access to a publication file format of the published article:

https://journals.abcjournal.aosis.co.za/index.php/abc/article/view/1306/1266
 
Coverage — — —
Rights Copyright (c) 1980 D. Wiens, B. A. Barlow https://creativecommons.org/licenses/by/4.0
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