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n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane
Thesis (DSc (Genetics))--University of Pretoria, 1985
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| Format: | Thesis |
| Language: | Afrikaans |
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University of Pretoria
2024
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| _version_ | 1867613703156793344 |
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| access_status_str | Open Access |
| author2 | Van Leyveld, Hester |
| author_browse | Van Leyveld, Hester |
| author_facet | Van Leyveld, Hester |
| collection | Thesis |
| dc_rights_str_mv | © 2024 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (DSc (Genetics))--University of Pretoria, 1985 |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/99562 |
| institution | University of Pretoria (South Africa) |
| language | afr |
| last_indexed | 2026-06-10T12:40:21.476Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/99562 n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane Van Leyveld, Hester Fossey, Annabel Sitogenetiese ondersoek Suider-Afrikaanse korthoringsprinkane UCTD Thesis (DSc (Genetics))--University of Pretoria, 1985 A cytogenetic survey was carried out on a number of Southern African short horned grasshopper species (OR.TBOPTKR.A), the aim being to expand the existing limited information. New methods of analysis were developed, while existing methods were improved. 438 individuals of 116 species (7 families) were studied. Surprisingly many cytogenetic variations were found. To simplify the analysis, a bivalent type analysis was done. From this analysis mean chiasma frequencies and chiasma localization could be determined. To simplify comparisons between species, the bivalent types are presented in the form of histograms. The male zygotic chromosome numbers of the following families are: ACRIDIDAK, CBAR.ILAIDAK, Lentulidae and LKNTULIDAK 2n6"=23(XO); PAIIPBAGIDAE and PYR.GOIIOIPBIDAK 2n~l 9(XO); KUIIASTACIDAK 2n~l 7(XO). Their karyotypes consist mostly of acrocentric chromosomes. Pericentric inversion polymorphisms were found in 3 ACRIDIDAK species. One Lentulidae species is polytypic for centric fusion translocations. Supernumerary heterochromatin is present in the form of autosomal segments and B-chromosomes. The segments were found in 13 species being most prevalent in the genera 0edaleus and Acrotylus. They are found in the smaller bivalents in either the homozygotic of heterozygotic state. They are located in the chromosomes as follows: distal (67,70%), proximal (12,12%), interstitial (9,09%) and extrinsic (9,09%). B chromosomes were found only in 8 species appearing in two sizes; small (smaller than the smallest chromosome) and large (three quarters the size of the X-chromosome). Chiasma localization and/or lowered chiasma frequency occurred in 7 ACR.IDIDAE species. The frequency is limited in some species, as is the position to the proximal or distal regions of the bivalents. In there’s the chiasmata restricted to the proximal and distal parts of the bivalents without having any inf1uence on the chiasma, frequency. Crossing over in the short arm is particularly rare, but overall relatively frequent in 8 genera. It is clear that a fair amount of cytogenetic variation exists in Southern African short horned grasshoppers. A few species groups could be identified, warranting further study. Genetics DSc (Genetics) 2024-11-27T09:16:15Z 2024-11-27T09:16:15Z 21/12/02 1985 Thesis http://hdl.handle.net/2263/99562 afr © 2024 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Sitogenetiese ondersoek Suider-Afrikaanse korthoringsprinkane UCTD n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane |
| title | n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane |
| title_full | n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane |
| title_fullStr | n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane |
| title_full_unstemmed | n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane |
| title_short | n Sitogenetiese ondersoek van Suider-Afrikaanse korthoringsprinkane |
| title_sort | n sitogenetiese ondersoek van suider afrikaanse korthoringsprinkane |
| topic | Sitogenetiese ondersoek Suider-Afrikaanse korthoringsprinkane UCTD |
| url | http://hdl.handle.net/2263/99562 |