| 1. |
- Fahmy, Khalid, et al.
(författare)
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Expression analysis of a family of developmentally-regulated cytosolic sulfotransferases (SULTs) in Drosophila.
- 2013
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 1601-5223 .- 0018-0661. ; 150:2-3, s. 44-48
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Tidskriftsartikel (refereegranskat)abstract
- We have compared the amino acid sequence of all four cytosolic sulfotransferases (SULTs) in Drosophila and analyzed their spatial expression patterns during development. Three out of four SULTs show distinct expression activity during embryogenesis, while the 4th SULT shows expression only post-embryonically. st1, st3 and st4 are expressed in non-overlapping expression domains mainly confined to organs of the alimentary canal such as esophagus, malphigian tubules, hindgut, as well as in the tracheal system. All these organs are surrounded by the hemolymph suggesting that Drosophila SULTs exert their function in detoxification of substances upon influx from the hemolymph.
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| 2. |
- Brown, Keith S., Jr., et al.
(författare)
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Chromosomal evolution in the South American Riodinidae (Lepidoptera Papilionoidea)
- 2012
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 149:4, s. 128-138
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Tidskriftsartikel (refereegranskat)abstract
- We give the haploid chromosome numbers of 173 species or subspecies of Riodinidae as well as of 17 species or subspecies of neotropical Lycaenidae for comparison. The chromosome numbers of riodinids have thus far been very poorly known. We find that their range of variation extends from n =?9 to n =?110 but numbers above n =?31 are rare. While lepidopterans in general have stable chromosome numbers, or variation is limited at most a subfamily or genus, the entire family Riodinidae shows variation within genera, tribes and subfamilies with no single modal number. In particular, a stepwise pattern with chromosome numbers that are about even multiples is seen in several unrelated genera. We propose that this variation is attributable to the small population sizes, fragmented populations with little migration, and the behavior of these butterflies. Small and isolated riodinid populations would allow for inbreeding to take place. Newly arisen chromosomal variants could become fixed and contribute to reproductive isolation and speciation. In contrast to the riodinids, the neotropical Lycaenidae (Theclinae and Polyommatinae) conform to the modal n =?24 that characterizes the family.
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| 3. |
- Dida, Mulatu Geleta, et al.
(författare)
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Genetic diversity in sorghum (Sorghum bicolor (L.) Moench) accessions of Zambia as revealed by simple sequence repeats (SSR)
- 2011
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 148, s. 52-62
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Tidskriftsartikel (refereegranskat)abstract
- Twenty seven accessions of sorghum conserved in the national gene bank of Zambia, representing two of the three agroecological regions of the country, were investigated using simple sequence repeats (SSR) markers in order to determine the extent and distribution of its genetic diversity. We used 10 microsatellite primer-pairs, which generated 2-9 alleles per locus and a total of 44 alleles across the 27 accessions. The observed heterozygosity (Ho(P)) among the accessions ranged from 0 to 0.19 with an average of 0.04 whereas the average expected heterozygosity (He(P)) among accessions was 0.07 in line with the fact that sorghum is predominately inbreeder. The analysis of molecular variance (AMOVA) revealed that 82% of the total genetic variation was attributable to the genetic variation among accessions (F(ST) = 0.824; p < 0.001) whereas the genetic variation within accessions accounted for 18% of the total genetic variation. AMOVA on sorghum accessions grouped based on four ethnic groups (Soli, Chikunda, Lozi and Tonga) associated with collection sites revealed a highly significant variation among groups (23%; p < 0.001). Although cluster analysis grouped most accessions according to their sites of collection, some accessions that originated from the same site were placed under different clusters. In addition to the extent and pattern of genetic diversity, consideration should also be given to other factors such as ecogeographic and ethnic differences when sampling sorghum genetic resources for rational and efficient conservation and utilization in the breeding program.
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| 4. |
- Mujaju, Claid, et al.
(författare)
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Genetic diversity in watermelon (Citrullus lanatus) landraces from Zimbabwe revealed by RAPD and SSR markers
- 2010
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 147, s. 142-153
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Tidskriftsartikel (refereegranskat)abstract
- Low polymorphism in cultivated watermelon has been reported in previous studies, based mainly on US Plant Introductions and watermelon cultivars, most of which were linked to breeding programmes associated with disease resistance. Since germplasm sampled in a putative centre of origin in southern Africa may harbour considerably higher variability, DNA marker-based diversity was estimated among 81 seedlings from eight accessions of watermelon collected in Zimbabwe; five accessions of cow-melons (Citrullus lanatus var. citroides) and three of sweet watermelons (C. lanatus var. lanatus). Two molecular marker methods were used, random amplified polymorphic DNA (RAPD) and simple sequence repeats (SSR) also known as microsatellite DNA. Ten RAPD primers produced 138 markers of which 122 were polymorphic. Nine SSR primer pairs detected a total of 43 alleles with an average of 4.8 alleles per locus. The polymorphic information content (PIC) ranged from 0.47 to 0.77 for the RAPD primers and from 0.39 to 0.97 for the SSR loci. Similarity matrices obtained with SSR and RAPD, respectively, were highly correlated but only RAPD was able to provide each sample with an individual-specific DNA profile. Dendrograms and multidimensional scaling (MDS) produced two major clusters; one with the five cow-melon accessions and the other with the three sweet watermelon accessions. One of the most variable cow-melon accessions took an intermediate position in the MDS analysis, indicating the occurrence of gene flow between the two subspecies. Analysis of molecular variation (AMOVA) attributed most of the variability to within-accessions, and contrary to previous reports, sweet watermelon accessions apparently contain diversity of the same magnitude as the cow-melons.
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| 5. |
- Pham, Toan Duc, et al.
(författare)
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Comparative analysis of genetic diversity of sesame (Sesamum indicum L.) from Vietnam and Cambodia using agro-morphological and molecular markers
- 2011
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 148, s. 28-35
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to comparatively analyze the genetic diversity of sesame (Sesamum indicum L.) using agro-morphological and molecular markers. Twelve sesame populations collected from three regions in Cambodia and Vietnam were used in this study. A high genetic variation was revealed both by agro-morphological and RAPD markers within and among the 12 sesame populations. The range of agro-morphological trait based average taxonomic distance among populations (0.02 to 0.47) was wider than that of RAPD based genetic distance (0.06 to 0.27). The mean distance revealed by agro-morphological markers (0.23) and RAPD markers (0.22) was similar. RAPD based analysis revealed a relatively higher genetic diversity in populations from South Vietnam as compared to the other two regions. Interestingly, populations from this region also had higher values for yield related traits such as number of capsules per plant, number of seeds per capsule, and seed yield per plant suggesting positive correlation between the extent of genetic variation within population and yield related traits in sesame. A highly significant positive correlation (r = 0.88, P < 0.001) was found between agro-morphological and RAPD markers in estimating the genetic distance between populations. Both methods suggested the existence of a substantial amount of genetic diversity both in the Vietnamese and Cambodian populations. Although both agro-morphological and RAPD markers were found to be useful in genetic diversity analysis in sesame, their combined use would give superior results.
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| 6. |
- Rasmuson, Marianne
(författare)
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Trends in genetics - before the molecular era
- 2010
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Ingår i: Hereditas. - : Wiley-Blackwell. - 0018-0661 .- 1601-5223. ; 147:5, s. 243-249
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Tidskriftsartikel (refereegranskat)abstract
- Genetics grew into a scientific discipline during the first decade of the twentieth century, it prospered and became acknowledged in its first half, it widened into the molecular field during its second half. This expansion attracted scientists from nearby branches such as biochemistry, biophysics, cell biology, statistics and computer science, which started to call themselves geneticists without deeper insights into the classical genetics. They may be unaware of how far the science had advanced already before the molecular window was opened. Then, what is the essence of genetics? It is involved in all aspects of biology, and has branched into different disciplines, rather far apart. Still it is held together by its core, the evolutionary coalescence of all living organisms on earth and their surprisingly great conformity in physiological and hereditary mechanisms. In the early definitions before the year 1900 the word variation is often included, most bluntly as the science of variation. Similarities and differences between parent and offspring are also emphasised. Inheritance causes similarities but not complete likeness. The name of the subject, genetics, was introduced by W. Bateson in 1906 and defined as the scientific study of the heredity of individuals. Later definitions have become more extensive and include not only the transmission of the hereditary factors but also their nature and the way in which they influence the living organism at different stages and at different levels, from molecules to populations and ecosystems.
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| 7. |
- Saura, Anssi, et al.
(författare)
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Chromosome evolution in Neotropical butterflies
- 2013
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 150:2-3, s. 26-37
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Tidskriftsartikel (refereegranskat)abstract
- We list the chromosome numbers for 65 species of Neotropical Hesperiidae and 104 species or subspecies of Pieridae. In Hesperiidae the tribe Pyrrhopygini have a modal n = 28, Eudaminae and Pyrgini a modal n = 31, while Hesperiinae have n = around 29. Among Pieridae, Coliadinae have a strong modal n = 31 and among Pierinae Anthocharidini are almost fixed for n = 15 while Pierini vary with n = 26 as the most common chromosome number. Dismorphiinae show wide variation. We discuss these results in the context of chromosome numbers of over 1400 Neotropical butterfly species and subspecies derived from about 3000 populations published here and in earlier papers of a series. The overall results show that many Neotropical groups are characterized by karyotype instability with several derived modal numbers or none at all, while almost all taxa of Lepidoptera studied from the other parts of the world have one of n = 29-31 as modal numbers. Possibly chromosome number changes become fixed in the course of speciation driven by biotic interactions. Population subdivision and structuring facilitate karyotype change. Factors that stabilize chromosome numbers include hybridization among species sharing the same number, migration, sexual selection and possibly the distribution of chromosomes within the nucleus.
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| 8. |
- Von Bothmer, Roland
(författare)
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Connection between rod bivalents and incomplete meiotic association at NORs in Hordeum marinum Huds.
- 2012
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 149, s. 139-145
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Tidskriftsartikel (refereegranskat)abstract
- The hypothesis of a connection between rod bivalent formation and incomplete meiotic association at NORs of SAT-chromosomes of H. marinum is supported. PMCs of H. marinum ssp. gussoneanum (2x), two diploid ssp. marinum x ssp. gussoneanum (2x) hybrids and two ssp. gussoneanum (4x) x Secale cereale hybrids at metaphase I (M-I) were analyzed by in situ hybridization. The probe pTa71 labelled rDNA sites at NORs of a single pair of homologous or near-homologous SAT-chromosomes of H. marinum in each material. In the three diploids, M-I was regular with ring bivalents and one or a few rods (av.13.52 bound arms cell-1). More rod bivalents than the expected one out of seven, i.e. 30, 67 and 89% included rDNA-carrying chromosomes. Corresponding bound short arm frequencies were 0.89, 0.72 and 0.52, while long arms and arms of other chromosomes presented complete or near- complete association. The two heterogenomic hybrids had a less regular M-I (av. 8.04 bound arms cell-1) including 20% rDNA-carrying rods with bound arm frequencies of 0.29 in short and 0.87 in long arms. Positions of chromosome associations were established in all 150 rDNA-carrying bivalents. In 77 bivalents with short arm associations, 4% of these occurred proximally to, none at, and 96% distally to rDNA sites, i.e. in satellites. In 143 bivalents with long arm associations, 83% occurred at interstitial and 17% at terminal positions. The observations combine increased frequency of rDNA-carrying rods with decreased frequency of association at NOR regions of SAT-chromosomes. The basis for the relationship is discussed.
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| 9. |
- Von Bothmer, Roland
(författare)
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Analysis of DNA sequence polymorphism at the cMWG699 locus reveals phylogenetic relationships and allopolyploidy within Hordeum murinum subspecies
- 2010
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 147, s. 34-42
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Tidskriftsartikel (refereegranskat)abstract
- Hordeum murinum L. is one of the most widely distributed species in the genus Hordeum. This species is composed of three subspecies with three ploidy levels, namely subsp. glaucum (2x=14), subsp. murinum (4x=28) and subsp. leporinum (4x=28, 6x=42). These three subspecies are morphologically similar and are frequently referred to as the 'murinum complex'. Although many cytological studies suggest that the murinum complex is allopolyploid, one inter-specific hybridization study suggested that it is autopolyploid. The goals of the present study are to identify nucleotide variation in the cMWG699 locus in the polyploid genomes of the murinum complex, to conduct molecular phylogenetic analysis of this locus, and to clarify the allo- versus auto-polyploidy status of the murinum complex. For this purpose, PCR-RFLP analysis was conducted with HhaI and SspI restriction enzymes on 80 H. murinum accessions. Single enzyme digestion data revealed polymorphism between diploid and polyploids, and double-digestion revealed polymorphism between tetra- and hexaploids. The nucleotide sequences of clones clearly show that polyploid murinum species are allopolyploid. In addition, DNA sequence analysis indicated that one donor of the tetraploid was subsp. glaucum (2x), as has been suggested previously by cytological studies. The other diploid donors were not identified, but at least one group of sequences common to 4x and 6x genomes (namely clonetype B) was highly diverged from 2x subsp. glaucum. The two tetraploid subspecies, 4x subsp. murinum and 4x subsp. leporinum, had identical DNA sequences, suggesting that these two subspecies are not differentiated at the cMWG699 locus.
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| 10. |
- Arnqvist, Göran, et al.
(författare)
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Negative frequency dependent selection on sympatric mtDNA haplotypes in Drosophila subobscura
- 2016
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 153
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recent experimental evidence for selection on mitochondrial DNA (mtDNA) has prompted the question as to what processes act to maintain within-population variation in mtDNA. Balancing selection though negative frequency dependent selection (NFDS) among sympatric haplotypes is a possibility, but direct empirical evidence for this is very scarce. Findings: We extend the previous findings of a multi-generation replicated cage experiment in Drosophila subobscura, where mtDNA polymorphism was maintained in a laboratory setting. First, we use a set of Monte Carlo simulations to show that the haplotype frequency dynamics observed are inconsistent with genetic drift alone and most closely match those expected under NFDS. Second, we show that haplotype frequency changes over time were significantly different from those expected under either genetic drift or positive selection but were consistent with those expected under NFSD. Conclusions: Collectively, our analyses provide novel support for NFDS on mtDNA haplotypes, suggesting that mtDNA polymorphism may at least in part be maintained by balancing selection also in natural populations. We very briefly discuss the possible mechanisms that might be involved.
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