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- Kronhamn, Jesper, et al.
(författare)
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Genetic organization of the ci-M-pan region on chromosome IV in Drosophila melanogaster.
- 1999
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Ingår i: Genome. - 0831-2796 .- 1480-3321. ; 42:6, s. 1144-1149
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Tidskriftsartikel (refereegranskat)abstract
- The genes cubitus interruptus (ci), ribosomal protein S3A (RpS3A), and pangolin (pan) are localized within 73 kb in the cytological region 101F-102A on chromosome IV in Drosophila melanogaster. A region of 13 kb harbours the regulatory regions of both ci and pan, transcribed in opposite directions, and a 1.1-kb gene encoding RpS3A. This dense clustering gives rise to very complicated complementation patterns between different alleles in these loci. We investigated this region genetically and molecularly by use of an enhancer trap line (IA5), where the P-element was found to be inserted into the first intron of pan. Screens for imprecise excisions of the P-element were performed, and complementations between new and old established mutant lines were investigated. We found that when mutated or deleted the RpS3A gene gives rise to a Minute phenotype, and we conclude that M(4)101 encodes the ribosomal protein S3A.
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| 4. |
- Nilsson, Jan
(författare)
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Sex chromosome polymorphisms in Arctic charr and their evolutionary origins
- 2011
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Ingår i: Genome. - 0831-2796 .- 1480-3321. ; 54, s. 852-861
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Tidskriftsartikel (refereegranskat)abstract
- Current data on the Y-specific sex-determining region of salmonid fishes from genera Salvelinus, Salmo, and Oncorhynchus indicate variable polymorphisms in the homologous chromosomal locations of the sex-specific determining region. In the majority of the Atlantic lineage Arctic chaff, including populations from the Fraser River, in Labrador Canada, as well as Swedish and Norwegian strains, the sex-determining locus maps to linkage group AC-4. Previously, sex-linked polymorphisms (i.e., variation in the associated sex-linked markers on AC-4) have been described in Arctic charr. Here, we report further evidence for intraspecific sex linkage group polymorphisms in Arctic charr (i.e., the detection of the SEX locus on either the AC-1 or AC-21 linkage group) and a possible conservation of a sex linkage arrangement in Icelandic Arctic charr and Atlantic salmon, involving sex-linked markers on the AC-1/21 homeologs and the European AS-1/6 homeologous linkage groups in Atlantic salmon. The evolutionary origins for the multiple sex-determining regions within the salmonid family are discussed. We also relate the variable sex-determining regions in salmonids to their ancestral proto-teleost karyotypic origins and compare these findings with what has been observed in other teleost species in general.
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| 5. |
- Pelger, Susanne, et al.
(författare)
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Hordein variation in the genus Hordeum as recognized by monoclonal antibodies.
- 1992
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Ingår i: Genome. - : Canadian Science Publishing. - 0831-2796 .- 1480-3321. ; 35:2, s. 200-207
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: The composition of the major storage protein, hordein, in wild barley species has been studied by using gel electrophoresis, Coomassie staining, and immunoblot assays. We have shown earlier that it is possible to obtain cross-reaction outside the cultivated barley, with monoclonal antibodies raised against hordeins from the barley cultivar Bomi. These antibodies have now been used to investigate the hordein composition in all species of the Hordeum genus. The results showed that polypeptides similar to the two major hordein groups of cultivated barley, the B- and C-hordeins, are produced in all wild Hordeum species, and that there are both similarities and differences between the two hordein groups. The similarities indicate a common evolutionary origin, while the distinction between B- and C-hordeins in the entire genus clearly shows that the divergence of their coding genes preceded the divergence of the Hordeum species. The presence of the same antigenic site in two different species indicates that they are evolutionarily related. Among the wild species, two rarely occurring sites were exclusively found in H. vulgare ssp. spontaneum and H. bulbosum, which confirms that they are the cultivated barley's closest relatives. Some of the antibodies also gave an extensive reaction pattern with H. murinum, which suggests a fairly close relationship to H vulgare, though not as close as between H. vulgare and H. bulbosum.
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| 6. |
- Pelger, Susanne
(författare)
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Prolamin variation in the tribe Triticeae as recognized by monoclonal antibodies.
- 1993
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Ingår i: Genome. - : Canadian Science Publishing. - 0831-2796 .- 1480-3321. ; 36:6, s. 1042-1048
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Tidskriftsartikel (refereegranskat)abstract
- The isopropanol-soluble seed storage proteins, prolamins, were studied in 18 different genera of the tribe Triticeae by gel electrophoresis, Coomassie staining, and immunoblot assays. The monoclonal antibodies were originally raised against cultivated barley (Hordeum vulgare L.) hordein, and their reactions had been tested earlier on wild Hordeum species. The study showed that all the investigated Triticeae species produce prolamins and that structural similarities can be found throughout the tribe. The presence of the same antigenic sites in all the species indicates that the polypeptides contain well-conserved regions. They also indicate that the prolamins of the Triticeae species have a common evolutionary origin. In all the investigated species an antigenic site that is common to the B- and C-hordeins of barley was detected. Some of the reacting polypeptides also contained a site that is only present in the B-hordeins. The B-hordein specific site was found in all genera except Agropyron, Hordelymus, and Secale. This shows that although there are similarities between individual polypeptides, the composition of the various prolamin groups may vary between different genera. In the polyploid Elymus species different banding patterns were observed depending on what basic genomes were represented. The results suggest a direct correlation between the presence of a fast migrating polypeptide containing the B-hordein specific site and the presence of the H genome.
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| 7. |
- Ritter, Camila, et al.
(författare)
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Biodiversity assessments in the 21st century: The potential of insect traps to complement environmental samples for estimating eukaryotic and prokaryotic diversity using high-throughput DNA metabarcoding.
- 2019
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Ingår i: Genome. - : Canadian Science Publishing. - 1480-3321 .- 0831-2796. ; 62:3, s. 147-159
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Tidskriftsartikel (refereegranskat)abstract
- The rapid loss of biodiversity, coupled with difficulties in species identification, call for innovative approaches to assess biodiversity. Insects make up a substantial proportion of extant diversity and play fundamental roles in any given ecosystem. To complement morphological species identification, new techniques such as metabarcoding make it possible to quantify insect diversity and insect-ecosystem interactions through DNA sequencing. Here we examine the potential of bulk insect samples (i.e., containing many non-sorted specimens) to assess prokaryote and eukaryote biodiversity and to complement the taxonomic coverage of soil samples. We sampled 25 sites on three continents and in various ecosystems, collecting insects with Slam-traps (Brazil) and Malaise-traps (South Africa and Sweden). We then compared our diversity estimates with the results obtained with biodiversity data from soil samples from the same localities. We found a largely different taxonomic composition between the soil and insect samples, testifying to the potential of bulk insect samples to complement soil samples. Finally, we found that non-destructive DNA extraction protocols, which preserve insect specimens for morphological studies, constitute a promising choice for cost-effective biodiversity assessments. We propose that the sampling and sequencing of insect samples should become a standard complement for biodiversity studies based on environmental DNA.
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| 8. |
- Roslin, Tomas, et al.
(författare)
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The use of DNA barcodes in food web construction - terrestrial and aquatic ecologists unite!
- 2016
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Ingår i: Genome. - : Canadian Science Publishing. - 0831-2796 .- 1480-3321. ; 59:9, s. 603-628
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Tidskriftsartikel (refereegranskat)abstract
- By depicting who eats whom, food webs offer descriptions of how groupings in nature (typically species or populations) are linked to each other. For asking questions on how food webs are built and work, we need descriptions of food webs at different levels of resolution. DNA techniques provide opportunities for highly resolved webs. In this paper, we offer an expose of how DNA-based techniques, and DNA barcodes in particular, have recently been used to construct food web structure in both terrestrial and aquatic systems. We highlight how such techniques can be applied to simultaneously improve the taxonomic resolution of the nodes of the web (i.e., the species), and the links between them (i.e., who eats whom). We end by proposing how DNA barcodes and DNA information may allow new approaches to the construction of larger interaction webs, and overcome some hurdles to achieving adequate sample size. Most importantly, we propose that the joint adoption and development of these techniques may serve to unite approaches to food web studies in aquatic and terrestrial systems-revealing the extent to which food webs in these environments are structured similarly to or differently from each other, and how they are linked by dispersal.
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| 9. |
- Ruiz-Ruano, Francisco J., et al.
(författare)
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Transposable element landscapes illuminate past evolutionary events in the endangered fern Vandenboschia speciosa
- 2022
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Ingår i: Genome. - : Canadian Science Publishing. - 0831-2796 .- 1480-3321. ; 65:2, s. 95-103
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Tidskriftsartikel (refereegranskat)abstract
- Vandenboschia speciosa is an endangered tetraploid fern species with a large genome (10.5 Gb). Its geographical distribution is characterized by disjoined tertiary flora refuges, with relict populations that survived past climate crises. Here, we analyzed the transposable elements (TEs) and found that they comprise approximately 76% of the V. speciosa genome, thus being the most abundant type of DNA sequence in this gigantic genome. The V. speciosa genome is composed of 51% and 5.6% of Class I and Class II elements, respectively. LTR retrotransposons were the most abundant TEs in this species (at least 42% of the genome), followed by non-LTR retrotransposons, which constituted at least 8.7% of the genome of this species. We introduce an additional analysis to identify the nature of non-annotated elements (19% of the genome). A BLAST search of the non-annotated contigs against the V. speciosa TE database allowed for the identification of almost half of them, which were most likely diverged sequence variants of the annotated TEs. In general, the TE composition in V. speciosa resembles the TE composition in seed plants. In addition, repeat landscapes revealed three episodes of amplification for all TEs, most likely due to demographic changes associated with past climate crises.
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| 10. |
- Tyler, Torbjörn
(författare)
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Geographic structure of genetic variation in the widespread woodland grass Milium effusum L. A comparison between two regions with contrasting history and geomorphology
- 2002
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Ingår i: Genome. - : Canadian Science Publishing. - 0831-2796 .- 1480-3321. ; 45:6, s. 1248-1256
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Tidskriftsartikel (refereegranskat)abstract
- Allozyme variation in the forest grass Milium effusum L. was studied in 21-23 populations within each of two equally sized densely sampled areas in northern and southern Sweden. In addition, 25 populations from other parts of Eurasia were studied for comparison. The structure of variation was analysed with both diversity statistics and measures based on allelic richness at a standardised sample size. The species was found to be highly variable, but no clear geographic patterns in the distribution of alleles or in overall genetic differentiation were found, either within the two regions or within the whole sample. Thus, no inferences about the direction of postglacial migration could be made. Obviously, migration and gene flow must have taken place in a manner capable of randomising the distribution of alleles. However, there were clear differences in levels and structuring of the variation between the two regions. Levels of variation, both in terms of genetic diversity and allelic richness, were lower in northern Sweden as compared with southern Sweden. In contrast, different measures of geographic structure all showed higher levels of population differentiation in the northern region. This is interpreted as due to different geomorphological conditions in the two regions, creating a relatively continuous habitat and gene flow in the southern region as compared with the northern region where the species, although common, is confined to narrow and mutually isolated corridors in the landscape.
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