Geographic isolation of small populations in refugia during late Pleistocene glaciations resulted in population differentiation that in some cases lead to speciation. We report the karyotype of Microtus bavaricus, an evolutionary young and threatened rodent endemic to the Alps. Our results show that the karyotype of M. bavaricus is almost identical to that of M. liechtensteini (2N = 46, NF = 54). A close relationship between the two species was also supported by phylogenetic analysis of complete mitochondrial DNA sequences for the cytochrome b gene. The cytochrome b divergence between Microtus bavaricus and M. liechtensteini was 1.7 %, the lowest estimate observed among the 14 currently recognised species of Eurasian pine voles (subgenus Terricola).
The Rejvíz bog is an extensive mire complex in Central Europe, with up to 7 m deep sediments and two natural lakes. Recent vegetation is one of the best preserved examples of Pinus uncinata subsp. uliginosa (syn. P. rotundata) bog woodland in Central Europe. The origin and development of the mire and changes in the surrounding landscape vegetation are reconstructed using sediment stratigraphy, radiocarbon dating, pollen analysis and plant-macrofossils analysis, with particular emphasis on the processes that resulted in the origin of Rejvíz bog and on pine woodland dynamics. Based on identified species the water level changes were reconstructed. The sediment started to accumulate more than 9000 years ago at an open mixed-woodland spring with Dichodontium palustre. Later, poor fen vegetation with sedges and horsetails developed. Around 6170 cal. yr BC the fen became inundated for 2000 years and (semi)aquatic vegetation thrived. Next step in the succession followed a decline in water level which resulted in the development of drier oligothrophic vegetationwith a high representation of pine and dwarf shrubs. After ca 1020 cal. yr BC the mire became the bog it is now. Three wooded stages appeared in both the minerotrophic and ombrotrophic developmental phases: before 6720 cal. yr BC, during ca 1960–1020 cal. yr BC and recently. The vegetation in the surrounding landscape developed without marked human interventions up till ca the last six or five centuries, when deforestation and later settlement took place. Comparison with published data from the Góry Bystrzyckie/Orlické hory Mts suggests that not only regional, but also local vegetation changed in a similar way across the middle-altitude eastern Sudetes, following oscillations in climate rather than local changes in mire water regime.
The honeybee (Apis mellifera L.) has a large number of geographic subspecies distributed across Europe, Africa and Asia, many of which have been described. This identification is important for bee breeding and preserving honeybee biodiversity. To investigate the origin of Jordanian honeybees, 32 samples collected from different locations in Jordan were analyzed using four different enzyme systems: Bg/II site in cytochrome oxidase b (Cytb), EcoRI site in large ribosomal (lsRNA) subunit, XbaI site in cytochrome c oxidase I (COI) subunit and HinCII site in cytochrome c oxidase I (COI) subunit. The first three enzymes were found to be polymorphic. The DNA banding pattern analyses revealed that Jordanian honeybees belong to the East Mediterranean and Middle Eastern mitochondrial lineages.
Karyotypes of the polyploid parthenogenetic species Saga pedo from four localities in France and the Republic of Macedonia were constructed and compared. All these karyotypes consist of 70 chromosomes, which is more than twice that in other species of the genus. The chromosomes differ from each other, making the matching of homologues difficult. Karyotypes of French specimens are similar, except for differences in the heterochromatin. Compared to that of the Macedonian specimens those from French specimens differ by the shortening of a single chromosome. The difficulty experienced in identifying tetrads and even pairs of chromosomes indicates that either many chromosome rearrangements have occurred since the polyploidisation event(s) or that the addition of quite different genomes is the cause. On the other hand, that the karyotypes are similar indicates a common origin of both the Macedonian and French populations. Thus, most chromosome changes preceded the separation from their common ancestor. Both the DNA content and chromosome analyses suggest that the S. pedo karyotype is pentaploid and not tetraploid as previously proposed. This odd ploidy number rules out the hypothesis that it could only have originated by endoreduplication. It is more likely that it originated by the association of five copies of the 14,X haploid karyotype, which exists in the gametes of the closely related species, S. campbelli and S. rammei (male / female 2n = 27, X / 28, XX). Fertilization of a parthenogenetic 56, XXXX female by a 14, X spermatozoa could have resulted in the last increase in ploidy.
he oriental weather loach Misgurnus anguillicaudatus (Teleostei: Cobitidae) inhabits the waters of East Asia including Japanese Islands. The Japanese population of M. anguillicaudatus includes two major mitochondrial DNA (mtDNA) clades, but their evolutionary origin is unknown. In this study, we conducted phylogeographic analyses of M. anguillicaudatus that were based on mtDNA cytochrome b sequences to clarify the evolutionary origin of the two distinct mtDNA clades. This newly obtained data were integrated with the mtDNA sequence data obtained in previous studies and reanalysed. The results showed that one major clade originated because of mtDNA introgression from a loach of the genus Cobitis. The geographic range of the populations carrying non-introgressed mtDNA tended to be limited to the peripheral areas of the Japanese Islands, whereas the range of the populations carrying introgressed mtDNA was spread over wide regions of the Japanese Islands. These distribution and divergence patterns suggested that M. anguillicaudatus populations carrying introgressed mtDNA have spread and replaced the range of populations carrying non-introgressed mtDNA.