Fig 5 - uploaded by Gwang Hoon Kim
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Phylogenetic tree inferred from RAPD-PCR banding patterns in Antithamnion spp. (A) MP and NJ analyses of Antithamnion densumcomplex group. Tree length = 169. Consistency index (CI) -0.710, retention index (RI) -0.555, rescaled consistency index (RC) -0.394. Numbers above the branches indicate total number of character state changes. (B) Phylogenetic analysis of Antithamnion spp. from this study and those described by Kim et al. (2004). Tree length = 477. Consistency index (CI) -0.478, retention index (RI) -0.420, rescaled consistency index (RC) -0.201. Numbers above the branches indicate total number of character state changes
Source publication
The taxonomic criterion of Antithamnion sparsum was reappraised in comparison with A. densum and A. defectum based on crossing experiments, morphological observation, chromosome study and Random Amplified Polymorphic DNA (RAPD) analysis. These species had a very similar morphology but were sexually isolated. The chromosome number was n = ca. 24 for...
Citations
... In land plants, polyploidy is highly prevalent and has significantly contributed to genome complexity 33,34 . Cytogenetic investigations have suggested that both aneuploidy and polyploidy might have accompanied speciation in the Ceramiales order 12, [35][36][37] . We thus employed a series of genomic and phylogenomic approaches to clarify the potential impact of polyploidy in Bostrychia and the Ceramiales more generally. ...
Red seaweeds form part of an ancient lineage of eukaryotes that were one of the first to evolve multicellularity. Although they share a common evolutionary origin with modern-day plants and display complex multicellular development, we still lack comprehensive genome data from the most highly-evolved groups of red algae. Here, we present a chromosome-level genome assembly of Bostrychia moritziana , a species that is classified into the Rhodomelaceae family of the Ceramiales order, both of which constitute the largest and most diverse family and order of red algae, respectively. Contrary to the commonly held view that red algae generally have small genomes, we report significant genome size expansion in Bostrychia and other Ceramiales species, which we posit as one of at least three independent genome expansion events that occurred during red algal evolution. Our analyses suggest that these expansions do not involve polyploidy or ancient whole genome duplications, but in the case of Bostrychia appear to be largely driven by the dramatic proliferation of a single lineage of giant Plavaka DNA transposons. Consistent with increased genome size, we identify a substantial increase in gene content in Bostrychia that was shaped both by de novo gene emergence and by the amplification of gene families in common with other Ceramiales seaweeds, providing key insight into the genetic adaptations underpinning the evolutionary success of this species-rich order. Finally, our sex-specific assemblies enabled us to resolve the UV sex chromosomes in Bostrychia , which feature expanded gene-rich sex-linked regions. Notably, these sex-linked regions each harbour a distinct TALE-HD transcription factor orthologous to ancient regulators of haploid-diploid transitions in other multicellular lineages. Together, our findings offer a unique perspective of the genomic adaptations driving red algal diversity and demonstrate how this highly successful group of red seaweeds can provide insight into the evolutionary origins and universal principles of complex multicellular plant life.
... Хромосомы окрашивали раствором ацетокармина в уксусной кислоте (кармин -2 г, уксусная кислота -45 мл, ddH2O -50 мл) по методике, описанной Г.Х. Кимом с соавторами [Kim et al., 2008]. ...
We present new data on cytology and karyology of representatives of the genus Alaria from the eastern Kamchatka. Since, despite morphological differences, taxa previously reported from this region as A. angusta and A. marginata turned out to be genetically identical and conspecific to A. esculenta, we substantiated their independence as intraspecific taxa, A. esculenta – f. angustifolia and f. latifolia, respectively. Cytochemical studies showed that different forms of A. esculenta have different oligosaccharide composition on the surface of oocytes and female gametophytes, i. e. during life cycle stages that ensure maintenance of species heterozygosity and, possibly, reproductive isolation of its forms. In Asian region, A. esculenta has a haploid chromosome number, which is half from that recorded from the Atlantic and Arctic regions, 14 instead of 28, suggesting that northwest Pacific is the center of A. esculenta origin and its settlement in the World Ocean
Red algae (Rhodophyta) are an ancient group with unusual morphological, biochemical, and life-history features including a complete absence of flagella. Although the red algae present many opportunities for studying speciation, this has rarely been explicitly addressed. Here, we examine an aspect of paternal gene flow by determining fertilization success of female Neosiphonia harveyi (Ceramiales), which retains a morphological record of all successful and unsuccessful female gametes. High fertilization rates were observed except when there were no males at all within the tidepool, or in a submerged marina environment. Small numbers of reproductive males were able to saturate fertilization rates, suggesting that limited availability of sperm may be less significant in red algae than previously thought. In another member of the Ceramiales, Antithamnion, relatively large chromosomes permit karyological identification of polyploids. The Western Pacific species Antithamnion sparsum is closely related to the diploid species Antithamnion defectum, known only from the Eastern Pacific, and appears to have evolved from it. Molecular evidence suggests that A. sparsum is an autopolyploid, and that the European species known as Antithamnion densum is divergent from the A. sparsum/defectum complex.
