• Title/Summary/Keyword: Phylogenetic diversity

Search Result 631, Processing Time 0.022 seconds

Cyanobacterial Taxonomy: Current Problems and Prospects for the Integration of Traditional and Molecular Approaches

  • Komarek, Jiri
    • ALGAE
    • /
    • v.21 no.4
    • /
    • pp.349-375
    • /
    • 2006
  • The application of modern ecological, ultrastructural and molecular methods, aided by the cultivation of numerous cyanobacterial morphotypes, has substantially changed our knowledge of these organisms. It has led to major advances in cyanobacterial taxonomy and criteria for their phylogenetic classification. Molecular data provide basic criteria for cyanobacterial taxonomy; however, a correct phylogenetic system cannot be constructed without combining genetic data with knowledge from the previous 150 years research of cyanobacterial diversity. Thus, studies of morphological variation in nature, and modern morphological, ultrastructural, ecophysiological and biochemical characters need to be combined in a “polyphasic” approach. Taxonomic concepts for generic and infrageneric ranks are re-evaluated in light of combined phenotypic and molecular criteria. Despite their usefulness in experimental studies, the limitations of using strains from culture collections for systematic and nomenclatural purposes is highlighted. The need for a continual revision of strain identification and proper nomenclatural practice associated with either the bacteriological or botanical codes is emphasized. Recent advances in taxonomy are highlighted in the context of prospects for understanding cyanobacterial diversity from natural habitats, and the evolutionary and adaptational processes that cyanobacteria undergo.

Genetic Diversity and Phylogenetic Analysis of the mtDNA D-loop Region in Tibetan Sheep

  • Wang, X.;Chen, H.;Lei, C. Z.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.3
    • /
    • pp.313-315
    • /
    • 2007
  • Seventeen haplotypes were detected from the complete mitochondrial DNA control region sequences analyzed from eighty individuals of two Tibetan domestic sheep breeds. The nucleotide composition of all the sequences was 33.0% A, 29.7%T, 22.9%C and 14.4%G; G+C was 37.3%. The length of the sequences ranged from 1,107 bp to 1,259 bp. The difference between them was primarily due to 3-5 copy numbers of a 75 bp tandem repeat sequence. The NJ phylogenetic tree (the number of replications of bootstrap test is 1,000) presented three major domestic sheep lineages, which suggested that modern Tibetan sheep breeds are derived from three maternal sources.

Characterization of Ty3-gypsy-like Elements in Hibiscus syriacus

  • Jeung, Ji-Ung;Cho, Sung Ki;Lee, Seung Jae;Shin, Jeong Sheop
    • Molecules and Cells
    • /
    • v.19 no.3
    • /
    • pp.318-327
    • /
    • 2005
  • Southern blot analysis revealed a ubiquitous distribution and high copy number of Ty3-gypsy-like elements in the genome of Hibiscus syriacus. Comparative phylogenetic analysis of the large subunit of Rubisco and the integrase region of Ty3-gypsy elements in various plant species indicated that the retrotransposon-like sequences have different evolutionary histories and their own unique polymorphism in the H. syriacus population. Sequence-tagged site-restriction fragment length polymorphisms (STS-RFLP) analysis also indicated great variability in the numbers and sequences of Ty3-gypsy-like elements within H. syriacus varieties. Ty3-gypsy-like elements may still be active within H. syriacus, since Northern analysis of wounded leaves of H. syriacus variety Saehan with a probe for the integrase domain gave strong hybridization signals. The sequence heterogeneity and ubiquity of the Ty3-gypsy-like elements in H. syriacus genomes could provide reliable DNA markers for line identification as well for the analysis of genetic diversity in H. syriacus.

The complete chloroplast genome of Glycyrrhiza uralensis Fisch. isolated in Korea (Fabaceae)

  • KIM, Mi-Hee;PARK, Suhyeon;LEE, Junho;BAEK, Jinwook;PARK, Jongsun;LEE, Gun Woong
    • Korean Journal of Plant Taxonomy
    • /
    • v.51 no.4
    • /
    • pp.353-362
    • /
    • 2021
  • The chloroplast genome of Glycyrrhiza uralensis Fisch was sequenced to investigate intraspecific variations on the chloroplast genome. Its length is 127,689 bp long (34.3% GC ratio) with atypical structure of chloroplast genome, which is congruent to those of Glycyrrhiza genus. It includes 110 genes (76 protein-coding genes, four rRNAs, and 30 tRNAs). Intronic region of ndhA presented the highest nucleotide diversity based on the six G. uralenesis chloroplast genomes. A total of 150 single nucleotide polymorphisms and 10 insertion and deletion (INDEL) regions were identified from the six G. uralensis chloroplast genomes. Phylogenetic trees show that the six chloroplast genomes of G. uralensis formed the two clades, requiring additional studies to understand it.

A Review of the Phylogenetic Studies on the Kentish & Snowy Plovers

  • Woo-Yuel Kim;Dong-Yun Lee;Gun-hwa Kang;Ha-Cheol Sung
    • Proceedings of the National Institute of Ecology of the Republic of Korea
    • /
    • v.4 no.2
    • /
    • pp.63-68
    • /
    • 2023
  • The Kentish Plover (Charadrius alexandrinus ; family Charadriidae; genus Charadrius) is a small bird that moves from continent to continent depending on the season. On the Kentish Plovers, phylogenetic studies have been widely conducted to classify different species or subspecies and to determine the time of speciation. However, the perspectives on the interspecific or intraspecific relationships in the phylogenetic analysis of Kentish Plovers remain debatable. Here, we reviewed the differences between the Kentish and Snowy Plovers (C. nivosus ) in terms of their morphology, ecology, and genetic information. Particularly, their differences in genetic information can be well demonstrated; however, the intraspecies differences in the populations that live in different environments can relatively be poorly explained. We suggest that not only genetic features but also morphological, ecological, and behavioral traits are important when comparing the Kentish Plovers with other species, such as the Snowy Plovers, in phylogenetic studies. Furthermore, we suggest that phylogenetic studies on the subspecies of the Kentish and Snowy Plovers should be conducted for their better identification.

Sequence Diversity of a Domesticated Transposase Gene, MUG1, in Oryza Species

  • Kwon, Soon-Jae;Park, Kyong-Cheul;Son, Jae-Han;Bureau, Thomas;Park, Cheul-Ho;Kim, Nam-Soo
    • Molecules and Cells
    • /
    • v.27 no.4
    • /
    • pp.459-465
    • /
    • 2009
  • MUG1 is a MULE transposon-related domesticated gene in plants. We assessed the sequence diversity, neutrality, expression, and phylogenetics of the MUG1 gene among Oryza ssp. We found MUG1 expression in all tissues analyzed, with different levels in O. sativa. There were 408 variation sites in the 3886 bp of MUG1 locus. The nucleotide diversity of the MUG1 was higher than functionally known genes in rice. The nucleotide diversity (${\pi}$) in the domains was lower than the average nucleotide diversity in whole coding region. The ${\pi}$ values in nonsynonymous sites were lower than those of synonymous sites. Tajima D and Fu and Li $D^*$ values were mostly negative values, suggesting purifying selection in MUG1 sequences of Oryza ssp. Genome-specific variation and phylogenetic analyses show a general grouping of MUG1 sequences congruent with Oryza ssp. biogeography; however, our MUG1 phylogenetic results, in combination with separate B and D genome studies, might suggest an early divergence of the Oryza ssp. by continental drift of Gondwanaland. O. long-istaminata MUG1 divergence from other AA diploids suggests that it might not be a direct ancestor of the African rice species.

Genetic diversity analysis of Thai indigenous pig population using microsatellite markers

  • Charoensook, Rangsun;Gatphayak, Kesinee;Brenig, Bertram;Knorr, Christoph
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.10
    • /
    • pp.1491-1500
    • /
    • 2019
  • Objective: European pigs have been imported to improve the economically important traits of Thai pigs by crossbreeding and was finally completely replaced. Currently Thai indigenous pigs are particularly kept in a small population. Therefore, indigenous pigs risk losing their genetic diversity and identity. Thus, this study was conducted to perform large-scale genetic diversity and phylogenetic analyses on the many pig breeds available in Thailand. Methods: Genetic diversity and phylogenetics analyses of 222 pigs belonging to Thai native pigs (TNP), Thai wild boars (TWB), European commercial pigs, commercial crossbred pigs, and Chinese indigenous pigs were investigated by genotyping using 26 microsatellite markers. Results: The results showed that Thai pig populations had a high genetic diversity with mean total and effective ($N_e$) number of alleles of 14.59 and 3.71, respectively, and expected heterozygosity ($H_e$) across loci (0.710). The polymorphic information content per locus ranged between 0.651 and 0.914 leading to an average value above all loci of 0.789, and private alleles were found in six populations. The higher $H_e$ compared to observed heterozygosity ($H_o$) in TNP, TWB, and the commercial pigs indicated some inbreeding within a population. The Nei's genetic distance, mean $F_{ST}$ estimates, neighbour-joining tree of populations and individual, as well as multidimensional analysis indicated close genetic relationship between Thai indigenous pigs and some Chinese pigs, and they are distinctly different from European pigs. Conclusion: Our study reveals a close genetic relationship between TNP and Chinese pigs. The genetic introgression from European breeds is found in some TNP populations, and signs of genetic erosion are shown. Private alleles found in this study should be taken into consideration for the breeding program. The genetic information from this study will be a benefit for both conservation and utilization of Thai pig genetic resources.

Diversity of the Lichenized Fungi in King George Island, Antarctica, Revealed by Phylogenetic Analysis of Partial Large Subunit rDNA Sequences

  • Lee, Jin-Sung;Lee, Hong-Kum;Hur, Jae-Seoun;Andreev, Mikhail;Hong, Soon-Gyu
    • Journal of Microbiology and Biotechnology
    • /
    • v.18 no.6
    • /
    • pp.1016-1023
    • /
    • 2008
  • Lichens are predominant and important components of flora in the terrestrial ecosystem of Antarctica. However, relatively few researches on the phylogenetic position of Antarctic lichen-forming fungi have been accomplished. In this study, partial sequences of nuclear large subunit rDNAs from 50 Antarctic specimens were obtained and the phylogeny was reconstructed. Antarctic lichen species were distributed in 4 orders, including the monophyletic order Agyrales, paraphyletic orders Pertusariales and Teloschistales, and polyphyletic order Lecanorales. Species diversity was highest in the order Lecanorales, followed by Teloschistales and Pertusariales. Based on the phylogeny and sequence similarity analyses, it is proposed that the taxonomy of Stereocaulon alpinum, Physcia caesia, Usnea aurantiacoatra, and Cladonia species should be revised by careful examination of their phenotypic and molecular characteristics. Six species known to be endemic to Antarctica, Catillaria corymbosa, Himantormia lugubris, Leptogium puberulum, Pertusaria pertusa, Rhizoplaca aspidophora, and Umbilicaria antarctica, formed unique lineages, implying independent origins in the Antarctic area.

Genetic Diversity and Molecular Phylogeny of Cyanobacteria from Sri Lanka Based on 16S rRNA Gene

  • Wanigatunge, R.P.;Magana-Arachchi, D.N.;Chandrasekharan, N.V.;Kulasooriya, S.A.
    • Environmental Engineering Research
    • /
    • v.19 no.4
    • /
    • pp.317-329
    • /
    • 2014
  • The diversity of cyanobacteria in Sri Lanka was studied in different water reservoirs, paddy fields, brackish water and tsunami affected areas using light microcopy, 16S rRNA sequences, followed by phylogenetic analysis. Based on light microscopy, 24 genera were identified from environmental samples belonging to the orders Chroococcales, Oscillatoriales, Pleurocapsales and Nostocales. In cultures, 33 genera were identified from all five cyanobacterial orders, including Stigonematales. Based on 16S rRNA gene sequences and their morphology, two isolates were identified up to species level, 72 to genus level, one isolate up to family and 11 up to order level. Twelve isolates couldn't be assigned to any taxonomic level. The results of 16S rRNA gene sequences along with the phylogenetic analysis indicated that some cyanobacterial isolates could be accommodated to genus or order level. The 16S rRNA sequence analysis data in this study confirmed that order Nostocales and order Pleurocapsales cyanobacteria are monophyletic while orders Chroococcales, Oscillatoriales and Stigonematales cyanobacteria are polyphyletic. Polyphasic approach including the combination of light microscopy, cultures and the analysis of 16S rRNA gene sequences provide a promising approach to ascertain the diversity of cyanobacteria in different habitats.