scholarly journals Molecular taxonomy of some sponges (Demospongiae) using ribosomal (18s rrna) and partial mitochondrial (coi) genes

2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Ton That Huu Dat ◽  
Nguyen Thi Kim Cuc ◽  
Pham Viet Cuong

Sponges, the most ancient multicellular metazoan, were widely distributed across habitats. Vietnam is known to possess a high biodiversity of sponges, however, they are mostly identified based on morphological characteristics and lack the molecular data. In the current study, the phylogenetic relationship of some sponges (Demospongiae) in Vietnam was constructed using two independent markers (COI and 18S rRNA). In this paper the individual markers (COI and 18S rRNA) were successfully used to identify some sponge taxa at the species level. The obtained results showed the congruence of molecular taxonomy using two independent markers. However, our study showed that a combination of the two markers provided more information and supported better for sponge identification. At order level, the COI tree and 18S rRNA tree also recovered the same clades, indicating the congruence of COI and 18S rRNA genes in sponge classification. However, branching order of the clades in COI tree was weakly supported and slightly different from those in 18S rRNA tree. 

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 590
Author(s):  
Hyun Woo Bang ◽  
Heejin Moon ◽  
Jinwook Back

Benthic harpacticoids were collected from Korean waters. Two species were identified as members of the genus Longipedia Claus, 1863, because they have an extremely elongated distal segment of the P2 endopod. Longipedia koreana sp. nov. is morphologically most closely related to L. nichollsi Wells, 1980 and L. scotti Sars, 1903, but it can clearly be distinguished from both species based on the following morphological characteristics: P1 coxa with strong spinules near the outer margin and the distal element being much bigger than the proximal elements, P2 coxa with a small inner seta on the anterior surface, P4 exopod first segment without an inner element, and the P5 with a rectangular exopod (more than 3.5 times as long as wide). L. ulleungensis sp. nov. is similar to L. brevispinosa Gurney, 1927, L. spinulosa Itô, 1981, and L. weberi Scott A., 1909. However, L. ulleungensis sp. nov. is characterized by the P2 coxa with a reduced inner seta, the P4 exopod second segment without an inner seta, and the anal operculum with a long median projection, a single spine, and a group of outer spines on each side. In a molecular analysis using the mitochondrial cytochrome c oxidase subunit I (COI) and 18S ribosomal RNA (18S rRNA) genes, the inter-specific variation was 22.525–23.102% and 1.325–1.382% of COI and 18S rRNA between the two new species, respectively. A key to the family Longipediidae is provided herein.


Nematology ◽  
2014 ◽  
Vol 16 (9) ◽  
pp. 1019-1045 ◽  
Author(s):  
Mohammad Reza Atighi ◽  
Ebrahim Pourjam ◽  
Razieh Ghaemi ◽  
Majid Pedram ◽  
Gracia Liébanas ◽  
...  

Rotylenchus arasbaranensis n. sp., a new monosexual species is described and illustrated based on morphological, morphometric and molecular studies. The new species is characterised by having an offset and hemispherical lip region with 5-6 annuli, 32-36 μm long stylet, vulva located at 43.9-59.2% with a single epiptygma and rounded tail, rarely bilobed, with 6-8 annuli. The species R. striaticeps and the male of R. buxophilus are reported for the first time from Iran and R. fragaricus is reported and studied for the second time after its original description. The results of the phylogenetic analyses based on the sequences of the D2-D3 expansion region of the 28S, ITS1-rRNA and the partial 18S rRNA genes were provided for the studied species, confirming their differences from each other and determining the position of them and their relationships with closely related taxa. Also, the validity of Plesiorotylenchus is discussed on the basis of molecular data and its synonymisation (with only one sequence) with Rotylenchus is accepted.


Nematology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Sergei A. Subbotin ◽  
Donggeun Kim

Summary Molecular characterisation of two species of Meloinema: M. chitwoodi from Oregon, USA, and M. odesanens from South Korea, is given based on the partial 18S rRNA, the D2-D3 of 28S rRNA, ITS rRNA, and COI gene sequences. In the phylogenetic trees, Meloinema clustered with Meloidogyne, in a basal position and more closely with Meloidogyne indica and M. nataliei. The Shimodaira-Hasegawa (SH) maximum likelihood testing of an alternative topology with two gene fragments (D2-D3 of 28S rRNA and 18S rRNA genes) did not reject a sister relationship of Meloidogyne and Meloinema. Molecular results confirmed the view of Siddiqi (2000) that Meloidogyne and Meloinema evolved from a Pratylenchidae-type ancestor. The clade Meloinema + Meloidogyne + Nacobbus was rejected by the SH test of the D2-D3 of 28S rRNA gene sequence dataset. The molecular results suggested that the genus Nacobbus should be placed not in the Meloidogynidae, but in a separate subfamily, the Nacobbinae, under the family Pratylenchidae.


2021 ◽  
Vol 95 ◽  
Author(s):  
B. Neov ◽  
G.P. Vasileva ◽  
G. Radoslavov ◽  
P. Hristov ◽  
D.T.J. Littlewood ◽  
...  

Abstract The aim of the study is to test a hypothesis for the phylogenetic relationships among mammalian hymenolepidid tapeworms, based on partial (D1–D3) nuclear 28S ribosomal RNA (rRNA) genes, by estimating new molecular phylogenies for the group based on partial mitochondrial cytochrome c oxidase I (COI) and nuclear 18S rRNA genes, as well as a combined analysis using all three genes. New sequences of COI and 18S rRNA genes were obtained for Coronacanthus integrus, C. magnihamatus, C. omissus, C. vassilevi, Ditestolepis diaphana, Lineolepis scutigera, Spasskylepis ovaluteri, Staphylocystis tiara, S. furcata, S. uncinata, Vaucherilepis trichophorus and Neoskrjabinolepis sp. The phylogenetic analyses confirmed the major clades identified by Haukisalmi et al. (Zoologica Scripta 39: 631–641, 2010): Ditestolepis clade, Hymenolepis clade, Rodentolepis clade and Arostrilepis clade. While the Ditestolepis clade is associated with soricids, the structure of the other three clades suggests multiple evolutionary events of host switching between shrews and rodents. Two of the present analyses (18S rRNA and COI genes) show that the basal relationships of the four mammalian clades are branching at the same polytomy with several hymenolepidids from birds (both terrestrial and aquatic). This may indicate a rapid radiation of the group, with multiple events of colonizations of mammalian hosts by avian parasites.


2007 ◽  
Vol 74 (1) ◽  
pp. 329-332 ◽  
Author(s):  
Leah M. Feazel ◽  
John R. Spear ◽  
Alicia B. Berger ◽  
J. Kirk Harris ◽  
Daniel N. Frank ◽  
...  

ABSTRACT To determine the eucaryotic diversity of the hypersaline Guerrero Negro microbial mat, we amplified 18S rRNA genes from DNA extracted from this mat and constructed and analyzed clone libraries. The extent of eucaryotic diversity detected was remarkably low, only 15 species among 890 clones analyzed. Six eucaryotic kingdoms were represented, as well as a novel cluster of sequences. Nematode sequences dominated the clone libraries.


2020 ◽  
Vol 57 (2) ◽  
pp. 179-184
Author(s):  
P. F. Barradas ◽  
A. R. Flores ◽  
T. L. Mateus ◽  
F. Carvalho ◽  
F. Gärtner ◽  
...  

SummaryCrenosoma striatum is a host-specifi c metastrongiloid nematode causing respiratory tract disease in hedgehogs (Erinaceus europaeus). Since few studies have reported C. striatum in hedgehogs and little genetic data is available concerning this lungworm, this study aimed to determine the occurrence of C. striatum in a population sample of hedgehogs from Portugal, additionally providing morphological, histological and molecular data. From 2017 to 2018 a survey of infection was carried out in 11 necropsied hedgehogs. Worms were extracted from fresh lung tissues and microscopically evaluated. Molecular characterization of partial mitochondrial (12S rRNA) and nuclear (18S rRNA) genes was performed. The presence of lungworms in pulmonary tissues of five hedgehogs (45.5%) was detected. Morphological and histopathological analyses evidenced adult forms of nematodes consistent with C. striatum. Molecular characterization of 18S rRNA genes confirmed the classifi cation as C. striatum. Also, novel genetic data characterizing the mitochondrial (12S rRNA) gene of C. striatum is presented.This is the first report of C. striatum infection in hedgehogs of Portugal. The findings here reported provide new insights regarding the geographic distribution and the molecular identification of this lungworm species.


2020 ◽  
Vol 7 (1) ◽  
pp. 28-34
Author(s):  
Anbarasi G ◽  
Vishnupriya B

Conventional taxonomy is limited with delineating species and controversies arise with DNA barcoding based identifications. Hence, an alternative supporting approach is very much needed to identify species and differentiate them within the species based on the genetic material. 18S rRNA genes have been particularly helpful in analyzing phylogeny at the species level. In addition, bioinformatics which represents a new, growing area of science uses computational approaches to answer biological questions. Salt tolerant costal salt marsh plant of Suaeda maritima was selected for 18s rRNA sequencing to solve the ambiguity in itsspecies level identification. Similarity search of study species shared 99% similarity with 5 species of Atriplex canescens clone s128, Atriplex torreyi var. griffithsii clone p508, Spinacia oleracea, Oenothera laciniata clone,Beta vulgaris. Phylogenetic tree infer that S.maritima is closely related to Spinacia oleracea and Oenothera laciniata. Atriplex canescens (fourwing saltbush), Atriplex torreyi and Phaulothamnus spinescens, Celosia argentea found to be closely related and are in one group. Hence, this study result clearly shows thus study species evaluated from angiosperm and provides key step in understanding the evolution of salt tolerance in angiosperm.


Phytotaxa ◽  
2021 ◽  
Vol 480 (1) ◽  
pp. 1-21
Author(s):  
SOFIA S. SADOGURSKA ◽  
JOÃO NEIVA ◽  
ANNALISA FALACE ◽  
ESTER A. SERRÃO ◽  
ÁLVARO ISRAEL

Brown algae of the genus Cystoseira sensu lato form the most diverse and productive marine ecosystems throughout the Mediterranean Sea and have equal roles also in the Black Sea where they have been decreasing in the recent years. The taxonomy of Cystoseira s.l. taxa from the Black Sea is still not well understood, and questions arise when related taxa have to be delimited. In addition to morphological descriptions, this study provides for the first time molecular data of the Black Sea Cystoseira s.l. distinct morphologies as an additional tool to clarify their identities and phylogenetic affinities. The analysis of two mitochondrial markers (cytochrome oxidase subunit 1—COI, and 23S-tRNAVal intergenic spacer—mt-spacer) showed that Cystoseira s.l. specimens from the Black Sea belong to two recently resurrected genera, namely Gongolaria and Ericaria. Molecular data confirm the morphological identification of G. barbata, which is characterized by high morphological plasticity in the Black Sea. The morphological data presented in this study support the transition of G. barbata to the genus Gongolaria, which was previously proposed based solely on genetic data. For the Black Sea endemic taxon C. bosphorica, sequence divergence suggests conspecificity with Mediterranean Sea species E. crinita and E. barbatula. However, considering original morphological characteristics of the taxon, its geographical isolation, and endemism, the new combination Ericaria crinita f. bosphorica comb. nov. is proposed.


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