scholarly journals Mismatch induced speciation in Salmonella : model and data

2006 ◽  
Vol 361 (1475) ◽  
pp. 2045-2053 ◽  
Author(s):  
Daniel Falush ◽  
Mia Torpdahl ◽  
Xavier Didelot ◽  
Donald F Conrad ◽  
Daniel J Wilson ◽  
...  
Keyword(s):  
New Species ◽  
Natural Selection ◽  
Dna Sequence ◽  
Computer Simulations ◽  
De Novo ◽  
Sequence Data ◽  
Biological Species ◽  
Species Boundaries ◽  
Population Subdivision ◽  
Geographical Population

In bacteria, DNA sequence mismatches act as a barrier to recombination between distantly related organisms and can potentially promote the cohesion of species. We have performed computer simulations which show that the homology dependence of recombination can cause de novo speciation in a neutrally evolving population once a critical population size has been exceeded. Our model can explain the patterns of divergence and genetic exchange observed in the genus Salmonella , without invoking either natural selection or geographical population subdivision. If this model was validated, based on extensive sequence data, it would imply that the named subspecies of Salmonella enterica correspond to good biological species, making species boundaries objective. However, multilocus sequence typing data, analysed using several conventional tools, provide a misleading impression of relationships within S. enterica subspecies enterica and do not provide the resolution to establish whether new species are presently being formed.

A new Liopeltis Fitzinger, 1843 (Squamata: Colubridae) from Pulau Tioman, Peninsular Malaysia

Zootaxa ◽  
2020 ◽  
Vol 4766 (3) ◽  
pp. 472-484
Author(s):  
HANNAH E. SOM ◽  
L. LEE GRISMER ◽  
PERRY L. JR. WOOD ◽  
EVAN S. H. QUAH ◽  
RAFE M. BROWN ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
New Species ◽  
Dna Sequence ◽  
Rare Species ◽  
Sequence Data ◽  
Peninsular Malaysia ◽  
Tropical Asia ◽  
Dna Sequence Data ◽  
A New Species ◽  
Lines Of Evidence

Liopeltis is a genus of poorly known, infrequently sampled species of colubrid snakes in tropical Asia. We collected a specimen of Liopeltis from Pulau Tioman, Peninsular Malaysia, that superficially resembled L. philippina, a rare species that is endemic to the Palawan Pleistocene Aggregate Island Complex, western Philippines. We analyzed morphological and mitochondrial DNA sequence data from the Pulau Tioman specimen and found distinct differences to L. philippina and all other congeners. On the basis of these corroborated lines of evidence, the Pulau Tioman specimen is described as a new species, L. tiomanica sp. nov. The new species occurs in sympatry with L. tricolor on Pulau Tioman, and our description of L. tiomanica sp. nov. brings the number of endemic amphibians and reptiles on Pulau Tioman to 12. 

A new species of trypanosome, Trypanosoma desterrensis sp. n., isolated from South American bats

Parasitology ◽  
2003 ◽  
Vol 127 (3) ◽  
pp. 265-271 ◽  
Author(s):  
E. C. GRISARD ◽  
N. R. STURM ◽  
D. A. CAMPBELL
Keyword(s):  
New Species ◽  
Dna Sequence ◽  
Sequence Data ◽  
Rrna Gene ◽  
South American ◽  
Sequence Variability ◽  
Dna Sequence Data ◽  
Hybridization Probes ◽  
5S Rrna Gene ◽  
A New Species

Trypanosomes isolated from South American bats include the human pathogen Trypanosoma cruzi. Other Trypanosoma spp. that have been found exclusively in bats are not well characterized at the DNA sequence level and we have therefore used the SL RNA gene to differentiate and characterize kinetoplastids isolated from bats in South America. A Trypanosoma sp. isolated from bats in southern Brazil was compared with the geographically diverse isolates T. cruzi marinkellei, T. vespertilionis, and T. dionisii. Analysis of the SL RNA gene repeats revealed size and sequence variability among these bat trypanosomes. We have developed hybridization probes to separate these bat isolates and have analysed the DNA sequence data to estimate their relatedness. A new species, Trypanosoma desterrensis sp. n., is proposed, for which a 5S rRNA gene was also found within the SL RNA repeat.

scholarly journals Helminthosporium velutinum and H. aquaticum sp. nov. from aquatic habitats in Yunnan Province, China

Phytotaxa ◽  
2016 ◽  
Vol 253 (3) ◽  
pp. 179 ◽  
Author(s):  
DAN ZHU ◽  
ZONG-LONG LUO ◽  
DARBHE JAYARAMA BAHT ◽  
ERIC.H.C. MCKENZIE ◽  
ALI H. BAHKALI ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Tree ◽  
Dna Sequence ◽  
Yunnan Province ◽  
Sequence Data ◽  
Its Sequence ◽  
Aquatic Habitats ◽  
Submerged Wood ◽  
Dna Sequence Data ◽  
A New Species

Helminthosporium species from submerged wood in streams in Yunnan Province, China were studied based on morphology and DNA sequence data. Descriptions and illustrations of Helminthosporium velutinum and a new species H. aquaticum are provided. A combined phylogenetic tree, based on SSU, ITS and LSU sequence data, place the species in Massarinaceae, Pleosporales. The polyphyletic nature of Helminthosporium species within Massarinaceae is shown based on ITS sequence data available in GenBank.

scholarly journals The Genera of Fungi – G6: Arthrographis, Kramasamuha, Melnikomyces, Thysanorea, and Verruconis

2020 ◽  
Vol 6 (1) ◽  
pp. 1-24
Author(s):  
M. Hernández-Restrepo ◽  
A. Giraldo ◽  
R. van Doorn ◽  
M.J. Wingfield ◽  
J.Z. Groenewald ◽  
...  
Keyword(s):  
New Species ◽  
Dna Sequence ◽  
Type Species ◽  
New Genus ◽  
Sequence Data ◽  
Dna Sequence Data ◽  
Two New Species ◽  
First Time

The Genera of Fungi series, of which this is the sixth contribution, links type species of fungal genera to their morphology and DNA sequence data. Five genera of microfungi are treated in this study, with new species introduced in Arthrographis, Melnikomyces, and Verruconis. The genus Thysanorea is emended and two new species and nine combinations are proposed. Kramasamuha sibika, the type species of the genus, is provided with DNA sequence data for first time and shown to be a member of Helminthosphaeriaceae (Sordariomycetes). Aureoconidiella is introduced as a new genus representing a new lineage in the Dothideomycetes.

A new species of big-headed, fanged dicroglossine frog (Genus Limnonectes) from Thailand

Zootaxa ◽  
2008 ◽  
Vol 1807 (1) ◽  
pp. 26 ◽  
Author(s):  
DAVID S. McLEOD
Keyword(s):  
New Species ◽  
Dna Sequence ◽  
Sequence Data ◽  
Sequence Divergence ◽  
Type Material ◽  
Base Pairs ◽  
Dna Sequence Data ◽  
16S Gene ◽  
A New Species

A new species of the dicroglossine genus Limnonectes from eastern Thailand and its tadpole are described. Analysis of DNA sequence data from 2518 base-pairs of the mitochondrial 12S and 16S gene regions places the species within the complex of frogs currently referred to as Limnonectes kuhlii and demonstrates it to be a separate lineage (>18% sequence divergence from type-material of L. kuhlii from Java). The new species differs from L. kuhlii by having nuptial pads, a greater snout–vent length, and different relative finger lengths than specimens from Java. It has more extensive toe webbing, a different arrangement of nuptial pads, and a greater snout–vent length than Limnonectes laticeps. The new species, which lacks vocal slits, also can be distinguished from the morphologically similar Limnonectes namiyei from Japan, which possesses vocal slits.

Steinernema khuongin. sp. (Panagrolaimomorpha, Steinernematidae), a new entomopathogenic nematode species from Florida, USA

2018 ◽  
Vol 93 (2) ◽  
pp. 226-241 ◽  
Author(s):  
S.P. Stock ◽  
R. Campos-Herrera ◽  
F.E. El-Borai ◽  
L.W. Duncan
Keyword(s):  
New Species ◽  
Sequence Data ◽  
Novel Species ◽  
Entomopathogenic Nematode ◽  
Biological Species ◽  
Morphological Data ◽  
Biological Species Concept ◽  
The Novel ◽  
Ecological Data ◽  
Cross Hybridization

AbstractIn this study, molecular (ribosomal sequence data), morphological and cross-hybridization properties were used to identify a newSteinernemasp. from Florida, USA. Molecular and morphological data provided evidence for placing the novel species into Clade V, or the ‘glaseri-group’ ofSteinernemaspp. Within this clade, analysis of sequence data of the rDNA genes, 28S and internal transcribed spacer (ITS), depicted the novel species as a distinctive entity and closely related toS. glaseriandS. cubanum.Additionally, cross-hybridization assays showed that the new species is unable to interbreed with either of the latter two species, reinforcing its uniqueness from a biological species concept standpoint. Key morphological diagnostic characters forS. khuongin. sp. include the mean morphometric features of the third-stage infective juveniles: total body length (average: 1066 μm), tail length (average: 65 μm), location of the excretory pore (average: 80.5 μm) and the values ofc(average: 16.4),D% (average: 60.5),E% (average: 126) andH% (average: 46.6). Additionally, males can be differentiated fromS. glaseriandS. cubanumby the values of several ratios:D% (average: 68),E% (average: 323) and SW% (average: 120). The natural distribution of this species in Florida encompasses both natural areas and citrus groves, primarily in shallow groundwater ecoregions designated as ‘flatwoods’. The morphological, molecular, phylogenetic and ecological data associated with this nematode support its identity as a new species in theS. glaseri-group.

Eupholidoptera karatolosi sp.n. and E. mirzayani sp.n. (Orthoptera,  Tettigoniidae), two new bushcrickets from Greece and Iran

Zootaxa ◽  
2007 ◽  
Vol 1562 (1) ◽  
pp. 43-53
Author(s):  
MOHSEN MOFIDI-NEYESTANAK ◽  
DONALD L.J. QUICKE
Keyword(s):  
New Species ◽  
Dna Sequence ◽  
Related Species ◽  
Sequence Data ◽  
Identification Key ◽  
Phylogenetic Study ◽  
Species Relationships ◽  
Closely Related Species ◽  
Dna Sequence Data ◽  
Two New Species

Eupholidoptera karatolosi Mofidi-Neyestanak & Quicke from Greece and E. mirzayani Mofidi-Neyestanak & Quicke from Iran, two new species of bushcrickets (Orthoptera, Tettigoniidae: Platycleidini), are described and distinguished from closely related species based on morphology. Species relationships within Eupholidoptera Maran are discussed and some species are given new assignments. A simplified illustrated identification key to the species of Eupholidoptera is provided to accommodate the new species. They are being described since they have been used to generate DNA sequence data that will be published elsewhere as part of a phylogenetic study of the tribe Platycleidini.

Two new species of shrub frogs (Rhacophoridae: Pseudophilautus) from Sri Lanka

Zootaxa ◽  
2011 ◽  
Vol 2747 (1) ◽  
pp. 1 ◽  
Author(s):  
MADHAVA MEEGASKUMBURA ◽  
KELUM MANAMENDRA-ARACHCHI
Keyword(s):  
Mitochondrial Dna ◽  
New Species ◽  
Dna Sequence ◽  
Sequence Data ◽  
Outer Edge ◽  
Valid Species ◽  
Sri Lankan ◽  
Anthropogenic Habitats ◽  
Dna Sequence Data ◽  
Two New Species

Two new species of Sri Lankan shrub frogs of the genus Pseudophilautus are described. These species are diagnosed from their congeners on the basis of morphology, morphometrics and mitochondrial DNA sequence data. Pseudophilautus schneideri, new species, is distinguished from all Sri Lankan Pseudophilautus by its small size (< 22.8 mm SVL), distinct tympanum and supratympanic fold, sharp canthal edges, granular throat, chest and belly, and absence or presence of a vomerine ridge. Pseudophilautus hankeni, new species, is distinguished by its diminutive size (< 21.9 mm SVL), distinct tympanum, rounded canthal edges, tuberculated outer edge of lower arm, tuberculated dermal fold on outer edge of foot, granular throat, chest and belly, and the absence of a vomerine ridge. Pseudophilautus schneideri inhabits shrubs in open areas of the low to mid-elevations of the island’s south-western ‘wet zone’ (rainfall > 2,000 mm•yr -1 ), including anthropogenic habitats, while P. hankeni is found on shrubs in the understorey of montane forests of the highest peaks (c. 1,200– 1,600 m elevation) of the Knuckles region. These descriptions bring the total number of valid species of Sri Lankan Pseudophilautus to 67, 48 of which are extant.

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