scholarly journals Molecular data attest to the occurrence of autochthonous Daphnia pulex (Crustacea, Branchiopoda) populations in Sicily, Italy

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Luca Vecchioni ◽  
Marco Arculeo ◽  
Federico Marrone

Biological invasions are known to be among the most important threats to the long-term conservation of native biota, and their effects might be even more difficult to contrast when they are cryptic, i.e., when the non-native invaders cannot be easily recognised based on morphology, and can thus be confused with native taxa. Such cryptic invasions are known to widely occur in the cladoceran genus Daphnia O.F. Müller, 1785, so that the actual distribution and status of most species and lineages need to be checked with a genetic approach. In the frame of this work, we investigated if the Sicilian populations of D. (Daphnia) pulex Leydig, 1860 belonged to the allochthonous North American lineage, which is known to occur in several regions of the Palearctic and Afrotropical biogeographical regions, or rather to the autochthonous European lineage of the species. The molecular results obtained, based on a fragment of the mitochondrial gene encoding for NADH subunit dehydrogenase 5 (ND5), allowed us to rule out the allochthonous status of the species, confirming the presence of autochthonous relictual lineages of D. pulex in Sicily. The native status of these populations is in agreement with their local distribution, limited to natural and poorly-impacted water bodies mostly located in wooded areas at medium and high altitudes. The current local distribution of D. pulex in Sicily is possibly linked to the end of the last glacial maximum and the onset of warmer climatic conditions in the early Holocene, which led the species to take refuge in colder microthermal refugia located at high altitudes, determining their current relictual distribution. 

2000 ◽  
Vol 31 (1) ◽  
pp. 71-90 ◽  
Author(s):  
Nils Møller Andersen ◽  
Jakob Damgaard ◽  
Felix A.H. Sperling

AbstractWe examined phylogenetic relationships among gerrid water striders of the genus Aquarius Schellenberg using molecular and morphological characters. The molecular data sets included 780 bp sequence data from the mitochondrial gene encoding cytochrome oxidase subunit I (COI), and 515 bp sequence data from the nuclear gene encoding elongation factor I alpha (EF-1α). The morphological data set was a slightly modified version of a previously published data set. We included all 17 known species and one subspecies of Aquarius as well as five species from three related genera, Gigantometra gigas, Limnoporus esakii, L. rufoscutellatus, Gerris pingreensis, and G. lacustris. Unweighted parsimony analyses of the COI data set gave a single most parsimonious tree (MPT) with a topology quite similar to the morphological tree. Parsimony analyses of the EF-1α data set gave 3 MPT's and a strict consensus of these trees gave a tree with a slightly different topology. A combined analysis of the three data sets gave a single MPT with the same topology as for the morphological data set alone. The phylogeny of Aquarius presented here supports the monophyly of the A. najas, remigis, conformis and paludum species groups as well as previous hypotheses about their relationships. On the other hand, the inclusion of molecular data weakens the support for the monophyly of the genus Aquarius, and questions the specific status of the eastern North American A. nebularis (as separate from A. conformis) and members of the Nearctic A. remigis group. Finally, we discuss the implications of the reconstructed phylogeny in the biogeography and ecological phylogenetics of Aquarius.


2013 ◽  
Vol 145 (5) ◽  
pp. 509-520 ◽  
Author(s):  
Juan M. Nieto Nafría ◽  
Nicolás Pérez Hidalgo ◽  
David Martínez-Torres ◽  
William Villalobos Muller

AbstractAphid species colonising ferns belong to the subfamily Aphidinae (Hemiptera: Aphididae) and the majority of these to the tribe Macrosiphini. A new genus in this tribe and its type species: Gibbomyzus pteridophytorumnew genus, new species, are established. Apterous and alate viviparous females are described from specimens collected on Blechnum buchtienii Rosenstock (Blechnaceae) in Costa Rica and on Pteridium aquilinum (Linnaeus) Kuhn (Dennstaedtiaceae) and an unidentified fern in Mexico. The taxonomic validity of the two new taxa is discussed based on morphological and molecular data. Morphologically, the new genus is compared with genera with swollen siphunculi recorded in the New World, and also with genera living on ferns anywhere in the world. The identification key by Blackman and Eastop to aphids living on ferns is modified. Molecular analyses were carried out on the sequences of a fragment of the mitochondrial gene encoding for cytochrome c oxidase subunit 1 and of a fragment of the nuclear gene encoding elongation factor-1 alpha. In both analyses, G. pteridophytorumnewspecies sequences showed considerable divergence (∼4% or more) from those of 23 other species from diverse genera of Macrosiphini, supporting the conclusions of the morphological study and justifying the establishment of the new genus.


Author(s):  
Li Ding ◽  
Zening Chen ◽  
Chatmongkon Suwannapoom ◽  
Tan Van Nguyen ◽  
Nikolay A. Poyarkov ◽  
...  

An investigation of the taxonomic status of Pareas hamptoni (Hampton's Slug snake) based on morphological and molecular data revealed a new distinct species from the Golden Triangle region (comprising parts of southern China, and adjacent Laos and Thailand). The new species is shown to be a sister species to P. hamptoni but can be separated from the latter by having 3–5 dorsal scale rows at midbody slightly keeled (vs 5–9 scales strongly keeled); a lower number of ventrals, 170–188 (vs 185–195); and a lower number of subcaudals, 67–91 (vs 91–99). The new species is currently known from northwestern Thailand, northern Laos, and the southern part of Yunnan Province in China at elevations of 1,160–2,280 m a.s.l. We suggest that the new species to be considered of Least Concern (LC) in the IUCN‘s Red List categories. Problems of taxonomy and actual distribution of the P. hamptoni complex are briefly discussed; our results show P. hamptoni is now reliably known only from Myanmar and Vietnam, but its occurrence in Yunnan Province of China is likely.


Zootaxa ◽  
2018 ◽  
Vol 4403 (2) ◽  
pp. 378 ◽  
Author(s):  
EUGENYI A. MAKARCHENKO ◽  
MARINA A. MAKARCHENKO ◽  
ALEXANDER A. SEMENCHENKO ◽  
DMITRY M. PALATOV

Illustrated descriptions of the adult male, pupa and fourth instar larva, as well as DNA barcoding results of Chaetocladius (Chaetocladius) elisabethae sp. nov. in comparison with closely related species of Chaetocladius s. str. from the Moscow Region are provided. A reference 658 bp barcode sequence from a fragment of the mitochondrial gene cytochrome oxidase I (COI) was used as a tool for species delimitation. Comparisons with corresponding regions of COI between C. (s. str.) elisabethae sp. nov. and other species of the subgenus produced K2P genetic distances of 0.11–0.16, values well associated with interspecific variation. The barcodes of the new species were identical to the Chaetocladius sp. 2ES in BOLD systems. Molecular data were also used for the reconstruction of the phylogenetic relationships within the subgenus Chaetocladius s. str. 


2012 ◽  
Vol 23 (21) ◽  
pp. 4297-4312 ◽  
Author(s):  
Alicia García ◽  
Alejandro Collin ◽  
Olga Calvo

The transcriptional coactivator Sub1 has been implicated in several steps of mRNA metabolism in yeast, such as the activation of transcription, termination, and 3′-end formation. In addition, Sub1 globally regulates RNA polymerase II phosphorylation, and most recently it has been shown that it is a functional component of the preinitiation complex. Here we present evidence that Sub1 plays a significant role in transcription elongation by RNA polymerase II (RNAPII). We show that SUB1 genetically interacts with the gene encoding the elongation factor Spt5, that Sub1 influences Spt5 phosphorylation of the carboxy-terminal domain of RNAPII largest subunit by the kinase Bur1, and that both Sub1 and Spt5 copurify in the same complex, likely during early transcription elongation. Indeed, our data indicate that Sub1 influences Spt5–Rpb1 interaction. In addition, biochemical and molecular data show that Sub1 influences transcription elongation of constitutive and inducible genes and associates with coding regions in a transcription-dependent manner. Taken together, our results indicate that Sub1 associates with Spt5 and influences Spt5–Rpb1 complex levels and consequently transcription elongation rate.


Zootaxa ◽  
2018 ◽  
Vol 4476 (1) ◽  
pp. 40
Author(s):  
RYAN J. THONI ◽  
DHAN B. GURUNG

Torrent catfishes of the subfamily Glyptosterninae from Bhutan are examined based on morphological and molecular data. Five new species are described: Creteuchiloglanis bumdelingensis sp. nov., Exostoma mangdechhuensis sp. nov., Parachiloglanis benjii sp. nov., P. dangmechhuensis sp. nov., and P. drukyulensis sp. nov. Molecular data derived from the mitochondrial gene Cyt b and the nuclear gene RAG2 recovered relationships within Parachiloglanis and the Glyptosterninae. A dichotomous key to the Glyptosterninae of Bhutan is provided.


Zootaxa ◽  
2004 ◽  
Vol 634 (1) ◽  
pp. 1 ◽  
Author(s):  
Oscar Arribas ◽  
Salvador Carranza

Iberolacerta cyreni martinezricai is elevated to the species level (I. martinezricai) based on both morphological and molecular data. The phylogenetic analysis using two mitochondrial and one nuclear gene shows I. martinezricai is more closely related to I. monticola than to I. cyreni. A multivariate analysis of the morphological data also supports the affinities between I. martinezricai and I. monticola but, at the same time, clearly indicates that I. martinezricai is morphologically distinct from both I. monticola and I. cyreni. The molecular data suggests I. cyreni and the clade formed by I. monticola + I. martinezricai split approximately 6.1 Mya, during the Mesinian Salinity Crisis, when climatic conditions around the Mediterranean area changed dramatically as a result of the desiccation of the Mediterranean Sea. Separation between I. martinezricai and I. monticola occurred approximately 2 Mya but, with at least two equally plausible alternative hypotheses, their biogeography is still unclear. New data on the habitat and distribution of I. martinezricai indicates its distribution area is very small (12 15 km 2 ), and that it lives in a climatically extreme habitat for this kind of mountain species. As a result of that and the low numbers of individuals, I. martinezricai is considered here as Critically Endangered.


2003 ◽  
Vol 34 (3) ◽  
pp. 313-327 ◽  
Author(s):  
Herbert Zettel ◽  
Jakob Damgaard

AbstractWe investigated genetic diversity and phylogeny of all water strider species assigned to the Aquarius paludum species group on basis of 425 bp DNA sequence data from the mitochondrial gene encoding cytochrome oxidase subunit I (COI). Parsimony analyses and genetic distances confirmed the taxonomic status of the two recently described species Aquarius lili Polhemus & Polhemus, 1994 from Timor and A. philippinensis Zettel & Ruiz, 2003 from the Philippines as being separate from the widespread Oriental A. adelaidis (Dohrn, 1860). Molecular clock estimates suggest that the disjunct zoogeographical pattern among the three species is due to a Pliocene/Pleistocene long-range dispersal, rather than a Mesozoic vicariance event as previously suggested. However, when we superimposed the disjunct distribution of Southern Hemisphere representatives of the paludum-group onto their phylogenetic relationship, the pattern indicated vicariance events following the break-up of Gondwana.


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