A preliminary assessment of genetic divergence and distribution of Malagasy cave fish in the genus Typhleotris (Teleostei: Milyeringidae)

Zootaxa ◽  
2018 ◽  
Vol 4378 (3) ◽  
pp. 367 ◽  
Author(s):  
MIGUEL VENCES ◽  
JEAN R. RASOLOARINIAINA ◽  
JANA C. RIEMANN

The genus Typhleotris contains three poorly known blind fish species, inhabiting aquifers in the limestone plateau of south-western Madagascar. Until recently these species were known from only few localities, and their pattern of genetic differentiation remains poorly studied. In this study we analyse 122 Typhleotris tissue samples collected from 12 localities, spanning the entire known range of the genus, and use DNA sequences to assign these samples to the three species known. The phylogeny based on the mitochondrial marker cox1 revealed three main clades corresponding to the three species: Typhleotris madagascariensis, T. mararybe and T. pauliani, differing by uncorrected pairwise sequence divergences of 6.3-9.8%. The distribution ranges of the three species overlapped widely: T. mararybe was collected only in a southern group of localities, T. madagascariensis was found in both the southern and the central group of localities, and T. pauliani occurred from the northernmost site to the southern group of localities; yet the three species did not share haplotypes in two nuclear genes, except for three individuals that we hypothesize are hybrids of T. pauliani with T. madagascariensis and T. mararybe. This pattern of concordant mitochondrial and nuclear divergence despite sympatry strongly supports the status of all three taxa as separate species. Phylogeographic structure was obvious in T. madagascariensis, with two separate shallow mitochondrial clades occupying (1) the central vs. (2) the southern group of populations, and in T. pauliani, with separate mitochondrial clades for (1) the northern vs. (2) the central/southern populations. The widespread occurrence of these three cave fish species suggests that the aquifers in south-western Madagascar have at least in the past allowed episodic dispersal and gene flow of subterraneous organisms, whereas the phylogeographic pattern of T. madagascariensis and T. pauliani provides evidence for isolation and loss of connectivity in the more recent past. 

2017 ◽  
Vol 49 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Tetiana LUTSAK ◽  
Fernando FERNÁNDEZ-MENDOZA ◽  
Olga NADYEINA ◽  
Ayhan ŞENKARDEŞLER ◽  
Christian PRINTZEN

AbstractMost lichen-forming fungi are characterized by the production of secondary metabolites. Differences in metabolite patterns have frequently served to distinguish lichen taxa with subsequent controversies about the rank of chemical variants (chemotype, variety, subspecies or species). Using a model system, we investigate whether production of norstictic acid within a group of lichenized ascomycetes is correlated with phylogenetic patterns, population differentiation or single and multi-locus haplotypes. Our study is based on DNA sequences of three gene loci (ITS, GPD, mtLSU) together with HPLC (311) and TLC (594) data from a total of 594 samples of three closely related fruticose lichens: Cetraria aculeata and C. muricata without norstictic acid, and C. steppae with norstictic acid. In nature, C. aculeata and C. steppae often occur together and the status of C. steppae as a separate species has been questioned. Our results show geographical but no phylogenetic structure of norstictic acid production and few significant associations between genetic clusters and the occurrence of norstictic acid. All frequently distributed haplotypes display differences in norstictic acid content. The few associations at the population level are most likely a by-product of spatial genetic structure, because norstictic acid was expressed only in individuals from the Mediterranean-Central Asian part of the study area. We conclude that the production of norstictic acid in the C. aculeata group is most likely triggered by the environment (climate, edaphic factors, associated symbionts). Cetraria steppae might be a different evolutionary lineage restricted to warm temperate regions but it is not uniquely characterized by the presence of norstictic acid.


Phytotaxa ◽  
2015 ◽  
Vol 202 (2) ◽  
pp. 165 ◽  
Author(s):  
Bo Xu ◽  
Xin-Fen Gao ◽  
Libing Zhang

Lespedeza fasciculiflora Franchet is currently divided into two varieties, var. fasciculiflora and var. hengduanshanensis C.J. Chen. A detailed comparison of the plants from wild populations and specimens of the two varieties revealed that var. hengduanshanensis was sufficiently distinct from var. fasciculiflora to be recognized as a separate species. Our phylogenetic analysis based on DNA sequences, moreover, showed that the two varieties are not even closely related. We therefore here elevate the status of L. fasciculiflora var. hengduanshanensis to species L. hengduanshanensis (C.J. Chen) B. Xu, X.F. Gao & Li Bing Zhang, comb. & stat. nov..


Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 351-360 ◽  
Author(s):  
Neil Davies ◽  
Francis X Villablanca ◽  
George K Roderick

Abstract The Mediterranean fruit fly, Ceratitis capitata, is a devastating agricultural pest that threatens to become established in vulnerable areas such as California and Florida. Considerable controversy surrounds the status of Californian medfly infestations: Do they represent repeated introductions or the persistence of a resident population? Attempts to resolve this question using traditional population genetic markers and statistical methods are problematic because the most likely source populations in Latin America were themselves only recently colonized and are genetically very similar. Here, significant population structure among several New World medfly populations is demonstrated through the analysis of DNA sequence variation at four intron loci. Surprisingly, in these newly founded populations, estimates of population structure increase when measures of subdivision take into account the relatedness of alleles as well as their frequency. A nonequilibrium, likelihood-based statistical test that utilizes multilocus genotypes suggests that the sole medfly captured in California during 1996 was introduced from Latin America and was less likely to be a remnant of an ancestral Californian population. Many bioinvasions are hierarchical in nature, consisting of several sequential or overlapping invasion events, the totality of which can be termed a metainvasion. Phylogenetic data from multilocus DNA sequences will be vital to understanding the evolutionary and ecological processes that underlie metainvasions and to resolving their constituent levels.


2018 ◽  
Vol 64 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Monica Monea ◽  
Anca Maria Pop ◽  
Veronica Grozescu ◽  
Alexandra Stoica ◽  
Simona Mocanu ◽  
...  

AbstractObjective: The purpose of our study was to determine the level of correlation between histopathologic results after surgery for chronic apical periodontitis and the radiographic and clinical diagnosis. The status of gold standard technique of histologic examination was evaluated in the diagnosis of apical radiolucency in necrotic teeth.Methods: Out of 154 patients with incorrect root fillings and apical radiolucency included in an endodontic retreatment protocol, 87 patients (108 teeth) were scheduled for apical surgery at 3-6 months control recall. Clinical and radiographic exams were completed prior to surgery and compared to the histological results of apical biopsies. The collected data were statistically analyzed with the SPSS version 20.0 and the Chi-square test was used to determine the associations between clinical and histologic diagnosis. A value of p <0.05 was considered statistically significant.Results: There was a statistically significant difference between the number of cases diagnosed as granulomas or cysts during clinical and radiological evaluation compared to histologic evaluation of tissue samples, with 40.9% to 75.9% and 54.2% to 16.8% respectively (p<0.05).Conclusions: The final diagnosis was obtained only after histologic examination of apical tissue samples, which means that the observations made based on radiologic investigations must be confirmed by biopsy.


2017 ◽  
Vol 65 (4) ◽  
pp. 240 ◽  
Author(s):  
L. S. Umbrello ◽  
P. A. Woolley ◽  
M. Westerman

The status of Pseudantechinus roryi relative to its congeners has been determined from DNA sequences obtained from both nuclear and mitochondrial gene loci. Although all other recognised species of Pseudantechinus form reciprocally monophyletic lineages in phylogenetic analyses, individuals identified in museum collections as Ps. roryi (including type specimens) were indistinguishable from those identified as Ps. macdonnellensis. Ps. roryi is thus considered to be a synonym of Ps. macdonnellensis. Neighbour-joining network analyses failed to reveal any clear biogeographic differences between populations of Ps. macdonnellensis other than some evidence of isolation by distance.


2012 ◽  
Vol 33 (1) ◽  
pp. 55-67 ◽  
Author(s):  
Marcela A. Vidal ◽  
Juan Carlos Ortiz ◽  
Juan Carlos Marín ◽  
Elie Poulin ◽  
Patricio I. Moreno

Comparative phylogeography describes the patterns of evolutionary divergence and whether or not they are congruent, in co-distributed populations of different taxa. If the populations of these taxa have been co-distributed for a prolonged time, and if the times between processes of perturbation or vicariance have been more or less stable, it is expected that patterns of divergence will be congruent in closely related species, for example because of similar biological and demographic characteristics. Liolaemus pictus and L. cyanogaster are widely co-distributed lizard species in southern Chile, occurring in a region with a complex topology. We analyzed the phylogeographic structure of the two lizard species using Cytochrome b DNA sequences to estimate their genetic structure in response to historical events. Our results suggest an evolutionary pattern of genetic diversity for each species that is consistent with the geomorphological history of the region, suggesting a complex phylogeographic history in Liolaemus species. Also, the high levels of divergence among haplotypes in several populations suggest the possibility that their origin might predate the middle Pleistocene in both species. Finally, our results are consistent with our hypothesis that two species have responded to historical events in parallel, where historical process have been sufficient to influence their phylogeographical structure (0.80 congruency between topologies).


2020 ◽  
Author(s):  
Patrick J. Brownsey ◽  
Daniel J. Ohlsen ◽  
Lara D. Shepherd ◽  
Whitney L. M. Bouma ◽  
Erin L. May ◽  
...  

Five indigenous species of Pellaea in Australasia belong to section Platyloma. Their taxonomic history is outlined, morphological, cytological and genetic evidence for their recognition reviewed, and new morphological and chloroplast DNA-sequence data provided. Australian plants of P. falcata (R.Br.) Fée are diploid and have longer, narrower pinnae than do New Zealand plants previously referred to P. falcata, which are tetraploid. Evidence indicates that P. falcata does not occur in New Zealand, and that collections so-named are P. rotundifolia (G.Forst.) Hook. Chloroplast DNA sequences are uninformative in distinguishing Australian P. falcata from New Zealand P. rotundifolia, but show that Australian P. nana is distinct from both. Sequence data also show that Australian and New Zealand populations of P. calidirupium Brownsey &amp; Lovis are closely related, and that Australian P. paradoxa (R.Br.) Hook. is distinct from other Australian species. Although P. falcata is diploid and P. rotundifolia tetraploid, P. calidirupium, P. nana (Hook.) Bostock and P. paradoxa each contain multiple ploidy levels. Diploid populations of Pellaea species are confined to Australia, and only tetraploids are known in New Zealand. Evolution of the group probably involved hybridisation, autoploidy, alloploidy, and possibly apomixis. Further investigation is required to resolve the status of populations from Mount Maroon, Queensland and the Kermadec Islands.


Our Nature ◽  
1970 ◽  
Vol 8 (1) ◽  
pp. 164-169
Author(s):  
K. Bagra ◽  
D.N. Das

Arunachal Pradesh being rich in fishery resources biophysically, the status of the fish diversity is not known from all the water bodies. A case study was undertaken in the river Siyom (28°11′25′′-28°10′52′′N and 94°45′17′′-97°47′51′′E) of West Siang district, Arunachal Pradesh from 2002 to 2004 with the fragmentary work till 2007. For the purpose, sampling of fish was done from the river time to time using local contraption along with modern nets. A total of 44 species of fishes belongs to 9 families were identified. Fishes of family Cyprinidae were found to be dominant followed by Balitoridae. Some of the fish species were found very rare in the river, which may be due to various anthropogenic factors. Therefore, in addition to social restriction on community fishing some awareness measures need to be taken to prevent the destructive fishing activities in the river.DOI: 10.3126/on.v8i1.4324


Zootaxa ◽  
2008 ◽  
Vol 1703 (1) ◽  
pp. 47 ◽  
Author(s):  
DAVID J. WILLIAMS ◽  
MARK O'SHEA ◽  
ROLAND L. DAGUERRE ◽  
CATHARINE E. POOK ◽  
WOLFGANG WÜSTER ◽  
...  

Pseudonaja textilis is a widespread and common snake in eastern parts of Australia, but its distribution in New Guinea is poorly understood, and the origin of the New Guinea populations and its timing have been the subject of much speculation. Phylogenetic analysis of mitochondrial DNA sequences from three New Guinea populations of P. textilis indicates that New Guinea was colonised from two independent eastern and western migration routes most likely in the Pleistocene. One dispersal event from northern Queensland led to the populations in eastern New Guinea (Milne Bay, Oro and Central Provinces, Papua New Guinea), whereas another, from Arnhem Land to central southern New Guinea, led to the populations from the Merauke area, Indonesian Papua. The results are consistent with the effects of Pleistocene sea level changes on the physical geography of Australasia, and are thus suggestive of a natural rather than anthropogenic origin of the New Guinea populations. The taxonomic status of the New Guinean populations is discussed.


Phytotaxa ◽  
2019 ◽  
Vol 401 (3) ◽  
pp. 190
Author(s):  
ZHENYAN YANG ◽  
CHENGJIN YANG ◽  
YUNHENG JI

Paris variabilis, a new species from the Wumengshan Mountains, southwestern China, is described and illustrated. The new species is placed in Paris section Euthyra. The new taxon was determined to be most morphologically similar to P. vietnamensis but differs in its oblong leaf blades with an acute apex, stamens 2–4 × petal number, greenish yellow filaments and an enlarged, purplish red style base. The phylogenetic placement of this species was assessed based on nuclear ribosomal ITS DNA sequences data. The results of morphological and phylogenetic analyses support the status of the taxon as a new species.


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