scholarly journals Repeated trans-watershed hybridization among haplochromine cichlids (Cichlidae) was triggered by Neogene landscape evolution

2012 ◽  
Vol 279 (1746) ◽  
pp. 4389-4398 ◽  
Author(s):  
Julia Schwarzer ◽  
Ernst Roelof Swartz ◽  
Emmanuel Vreven ◽  
Jos Snoeks ◽  
Fenton Peter David Cotterill ◽  
...  
Keyword(s):  
Nuclear Dna ◽  
Congo Basin ◽  
Alternative View ◽  
Species Flock ◽  
East African ◽  
Haplochromine Cichlids ◽  
Mtdna Haplotypes ◽  
Phylogenetic Hypotheses ◽  
Explosive Speciation ◽  
East African Lakes

The megadiverse haplochromine cichlid radiations of the East African lakes, famous examples of explosive speciation and adaptive radiation, are according to recent studies, introgressed by different riverine lineages. This study is based on the first comprehensive mitochondrial and nuclear DNA dataset from extensive sampling of riverine haplochromine cichlids. It includes species from the lower River Congo and Angolan (River Kwanza) drainages. Reconstruction of phylogenetic hypotheses revealed the paradox of clearly discordant phylogenetic signals. Closely related mtDNA haplotypes are distributed thousands of kilometres apart and across major African watersheds, whereas some neighbouring species carry drastically divergent mtDNA haplotypes. At shallow and deep phylogenetic layers, strong signals of hybridization are attributed to the complex Late Miocene/Early Pliocene palaeohistory of African rivers. Hybridization of multiple lineages across changing watersheds shaped each of the major haplochromine radiations in lakes Tanganyika, Victoria, Malawi and the Kalahari Palaeolakes, as well as a miniature species flock in the Congo basin (River Fwa). On the basis of our results, introgression occurred not only on a spatially restricted scale, but massively over almost the whole range of the haplochromine distribution. This provides an alternative view on the origin and exceptional high diversity of this enigmatic vertebrate group.

scholarly journals Freshwater diatoms in the Democratic Republic of the Congo: a historical overview of the research and publications

PhytoKeys ◽  
2019 ◽  
Vol 136 ◽  
pp. 107-125
Author(s):  
Christine Cocquyt ◽  
Edit Lokele Ndjombo ◽  
Simon Tutu Tsamemba ◽  
Hippolyte Nshimba Seya wa Malale
Keyword(s):  
Democratic Republic ◽  
Congo Basin ◽  
East African ◽  
Dr Congo ◽  
African Lakes ◽  
Freshwater Diatoms ◽  
Republic Of The Congo ◽  
Almost All ◽  
East African Lakes ◽  
Local Research

An overview of the diatom research in the DR Congo is given based on literature data starting in 1938 with the work of Zanon and excluding the East African Lakes as these were already discussed in previous papers. For each literature record the diatom genera mentioned are presented as well as all diatom taxa described from the Congo as new. In total, 106 new taxa were documented, of which Nitzschia with 40 taxa is far the most important genus followed by Navicula s.l. and Pinnularia and with 15 and 13 taxa respectively. Particular attention was paid to the local research of students found in unpublished theses at bachelor, licentiate, master and PhD level. Diatom records in these works are almost all restricted to genus level, although in the last decade an attempt to delimit species can be observed. This accompanies the renewed taxonomic interest in the Congo basin during the last decade. Renewed taxonomic interest can also be seen in the genera: the first period being situated during the lumping period, while more recent works follow the current taxonomic classification, for example Navicula s.l. versus Navicula, Cavinula, Craticula, Diadesmis, Geissleria, Humidophila, Luticola, etc.

Stratigraphic studies of East African lakes

1969 ◽  
Vol 17 (1) ◽  
pp. 147-153 ◽  
Author(s):  
D. A. Livingstone ◽  
R. L. Kendall
Keyword(s):  
East African ◽  
African Lakes ◽  
East African Lakes

The Geological Work of the Cambridge Expedition to the East African Lakes, 1930–31

1934 ◽  
Vol 71 (3) ◽  
pp. 97-112 ◽  
Author(s):  
V. E. Fuchs
Keyword(s):  
Royal Society ◽  
East African ◽  
African Lakes ◽  
Geological Work ◽  
Lake Deposits ◽  
East African Lakes

From November, 1930, till October, 1931, the Cambridge Expedition led by Dr. E. B. Worthington, carried out biological work on the Kenya and Uganda lakes. Owing to a grant from the Royal Society I was able to accompany the Expedition as geologist, with the object of studying the Pleistocene lake deposits and making collections of fossils from them.

Explosive Speciation and Adaptive Radiation of East African Cichlid Fishes

2011 ◽  
pp. 333-362 ◽  
Author(s):  
Christian Sturmbauer ◽  
Martin Husemann ◽  
Patrick D. Danley
Keyword(s):  
Adaptive Radiation ◽  
East African ◽  
Cichlid Fishes ◽  
African Cichlid ◽  
Explosive Speciation

Bacterial Gmgts in East African Lakes: Sources and their Potential as Paleotemperature Indicators

2019 ◽  
Author(s):  
A.J. Baxter ◽  
E.C. Hopmans ◽  
J.M. Russell ◽  
L.G.J. van Bree ◽  
F. Peterse ◽  
...  
Keyword(s):  
East African ◽  
African Lakes ◽  
East African Lakes

scholarly journals Sirt4 Modulates Oxidative Metabolism and Sensitivity to Rapamycin Through Species-Dependent Phenotypes in Drosophila mtDNA Haplotypes

2020 ◽  
Vol 10 (5) ◽  
pp. 1599-1612
Author(s):  
Richard Sejour ◽  
Roger A. Sanguino ◽  
Monika Mikolajczak ◽  
Walishah Ahmadi ◽  
Eugenia Villa-Cuesta
Keyword(s):  
Oxidative Metabolism ◽  
Nuclear Dna ◽  
Metabolic Response ◽  
Symbiotic Relationship ◽  
Tor Signaling ◽  
Epistatic Interactions ◽  
Multifaceted Approach ◽  
Suitable Candidate ◽  
Link Type ◽  
Mtdna Haplotypes

The endosymbiotic theory proposes that eukaryotes evolved from the symbiotic relationship between anaerobic (host) and aerobic prokaryotes. Through iterative genetic transfers, the mitochondrial and nuclear genomes coevolved, establishing the mitochondria as the hub of oxidative metabolism. To study this coevolution, we disrupt mitochondrial-nuclear epistatic interactions by using strains that have mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) from evolutionarily divergent species. We undertake a multifaceted approach generating introgressed Drosophila strains containing D. simulans mtDNA and D. melanogaster nDNA with Sirtuin 4 (Sirt4)-knockouts. Sirt4 is a nuclear-encoded enzyme that functions, exclusively within the mitochondria, as a master regulator of oxidative metabolism. We exposed flies to the drug rapamycin in order to eliminate TOR signaling, thereby compromising the cytoplasmic crosstalk between the mitochondria and nucleus. Our results indicate that D. simulans and D. melanogaster mtDNA haplotypes display opposite Sirt4-mediated phenotypes in the regulation of whole-fly oxygen consumption. Moreover, our data reflect that the deletion of Sirt4 rescued the metabolic response to rapamycin among the introgressed strains. We propose that Sirt4 is a suitable candidate for studying the properties of mitochondrial-nuclear epistasis in modulating mitochondrial metabolism.

Grass cuticles: a new paleoecological tool for East African lake sediments

1976 ◽  
Vol 54 (15) ◽  
pp. 1725-1734 ◽  
Author(s):  
Patricia G. Palmer
Keyword(s):  
Pollen Grains ◽  
East African ◽  
Tropical Africa ◽  
The Past ◽  
Fossil Material ◽  
Fossil Records ◽  
Many Core ◽  
Source Of Information ◽  
African Lake ◽  
East African Lakes

Reconstruction of past vegetation in grassy environments of tropical Africa is hindered by the indistinguishability of grass pollen grains. For these regions, it is necessary to use other fossil material (e.g. grass leaf fragments) to obtain additional paleoecological data. Since many core samples from East African lakes are rich in cuticular fragments of grasses, the identification of these fragments can provide paleobotanical information to complement pollen studies. Light microscopy and scanning electron microscopy are used to identify fossil cuticles to the level of subfamily, tribe, or genus. This new technique provides a much-needed source of information for reconstructing the past vegetation and past climate of regions where grasses are important elements in the fossil records.

The destruction of an endemic species flock: quantitative data on the decline of the haplochromine cichlids of Lake Victoria

1992 ◽  
Vol 34 (1) ◽  
pp. 1-28 ◽  
Author(s):  
Frans Witte ◽  
Tijs Goldschmidt ◽  
Jan Wanink ◽  
Martien van Oijen ◽  
Kees Goudswaard ◽  
...  
Keyword(s):  
Endemic Species ◽  
Quantitative Data ◽  
Lake Victoria ◽  
Species Flock ◽  
Haplochromine Cichlids
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