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1.
Acta Biol Hung ; 68(3): 267-278, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28901805

RESUMO

Microscopic inclusions have been observed in 7 out of 106 European eel (Anguilla anguilla L.) sagittae using polarizing microscope and scanning electron microscope meanwhile the annual increments were studied to characterize the age structure of the population living in Lake Balaton. The presence of vaterite, a rare calcium carbonate polymorph was observed in these inclusions using Raman spectroscopy. Vateritic sagittae in wild fish are usually considered as symptom of physiological stress. The observed fusiform inclusions represent a new morphological type of vaterite inclusions in eel otolith. Two alternatives are hypothesized to explain their formation: 1) metabolic disorder, such as erroneous protein synthesis; 2) introduction of an alien protein into the eel's inner ear. The origin and physiological significance of this new morphological type of vateritic inclusions is still an open question. Same as whether it can be found in other species or specific only to eel otoliths.


Assuntos
Anguilla/metabolismo , Carbonato de Cálcio/metabolismo , Corpos de Inclusão/metabolismo , Corpos de Inclusão/ultraestrutura , Anguilla/anatomia & histologia , Animais , Europa (Continente) , Distribuição Tecidual
2.
PLoS One ; 7(1): e30043, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22253871

RESUMO

The concept of climate variability facilitating adaptive radiation supported by the "Court Jester" hypothesis is disputed by the "Red Queen" one, but the prevalence of one or the other might be scale-dependent. We report on a detailed, comprehensive phylo-geographic study on the ∼4 kb mtDNA sequence in underground blind mole rats of the family Spalacidae (or subfamily Spalacinae) from the East Mediterranean steppes. Our study aimed at testing the presence of periodicities in branching patterns on a constructed phylogenetic tree and at searching for congruence between branching events, tectonic history and paleoclimates. In contrast to the strong support for the majority of the branching events on the tree, the absence of support in a few instances indicates that network-like evolution could exist in spalacids. In our tree, robust support was given, in concordance with paleontological data, for the separation of spalacids from muroid rodents during the first half of the Miocene when open, grass-dominated habitats were established. Marine barriers formed between Anatolia and the Balkans could have facilitated the separation of the lineage "Spalax" from the lineage "Nannospalax" and of the clade "leucodon" from the clade "xanthodon". The separation of the clade "ehrenbergi" occurred during the late stages of the tectonically induced uplift of the Anatolian high plateaus and mountains, whereas the separation of the clade "vasvarii" took place when the rapidly uplifting Taurus mountain range prevented the Mediterranean rainfalls from reaching the Central Anatolian Plateau. The separation of Spalax antiquus and S. graecus occurred when the southeastern Carpathians were uplifted. Despite the role played by tectonic events, branching events that show periodicity corresponding to 400-kyr and 100-kyr eccentricity bands illuminate the important role of orbital fluctuations on adaptive radiation in spalacids. At the given scale, our results supports the "Court Jester" hypothesis over the "Red Queen" one.


Assuntos
Evolução Biológica , Cegueira/genética , Mudança Climática , Ratos-Toupeira/genética , Animais , Sequência de Bases , DNA Mitocondrial/genética , Geografia , Funções Verossimilhança , Região do Mediterrâneo , Dados de Sequência Molecular , Filogenia , Fatores de Tempo
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