Mitochondrial genotyping of cultured Piaractus brachypomus revealed low diversity and mutations in regions involved in metabolisms and proliferation

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

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Lithostratigraphy of the Kweekvlei Formation (Witteberg Group), Cape Supergroup

South African Journal of Geology ◽

10.25131/gssajg.120.3.421 ◽

2017 ◽

Vol 120 (3) ◽

pp. 421-432 ◽

Cited By ~ 2

Author(s):

C. Browning ◽

M. Reid

Keyword(s):

South Africa ◽

Transition Zone ◽

Distal Part ◽

Vascular Plant ◽

Trace Fossil ◽

Plant Debris ◽

Lower Carboniferous ◽

Fossil Assemblage ◽

Low Diversity ◽

Storm Wave

AbstractThe Lower Carboniferous, probably Tournaisian, Kweekvlei Formation is part of the Witteberg Group (Cape Supergroup) of South Africa. Together with the overlying Floriskraal Formation, it forms an upward-coarsening succession within the Lake Mentz Subgroup. Sedimentary features of the Kweekvlei Formation suggest deposition in a storm-wave dominated marine setting, within the storm-influenced, distal part of an offshore transition zone environment. This predominantly argillaceous formation preserves a low diversity trace fossil assemblage. Reworked vascular plant debris (including the problematic genus Praeramunculus sp.) and a shark spine have been reported for the Kweekvlei Formation. There are no known stratigraphic equivalents in South Africa.

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HIGH ABUNDANCE AND LOW DIVERSITY OF TETRAPOD VERTEBRATES IN THE SOLITE QUARRY LAGERSTÄTTE (UPPER TRIASSIC, VIRGINIA-NORTH CAROLINA)

10.1130/abs/2016se-273827 ◽

2016 ◽

Author(s):

Alexander K. Hastings ◽

◽

Christina J. Byrd

Keyword(s):

North Carolina ◽

Upper Triassic ◽

High Abundance ◽

Low Diversity

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Genomic Characterization of the Three Balkan Livestock Guardian Dogs

Sustainability ◽

10.3390/su13042289 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2289

Author(s):

Mateja Janeš ◽

Minja Zorc ◽

Maja Ferenčaković ◽

Ino Curik ◽

Peter Dovč ◽

...

Keyword(s):

Conservation Management ◽

Diversity Management ◽

Genomic Diversity ◽

Mountainous Areas ◽

Autosomal Snps ◽

The Balkans ◽

Gray Wolves ◽

Low Diversity ◽

Genomic Characterization

Balkan Livestock Guardian Dogs (LGD) were bred to help protect sheep flocks in sparsely populated, remote mountainous areas in the Balkans. The aim of this study was genomic characterization (107,403 autosomal SNPs) of the three LGD breeds from the Balkans (Karst Shepherd, Sharplanina Dog, and Tornjak). Our analyses were performed on 44 dogs representing three Balkan LGD breeds, as well as on 79 publicly available genotypes representing eight other LGD breeds, 70 individuals representing seven popular breeds, and 18 gray wolves. The results of multivariate, phylogenetic, clustering (STRUCTURE), and FST differentiation analyses showed that the three Balkan LGD breeds are genetically distinct populations. While the Sharplanina Dog and Tornjak are closely related to other LGD breeds, the Karst Shepherd is a slightly genetically distinct population with estimated influence from German Shepard (Treemix analysis). Estimated genomic diversity was high with low inbreeding in Sharplanina Dog (Ho = 0.315, He = 0.315, and FROH>2Mb = 0.020) and Tornjak (Ho = 0.301, He = 0.301, and FROH>2Mb = 0.033) breeds. Low diversity and high inbreeding were estimated in Karst Shepherds (Ho = 0.241, He = 0.222, and FROH>2Mb = 0.087), indicating the need for proper diversity management. The obtained results will help in the conservation management of Balkan LGD dogs as an essential part of the specific grazing biocultural system and its sustainable maintenance.

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Biopolymeric Materials Used as Nonviral Vectors: A Review

Polysaccharides ◽

10.3390/polysaccharides2010007 ◽

2021 ◽

Vol 2 (1) ◽

pp. 100-109

Author(s):

Jailson de Araújo Santos ◽

Daniel Barbosa Liarte ◽

Alessandra Braga Ribeiro ◽

Marcia dos Santos Rizzo ◽

Marcília Pinheiro da Costa ◽

...

Keyword(s):

Chemical Structure ◽

Web Of Science ◽

Gene Transfection ◽

Genetic Material ◽

Nonviral Vectors ◽

Cationic Polymers ◽

Genetic Trait ◽

Low Diversity ◽

Different Types ◽

Materials Used

Bacterial transformation and gene transfection can be understood as being the results of introducing specific genetic material into cells, resulting in gene expression, and adding a new genetic trait to the host cell. Many studies have been carried out to investigate different types of lipids and cationic polymers as promising nonviral vectors for DNA transfer. The present study aimed to carry out a systematic review on the use of biopolymeric materials as nonviral vectors. The methodology was carried out based on searches of scientific articles and applications for patents published or deposited from 2006 to 2020 in different databases for patents (EPO, USPTO, and INPI) and articles (Scopus, Web of Science, and Scielo). The results showed that there are some deposits of patents regarding the use of chitosan as a gene carrier. The 16 analyzed articles allowed us to infer that the use of biopolymers as nonviral vectors is limited due to the low diversity of biopolymers used for these purposes. It was also observed that the use of different materials as nonviral vectors is based on chemical structure modifications of the material, mainly by the addition of cationic groups. Thus, the use of biopolymers as nonviral vectors is still limited to only a few polysaccharide types, emphasizing the need for further studies involving the use of different biopolymers in processes of gene transfer.

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Diversity and community structure of Ephemeroptera in freshwater stream of Megamalai hills, Tamil Nadu, India

ENTOMON ◽

10.33307/entomon.v46i4.638 ◽

2021 ◽

Vol 46 (4) ◽

pp. 279-284

Author(s):

S. Barathy ◽

T. Sivaruban ◽

Srinivasan Pandiarajan ◽

Isack Rajasekaran ◽

M. Bernath Rosi

Keyword(s):

Community Structure ◽

Species Diversity ◽

Air Temperature ◽

Tamil Nadu ◽

Dominant Species ◽

Diversity Indices ◽

Low Diversity ◽

Freshwater Stream ◽

Species Diversity Indices ◽

High Diversity

In the study on the diversity and community structure of Ephemeroptera in the freshwater stream of Chinnasuruli falls on Megamalai hills, a total of 523 specimens belonging to thirteen genera and five families were collected in six month periods. Of the five families, Teloganodidae and Leptophlebiidae exhibited high diversity and Caenidae showed low diversity. Choroterpes alagarensis (Leptophlebiidae) is the most dominant species. Diversity indices such as Shannon and Simpson indices showed that diversity was maximum in November and December and it was minimum in August and January. Canonical Correspondence Analysis revealed that rainfall, water flow, turbidity, and air temperature were the major stressors in affecting the Ephemeropteran community structure.

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The recovery of early vertebrates and reef ecosystems following the late Silurian carbon isotope excursion: the Burgen outlier, Gotland, Sweden

10.5194/egusphere-egu21-13333 ◽

2021 ◽

Author(s):

Emilia Jarochowska ◽

Oskar Bremer ◽

Alexandra Yiu ◽

Tiiu Märss ◽

Henning Blom ◽

...

Keyword(s):

Carbon Isotope ◽

Carbonate Platform ◽

Fish Diversity ◽

Global Environmental ◽

Carbon Isotope Excursion ◽

Low Diversity ◽

Early Vertebrates ◽

Carbonate Factory ◽

Faunal Distribution ◽

Rapid Regression

The Ludfordian Carbon Isotope Excursion (LCIE) reached the highest known &#948;13C values in the Phanerozoic. It was a global environmental perturbation manifested in a rapid regression attributed to glacial eustasy. Previous studies suggested that it has also heavily affected the diversity of conodonts, early vertebrates and reef ecosystems, but the timing of the crisis and recovery remained complicated owing to the lateral variability of &#948;13C values in epeiric platforms and rapid facies shifts, which drove faunal distribution. One of the best records of this interval is available in the Swedish island of Gotland, which preserves tectonically undisturbed strata deposited in a Silurian tropical carbonate platform. We revisited the world-renowned collection of the late Lennart Jeppsson, hosted at the Swedish Museum of Natural History, Stockholm, which holds the key to reconstruct the dynamics of faunal immigration and diversification following the LCIE. Here we focus on the Burgen erosional outlier, which remained a mystery, as it had been correlated with the excursion strata, but preserved a high diversity of conodonts and reefal ecosystems. We re-examined key outcrops and characterized macro- and microfacies, as well as chemostratigraphy and unpublished fauna in the collection. Strata in the Burgen outlier&#160;represent back-shoal facies of the Burgsvik Oolite Member and correspond to the Ozarkodina snajdri Conodont Biozone. The shallow-marine position compared to the more continental setting of coeval strata in southern Gotland, is reflected in the higher &#948;13Ccarb values, reaching +9.2&#8240;. The back-shoal succession in this outcrop includes reefs, which contain a large proportion of microbial carbonates and have therefore been previously compared with low-diversity buildups developed in a stressed ecosystem. However, the framework of these reefs is built by a diverse coral-stromatoporoid-bryozoan fauna, indicating that a high microbial contribution might be a characteristic of the local carbonate factory rather than a reflection of restricted conditions.&#160;In the case of conodonts, impoverishment following the LCIE might be a product of facies preferences, as the diverse environments in the outlier yielded at least 20 of the 21 species known from the Burgsvik Formation in Gotland. Fish diversity also returned to normal levels following the LCIE with an estimated minimum of 9 species. Thelodont scales appear to dominate samples from the Burgen outlier, which is in line with previous reports. Our observations highlight how palaeoenvironmental reconstructions inform fossil niche and diversity analyses, but also how fossil museum collections continuously contribute new data on past biodiversity.

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Hirnantia Fauna from the Condroz Inlier, Belgium: another case of a relict Ordovician shelly fauna in the Silurian?

Journal of Paleontology ◽

10.1017/jpa.2021.74 ◽

2021 ◽

pp. 1-27

Author(s):

Sofia Pereira ◽

Jorge Colmenar ◽

Jan Mortier ◽

Jan Vanmeirhaeghe ◽

Jacques Verniers ◽

...

Keyword(s):

Sea Level ◽

Mass Extinction ◽

Late Ordovician ◽

Lake District ◽

Low Diversity ◽

Hirnantia Fauna ◽

And Sea Level

Abstract The end-Ordovician mass extinction, linked to a major glaciation, led to deep changes in Hirnantian–Rhuddanian biotas. The Hirnantia Fauna, the first of two Hirnantian survival brachiopod-dominated communities, characterizes the lower–mid Hirnantian deposits globally, and its distribution is essential to understand how the extinction took place. In this paper, we describe, illustrate, and discuss the first macrofossiliferous Hirnantia Fauna assemblage from Belgium, occurring in the Tihange Member of the Fosses Formation at Tihange (Huy), within the Central Condroz Inlier. Six fossiliferous beds have yielded a low-diversity, brachiopod-dominated association. In addition to the brachiopods (Eostropheodonta hirnantensis, Plectothyrella crassicosta, Hirnantia sp., and Trucizetina? sp.), one trilobite (Mucronaspis sp.), four pelmatozoans (Xenocrinus sp., Cyclocharax [col.] paucicrenulatus, Conspectocrinus [col.] celticus, and Pentagonocyclicus [col.] sp.), three graptolites (Cystograptus ancestralis, Normalograptus normalis, and ?Metabolograptus sp.), together with indeterminate machaeridians and bryozoans were identified. The graptolite assemblage, from the Akidograptus ascensus-Parakidograptus acuminatus Biozone, indicates an early Rhuddanian (Silurian) age, and thus, an unexpectedly late occurrence of a typical Hirnantia Fauna. This Belgian association may represent an additional example of relict Hirnantia Fauna in the Silurian, sharing characteristics with the only other known from Rhuddanian rocks at Yewdale Beck (Lake District, England), although reworking has not been completely ruled out. The survival of these Hirnantian taxa into the Silurian might be linked to delayed post-glacial effects of rising temperature and sea-level, which may have favored the establishment of refugia in these two particular regions that were paleogeographically close during the Late Ordovician–early Silurian.

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Spatangoid echinoids from the Eocene of Jamaica

Journal of Paleontology ◽

10.1017/s0022336000032777 ◽

2000 ◽

Vol 74 (4) ◽

pp. 654-661 ◽

Cited By ~ 1

Author(s):

Stephen K. Donovan ◽

Deborah-Ann C. Rowe

Keyword(s):

New Species ◽

First Record ◽

Trace Fossils ◽

Upper Eocene ◽

Area Effects ◽

Low Diversity ◽

First Time ◽

Incomplete Sampling

Paleocene spatangoids are unknown from the Antilles, apart from evidence from trace fossils. The peak of spatangoid diversity was the Eocene. Jamaican Oligo-Miocene spatangoids have a relatively low diversity compared with that of the Antillean region. Plio-Pleistocene spatangoids are poorly known from the Antilles (four genera), in contrast to the Oligo-Miocene (16 genera) and Holocene (17 genera). The depauperate Paleocene and Plio-Pleistocene spatangoid faunas are probably in part artifacts of incomplete sampling, facies-related absences, outcrop area effects and the relative brevity of these stratigraphic intervals.To the large echinoid fauna of the Swanswick Formation (Middle-Upper Eocene) of Jamaica is added the schizasterid Aguayoaster schickleri new species. This is the first record of this genus outside Cuba; it is distinctly more elongate than all other known specimens of this genus. The schizasterid Caribbaster loveni (Cotteau, 1875) is recorded from the Swanswick Formation for the first time, the youngest occurrence of this genus in Jamaica. The coeval Claremont Formation has not previously yielded spatangoid echinoids; the brissid Eupatagus cf. antillarum (Cotteau) from a new locality is the first spatangoid known from a lagoonal unit of the White Limestone Group.

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Evolution to alternative levels of stable diversity leaves areas of niche space unexplored

10.1101/2021.01.06.425548 ◽

2021 ◽

Author(s):

Ilan N. Rubin ◽

Iaroslav Ispolatov ◽

Michael Doebeli

Keyword(s):

Evolutionary Dynamics ◽

Natural Populations ◽

Metastable States ◽

Community Diversity ◽

Limited Resources ◽

Niche Space ◽

Stable States ◽

Low Diversity ◽

Population Sizes ◽

Adaptive Radiations

AbstractOne of the oldest and most persistent questions in ecology and evolution is whether natural communities tend to evolve toward saturation and maximal diversity. Robert MacArthur’s classical theory of niche packing and the theory of adaptive radiations both imply that populations will diversify and fully partition any available niche space. However, the saturation of natural populations is still very much an open area of debate and investigation. Additionally, recent evolutionary theory suggests the existence of alternative evolutionary stable states (ESSs), which implies that some stable communities may not be fully saturated. Using models with classical Lokta-Volterra ecological dynamics and three formulations of evolutionary dynamics (a model using adaptive dynamics, an individual-based model, and a partial differential equation model), we show that following an adaptive radiation, communities can often get stuck in low diversity states when limited by mutations of small phenotypic effect. These low diversity metastable states can also be maintained by limited resources and finite population sizes. When small mutations and finite populations are considered together, it is clear that despite the presence of higher-diversity stable states, natural populations are likely not fully saturating their environment and leaving potential niche space unfilled. Additionally, within-species variation can further reduce community diversity from levels predicted by models that assume species-level homogeneity.Author summaryUnderstanding if and when communities evolve to saturate their local environments is imperative to our understanding of natural populations. Using computer simulations of classical evolutionary models, we study whether adaptive radiations tend to lead toward saturated communities in which no new species can invade or remain trapped in alternative, lower diversity stable states. We show that with asymmetric competition and small effect mutations, evolutionary Red Queen dynamics can trap communities in low diversity metastable states. Moreover, limited resources not only reduces community population sizes, but also reduces community diversity, denying the formation of saturated communities and stabilizing low diversity, non-stationary evolutionary dynamics. Our results are directly relevant to the longstanding questions important to both ecological empiricists and theoreticians on the species packing and saturation of natural environments. Also, by showing the ease evolution can trap communities in low diversity metastable stats, we demonstrate the potential harm in relying solely on ESSs to answer questions of biodiversity.

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