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1.
Alejandro E.J. Valenzuela Andrea Raya Rey Laura Fasola Ricardo A. Sáenz Samaniego Adrián Schiavini 《Mammalian Biology》2013,78(2):104-110
The American mink (Neovison vison) is a semi-aquatic, generalist carnivore released onto Tierra del Fuego (TDF) Island in the 1940s, subsequently spreading to adjacent islands in the archipelago with potential effects on native prey populations. Knowledge of this new predator's trophic ecology is essential to identify threats, plan control strategies and conserve native fauna. We studied seasonal mink diet in TDF in different habitats. We identified undigested remains from 493 scats collected between May 2005 and March 2009 along marine coasts and freshwater shores (rivers and lakes). Small mammals and fish were the main mink prey in TDF (over 65% of diet items). Seasonal variations were not detected, but diet did vary significantly between marine and freshwater habitats, where more terrestrial items were consumed. Among mammals, mink consumed more small native rodents than exotic species. Native fish consumption was also important with greater representation of species from the families Nototheniidae and Galaxiidae in marine and freshwater habitats respectively. Birds were the third item in importance, but did not constitute a particularly large part of the mink's diet on TDF. Overall, differences found in mink diet between habitats reflected their generalist/opportunistic feeding behaviour and did not differ greatly from observations in its native range or in other areas where it has been introduced. Our results establish the interactions between this novel predator and its prey and also illustrate the need to continue research on native prey populations to quantify mink impact on them and understand the ecological context of this biotic assemblage. 相似文献
2.
The Use of Kosher Phenotyping for Mapping QTL Affecting Susceptibility to Bovine Respiratory Disease
Ehud Lipkin Maria Giuseppina Strillacci Harel Eitam Moran Yishay Fausta Schiavini Morris Soller Alessandro Bagnato Ariel Shabtay 《PloS one》2016,11(4)
Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in feedlot cattle, caused by multiple pathogens that become more virulent in response to stress. As clinical signs often go undetected and various preventive strategies failed, identification of genes affecting BRD is essential for selection for resistance. Selective DNA pooling (SDP) was applied in a genome wide association study (GWAS) to map BRD QTLs in Israeli Holstein male calves. Kosher scoring of lung adhesions was used to allocate 122 and 62 animals to High (Glatt Kosher) and Low (Non-Kosher) resistant groups, respectively. Genotyping was performed using the Illumina BovineHD BeadChip according to the Infinium protocol. Moving average of -logP was used to map QTLs and Log drop was used to define their boundaries (QTLRs). The combined procedure was efficient for high resolution mapping. Nineteen QTLRs distributed over 13 autosomes were found, some overlapping previous studies. The QTLRs contain polymorphic functional and expression candidate genes to affect kosher status, with putative immunological and wound healing activities. Kosher phenotyping was shown to be a reliable means to map QTLs affecting BRD morbidity. 相似文献
3.
Summary Transverse sections of leaves of some aluminium-accumulating and nonaccumulating species of the cerrado vegetation of central
Brazil were coloured using aluminon to identify the tissues where aluminium occurs or is deposited. None of the tissues of
the nonaccumulating species showed evidence of high concentrations of Al. All of the aluminium accumulating species showed
high concentrations of Al in all of the elements of the phloem of the midrib and the secondary veins and total absence of
it in the vessel members, xylem fibres and the palisade parenchyma. Walls and contents of the collenchyma of the midrib, epidermal
cells, guard cells of the stomata and spongy parenchyma showed evidence of high concentrations of Al in the accumulating species. 相似文献
4.
Background
Molluscs are the most diverse marine phylum and this high diversity has resulted in considerable taxonomic problems. Because the number of species in Canadian oceans remains uncertain, there is a need to incorporate molecular methods into species identifications. A 648 base pair segment of the cytochrome c oxidase subunit I gene has proven useful for the identification and discovery of species in many animal lineages. While the utility of DNA barcoding in molluscs has been demonstrated in other studies, this is the first effort to construct a DNA barcode registry for marine molluscs across such a large geographic area.Methodology/Principal Findings
This study examines patterns of DNA barcode variation in 227 species of Canadian marine molluscs. Intraspecific sequence divergences ranged from 0–26.4% and a barcode gap existed for most taxa. Eleven cases of relatively deep (>2%) intraspecific divergence were detected, suggesting the possible presence of overlooked species. Structural variation was detected in COI with indels found in 37 species, mostly bivalves. Some indels were present in divergent lineages, primarily in the region of the first external loop, suggesting certain areas are hotspots for change. Lastly, mean GC content varied substantially among orders (24.5%–46.5%), and showed a significant positive correlation with nearest neighbour distances.Conclusions/Significance
DNA barcoding is an effective tool for the identification of Canadian marine molluscs and for revealing possible cases of overlooked species. Some species with deep intraspecific divergence showed a biogeographic partition between lineages on the Atlantic, Arctic and Pacific coasts, suggesting the role of Pleistocene glaciations in the subdivision of their populations. Indels were prevalent in the barcode region of the COI gene in bivalves and gastropods. This study highlights the efficacy of DNA barcoding for providing insights into sequence variation across a broad taxonomic group on a large geographic scale. 相似文献5.
Gabriela Scioscia Andrea Raya Rey Ricardo A. Saenz Samaniego Olga Florentín Adrián Schiavini 《Polar Biology》2014,37(10):1421-1433
Knowledge of seabirds’ diet at each breeding site and its temporal variation is key to understanding and evaluating how changes in marine resources affect each seabird population. In this study, we determined the diet of Magellanic penguins (MP, Spheniscus magellanicus) at Martillo Island, accounting for sex, breeding stage and year. We analyzed a total of 144 stomach contents during three consecutive breeding seasons (2006–2007, 2007–2008 and 2008–2009) and stages (incubation, early and late chick-rearing). MP fed mainly on fuegian sprat (Sprattus fuegensis), which represented 75 % of the biomass consumed by birds during the entire study. The next important prey was squat lobster (Munida gregaria), followed by Patagonian squid (Loligo gahi). Both sexes consumed similar prey items. We observed variation in diet relative composition among breeding years and stages. Fuegian sprat consumption decreased throughout the years whereas squat lobster increased. Penguins consumed a higher proportion of squat lobster and Patagonian squid during the incubation stage than in the chick-rearing stages, whereas fuegian sprat was almost the only prey item consumed during the late chick-rearing stage. MPs show certain flexibility in the use of resources probably as a response to changes in prey populations. Variability in the diet among different reproductive stages could be related to changes in the distribution and abundance of their main prey near the colony during the breeding season together with changes in the energy requirements of seabirds. 相似文献
6.
Katie J Torley Juliano C da Silveira Peter Smith Russell V Anthony DN Rao Veeramachaneni Quinton A Winger Gerrit J Bouma 《Reproductive biology and endocrinology : RB&E》2011,9(1):2
Background
Gonadal differentiation in the mammalian fetus involves a complex dose-dependent genetic network. Initiation and progression of fetal ovarian and testicular pathways are accompanied by dynamic expression patterns of thousands of genes. We postulate these expression patterns are regulated by small non-coding RNAs called microRNAs (miRNAs). The aim of this study was to identify the expression of miRNAs in mammalian fetal gonads using sheep as a model. 相似文献7.
Lourens Poorter Masha T. van der Sande Eric J. M. M. Arets Nataly Ascarrunz Brian Enquist Bryan Finegan Juan Carlos Licona Miguel Martínez‐Ramos Lucas Mazzei Jorge A. Meave Rodrigo Muñoz Christopher J. Nytch Alexandre A. de Oliveira Eduardo A. Perez‐García Jamir Prado‐Junior Jorge Rodríguez‐Velazques Ademir Roberto Ruschel Beatriz Salgado‐Negret Ivan Schiavini Nathan G. Swenson Elkin A. Tenorio Jill Thompson Marisol Toledo Maria Uriarte Peter van der Hout Jess K. Zimmerman Marielos Peña‐Claros 《Global Ecology and Biogeography》2018,27(3):389-390
8.
Molecular evolution of mitochondrial 12S RNA and cytochrome b sequences in the pantherine lineage of Felidae 总被引:4,自引:2,他引:2
DNA sequence comparisons of two mitochondrial DNA genes were used to infer
phylogenetic relationships among 17 Felidae species, notably 15 in the
previously described pantherine lineage. The polymerase chain reaction
(PCR) was used to generate sequences of 358 base pairs of the mitochondrial
12S RNA gene and 289 base pairs of the cytochrome b protein coding gene.
DNA sequences were compared within and between 17 felid and five nonfelid
carnivore species. Evolutionary trees were constructed using phenetic,
cladistic, and maximum likelihood algorithms. The combined results
suggested several phylogenetic relationships including (1) the recognition
of a recently evolved monophyletic genus Panthera consisting of Panthera
leo, P. pardus, P. onca, P. uncia, P. tigris, and Neofelis nebulosa; (2)
the recent common ancestry of Acinonyx jubatus, the African cheetah, and
Puma concolor, the American puma; and (3) two golden cat species, Profelis
temmincki and Profelis aurata, are not sister species, and the latter is
strongly associated with Caracal caracal. These data add to the growing
database of vertebrate mtDNA sequences and, given the relatively recent
divergence among the felids represented here (1-10 Myr), allow 12S and
cytochrome b sequence evolution to be addressed over a time scale different
from those addressed in most work on vertebrate mtDNA.
相似文献
9.
Marcela Liljesthröm Steven D. Emslie Dargan Frierson Adrián Schiavini 《Polar Biology》2008,31(4):465-474
We studied predation risk in relation to nest location and subcolony size in Southern Rockhopper Penguins (Eudyptes chrysocome chrysocome) during the chick-rearing period. Striated Caracaras (Phalcoboenus australis), the main predator, preferentially attacked from tussock grasses which are found in the periphery of all subcolonies (peripheral
tussocks) and often scattered within them (central tussocks). The greatest numbers of predation and attempted predation events
were observed on nests in the periphery of the subcolony next to peripheral tussocks, and on those nests next to central tussocks.
Central tussocks offer Striated Caracaras an additional “edge” area from which to prey, much in the same way as do the peripheral
tussocks. Predation rate per individual was not correlated with subcolony size possibly due to the presence of central tussocks
which, by creating an extra edge area, change the subcolony shape. There is a suggestion (P = 0.06) of increased probability of nest success with subcolony size. 相似文献
10.
Xin Zhou Sarah J Adamowicz Luke M Jacobus R Edward DeWalt Paul DN Hebert 《Frontiers in zoology》2009,6(1):1-9