Speciation in Sapsuckers (Sphyrapicus): I. Genetic Differentiation

The Auk ◽  
1983 ◽  
Vol 100 (4) ◽  
pp. 871-884 ◽  
Author(s):  
Ned K. Johnson ◽  
Robert M. Zink

Abstract We report the results of an electrophoretic analysis at 39 presumptive genetic loci of 88 specimens in the picid genus Sphyrapicus, here treated as comprising the following species: Williamson's Sapsucker (S. thyroideus), Yellow-bellied Sapsucker (S. varius), Red-naped Sapsucker (S. nuchalis), and Red-breasted Sapsucker (S. ruber). Seventeen loci (43.5%) were polymorphic. Values for observed heterozygosity in S. ruber ruber, S. ruber daggetti, and in three populations of S. nuchalis were uniform and averaged 0.043, the mean value reported for other birds. However, S. varius, at 0.022, and S. thyroideus, at 0.016, have low values of H. Values for percentage of polymorphic loci ranged from 12.8 to 20.5 in S. ruber and S. nuchalis, 12.8 in S. varius, and 7.7 in S. thyroideus. In contrast, all four species exhibited a similar mean number of alleles per locus (1.12-1.21). Genetic distances between populations of the same species are either very low or zero. Genetic distances are also very low between the phenotypically dissimilar ruber and nuchalis (D̄ = 0.004), two forms we consider to be biological species based on their assortative mating in sympatry. This is the lowest avian interspecific D-value ever reported and is similar to that found between avian subspecies. Phenotypically, varius and nuchalis are very similar, yet the average genetic distance between samples of these forms, 0.029, is comparable to interspecific values reported for other avian congeners and is our chief basis for treating the two forms as separate species. S. thyroideus is strongly differentiated genetically from varius (D̄ = 0.142), from nuchalis (D̄ = 0.197), and from ruber (D̄ = 0.186). FST statistics point to little or no population subdivision within ruber and nuchalis but substantial subdivision within the superspecies varius (S. varius + S. nuchalis + S. ruber). The genetic information suggests that the Williamson's Sapsucker represents the oldest lineage in the genus. S. thyroideus split from its sister clade (superspecies S. varius) between 3 and 4 MYBP. S. ruber and S. nuchalis are sister species that evolved very recently, either during or since the Pleistocene and sometime after their common ancestor diverged from S. varius.

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Salvatore Bordonaro ◽  
Anna Maria Guastella ◽  
Andrea Criscione ◽  
Antonio Zuccaro ◽  
Donata Marletta

The genetic variability of Pantesco and other two Sicilian autochthonous donkey breeds (Ragusano and Grigio Siciliano) was assessed using a set of 14 microsatellites. The main goals were to describe the current differentiation among the breeds and to provide genetic information useful to safeguard the Pantesco breed as well as to manage Ragusano and Grigio Siciliano. In the whole sample, that included 108 donkeys representative of the three populations, a total of 85 alleles were detected. The mean number of alleles was lower in Pantesco (3.7), than in Grigio Siciliano and Ragusano (4.4 and 5.9, resp.). The three breeds showed a quite low level of gene diversity (He) ranging from 0.471 in Pantesco to 0.589 in Grigio. The overall genetic differentiation index (Fst) was quite high; more than 10% of the diversity was found among breeds. Reynolds’ () genetic distances, correspondence, and population structure analysis reproduced the same picture, revealing that, (a) Pantesco breed is the most differentiated in the context of the Sicilian indigenous breeds, (b) within Ragusano breed, two well-defined subgroups were observed. This information is worth of further investigation in order to provide suitable data for conservation strategies.


2004 ◽  
Vol 64 (3b) ◽  
pp. 639-644 ◽  
Author(s):  
P. S. R. De Mattos ◽  
M. A. Del Lama ◽  
R. H. Toppa ◽  
A. R. Arno Rudi Schwantes

Electrophoretic analysis of presumptive twenty gene loci products was conducted in hemolisates and plasma samples of twenty-eight maned wolves (Chrysocyon brachyurus) from an area in northeastern São Paulo State, Brazil. The area sampled was divided into three sub-areas, with the Mogi-Guaçu and Pardo rivers regarded as barriers to the gene flow. The polymorphism degree and heterozygosity level (intralocus and average) estimated in this study were similar to those detected by other authors for maned wolves and other species of wild free-living canids. The samples of each sub-area and the total sample exhibited genotype frequencies consistent with the genetic equilibrium model. The values of the F-statistics evidenced absence of inbreeding and population subdivision and, consequently, low genetic distances were found among the samples of each area.


2011 ◽  
Vol 56 (No. 4) ◽  
pp. 163-175 ◽  
Author(s):  
L. Vostrý ◽  
O. Kracíková ◽  
B. Hofmanová ◽  
V. Czerneková ◽  
T. Kott ◽  
...  

The Old Kladruber horse is the oldest original Czech horse breed &ndash; gene resource, with pedigree records spanning three centuries. Because the population is closed, there is a concern about the loss of genetic variation. The genetic diversity within and amongst sire lines was evaluated using microsatellite markers and based on pedigree information. The DNA analysis, covering 16 microsatellite loci, revealed that the genetic diversity (observed heterozygosity = 0.637, genetic diversity = 0.678 and the mean number of alleles = 8.25) for the Old Kladruber horse is consistent with other populations of horses. Inter-line genetic difference in sire lines reached the mean value (the F<sub>ST</sub> values ranged from 0.020 to 0.017). Differences amongst the sire lines were identified using genetic distances and principal component analysis. One gene cluster comprised black variation sire lines, while the second cluster included the sire lines of the grey variation. In the subjects monitored, the average inbreeding coefficient of 0.076 was estimated on the basis of pedigree information. The highest mean values of the coefficient of relationship were estimated within the colour variations. When comparing the genetic distance and the average coefficient of relationship, differences were found out. These results are useful for the development of breeding strategies which consider classical horse breeding as well as recent achievements of population and conservation genetics.


2021 ◽  
Vol 66 (No. 1) ◽  
pp. 1-12
Author(s):  
Lenka Štohlová Putnová ◽  
Radek Štohl

The paper demonstrates the dependability of assignment testing in the identification of an appropriate breed to monitor comprehensive genetic information from molecular markers to analyse the collection of real population data covering 22 horse breeds registered in the Czech Republic, including native breeds and genetic resources. If 17 microsatellites are used, the mean number of alleles per locus corresponds to 10.4. The count of alleles at the individual loci ranges between five (HTG07) and 17 (ASB17). The loci ASB02, ASB23, HMS03, HTG10, and VHL20 exhibit the highest gene diversity and observed heterozygosity (both above 80%), with the mean value of 0.77 and 0.73, respectively. The moderate total inbreeding coefficient (5.2%) is estimated across all the loci and breeds. The levels of apparent breed differentiation span from zero between the Czech Warmblood and Slovak Warmblood to 0.15 between the Shetland Pony and Standardbred. The phylogenetic breed relationships are revealed via the NeighbourNet dendrogram constructed from Reynolds’ genetic distances, which clearly separate the Coldblood draught, Hot/Warmblood, and Pony horses. Our results reveal that the Bayesian approach (the Rannala and Mountain technique) provides the most intensive prediction power (83.6%) out of the GeneClass tools and that the Bayes Net algorithm exhibits the best efficiency (78.4%) from the WEKA machine learning workbench options, considering the use of the five-fold cross validation technique. The algorithms could be trained on large real reference data sets, and thus there appears another viable perspective for machine learning in horse ancestry testing. In this context, it is also important to stress the fact that innovated computational tools will potentially lead towards structuring a novel web server to allow the identification of horse breeds.


Author(s):  
Thierry Backeljau ◽  
Philippe Bouchet ◽  
Serge Gofas ◽  
Luc De Bruyn

Two morphotypes of the venerid bivalve Chamelea gallina (L.), viz. C. gallina s.s. and C. striatula, were electrophoretically compared at seven polymorphic enzyme loci. In three populations from the Ría Formosa (southern Portugal), both morphotypes occurred sympatrically. Analyses of genotype frequencies in these mixed populations revealed departures from Hardy-Weinberg expectations at nearly all loci. These deviations were mainly attributable to a Wahlund effect, caused by mixing the two morphotypes. Nei's mean unbiased genetic distance between the two forms was D=1·138, while the mean genetic distances between populations within morphotypes were D=0·083 in C. gallina s.s. and D=0·229 in C. striatula. It is therefore concluded that C. gallina and C. striatula are reproductively isolated (biological) species, the geographical distribution of which is outlined.


2019 ◽  
Vol 23 (5) ◽  
pp. 569-574 ◽  
Author(s):  
L. A. Khrabrova ◽  
N. V. Blohina ◽  
O. I. Suleymanov ◽  
G. А. Rozhdestvenskaya ◽  
V. F. Pustovoy

The Thoroughbred (TB) horse is the best racehorse breed used in the racing industry. This breed has had a closed studbook for about 300 years. In Russia TB horses have been bred since the second half of the XVIII century. The modern Russian Stud Book register of TB horses is partially presented by stallions and broodmares imported from different countries. The genealogical structure of the breed is represented by 17 lines, among which the Northern Dancer line dominates (30.9 %). The study of features of different lines of TB was carried out on 17 loci of DNA microsatellites (VHL20, HTG4, AHT4, HMS7, HTG6, AHT5, HMS6, ASB23, ASB2, HTG10, HTG7, HMS3, HMS2, ASB17, LEX3, HMS1 and CA425) to assess genetic differentiation of the genealogical structure. The results of the DNA typing of 8091 Thoroughbred horses across microsatellite loci show that the gene pool of the domestic population is represented by 100 alleles typical of the breed. A comparative analysis of the genotypes of horses representing different lines indicates that they differ in the number of alleles (85–99), allele frequencies, the level of polymorphism Ae (2.93–3.48) and the degree of the observed heterozygosity Ho (0.653–0.739). The genetic distances between the lines varied in a wide range from 0.014 (Nasrullah – Northern Dancer) to 0.125 (Massine – Teddy). The correspondence to HWE was maintained in most lines, which is confirmed by the negative values of Fis. Cluster analysis demonstrated the correspondence of the obtained dendrogram of Nei’s genetic distances to its genealogical scheme of lines. Genetic differentiation of lines by index Fst varied in a range 0.005–0.073 at the mean value Fst = 0.024. The data indicate genetic differentiation of lines of TB at the STR markers and confirm the effectiveness of the system of linear breeding for the maintenance of interbreed biodiversity.


Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.


1987 ◽  
Vol 26 (06) ◽  
pp. 253-257
Author(s):  
M. Mäntylä ◽  
J. Perkkiö ◽  
J. Heikkonen

The relative partition coefficients of krypton and xenon, and the regional blood flow in 27 superficial malignant tumour nodules in 22 patients with diagnosed tumours were measured using the 85mKr- and 133Xe-clearance method. In order to minimize the effect of biological variables on the measurements the radionuclides were injected simultaneously into the tumour. The distribution of the radiotracers was assumed to be in equilibrium at the beginning of the experiment. The blood perfusion was calculated by fitting a two-exponential function to the measuring points. The mean value of the perfusion rate calculated from the xenon results was 13 ± 10 ml/(100 g-min) [range 3 to 38 ml/(100 g-min)] and from the krypton results 19 ± 11 ml/(100 g-min) [range 5 to 45 ml/(100 g-min)]. These values were obtained, if the partition coefficients are equal to one. The equations obtained by using compartmental analysis were used for the calculation of the relative partition coefficient of krypton and xenon. The partition coefficient of krypton was found to be slightly smaller than that of xenon, which may be due to its smaller molecular weight.


1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.


1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.


Sign in / Sign up

Export Citation Format

Share Document