scholarly journals Genetic variation is predominantly structured by geography rather than host in feather mites (Acariformes: Sarcoptiformes) associated with tanagers (Aves: Thraupidae) in Brazil

2021 ◽  
Vol 3 ◽  
pp. ec03044
Author(s):  
Luiz Gustavo de A. Pedroso ◽  
Pavel B. Klimov ◽  
Fabio A. Hernandes
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Geographic Distribution ◽  
Host Species ◽  
Intimate Relationship ◽  
Genetic Distances ◽  
Southern Brazil ◽  
Feather Mites ◽  
Molecular Barcode ◽  
Cox 1

Feather mites are the most common ectosymbionts on birds. These obligatory symbionts are mainly transmitted during their host’s parental care, which creates high host specificity. Due to this intimate relationship, it is thought that their geographic distribution is restricted by their host distribution, or that a host species harbors the same mite composition across its whole range. However, our knowledge regarding the geographic distribution of feather mites remains scarce, with only a few studies indicating disconnections between mite and host distributions, especially in widespread hosts. Here, we investigate the feather mites distribution on four tanager species, three widespread – Thraupis sayaca (L.), T. palmarum (Wied), and Stilpnia cayana (L.) from Northern and Southern Brazil; and the Amazonian T. episcopus (L.). Feather mites were identified using the molecular barcode marker COX-1 using K2P genetic distances. We found a strong genetic structure between Northern and Southern populations of tanagers of more than 10%, even among conspecific hosts. Therefore, the mite distribution on Brazilian tanagers is predominantly shaped by geography rather than by host species. These features in turn reflect historical horizontal transmissions among the hosts, suggesting a high potential for frequent host switches in these symbionts.

Genetic structure analysis of domestic duck populations in eastern China

2008 ◽  
Vol 5 (3) ◽  
pp. 183-187
Author(s):  
Li Hui-Fang ◽  
Song Wei-Tao ◽  
Zhu Wen-Qi ◽  
Xu Wen-Juan ◽  
Tang Qing-Ping
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Eastern China ◽  
Genetic Distances ◽  
Domestic Duck ◽  
Average Heterozygosity ◽  
Rich Diversity ◽  
Breed Differences ◽  
The Rich

AbstractUsing microsatellite markers, the genetic structure of nine domestic duck (Anas platyrhynchos) populations in eastern China was analysed. The results showed that the heterozygosity was high in these populations, ranging from 0.5137 to 0.6055, with an average heterozygosity of 0.5523, reflecting the rich diversity. Considerable breed differentiation was observed and 25.65% of the total genetic variation came from breed differences; this low differentiation result affirmed that each breed has its own genetic diversity. The DA genetic distances suggested that greater differentiation existed between populations. The duck populations were clustered into four groups based on neighbour joining (NJ) clustering, and the clustering results showed relationships with duck breed distributions and economic utilization.

Feather mites of the new genus Bernierinyssus gen. n. (Acariformes: Pteronyssidae) from endemic Malagasy warblers (Passeriformes: Bernieridae)—a lineage showing symbiotic cospeciation with their avian hosts

2020 ◽  
Vol 25 (10) ◽  
pp. 1765-1802
Author(s):  
S. V. Mironov ◽  
P. B. Klimov ◽  
N. L. Block ◽  
B. M Oconnor
Keyword(s):  
Host Species ◽  
Molecular Phylogenetics ◽  
Sequence Data ◽  
Bird Species ◽  
Mite Species ◽  
Genetic Distances ◽  
Morphological Evidence ◽  
Feather Mites ◽  
Bird Species Richness ◽  
Specificity Pattern

A new feather mite genus Bernierinyssus gen. n. (Analgoidea: Pteronyssidae), associated with endemic Malagasy warblers (Passeriformes: Bernieridae), is proposed based on morphological evidence and DNA sequence data. Within this genus, we detected six mite species, including five new species described here: Bernierinyssus angulatus sp. n. from Crossleyia xanthophrys, B. bernieriae sp. n. from Bernieria madagascariensis, B. bifenestratus sp. n. from Hartertula flavoviridis, B. randiae sp. n. from Randia pseudozosterops, B. xanthomixis sp. n. from Xanthomixis zosterops (type host) and X. cinereiceps, and B. oxylabis (Mironov and Wauthy 2005) comb. n. (transferred from Pteronyssoides Hull). Phylogenetic relationships of these mites were nearly perfectly congruent with those of their hosts, indicating that ancestral Bernierinyssus probably co-dispersed to Madagascar on the common ancestor of Malagasy warblers and then cospeciated with their hosts. Species of Bernierinyssus are well-delimited based on several lines of evidence: morphology (clear among-specific differences in discrete characters), host associations (one mite species per one host species, except for B. xanthomixis), genetic distances (large COX1 barcoding gap between among- and within-species K2P distances: 8.22¨C12.38% vs 0¨C2.9%, respectively), and molecular phylogenetics (all species are well-supported, monophyletic clades). Our study suggests that species of the genus Bernierinyssus have evolved slower than their avian hosts or co-associated feather lice. Despite the discordance in the mitochondrial DNA evolutionary rates, speciation events in mites largely corresponded to bird species divergences, resulting in a nearly perfect correlation between mite and bird species richness (Eichler's Rule). The mite B. xanthomixis was associated with two avian species, but still formed two distinct shallow lineages (COX1 distance: 1.65%) separated by the host species. The nearly strict host-specificity pattern found in Bernierinyssus contrasts with that of continental feather mites, which tend to be less host-specific and have nearly equal proportions of single-host vs multi-host species.

scholarly journals Genetic structure of the Capoeta aculeata populations inferred from microsatellite DNA loci

2020 ◽  
Vol 21 (10) ◽  
Author(s):  
Habibollah Gandomkar ◽  
Seyed Pezhman Hosseini Shekarabi ◽  
Hossein Ali Abdolhay ◽  
Sajad Nazari ◽  
MEHDI SHAMSAEI MEHRJAN
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Microsatellite Loci ◽  
Microsatellite Dna ◽  
Pairwise Comparison ◽  
Genetic Distances ◽  
River Population ◽  
Allelic Distribution ◽  
Dna Microsatellite ◽  
Three Rivers

Abstract. Gandomkar H, Shekarabi SPH, Abdolhay HA, Nazari S, Mehrjan MS. 2020. Genetic structure of the Capoeta aculeata populations inferred from microsatellite DNA loci. Biodiversitas 21: 4565-4570. The present study aimed to investigate the genetic variation of Capoeta aculeata on the basis of DNA microsatellite loci from three rivers (Beshar, Khersan, Maroun) in Kohgiluyeh and Boyer-Ahmad Province in Iran. DNA from fin clips of 120 specimens extracted and was examined with eight microsatellite markers. Genetic differences between the populations were discerned by pairwise comparison based on allelic distribution. The average number of alleles per locus ranged from 4 to 14, while the average observed heterozygosity (Ho) at various loci varied between 0.212 to 0.579, implying that a moderate level of genetic variation. Among three populations, Maroun River population displayed the highest level of variability in terms of heterozygosity. Tests of Hardy-Weinberg showed that the microsatellite loci deviated significantly in the populations. The results indicate that some of the populations were significantly differentiated from one another based on pairwise FST estimates. Genetic distance-based measures supported the clustering of Maroun, Beshar, and Khersan rivers. The neighbor-joining dendrogram topology constructed on the basis of genetic distances among populations supported observed division between the populations. The non-significant differentiation between C. aculeata samples from Beshar and Khersan can be explained by a relative disconnection of these two populations and/or small amounts of gene flow.

scholarly journals Genetic diversity in Tunisian horse breeds

2017 ◽  
Vol 60 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Bayrem Jemmali ◽  
Mohamed Mezir Haddad ◽  
Nawel Barhoumi ◽  
Syrine Tounsi ◽  
Faten Lasfer ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Microsatellite Loci ◽  
Genomic Dna ◽  
Genetic Distances ◽  
Jugular Veins ◽  
Blood Samples ◽  
Important Amount

Abstract. This study aimed at screening genetic diversity and differentiation in four horse breeds raised in Tunisia, the Barb, Arab-Barb, Arabian, and English Thoroughbred breeds. A total of 200 blood samples (50 for each breed) were collected from the jugular veins of animals, and genomic DNA was extracted. The analysis of the genetic structure was carried out using a panel of 16 microsatellite loci. Results showed that all studied microsatellite markers were highly polymorphic in all breeds. Overall, a total of 147 alleles were detected using the 16 microsatellite loci. The average number of alleles per locus was 7.52 (0.49), 7.35 (0.54), 6.3 (0.44), and 6 (0.38) for the Arab-Barb, Barb, Arabian, and English Thoroughbred breeds, respectively. The observed heterozygosities ranged from 0.63 (0.03) in the English Thoroughbred to 0.72 in the Arab-Barb breeds, whereas the expected heterozygosities were between 0.68 (0.02) in the English Thoroughbred and 0.73 in the Barb breeds. All FST values calculated by pairwise breed combinations were significantly different from zero (p  <  0.05) and an important genetic differentiation among breeds was revealed. Genetic distances, the factorial correspondence, and principal coordinate analyses showed that the important amount of genetic variation was within population. These results may facilitate conservation programs for the studied breeds and enhance preserve their genetic diversity.

scholarly journals Genomic variation in the American pika: signatures of geographic isolation and implications for conservation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kelly B. Klingler ◽  
Joshua P. Jahner ◽  
Thomas L. Parchman ◽  
Chris Ray ◽  
Mary M. Peacock
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Sierra Nevada ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Thermal Sensitivity ◽  
Genomic Variation ◽  
Genome Wide ◽  
A Genome ◽  
American Pika

Abstract Background Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. Results Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006–0.0009; θW = 0.0005–0.0007) relative to populations in California (π = 0.0014–0.0019; θW = 0.0011–0.0017) and the Rocky Mountains (π = 0.0025–0.0027; θW = 0.0021–0.0024), indicating substantial genetic drift in these isolated populations. Tajima’s D was positive for all sites (D = 0.240–0.811), consistent with recent contraction in population sizes range-wide. Conclusions Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.

Genetic Relationships of Cory's Shearwater: Parentage, Mating Assortment, and Geographic Differentiation Revealed by DNA Fingerprinting

The Auk ◽  
2000 ◽  
Vol 117 (3) ◽  
pp. 651-662 ◽  
Author(s):  
Corinne Rabouam ◽  
Vincent Bretagnolle ◽  
Yves Bigot ◽  
Georges Periquet
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Dna Fingerprinting ◽  
Genetic Relatedness ◽  
Isolation By Distance ◽  
Genetic Relationships ◽  
Cory’S Shearwater ◽  
Genetic Structure Of Populations ◽  
The Social ◽  
Calonectris Diomedea

Abstract We used DNA fingerprinting to assess genetic structure of populations in Cory's Shearwater (Calonectris diomedea). We analyzed mates and parent-offspring relationships, as well as the amount and distribution of genetic variation within and among populations, from the level of subcolony to subspecies. We found no evidence of extrapair fertilization, confirming that the genetic breeding system matches the social system that has been observed in the species. Mates were closely related, and the level of genetic relatedness within populations was within the range usually found in inbred populations. In contrast to previous studies based on allozymes and mtDNA polymorphism, DNA fingerprinting using microsatellites revealed consistent levels of genetic differentiation among populations. However, analyzing the two subspecies separately revealed that the pattern of genetic variation among populations did not support the model of isolation by distance. Natal dispersal, as well as historic and/or demographic events, probably contributed to shape the genetic structure of populations in the species.

Significant genetic differences among Heterodera schachtii populations within and among sugar beet production areas

Nematology ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 165-177 ◽  
Author(s):  
Rasha Haj Nuaima ◽  
Johannes Roeb ◽  
Johannes Hallmann ◽  
Matthias Daub ◽  
Holger Heuer
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Spatial Scales ◽  
Geographic Distance ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Neutral Genetic Variation ◽  
Production Areas

Summary Characterising the non-neutral genetic variation within and among populations of plant-parasitic nematodes is essential to determine factors shaping the population genetic structure. This study describes the genetic variation of the parasitism gene vap1 within and among geographic populations of the beet cyst nematode Heterodera schachtii. Forty populations of H. schachtii were sampled at four spatial scales: 695 km, 49 km, 3.1 km and 0.24 km. DGGE fingerprinting showed significant differences in vap1 patterns among populations. High similarity of vap1 patterns appeared between geographically close populations, and occasionally among distant populations. Analysis of spatially sampled populations within fields revealed an effect of tillage direction on the vap1 similarity for two of four studied fields. Overall, geographic distance and similarity of vap1 patterns of H. schachtii populations were negatively correlated. In conclusion, the population genetic structure was shaped by the interplay between the genetic adaptation and the passive transport of this nematode.

scholarly journals Microfluidic PCR Combined with Pyrosequencing for Identification of Allelic Variants with Phenotypic Associations among Targeted Salmonella Genes

2012 ◽  
Vol 78 (20) ◽  
pp. 7480-7482 ◽  
Author(s):  
Min Yue ◽  
Robert Schmieder ◽  
Robert A. Edwards ◽  
Shelley C. Rankin ◽  
Dieter M. Schifferli
Keyword(s):  
Genetic Variation ◽  
Antimicrobial Resistance ◽  
Host Species ◽  
Massive Parallel Sequencing ◽  
Allelic Variants ◽  
Parallel Sequencing ◽  
Content Type ◽  
Potential Applications ◽  
Fimbrial Adhesins ◽  
Diagnostic Microbiology

ABSTRACTA novel targeted massive parallel sequencing approach identified genetic variation in eight known or predicted fimbrial adhesins for 46Salmonellastrains. The results highlight associations between specific adhesin alleles, host species, and antimicrobial resistance. The differentiation of allelic variants has potential applications for diagnostic microbiology and epidemiological investigations.

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