Cynips quercusfolii is an oak gall wasp species distributed across the western Palearctic region. In this study, C. quercusfolii adults were used to investigate the possible effects of past climatic ...fluctuations and topography on the genetic structure of this species in Turkey. For this, the partial mitochondrial DNA (mtDNA) cytochrome b gene (cyt b) and nuclear DNA (nDNA) ITS2 region of 294 individuals from 38 populations covering the distribution of this species in Turkey were sequenced. The sequences generated 125 mtDNA haplotypes and 30 nDNA alleles. High variation was revealed in Turkish populations of C. quercusfolii (h = 0.7328 and π = 0.0102 for cyt b, and h = 0.5865 and π = 0.0058 for ITS2). Demographic analyses and high haplotype versus low nucleotide diversity indicated that C. quercusfolii populations might have undergone a series of expansions and contractions in the past. Phylogenetic analyses showed that this species is structured geographically between east and west due to a major physical barrier, the Anatolian Diagonal. Furthermore, divergence times of the lineages implied that deep splits occurred before the Pleistocene, while intermediate to shallow splits were associated with climatic changes during the Pleistocene. We conclude that ongoing geological events and associated climatic cycles were responsible for the current population genetic structure of this species in Turkey.
Tabanus bromius (Diptera: Tabanidae) is one of the most notable Tabanidae species of veterinary and medical importance distributed throughout the Palearctic region. In this study, we investigate the ...genetic diversity and the phylogeographic structure of T. bromius sampled from Turkey, Croatia, and Iran.
For this purpose, a 686-base-pair (bp) fragment of mitochondrial DNA cytochrome oxidase I gene (COI) and 1339 bp of the nuclear DNA internal transcribed spacer (ITS) were sequenced from 247 individuals representing 15 populations.
The sequences generated 169 COI haplotypes and 90 ITS alleles. A higher haplotype/allele diversity (h = 0.9909 for the COI gene and Ad = 0.8193 for the ITS region) compared to a low nucleotide diversity (π = 0.020605 for COI gene and π = 0.013667 for the ITS region), present for a high number of singleton and private haplotypes/alleles imply population expansion in the past. The results of phylogenetic analysis led to the uncovering of geographically significant groupings of lineages with regard to the entrance of the species into Anatolia and the location of major geographic barriers. According to current data, the species appears to have entered Turkey from Caucasia and Iran. A molecular clock applied to the COI data suggests that T. bromius diverged from the outgroup species nearly 8.83 million years ago, around the end of the Miocene era.
The results of this study indicate remarkable genetic diversity across the studied range of the species. High haplotype/allele versus low nucleotide diversity and demographic analyses implied that the T. bromius populations have undergone a series of expansions and retreats in the past. Our current findings suggest that T. bromius split from outgroups around the Late Miocene. Subsequent diversification events during the climatic and environmental fluctuation times of the Late Pliocene and Early Pleistocene periods also significantly influenced the species, resulting in the formation of some major genetic lineages. The phylogenetic analyses indicate that T. bromius most likely entered Turkey from the Caucasus region and Iran.
Sequence data for the nuclear ITS2 region and part of the mitochondrial cytochrome b gene were used to reveal intraspecific phylogeography and population genetic structure of the oak gall wasp ...Trigonaspis synaspis from Anatolia. One hundred and sixty six individuals representing 21 populations yielded 50 unique cyt b haplotypes and 15 ITS2 alleles. Genetic diversity estimates indicated the existence of high molecular variation, with average gene diversities of 0.85541 and 0.3119 for cyt b and ITS2 respectively. Likewise, nucleotide diversity was 0.01346 for cyt b and 0.0015 for ITS2. Pairwise divergence ranged from 0.2% to 3.1% between cyt b haplotypes, and from 0.2% to 2.8% between ITS2 alleles. Phylogenetic analyses of the cyt b haplotypes conducted using three different approaches produced mostly similar topologies, and major clades generally grouped haplotypes with similar geographic origins. Contrary to the mtDNA results, ITS2 analyses produced largely similar but polytomous topologies lacking apparent geographic structure.
Approximate Bayesian computation (ABC) is a powerful and widely used approach in inference of population history. However, the computational effort required to discriminate among alternative ...historical scenarios often limits the set that is compared to those considered more likely a priori. While often justifiable, this approach will fail to consider unexpected but well‐supported population histories. We used a hierarchical tournament approach, in which subsets of scenarios are compared in a first round of ABC analyses and the winners are compared in a second analysis, to reconstruct the population history of an oak gall wasp, Synergus umbraculus (Hymenoptera, Cynipidae) across the Western Palaearctic. We used 4,233 bp of sequence data across seven loci to explore the relationships between four putative Pleistocene refuge populations in Iberia, Italy, the Balkans and Western Asia. We compared support for 148 alternative scenarios in eight pools, each pool comprising all possible rearrangements of four populations over a given topology of relationships, with or without founding of one population by admixture and with or without an unsampled “ghost” population. We found very little support for the directional “out of the east” scenario previously inferred for other gall wasp community members. Instead, the best‐supported models identified Iberia as the first‐regional population to diverge from the others in the late Pleistocene, followed by divergence between the Balkans and Western Asia, and founding of the Italian population through late Pleistocene admixture from Iberia and the Balkans. We compare these results with what is known for other members of the oak gall community, and consider the strengths and weaknesses of using a tournament approach to explore phylogeographic model space.
Intraspecific genetic diversity and phylogenetic relationships of Andricus lucidus haplotypes from Turkey were studied by PCR-RFLP analysis. A total of 26 haplotypes were detected among 144 ...individuals collected from 9 populations. The estimated average haplotype and nucleotide diversity within populations were 0.8089 and 0.115542, respectively. Nucleotide divergence estimates among the analyzed oak gall wasp populations ranged between 0.012% and 7.3%. Dendrograms indicated that there was a relationship between the geographical distribution of haplotypes and their clustering. AMOVA analysis for estimation of the partitioning of genetic differentiation at all different hierarchical levels was statistically significant. Analysis of variance revealed that the highest genetic variance (61.21%) was present within populations and a significant partitioning of variance (26.85%) was found among groups. Overall, the present study indicates that the oak gall wasp haplotypes found in different populations from Turkey have a significant amount of genetic diversity and form geographically significant groupings.
Dünyada yaşamın ilk ortaya çıkmasından bu yana pek çok farklı yaşam formu hem birbirleri ile hem de cansız çevre faktörleriyle etkileşim içinde bulunmuşlar ve evrimleşerek çeşitlenmişlerdir. Bu ...etkileşimler arasında en dikkat çekici olanlarından biri bitkiler ile gal oluşturan böcekler arasında görülür. Özellikle gal arıları (Hymenoptera, Cynipidae) oldukça karmaşık gal yapıları ile adaptif radyasyonun en güzel örneklerinden birini sergiler. Sıra dışı bitki yapıları olan gallerin oluşabilmesi için herbivor böcek, bitkinin savunma bariyerlerini tek tek geçerek konak genomunu yeniden programlar ve onun öz kaynaklarını kendi lehine kullanır. Gal oluşum sürecinde hücre proliferasyonunun başlatılması sonrasında konak için tamamen yeni ve olağan dışı yapıların oluşumuna kadar bir dizi gen, molekül ve metabolik yol ve yolak kullanılır. Son yıllarda yapılan moleküler çalışmalarda artış olsa da gal oluşumu, moleküler mekanizmalar ve gal komünitelerindeki evrimsel ilişkiler henüz yeni yeni aydınlatılmaya başlanmıştır. Bu derleme çalışmasında gal oluşumu, meşe gal arıları (Cynipidae, Cynipini) temel alınarak morfolojik ve güncel moleküler bilgiler ışığında kısaca özetlenmeye çalışılmıştır.
Since the emergence of life on Earth, numerous different life forms have interacted with both each other and their environment and evolved over time. One of the most remarkable interactions is observed between plants and gall forming insects, where gall wasps (Hymenoptera, Cynipidae) represent one of the most significant examples of adaptive radiation through inducing very complicated gall structures. For the formation of these extraordinary gall structures, herbivorous insects bypass the plant's defense barriers and reprogram the host genome, utilizing its resources for their own benefit. Through gall formation, a series of genes, molecules, metabolic pathways, and routes are utilized, starting from the initiation of cell proliferation to the formation of entirely new and extraordinary structures for the host. While there has been an increase in molecular studies in recent years, gall formation, molecular mechanisms, and evolutionary relationships within gall communities have not been completely understood yet. This review aims to provide a brief summary of gall formation based on oak gall wasps (Cynipidae, Cynipini), incorporating morphological and current molecular information.
A 433-bp fragment of the mitochondrial cytochrome b gene and the entire nuclear ITS2 region were sequenced in an oak gall wasp species, Andricus curtisii, which represents 21 populations across its ...range in Turkey. Forty cytochrome b haplotypes and 63 ITS2 alleles were discovered among the 161 individuals studied. Remarkable genetic variation was detected in the species, with an average haplotype diversity (h) of 0.72 and 0.76 and an average nucleotide diversity (π) of 0.06 and 0.01 for the cyt b gene and the ITS region, respectively. Most populations were genetically distinct, possessing unique cytochrome b haplotypes. Maximum likelihood and Bayesian phylogenetic analyses and application of the haplotype network to both datasets revealed that the most basally located haplotypes/alleles were from the eastern part of Turkey. The detection of older sequences in the phylogenetic trees of the easterly located populations implied an eastern origin of the species. The application of a conventional insect mitochondrial DNA clock to the dataset suggested a splitting of ingroup haplotypes from the outgroup lineages predating the Pleistocene epoch and the formation of two major haplogroups that coincided with the oscillation of the early Pleistocene glaciations.
•Mitochondrial and nuclear DNA sequences of Andricus curtisii in Turkey showed high level of genetic diversity across Turkey.•Phylogenetic and phylogeographic analyses supported an eastern origin of haplotypes/alleles.•Analysis showed that a splitting event of ingroup haplotypes from the outgroup lineages predated the Pleistocene.•Two major haplogroup formation of the ingroup sequences coincided with the oscillation in the early Pleistocene glaciations.
Cynips quercusfolii is an oak gall wasp species distributed across the western Palearctic region. In this study, C. quercusfolii adults were used to investigate the possible effects of past climatic ...fluctuations and topography on the genetic structure of this species in Turkey. For this, the partial mitochondrial DNA (mtDNA) cytochrome b gene (cyt b) and nuclear DNA (nDNA) ITS2 region of 294 individuals from 38 populations covering the distribution of this species in Turkey were sequenced. The sequences generated 125 mtDNA haplotypes and 30 nDNA alleles. High variation was revealed in Turkish populations of C. quercusfolii (h = 0.7328 and π = 0.0102 for cyt b, and h = 0.5865 and π = 0.0058 for ITS2). Demographic analyses and high haplotype versus low nucleotide diversity indicated that C. quercusfolii populations might have undergone a series of expansions and contractions in the past. Phylogenetic analyses showed that this species is structured geographically between east and west due to a major physical barrier, the Anatolian Diagonal. Furthermore, divergence times of the lineages implied that deep splits occurred before the Pleistocene, while intermediate to shallow splits were associated with climatic changes during the Pleistocene. We conclude that ongoing geological events and associated climatic cycles were responsible for the current population genetic structure of this species in Turkey.
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