The relationship between mitochondrial ND5 gene polymorphisms and in vitro embryo production in Sanjabi sheep

The aim of this study was to investigate mitochondrial ND5 gene polymorphisms and their relationship with in vitro maturation (IVM) and in vitro culture (IVC) of Sanjabi sheep. Blood and ovarian samples of adult ewes were obtained from a local slaughterhouse. For each ovarian sample, cumulus–oocyte complexes larger than 3 mm in diameter were aspirated from follicles, and their IVM and IVC rates were recorded. A 666-bp fragment of the ND5 gene was amplified using the polymerase chain reaction. The samples were genotyped using a modified single-stranded conformation polymorphism (SSCP) method, and an association study was conducted with IVM and IVC rates. Six different SSCP patterns, designated A, B, C, D, E and F with respective frequencies of 8, 47, 4, 4, 32 and 5%, respectively, were observed. According to the results of association analysis, there was no significant association between the ND1 gene polymorphisms and the IVM and IVC rates (P > 0.05).

Rewinding the molecular clock in the genus Carabus (Coleoptera: Carabidae) in light of fossil evidence and the Gondwana split: A reanalysis

Molecular clocks have become powerful tools given increasing sequencing and fossil resources. However, calibration analyses outcomes depend on the choice of priors. Here, we revisited the seminal dating study published by Andújar and coworkers of the genus Carabus proposing that prior choices need re-evaluation. We hypothesized that reflecting fossil evidence and the Gondwanan split properly significantly rewinds the molecular clock. We re-used the dataset including five mitochondrial and four nuclear DNA fragments with a total length of 7888 nt. Fossil evidence for Oligocene occurrence of Calosoma was considered. Root age was set based on the fossil evidence of Harpalinae ground beetles in the Upper Cretaceous. Paleogene divergence of the outgroup taxa Ceroglossini and Pamborini is introduced as a new prior based on current paleontological and geological literature. The ultrametric time-calibrated tree of the extended nd5 dataset resulted in a median TMRCA Carabus of 53.92 Ma (HPD 95% 45.01–63.18 Ma), roughly 30 Ma older than in the Andújar study. The splits among C. rugosus and C. morbillosus (A), C. riffensis from the European Mesocarabus (B), and Eurycarabus and Nesaeocarabus (C) were dated to 17.58 (12.87–22.85), 24.14 (18.02–30.58), and 21.6 (16.44–27.43) Ma. They were decidedly older than those previously reported (7.48, 10.93, and 9.51 Ma). These changes were driven almost entirely by constraining the Carabidae time-tree root with a Harpalinae amber fossil at ~99 Ma. Utilizing the nd5 dating results of three well-supported Carabus clades as secondary calibration points for the complete MIT-NUC dataset led to a TMRCA of Carabus of 44.72 (37.54–52.22) Ma, compared with 25.16 Ma (18.41–33.04 Ma) in the previous study. Considering fossil evidence for Oligocene Calosoma and Late Cretaceous Harpalini together with the Gondwanan split as a new prior, our new approach supports the origin of genus Carabus in the Eocene. Our results are preliminary because of the heavy reliance on the nd5 gene, and thus will have to be tested with a sufficient set of nuclear markers. Additionally, uncertainties due to dating root age of the tree based on a single fossil and outgroup taxon affect the results. Improvement of the fossil database, particularly in the supertribe Carabitae, is needed to reduce these uncertainties in dating Carabus phylogeny.

Comparative Genetics Using Three mtDNA Markers in Aedes aegypti (Linnaeus) Populations from Four Municipalities in the Satate of Mato Grosso, Brazil.

Aedes aegypti mosquito has spread throughout the tropical and subtropical world and is currently the primary species responsible for transmitting dengue, urban yellow fever, Chikungunya, and Zika virus. This study aimed to investigate the inter- and intrapopulational genetic variability of Aedes aegypti through mitochondrial DNA, COI, ND4, and ND5 molecular markers in four municipalities in Mato Grosso. We used the Geneious software to build dendrograms for differentiating populations from each municipality. The interpopulational genetic distance obtained from sequence analysis showed a difference within populations through groups' formation in the ordering. Besides, we identified a difference in the interindividual genetic distance values, notably for the ND5 gene from the populations captured in the four municipalities. We recorded the smallest interindividual genetic distance within populations for populations from Chapada dos Guimarães. Extrinsic factors, including breeding habitat removal, can contribute to decreasing variability. Consequently, the dendrogram showed some similarities. Ovitrap monitoring, vector elimination, and genetic flow investigation stimulate actions to prevent transmitted diseases and support essential effective measures to control and fight Ae. aegypti.

Mitogenome Analysis of Four Lamiinae Species (Coleoptera: Cerambycidae) and Gene Expression Responses by Monochamus alternatus When Infected with the Parasitic Nematode, Bursaphelenchus mucronatus

We determined the mitochondrial gene sequence of Monochamus alternatus and three other mitogenomes of Lamiinae (Insect: Coleoptera: Cerambycidae) belonging to three genera (Aulaconotus, Apriona and Paraglenea) to enrich the mitochondrial genome database of Lamiinae and further explore the phylogenetic relationships within the subfamily. Phylogenetic trees of the Lamiinae were built using the Bayesian inference (BI) and maximum likelihood (ML) methods and the monophyly of Monochamus, Anoplophora, and Batocera genera was supported. Anoplophora chinensis, An. glabripennis and Aristobia reticulator were closely related, suggesting they may also be potential vectors for the transmission of the pine wood pathogenic nematode (Bursaphelenchus xylophilus) in addition to M. alternatus, a well-known vector of pine wilt disease. There is a special symbiotic relationship between M. alternatus and Bursaphelenchus xylophilus. As the native sympatric sibling species of B. xylophilus, B. mucronatus also has a specific relationship that is often overlooked. The analysis of mitochondrial gene expression aimed to explore the effect of B. mucronatus on the energy metabolism of the respiratory chain of M. alternatus adults. Using RT-qPCR, we determined and analyzed the expression of eight mitochondrial protein-coding genes (COI, COII, COIII, ND1, ND4, ND5, ATP6, and Cty b) between M. alternatus infected by B. mucronatus and M. alternatus without the nematode. Expression of all the eight mitochondrial genes were up-regulated, particularly the ND4 and ND5 gene, which were up-regulated by 4–5-fold (p < 0.01). Since longicorn beetles have immune responses to nematodes, we believe that their relationship should not be viewed as symbiotic, but classed as parasitic.

Rewinding the molecular clock in the genus Carabus (Coleoptera: Carabidae) in light of fossil evidence and the Gondwana split: a re-analyses

1AbstractBackgroundMolecular clocks have become powerful tools given increasing sequencing and fossil resources. However, outcome of calibration analyses depend on choosing priors. Here we revisit a seminal dating study of the genus Carabus by Andujar et al. proposing that their prior choices need re-evaluation with the hypothesis that reflecting fossil evidence and the Gondwanan split properly rewinds the molecular clock significantly. We used the same dataset including five mitochondrial and four nuclear DNA fragments with 7888 nt total length. We set the root age based on the fossil evidence of Harpalinae ground beetles in the Upper Cretaceous and introduce the Paleogene divergence of the outgroup taxa Ceroglossus (endemic to South-America) and Pamborus + Maoripamborus (Australia, New Zealand) as a new prior based on current paleontological and geological literature.ResultsThe ultrametric time-calibrated tree of the extended nd5 dataset resulted in a median TMRCA Carabus age of 58.48 Ma (HPD95% 46.61-72.04), roughly 35 Ma older than in the Andujar study. The splits between C. rugosus and C. morbillosus (A), between C. riffensis from the European Mesocarabus (B), and between Eurycarabus and Nesaeocarabus (C) were dated to 19.19 (13.54-25.87), 25.95 (18.8-34.62), and 23.98 (17.28-31.47) Ma and were thus decidedly older than previously reported (7.48, 10.93, and 9.51 Ma). These changes were driven solely by constraining the Carabidae time tree root with Harpalinae amber fossils at ∼99 Ma. Utilizing the nd5 dating results of three well supported Carabus clades as secondary calibration points for the complete MIT-NUC data set lead to a TMRCA of Carabus of 53.56 (41.25-67.05) Ma compared to 25.16 (18.41-33.04) in Andujar’s study.ConclusionTaking into account the Gondwanan split as a new prior, together with the fossil evidence of the outgroup taxon Harpalini in the Late Cretaceous, our new approach supports an origin of the genus Carabus in the Paleocene-Early Eocene. Our results are preliminary due to the heavy reliance on the nd5 gene and thus will have to be tested with sufficient set of nuclear markers. In addition, uncertainties arise from dating the root age of the tree based on a single fossil and outgroup taxon which has a major effect on the results. Improvement of the fossil data base particularly in the supertribe Carabitae is thus strongly needed to reduce the currently large uncertainties in dating Carabus phylogeny.

Genetic analysis of mitochondrial ND5 gene of siberian ibex (Capra Sibirica, Pallas, 1776) population in Mongolia

The Siberian ibex (Capra sibirica) from Central Asia is believed to be the most ancient species of the genus Capra. In Mongolia, it is distributed in the areas of Mongolian Altai, Gobi-Altai, Dzungaria, Altai, Khan Khuhii, Khoridal Saridag and Ulaan Taiga as well as in the desert and semi-desert steppe zones of Dundgobi and Dornogobi aimags (provinces). In the current study, we investigated the mitochondrial ND5 gene fragments of the Siberian ibex population from different parts of Mongolia. Nine haplotypes, including 6 shared and 3 unique haplotypes were identified among these populations. Furthermore, Tajima’s statistics and Fu’s statistics did not reveal significant positive value across the population, indicating population decline and balancing selection.In the phylogenetic tree by 9 haplotypes, no separated clusters were generated. In addition, nucleotide diversity was 0.015, haplotype diversity was 0.86 and the average number of differences in nucleotides was 8.2 in the overall population. These results suggest that genetic diversity across all the populations was low, while haplotype diversity and the average number of differences in nucleotides were high.

Are 45 years of reproductive isolation enough to prevent the amplification of mitochondrial genes in the Pacific oyster?

The Pacific oyster culture in Mexico began 45 years ago, first with spat imported from the USA and now with spat produced in several local hatcheries. Oyster farmers do not know the parameters that define the quality of the spat they buy, among them the level of genetic variability available in the lots offered. In order to evaluate and compare the genetic variability in spat produced by four Mexican hatcheries, an attempt was made to amplify and sequence the non-coding region and the ND5 gene of the oyster mitochondrial DNA with oligos reported in the scientific literature. The amplification of the non-coding region was not possible due to the bad design of the oligos. Despite the integrity of the extracted oyster DNA, the ND5 gene was not able to be amplified possibly due to the modification of the oligo recognition site in the gene. The generational separation of the oyster cultivated in Mexico from its original source population makes it necessary to obtain new mitochondrial sequences in order to design new oligos suitable for the populations established in Mexico.

Genetic structure of the Chagas disease vector Triatoma infestans (Hemiptera: Reduviidae) based on nuclear and mitochondrial DNA sequences

In the present study, we analysed the genetic structure of Triatoma infestans populations with a phylogeographical approach using sequences of the mitochondrial NADH dehydrogenase subunit 5 (ND5) and the nuclear elongation factor-1 alpha (EF-1α) genes of bugs obtained from Argentina and Bolivia. Spatially circumscribed haplogroups were distinguished from the ND5 gene sequences, one distributed exclusively to the south of the studied area and, in agreement with the results from the EF-1α gene, one haplogroup limited to Bolivia and another to Morajú located in the Chaco region of Argentina. In both the ND5 and EF-1α networks, the most widespread haplogroup or allele group showed a star-like topology, which is compatible with a recent demographic expansion. The asymmetric historical gene flow detected from a population of the Chaco region towards Bolivia and the spatiotemporal phylogeographical reconstruction of lineage dispersal would support the hypothesis that postulates the Chaco biogeographical region as the area of origin for the species. However, additional studies with a broader sampling in the Andean region are needed to define with certainty whether the origin of T. infestans is Chacoan or Andean.