Alternated selection mechanisms maintain adaptive diversity in different demographic scenarios of a large carnivore

Background

Different population trajectories are expected to impact the signature of neutral and adaptive processes at multiple levels, challenging the assessment of the relative roles of different microevolutionary forces. Here, we integrate adaptive and neutral variability patterns to disentangle how adaptive diversity is driven under different demographic scenarios within the Iberian wolf (Canis lupus) range. We studied the persistent, the expanding and a small, isolated group within the Iberian wolf population, using 3 MHC class II genes (DRB1, DQA1, and DQB1), which diversity was compared with 39 microsatellite loci.

Results

Both the persistent and the expanding groups show evidence of balancing selection, revealed by a significant departure from neutrality at MHC loci, significant higher observed and expected heterozygosity and lower differentiation at MHC than at neutral loci, and signs of positive selection. However, despite exhibiting a significantly higher genetic diversity than the isolated group, the persistent group did not show significant excess of MHC heterozygotes. The expanding group, while showing a similar level of genetic diversity than the persistent group, displays by contrast a significant excess of MHC heterozygotes, which is compatible with the heterozygote advantage mechanism. Results are not clear regarding the role of drift and selection in the isolated group due to the small size of this population. Although diversity indices of MHC loci correspond to neutral expectations in the isolated group, accelerated MHC divergence, revealed by a higher differentiation at MHC than neutral loci, may indicate diversifying selection.

Conclusion

Different selective pressures were observed in the three different demographic scenarios, which are possibly driven by different selection mechanisms to maintain adaptive diversity.

Electronic supplementary material

The online version of this article (10.1186/s12862-019-1420-5) contains supplementary material, which is available to authorized users.

Cardiovascular responses to different stages of restorative dental treatment unaffected by local anaesthetic type

BACKGROUND

The aim of this study was to evaluate the cardiovascular effects of maxillary infiltration using 2% lidocaine with 1:100,000 adrenaline, 4% articaine with 1:200,000 adrenaline, and 4% articaine with 1:100,000 adrenaline in different stages during restorative dental procedures.

METHODS

Twenty healthy patients randomly received 1.8 mL of the three local anaesthetics. Systolic blood pressure, average blood pressure, diastolic blood pressure, and heart rate were evaluated by the oscillometric and photoplethysmograph methods in seven stages during the appointment.

RESULTS

Statistical analysis by ANOVA and Tukey tests of cardiovascular parameters did not show significant differences between the anaesthetic associations. There were significant differences for the parameters among different clinical stages.

CONCLUSIONS

The variation of cardiovascular parameters was similar for lidocaine and articaine with both adrenaline concentrations and showed no advantage of one drug over the other. Cardiovascular parameters were influenced by the stages of the dental procedures, which showed the effect of anxiety during restorative dental treatment.

Cardiovascular alterations caused by the administration of 2% mepivacaine HCl with 1:20,000 levonordefrin (Carbocain) in dogs

We studied possible cardiovascular effects (systolic, diastolic, mean arterial blood pressures, and heart rate) caused by intraoral infiltrative administration of 2% mepivacaine HCl with 1:20,000 levonordefrin in dogs (Canis familiaris), using a Beckman electrophysiograph. Doses used were 0.514 and 1.542 mg/kg body weight corresponding to one and three 1.8-ml cartridges, respectively, in 70-kg average weight adult men. A statistically significant increase was observed in the systolic and the mean arterial blood pressures.