Interaction between COMT rs5993883 and second generation antipsychotics is linked to decreases in verbal cognition and cognitive control in bipolar disorder

Abstract Background Second generation antipsychotics (SGAs) are increasingly utilized in Bipolar Disorder (BD) but are potentially associated with cognitive side effects. Also linked to cognitive deficits associated with SGA-treatment are catechol-O-methyltransferase (COMT) gene variants. In this study, we examine the relationship between cognition in SGA use and COMT rs5993883 in cohort sample of subjects with BD. Methods Interactions between SGA-treatment and COMT rs5993883 genotype on cognition was tested using a battery of neuropsychological tests performed in cross-sectional study of 246 bipolar subjects. Results The mean age of our sample was 40.15 years and was comprised of 70 % female subjects. Significant demographic differences included gender, hospitalizations, benzodiazepine/antidepressant use and BD-type diagnosis. Linear regressions showed that the COMT rs5993883 GG genotype predicted lower verbal learning (p = 0.0006) and memory (p = 0.0026) scores, and lower scores on a cognitive control task (p = 0.004) in SGA-treated subjects. Interestingly, COMT GT- or TT-variants showed no intergroup cognitive differences. Further analysis revealed an interaction between SGA-COMT GG-genotype for verbal learning (p = 0.028), verbal memory (p = 0.026) and cognitive control (p = 0.0005). Conclusions This investigation contributes to previous work demonstrating links between cognition, SGA-treatment and COMT rs5993883 in BD subjects. Our analysis shows significant associations between cognitive domains such as verbal-cognition and cognitive control in SGA-treated subjects carrying the COMT rs5993883 GG-genotype. Prospective studies are needed to evaluate the clinical significance of these findings.http://deepblue.lib.umich.edu/bitstream/2027.42/134550/1/40359_2016_Article_118.pd

Climate-mediated diversification of turtles in the Cretaceous

The file attached is the published version of the article

Consequences of maternal effects on offspring size, growth and survival in the desert tortoise

Maternal body size can have notable consequences on reproductive success. For example, fecundity often increases with body size. Less is known, however, about the relationship between maternal size and factors affecting offspring fitness, including size, growth and survival. Here, we examined the relationship between hatchling and maternal body size in the Mojave Desert tortoise Gopherus agassizii. We further examined the relationships between survival and growth after 1 year and size at hatching. We found that larger females tended to produce larger offspring; post-hatching growth and survival also correlated positively with size at hatching. Our results suggest that, in desert tortoises, maternal body size may indirectly influence offspring fitness via growth and survival for at least the first year of life. Such an advantage early in life may confer long-term benefits for individuals, especially in species thought to have high juvenile mortality or that inhabit highly variable environments

Phylogeographic uniformity in mitochondrial DNA of the snapping turtle (Chelydra serpentina)

Previous studies have revealed considerable genetic variation, geographic localization, and genealogical depth for mitochondrial DNA (mtDNA) haplotypes within each of several species of freshwater turtles in the south-eastern United States of America. Here we report a notable exception to such phylogeographic patterns. In control-region sequences of 66 snapping turtles (Chelydra serpentina) collected from 10 south-eastern states, a single mtDNA haplotype predominated and the two rare variants detected were nearly identical to the common genotype. This pattern of low mtDNA variation and a lack of appreciable geographic population structure is extremely unusual for a widely distributed animal species. For purposes of taxonomy and conservation, these findings suggest the presence of only one 'evolutionarily significant unit' for C. serpentina in this otherwise phylogeographically rich region of the country. Possible explanations for this phylogeographic pattern in the snapping turtle are considered

Delimiting road-effect zones for threatened species: Implications for mitigation fencing

Context Roads are a pernicious form of habitat loss for many wildlife populations because their effects often extend far beyond the roads themselves, giving rise to reduced wildlife abundance in road-effect zones. Quantifying the extent of road-effect zones more accurately portrays their impact on populations and the true extent to which habitat is lost for many species. Aim The purpose of the present study was to evaluate ways of determining the extent of road-effect zones for a model study species to better quantify the effect of roads on habitat loss. Methods We conducted road-side surveys for signs of Mojave desert tortoises (Gopherus agassizii) 0, 200, 400, 800 and 1600m from county roads and interstates, two of the most common road types in critical habitat of this threatened species. Using data from these road-side surveys, we estimated the extent of road-effect zones using piecewise regression and modified von Bertalanffy models. Key results We found reduced abundances of tortoise sign along both county roads and interstates. Reductions extended farther from the large, high-traffic interstate than from the smaller, lower-traffic county roads (306m versus 230m). The increase in the abundance of tortoise signs with distance from roads approximated a negative exponential curve. Conclusions Interstate and county roads both contribute to habitat loss in road-side areas by making these habitats unsuitable to desert tortoises, presumably by removing animals via mortality from collisions with vehicles. Larger roads with greater traffic have more extensive effects. Implications Roadside mitigation fencing has been proposed as one way to reduce mortality of desert tortoises and to reclaim habitat by allowing tortoises to recolonise currently depauperate road-effect zones. Immediate mortality is more likely to be prevented by fencing county roads where tortoises occur closer to roads and are more likely to be struck by vehicles and killed. However, fencing interstate should yield more reclaimed habitat than that obtained from fencing county roads. Managers must consider balancing these goals along with other concerns when deciding where to place roadside fencing

Delimiting road-effect zones for threatened species: Implications for mitigation fencing

Context Roads are a pernicious form of habitat loss for many wildlife populations because their effects often extend far beyond the roads themselves, giving rise to reduced wildlife abundance in road-effect zones. Quantifying the extent of road-effect zones more accurately portrays their impact on populations and the true extent to which habitat is lost for many species. Aim The purpose of the present study was to evaluate ways of determining the extent of road-effect zones for a model study species to better quantify the effect of roads on habitat loss. Methods We conducted road-side surveys for signs of Mojave desert tortoises (Gopherus agassizii) 0, 200, 400, 800 and 1600m from county roads and interstates, two of the most common road types in critical habitat of this threatened species. Using data from these road-side surveys, we estimated the extent of road-effect zones using piecewise regression and modified von Bertalanffy models. Key results We found reduced abundances of tortoise sign along both county roads and interstates. Reductions extended farther from the large, high-traffic interstate than from the smaller, lower-traffic county roads (306m versus 230m). The increase in the abundance of tortoise signs with distance from roads approximated a negative exponential curve. Conclusions Interstate and county roads both contribute to habitat loss in road-side areas by making these habitats unsuitable to desert tortoises, presumably by removing animals via mortality from collisions with vehicles. Larger roads with greater traffic have more extensive effects. Implications Roadside mitigation fencing has been proposed as one way to reduce mortality of desert tortoises and to reclaim habitat by allowing tortoises to recolonise currently depauperate road-effect zones. Immediate mortality is more likely to be prevented by fencing county roads where tortoises occur closer to roads and are more likely to be struck by vehicles and killed. However, fencing interstate should yield more reclaimed habitat than that obtained from fencing county roads. Managers must consider balancing these goals along with other concerns when deciding where to place roadside fencing

Effects of roads and roadside fencing on movements, space use, and carapace temperatures of a threatened tortoise

Roads are widespread features of many landscapes that can negatively affect wildlife, most notably through animal-vehicle collisions. Roadside fencing has increasingly been installed to help eliminate this source of mortality. While fencing may reduce road mortality, other types of wildlife responses to this novel barrier are not well understood. Here, we examined the movement behavior, space use, and carapace temperatures of Mojave Desert Tortoises (Gopherus agassizii) as they interacted with a roadside fence and an unfenced road. Using GPS loggers, we tracked tortoise movements for two years at 15-min intervals. We found that carapace temperatures were greater near structures (fence or unfenced road) than away from structures; tortoises near the unfenced road had higher mean carapace temperatures, but tortoises along the fence experienced more extreme upper temperatures that approached the species' thermal limit. Movement speeds were also higher along the structures than away from them. Tortoise home range sizes decreased with proximity to the fence or road; fragmentation of home ranges and road-crossing avoidance may have contributed to smaller home ranges along the fenced and unfenced road, respectively. While tortoises crossed the road significantly less than expected by chance, they did so primarily in May and July and in areas with washes, indicating that placement of roadside fencing and animal underpasses could be optimized by targeting areas where roads intersect washes. Taken together, our results suggest that roadside fencing can affect behavior, space use, and thermal ecology of tortoises, which may require refinements to future conservation strategies involving roadside fencing

Comparing growth and body condition of indoor-reared, outdoor-reared,and direct-released juvenile mojave desert tortoises

Desert Tortoise (Gopherus agassizii) populations have declined, and head-starting hatchlings in captivity until they are larger and older, and presumably more likely to survive, is one strategy being evaluated for species recovery. Previous studies have reared hatchlings in outdoor, predator-proof pens for 5–9 y before release, in efforts to produce hatchlings in excess of 100–110 mm midline carapace length that are believed to be predation-resistant. We began a comparative study to evaluate indoor-rearing to shorten this rearing period by facilitating faster initial growth. We assigned 70 neonates from the 2015 hatching season to three treatment groups: (1) indoor-reared (n = 30), (2) outdoor-reared (n = 20), and (3) direct-release (n = 20). We released direct-release hatchlings shortly after hatching in September 2015 and monitored them 1–2 times per week with radio telemetry. We head-started the indoor-and outdoor-reared treatment groups for 7 mo before releasing them in April 2016. Indoor-reared tortoises were fed five times per week (September to March). Outdoor-reared tortoises had access to native forage and we gave them supplemental water and food once per week while active before winter dormancy. Indoor-reared tortoises grew > 16 times faster than direct-release tortoises and > 8 times faster than outdoor-reared tortoises; however, indoor-reared tortoises weighed less and had softer shells than comparatively sized older (3–4 y-old) tortoises raised outdoors. Increasing the duration of the indoor-rearing period or incorporating a combination of both indoor and later outdoor husbandry may increase shell hardness among head-starts, while retaining the growth-promoting effect of indoor rearing and shortening overall captivity duration

Comparing growth and body condition of indoor-reared, outdoor-reared,and direct-released juvenile mojave desert tortoises

Desert Tortoise (Gopherus agassizii) populations have declined, and head-starting hatchlings in captivity until they are larger and older, and presumably more likely to survive, is one strategy being evaluated for species recovery. Previous studies have reared hatchlings in outdoor, predator-proof pens for 5–9 y before release, in efforts to produce hatchlings in excess of 100–110 mm midline carapace length that are believed to be predation-resistant. We began a comparative study to evaluate indoor-rearing to shorten this rearing period by facilitating faster initial growth. We assigned 70 neonates from the 2015 hatching season to three treatment groups: (1) indoor-reared (n = 30), (2) outdoor-reared (n = 20), and (3) direct-release (n = 20). We released direct-release hatchlings shortly after hatching in September 2015 and monitored them 1–2 times per week with radio telemetry. We head-started the indoor-and outdoor-reared treatment groups for 7 mo before releasing them in April 2016. Indoor-reared tortoises were fed five times per week (September to March). Outdoor-reared tortoises had access to native forage and we gave them supplemental water and food once per week while active before winter dormancy. Indoor-reared tortoises grew > 16 times faster than direct-release tortoises and > 8 times faster than outdoor-reared tortoises; however, indoor-reared tortoises weighed less and had softer shells than comparatively sized older (3–4 y-old) tortoises raised outdoors. Increasing the duration of the indoor-rearing period or incorporating a combination of both indoor and later outdoor husbandry may increase shell hardness among head-starts, while retaining the growth-promoting effect of indoor rearing and shortening overall captivity duration