No association between Angiotensin Converting Enzyme (ACE) gene variation and endurance athlete status in Kenyans

East African runners are continually successful in international distance running. The extent to which genetic factors influence this phenomenon is unknown. The insertion (I) rather than deletion (D) of a 287 bp fragment in the human angiotensin converting enzyme (ACE) gene is associated with lower circulating and tissue ACE activity and with endurance performance amongst Caucasians. To assess the association between ACE gene variation and elite endurance athlete status in an African population successful in distance running, DNA samples were obtained from 221 national Kenyan athletes (N), 70 international Kenyan athletes (I), and 85 members of the general Kenyan population (C). Blood samples were obtained from C and assayed for circulating ACE activity. ACE I/D (rs????--from NCBI SNPdb first time poly mentioned) genotype was determined, as was genotype at A22982GD (rs????--from NCBI SNPdb first time poly mentioned) which has been shown to associate more closely with ACE levels in African subjects than the I/D polymorphism. ACE I/D and A22982G genotypes explained 13 and 24% of variation in circulating ACE activity levels (P = 0.034 and <0.001 respectively). I/D genotype was not associated with elite endurance athlete status (df = 4, chi(2) = 4.1, P=0.39). In addition, genotype at 22982 was not associated with elite endurance athlete status (df = 4, chi(2) = 5.7, P = 0.23). Nor was the A allele at 22982, which is associated with lower ACE activity, more prevalent in N (0.52) or I (0.41) relative to C (0.53). We conclude that ACE I/D and A22982G polymorphisms are not strongly associated with elite endurance athlete status amongst Kenyans.     

Towards a global database of weed risk assessments: a test of transferability for the tropics

Worldwide spread and establishment of alien plant species continues to accelerate and damage ecological and agricultural systems. Early warning and prevention of high-risk introductions is the most cost-effective approach to minimise losses while maximising benefits, and the Australian Weed Risk Assessment (A-WRA) system has been the most well-developed and successful predictive scheme. However, any system would be limited if the results or scores were confined to the locality of assessment. We compiled A-WRA scores conducted in four tropical to sub-tropical regions and tested the accuracy of these scores for predicting naturalisations for a separate well-documented, equatorial, exotic flora where weed risk assessments have never been conducted. Receiver Operating Characteristic (ROC) curves reflect high accuracies of predictions, comparable to those in other studies. No significant differences in accuracy were found between each regional subset and the compiled set of scores. Our results show that A-WRA scores assessed at one locality can be used for others of similar climate, increasing the utility of every species’ assessment. A global database of A-WRA scores would enable rapid local decision-making in border controls on imported plant species. A growing record of species assessments would also facilitate monitoring evolutionary and ecological aspects of invasive species.     

Does Booby Egg Dumping Amount to Quasi‐Parasitism?

Quasi‐parasitism occurs when a paired male facilitates dumping in its own nest by an extra‐pair female with which it has recently copulated. Although numerous observations hint at quasi‐parasitism in diverse avian species, direct behavioral confirmation of male complicity is required to exclude the alternative adaptive explanations enumerated by Griffith et al. [Behav. Ecol. Sociobiol. 56 (2004) 191]. Our direct observations on dumping by female blue‐footed boobies (Sula nebouxii) show apparent male ambivalence: males were hostile to eggs dumped by their extra‐pair partners but half‐hearted in repelling those partners after the act of dumping. Hostility was evidenced when a host male that was present during dumping destroyed the extra‐pair partner's egg and when extra‐pair partners selectively dumped when the host male was absent or distracted rather than when it was alone on the territory. Host males appear to deter dumping by their extra‐pair partners rather than facilitating it, and their partial tolerance of females that have dumped may be a result of their general tolerance of unaccompanied females. Although paired male boobies sometimes copulate with females that dump into their nests, apparently this is not quasi‐parasitism.     

Genetic impoverishment of the last black grouse (Tetrao tetrix) population in the Netherlands: detectable only with a reference from the past

We have studied a small isolated population of black grouse (Tetrao tetrix) in the Netherlands to examine the impact of isolation and reduction in numbers on genetic diversity. We compared the genetic diversity in the last extant Dutch population with Dutch museum samples and three other black grouse populations (from England, Austria and Norway, respectively) representing isolated and continuous populations. We found significantly lower allelic richness, observed and expected heterozygosities in the present Dutch population compared to the continuous populations (Austria and Norway) and also to the historical Dutch population. However, using a bottleneck test on each population, signs of heterozygosity excess were only found in the likewise isolated English population despite that strong genetic drift was evident in the present Dutch population in comparison to the reference populations, as assessed both in pairwise F(ST)and STRUCTURE analyses. Simulating the effect of a population reduction on the Dutch population from 1948 onwards, using census data and with the Dutch museum samples as a model for the genetic diversity in the initial population, revealed that the loss in number of alleles and observed heterozygosity was according to genetic drift expectations and within the standard error range of the present Dutch population. Thus, the effect of the strong decline in the number of grouse on genetic diversity was only detectable when using a reference from the past. The lack of evidence for a population reduction in the present Dutch population by using the program bottleneck was attributed to a rapidly found new equilibrium as a consequence of a very small effective population size.     

Endogenous cholesterol synthesis is associated with VLDL-2 apoB-100 production in healthy humans

Subjects with high plasma cholesterol levels exhibit a high production of VLDL apolipoprotein B-100 (apoB-100), suggesting that cholesterol is a mediator for VLDL production. The objective of the study was to examine whether endogenous cholesterol synthesis, reflected by the lathosterol-cholesterol ratio (L-C ratio), affects the secretory rates of different VLDL subfractions. Ten healthy subjects were studied after overnight fasting. During a 10 h primed, constant infusion of 13C-valine (15 micromol/kg/h), enrichment was determined in apoB-100 from ultracentrifugally isolated VLDL-1 and VLDL-2 by gas chromatography mass spectrometry. The synthesis rates of VLDL-1 apoB-100 and VLDL-2 apoB-100, catabolism, and transfer were estimated by compartmental analysis. Mean VLDL-1 apoB-100 pool size was 90 +/- 15 mg, and mean VLDL-2 apoB-100 pool size was 111 +/- 14 mg. Absolute synthesis rate of VLDL-1 apoB-100 was 649 +/- 127 mg/day and 353 +/- 59 mg/day for VLDL-2 apoB-100. There was a strong association between the absolute synthesis rate of VLDL-2 apoB-100 and L-C ratio (r 2 = 0.61, P < 0.01). In contrast, no correlation was observed between L-C ratio and absolute synthesis rate of VLDL-1 apoB-100 (r 2 = 0.302, P = 0.09). In conclusion, these data provide additional support for an independent regulation of VLDL-1 apoB-100 and VLDL-2 apoB-100 production.Endogenous cholesterol synthesis is correlated only with the VLDL-2 apoB-100 production.     

Estimating site occupancy and detectability of the threatened partridge pigeon (Geophaps smithii) using camera traps

Since European settlement, many granivorous birds of northern Australia's savanna landscapes have declined. One such example, the partridge pigeon (Geophaps smithii), has suffered a significant range contraction, disappearing from at least half of its pre‐European range. Multiple factors have been implicated in this decline, including the loss of traditional Aboriginal burning practices, grazing by large exotic herbivores and predation by feral cats (Felis catus). While populations of partridge pigeon on the Tiwi Islands may be particularly important for the long‐term persistence of this species, they too may be at risk of decline. However, as a reliable method to detect this species has not yet been developed and tested, we lack the ability to identify, at an early stage, the species' decline in a given location or region. This severely limits our capacity to make informed management decisions. Here, we demonstrate that the standard camera trapping approach for native mammal monitoring in northern Australia attained an overall probability of detecting partridge pigeon greater than 0.98. We thus provide a robust estimate of partridge pigeon site occupancy (0.30) on Melville Island, the larger of the two main Tiwi Islands. The information presented here for the partridge pigeon represents a critical first step towards the development of optimal monitoring programmes with which to gauge population trajectories, as well as the response to remedial management actions. In the face of ongoing biodiversity loss, such baseline information is vital for management agencies to make informed decisions and should therefore be sought for as many species as possible.