Mating system, philopatry and patterns of kinship in the cooperatively breeding subdesert mesite Monias benschi

In the first molecular study of a member of the threatened avian family, Mesitornithidae, we used nine polymorphic microsatellite loci to elucidate parentage, patterns of within-group kinship and occurrence of extra-group paternity in the subdesert mesite Monias benschi, of southwest Madagascar. We found this cooperatively breeding species to have a very fluid mating system. There was evidence of genetic monogamy and polygynandry: of the nine groups with multiple offspring, six contained one breeding pair with unrelated helpers and three contained multiple male and female breeders with related helpers. Although patterns of within-group kinship varied, there was a strong positive relationship between group size and relatedness, suggesting that groups form by natal philopatry. There was also a strong positive correlation between within-sex and between-sex relatedness, indicating that unlike most cooperatively breeding birds, philopatry involved both sexes. In contrast to predictions of kin selection and reproductive skew models, all monogamous groups contained unrelated individuals, while two of the three polygynandrous groups were families. Moreover, although between-group variation in seasonal reproductive success was related to within-group female relatedness, relatedness among males and between the sexes had no bearing on a group's reproductive output. While kin selection may underlie helping behaviour in females, factors such as direct long-term fitness benefits of group living probably determine helping in males. Of the 14 offspring produced by fully sampled groups, at least two were sired by males from neighbouring groups: one by a breeding male and one by a nonbreeding male, suggesting that males may augment their reproductive success through extra-group paternity.     

Genome-wide gene expression in response to parasitoid attack in <Emphasis Type="Italic">Drosophila</Emphasis>

Background  

Parasitoids are insect parasites whose larvae develop in the bodies of other insects. The main immune defense against parasitoids is encapsulation of the foreign body by blood cells, which subsequently often melanize. The capsule sequesters and kills the parasite. The molecular processes involved are still poorly understood, especially compared with insect humoral immunity.     

No trade-off between learning ability and parasitoid resistance in Drosophila melanogaster

Learning ability and immunity to parasites are linked at the physiological level in several insect species. The aim of this work was to investigate the relationship between learning and immunity at an evolutionary level. We tested whether selection for improved learning ability in Drosophila melanogaster led to changes in parasitoid resistance as a correlated response. Similarly, we assayed whether selection for better parasitoid resistance led to a change in learning ability. There was no significant difference between selected and control lines in either case; the estimated confidence intervals for the differences indicate that a trade-off relationship is unlikely.     

Why Seychelles Warblers fail to recolonize nearby islands: unwilling or unable to fly there?

The Seychelles Warbler Acrocephalus sechellensis is a rare island endemic which, from 1920 to 1988, occurred only on Cousin Island (29 ha) in the Seychelles. Despite the saturated nature of this population and the possibility of obtaining higher reproductive success on new nearby islands, inter-island dispersal by Seychelles Warblers is extremely rare (0.10%). We test the hypothesis that Seychelles Warblers show an adaptation typical for island birds: a low-cost reduced-size flight apparatus. We compared the anatomy of the flight apparatus (wing shape, wing loading, skeletal parts and musculature) of Seychelles Warblers with that of three closely related migratory Acrocephalus species (Eurasian Reed Warbler A. scirpaceus , Australian Reed Warbler A. australis and African Reed Warbler A. baeticatus ). Seychelles Warblers do not differ from the migratory warblers in pectoral mass and skeletal attachment area relative to body mass, wing shape and wing loading. Seychelles Warblers show the morphological structures required for sustained flight, but may have the behavioural reluctance to cross what they may regard as extensive bodies of water.     

Factors influencing paternity success in Antechinus agilis: last‐male sperm precedence,timing of mating and genetic compatibility

We describe the patterns of paternity success from laboratory mating experiments conducted in Antechinus agilis, a small size dimorphic carnivorous marsupial (males are larger than females). A previous study found last‐male sperm precedence in this species, but they were unable to sample complete litters, and did not take male size and relatedness into account. We tested whether last‐male sperm precedence regardless of male size still holds for complete litters. We explored the relationship between male mating order, male size, timing of mating and relatedness on paternity success. Females were mated with two males of different size with either the large or the small male first, with 1 day rest between the matings. Matings continued for 6 h. In these controlled conditions male size did not have a strong effect on paternity success, but mating order did. Males mating second sired 69.5% of the offspring. Within first mated males, males that mated closer to ovulation sired more offspring. To a lesser degree, variation appeared also to be caused by differences in genetic compatibility of the female and the male, where high levels of allele‐sharing resulted in lower paternity success.     

Explicit experimental evidence for the role of mate guarding in minimizing loss of paternity in the Seychelles warbler

Extra-pair copulations (EPCs) (copulations outside the pair bond) resulting in extra-pair fertilizations (EPFs) are widespread in birds. To increase reproductive success, males should not only seek EPCs, but also prevent their females from having EPFs. Male Seychelles warblers (Acrocephalus sechellensis) follow their partner closely during the period when these females are most receptive (fertile period). The Seychelles warbler is the first species to offer explicit experimental evidence that mate guarding functions as paternity guarding: in territories where free-living males were induced to stop mate guarding during the pair female''s fertile period, the rates of intrusions by other males and successful EPCs (male mounting female) were significantly higher than those observed in the control group and in the absence of mate guarding the frequency of successful EPCs increased significantly with local male density. Male warblers do not assure their paternity through frequent copulations to devalue any sperm from other males: males do not copulate with their partners immediately following a successful EPC obtained by their partners, the frequency of successful within-pair copulations does not increase with the frequency of successful EPCs and females initiate all successful copulations and are capable of resisting copulation attempts.     

Kleptoparasitism as an explanation for paradoxical oviposition decisions of the parasitoid Asobara tabida

It is known that the braconid Asobara tabida, a parasitoid of Drosophila larvae, takes oviposition decisions in accordance with survival probabilities in several host species. Nevertheless, larvae of D. simulans, in which the survival probability is virtually zero, are readily accepted for oviposition by searching females. This even happens when they are offered together with D. melanogaster larvae, in which the parasitoid can develop. Here I show that A. tabida can act as a kleptoparasitoid in D. simulans larvae: it can develop in D. simulans larvae, once these larvae are parasitized by another parasitoid, the eucoilid Leptopilina boulardi. Analysis with an optimal foraging model suggests that the increase in survival probability and the occurrence of L. boulardi in the field are high enough to make this kleptoparasitic behaviour of A. tabida pay.     

Repercussions of the COVID-19 pandemic on athletes: a cross-sectional study

The COVID-19 pandemic has presented significant challenges and implications for the sports community. Thus, this study aimed to describe the prevalence of COVID-19 in Brazilian athletes and identify the epidemiological, clinical, athletic, life and health factors associated with the disease in these individuals. A cross-sectional study was performed involving 414 athletes from 22 different sports using an online questionnaire from August to November 2020. The association between the athletes’ characteristics and COVID-19 was evaluated using a logistic regression model. The prevalence of COVID-19 was 8.5%, although only 40% of athletes reported having been tested. Being under 27 years of age (3-fold), having children (~5-fold), having a teammate test positive for COVID-19 (2.5-fold), and smoking (14-fold) were associated with a possible higher risk of disease. Almost 20% of athletes self-reported musculoskeletal injuries during the period of the pandemic that was studied. Athletes with a university education (P = 0.02), a profession other than sports (P < 0.001), those from a low-income family (P = 0.01), and public health system users (P = 0.04) were significantly less frequently tested for COVID-19, whereas international competitors, athletes who received a wage, and athletes who had a teammate who tested positive for COVID-19 were 2-, 3-, and 15-fold more likely to be tested for COVID-19, respectively. Approximately 26% of the athletes who tested negative or were untested reported more than three characteristic COVID-19 symptoms, and 11% of athletes who tested positive for COVID-19 were asymptomatic. The identification of modifiable (have children, smoking, and teammates positively tested) and non-modifiable (age under 27 years) factors related to COVID-19 in athletes can contribute to implementing surveillance programmes to decrease the incidence of COVID-19 in athletes and its negative impacts in sports.     

Classical determinants of coronary artery disease as predictors of complexity of coronary lesions,assessed with the SYNTAX score

Background

We need new biomarkers that can predict cardiovascular disease to improve both diagnosis and therapeutic strategies. The CIRCULATING CELLS study was designed to study the role of several cellular mediators of atherosclerosis as biomarkers of coronary artery disease (CAD). An objective and reproducible method for the quantification of CAD extension is required to establish relationships with these potential biomarkers. We sought to analyse the correlation of the SYNTAX score with known CAD risk factors to test it as a valid marker of CAD extension.

Methods and results

A subgroup of 279 patients (67.4% males) were included in our analysis. Main exclusion criteria were a history of previous percutaneous coronary intervention or surgical revascularisation that prevent an accurate assessment of the SS. Diabetes mellitus, smoking, renal insufficiency, body mass index and a history of CAD and myocardial infarction were all positively and strongly associated with a higher SYNTAX score after adjustment for the non-modifiable biological factors (age and sex). In the multivariate model, age and male sex, along with smoking and renal insufficiency, remain statistical significantly associated with the SYNTAX score.

Conclusion

In a selected cohort of revascularisation-naive patients with CAD undergoing coronary angiography, non-modifiable cardiovascular risk factors such as advanced age, male sex, as well as smoking and renal failure were independently associated with CAD complexity assessed by the SYNTAX score. The SYNTAX score may be a valid marker of CAD extension to establish relationships with potential novel biomarkers of coronary atherosclerosis.