Genetics of insular Peromyscus leucopus populations at Norris Lake, Tennessee

A total of 138 Peromyscus leucopus were sampled from 9 island and 3 mainland sites at Norris Lake in eastern Tennessee. Liver and muscle extracts were used to identify 17 allozyme loci using starch gel electrophoresis, 9 of these loci were polymorphic. Using the 8 largest collection of insular mice and the two largest collections of mainland mice it was determined that the insular populations are no less genetically variable (estimated as P , proportion of polymorphic loci, and H0, mean individual heterozygosity) than the mainland populations. Genetic identities were not significantly correlated with geographical distances between island pairs. Gene flow is the probable mechanism that prevents these populations from diverging. Significant differences between island and mainland heterogeneity and among subpopulation genetic variance (Fst) estimates could not be shown. Significant genetic heterogeneity was found among the insular populations at the 4 most robustly polymorphic loci (EST, αGPD, IPO, and 6-PGD). Social structuring of these populations may account for the significant genetic heterogeneity among them. A pattern of heterozygote deficiency was found at the 6-P6D and EST loci in both insular and mainland populations. There are 4 possible explanations for these results: 1) negative heterosis, 2) population structuring, 3) Wahlund effect, and 4) the presence of null alleles. It could not be shown that insular P. leucopus populations were any more subject to the stochastic processes usually attributed to island habitation than the mainland populations at Norris Lake. A large difference was found between Fst estimates of males from 6 islands with the largest collections (Fst = .0399) and females from 4 islands with the largest collections (Fst = .1929). Sexual differences in dispersion probably account for these results. Males move further than females and are, therefore, probably less closely related to one another within a sample

Comparison of northern flying and red squirrel phylogenies with focus on the insular United States

Northern flying squirrel (Glaucomys sabrinus) and red squirrel (Tamiasciurus hudsonicus) populations are endemic to northern North America, including the Black Hills. The Black Hills populations are considered disjunct from other populations within their range. We examined insular populations to determine whether arboreal squirrels in the Black Hills each represent a unique population. We trapped and collected ear samples from northern flying and red squirrels in the Black Hills and in areas of Montana, Wyoming, Idaho, Utah, Minnesota, and Wisconsin to infer population phylogenies with special consideration of the Black Hills population. Microsatellite loci and two mtDNA sequences were used for phylogenetic data analyses, including neighbor-joining and maximum likelihood trees, percent divergence, and nucleotide diversity. For northern flying squirrels,mtDNA phylogenetic trees grouped individuals in the Black Hills population, suggesting extended isolation from other nearby mountain ranges. In both squirrels, phylogenetic trees inferred with nDNA provide similar topologies to the mtDNA of northern flying squirrels. Sequence divergence distances (range 0 to 1.0) for cytochrome-b among studied populations were relatively small (0.00 to 0.55 [northern flying squirrel] and 0.00 to 0.01 [red squirrel]), so divergence may be from an historical event. Nucleotide diversity (cytochrome-b) was higher than in some other ranges (0.07 [northern flying squirrel] and 0.08 [red squirrel]); however, heterozygosity was low in the Black Hills populations. These data suggest that northern flying squirrel and red squirrel populations in the Black Hills Mountains are not only geographically disjunct, but genetically unique from their conspecifics elsewhere

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Comparison of northern flying and red squirrel phylogenies with focus on the insular United States

Northern flying squirrel (Glaucomys sabrinus) and red squirrel (Tamiasciurus hudsonicus) populations are endemic to northern North America, including the Black Hills. The Black Hills populations are considered disjunct from other populations within their range. We examined insular populations to determine whether arboreal squirrels in the Black Hills each represent a unique population. We trapped and collected ear samples from northern flying and red squirrels in the Black Hills and in areas of Montana, Wyoming, Idaho, Utah, Minnesota, and Wisconsin to infer population phylogenies with special consideration of the Black Hills population. Microsatellite loci and two mtDNA sequences were used for phylogenetic data analyses, including neighbor-joining and maximum likelihood trees, percent divergence, and nucleotide diversity. For northern flying squirrels,mtDNA phylogenetic trees grouped individuals in the Black Hills population, suggesting extended isolation from other nearby mountain ranges. In both squirrels, phylogenetic trees inferred with nDNA provide similar topologies to the mtDNA of northern flying squirrels. Sequence divergence distances (range 0 to 1.0) for cytochrome-b among studied populations were relatively small (0.00 to 0.55 [northern flying squirrel] and 0.00 to 0.01 [red squirrel]), so divergence may be from an historical event. Nucleotide diversity (cytochrome-b) was higher than in some other ranges (0.07 [northern flying squirrel] and 0.08 [red squirrel]); however, heterozygosity was low in the Black Hills populations. These data suggest that northern flying squirrel and red squirrel populations in the Black Hills Mountains are not only geographically disjunct, but genetically unique from their conspecifics elsewhere

Extra-pair Paternity in Sandhill Cranes

Although cranes are known for “life-long” pair bonds, exceptions to this rule have been observed (i.e. divorcing pairs and individuals re-pairing following the death of a mate). With advancements in genetic techniques, another form of infidelity has been observed: extra-pair paternity (EPP; producing young with a bird while being socially paired to another mate) has been documented in many avian species. Is this true for cranes as well? Sandhill cranes (Grus canadensis) from a dense breeding population in southcentral Wisconsin were tested for EPP using 6 microsatellite DNA markers. The frequency of EPP ranged between 4.4% (2 of 45 chicks) and 11% (5 of 45 chicks). The 2 confirmed extra-pair chicks were from different broods of one pair that has been socially bonded for a minimum 12-year period. The social male was rejected as the genetic father in both cases. The 3 other cases of EPP (twice the social male was rejected as the genetic parent, once the social female was rejected) may be authentic infidelity or mate replacement prior to sampling. The range of EPP for this population of sandhill cranes is similar to other species with similar mating systems. For the confirmed cases of EPP, the female was able to increase her individual reproductive success without losing her territory

Mate Fidelity in a Dense Breeding Population of Sandhill Cranes

The objective of this study was to investigate mate switches observed in a dense breeding population of banded Sandhill Cranes (Grus canadensis). Over a 14-year period, 50 of 70 breeding pairs switched mates (71%), with 45 pairs switching permanently (64%). Mean mate retention between years was 83%, with an average pair bond lasting 5.7 years (range 1-13 years). Most permanent switches occurred following the death or disappearance of a mate, and overall permanent divorce (19%; 13 of 70 pairs) and annual divorce rates (6%) were low. Territory retention following mate switches was high. Males and females did not differ in their ability to retain their original territory. Retaining their original territory after a mate switch, however, did not increase reproductive fitness for either sex. Previous reproductive success was not a significant cause of divorce, nor did an individual crane’s reproductive success significantly increase following divorce. Five of the 13 divorced pairs (38%) fledged at least one chick to fall migration prior to divorcing. Also, 10 of 57 pairs that did not divorce went 5-8 years without fledging chicks without observation of divorce. There was evidence to suggest that sandhill cranes may choose to divorce in response to an opening on a nearby territory. Having a breeding territory may take precedence over reproductive success experienced by a pair. If a nearby territory becomes available, a breeding adult sandhill crane in this population may have to choose between staying with a current mate (possibly weighing reproductive history) and changing mates and perhaps territories to increase reproductive success

Nectar source diversity as an indicator of habitat suitability for the endangered uncompahgre fritillary, Boloria acrocnema (Nymphalidae)

Volume: 48Start Page: 173End Page: 17

Allozyme analysis of a known hybrid zone between Hyalophora euryalus and H. columbia gloveri (Lepidoptera: Saturniidae) in the California Sierra Nevada

Volume: 32Start Page: 79End Page: 8

A reconsideration of the taxonomic status of Euphydryas editha koreti (Lepidoptera: Nymphalidae) from the central Great Basin

Volume: 31Start Page: 278End Page: 28