Population Genetic Structure And Parasite Communities In A Nomadic Songbird, The Red Crossbill (Loxia Curvirostra)

Although much speciation occurs in allopatry, populations with overlapping geographic ranges may also experience reduced gene flow due to ecological differences. Parasites are an important feature of the biotic environment, and place important selective pressures on their hosts, potentially reducing gene flow among geographically separated host populations. However, virtually nothing is known about host-parasite interactions in systems where hosts have nomadic distributions, and where ecologically distinct populations exist in sympatry. I examined population genetic structuring and characterized bloodborne parasite communities across four ecologically distinct, but partially sympatric, “vocal types” of nomadic red crossbills (Loxia curvirostra) sampled at multiple sites. I found evidence for isolation by distance in one vocal type, but vocal types were not genetically differentiated from one another, nor were they characterized by significantly different parasite communities. Despite differences in foraging ecology, crossbill vocal types do not appear to be incipient species or subject to different parasite communities

Binding of the Bacillus subtilis LexA protein to the SOS operator

The Bacillus subtilis LexA protein represses the SOS response to DNA damage by binding as a dimer to the consensus operator sequence 5′-CGAACN(4)GTTCG-3′. To characterize the requirements for LexA binding to SOS operators, we determined the operator bases needed for site-specific binding as well as the LexA amino acids required for operator recognition. Using mobility shift assays to determine equilibrium constants for B.subtilis LexA binding to recA operator mutants, we found that several single base substitutions within the 14 bp recA operator sequence destabilized binding enough to abolish site-specific binding. Our results show that the AT base pairs at the third and fourth positions from the 5′ end of a 7 bp half-site are essential and that the preferred binding site for a LexA dimer is 5′-CGAACATATGTTCG-3′. Binding studies with LexA mutants, in which the solvent accessible amino acid residues in the putative DNA binding domain were mutated, indicate that Arg-49 and His-46 are essential for binding and that Lys-53 and Ala-48 are also involved in operator recognition. Guided by our mutational analyses as well as hydroxyl radical footprinting studies of the dinC and recA operators we docked a computer model of B.subtilis LexA on the preferred operator sequence in silico. Our model suggests that binding by a LexA dimer involves bending of the DNA helix within the internal 4 bp of the operator

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Public COAPI Toolkit of Open Access Policy Resources

The Coalition of Open Access Policy Institutions (COAPI, https://sparcopen.org/coapi ) is committed to sharing information and resources to assist in the development and implementation of institutional Open Access (OA) policies. The COAPI Toolkit includes a diverse collection of resources that COAPI members have developed in the course of their OA policy initiatives. These resources are openly accessible and published here under Creative Commons Attribution 4.0 licenses, unless otherwise noted on the resources themselves

Call to restrict neonicotinoids

On 28 April 2018 the European Parliament voted for a complete and permanent ban on all outdoor uses of the three most commonly used neonicotinoid pesticides. With the partial exception of the state of Ontario, Canada, governments elsewhere have failed to take action. Below is a letter, signed by 232 scientists from around the world, urgently calling for global action by policy makers to address this issue