Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

Background  

Research on the evolution of reproductive isolation in African cichlid fishes has largely focussed on the role of male colours and female mate choice. Here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference.     

RepSeq – A database of amino acid repeats present in lower eukaryotic pathogens

Background  

Amino acid repeat-containing proteins have a broad range of functions and their identification is of relevance to many experimental biologists. In human-infective protozoan parasites (such as the Kinetoplastid and Plasmodium species), they are implicated in immune evasion and have been shown to influence virulence and pathogenicity. RepSeq is a new database of amino acid repeat-containing proteins found in lower eukaryotic pathogens. The RepSeq database is accessed via a web-based application which also provides links to related online tools and databases for further analyses.     

Photosynthetic responses of cassava cultivars (Manihot esculenta Crantz) from different habitats to temperature

Maximum photosynthetic CO₂ exchange rates (P_n) of single attached leaves were determined for several cassava cultivars selected from different habitats and grown in pots outdoors at CIAT, Colombia, S.A. P_n rates were in a narrow range of 22 to 26 mol CO₂ m^–2s^–1 for all cultivars tested when measured at high photon flux density, normal air, optimum temperature and with low leaf-air vapor pressure differences. For all tested cultivars (9 cvs.), there was a broad optimum temperature for P_n between 25 to 35°C. At temperatures below and above this range P_n declined in all cultivars with P_n rates reaching 80% of maximum at 20 and 40°C. P_n temperature coefficient (Q₁₀) from 15–25°C was 1.6±0.2 across cultivars. No consistent relation existed between P_n, optimum temperature, and the original habitat.     

Biological Control of Sheep Parasites using Duddingtonia flagrans: Trials on Commercial Farms in Sweden

   

Trials were conducted on 3 commercial sheep farms in Sweden to assess the effect of administering spores of the nematode trapping fungus, Duddingtonia flagrans, together with supplementary feed to lactating ewes for the first 6 weeks from turn-out on pastures in spring. Also control groups of ewes, receiving only feed supplement, were established on all 3 farms. Groups were monitored by intensive parasitological investigation. The ewes and their lambs were moved in late June to saved pastures for summer grazing, the lambs receiving an anthelmintic treatment at this time. After approximately 6 weeks on summer pasture the lambs were weaned, treated a second time with anthelmintic, and returned to their original lambing pastures for finishing. Decisions as to when lambs were to be marketed were entirely at the discretion of the farmer co-operators. No difference in lamb performance was found between the two treatments on all three farms. This was attributed to the high levels of nutrition initially of the ewes limiting their post-partum rise in nematode faecal egg counts in spring, which in turn resulted in low levels of nematode infection on pastures throughout the autumn period. Additionally, pastures were of good quality for the lambs during the finishing period, so they grew at optimal rates as far as the farmers were concerned.     

Immigrant reproductive dysfunction facilitates ecological speciation

The distributions of species are not only determined by where they can survive – they must also be able to reproduce. Although immigrant inviability is a well‐established concept, the fact that immigrants also need to be able to effectively reproduce in foreign environments has not been fully appreciated in the study of adaptive divergence and speciation. Fertilization and reproduction are sensitive life‐history stages that could be detrimentally affected for immigrants in non‐native habitats. We propose that “immigrant reproductive dysfunction” is a hitherto overlooked aspect of reproductive isolation caused by natural selection on immigrants. This idea is supported by results from experiments on an externally fertilizing fish (sand goby, Pomatoschistus minutus). Growth and condition of adults were not affected by non‐native salinity whereas males spawning as immigrants had lower sperm motility and hatching success than residents. We interpret these results as evidence for local adaptation or acclimation of sperm, and possibly also components of paternal care. The resulting loss in fitness, which we call “immigrant reproductive dysfunction,” has the potential to reduce gene flow between populations with locally adapted reproduction, and it may play a role in species distributions and speciation.     

PCR-generated cDNA library of transition-stage maize embryos: cloning and expression of calmodulin genes during early embryogenesis

One hundred maize zygotic embryos microdissected at the transition stage were used to construct a cDNA library after non-selective PCR (NS-PCR) amplification of whole cDNA populations. The library contains 2.3 × 10⁵ recombinants and two different calmodulin cDNAs were cloned using a heterologous probe from petunia. Calmodulin expression was confirmed throughout maize embryogenesis at the mRNA, amplified cDNA and protein levels. Sequence analysis suggests a maize origin for both clones and negligible nucleotide changes linked to PCR. This library is the first described for early plant embryos and represents a breakthrough to isolate genes involved in embryo differentiation.     

Ultrasound enhanced prehospital thrombolysis using microbubbles infusion in patients with acute ST elevation myocardial infarction: Rationale and design of the Sonolysis study

Background

The CONSORT Statement provides recommendations for reporting randomized controlled trials. We assessed the extent to which leading medical journals that publish reports of randomized trials incorporate the CONSORT recommendations into their journal and editorial processes.

Methods

This article reports on two observational studies. Study 1: We examined the online version of 'Instructions to Authors' for 165 high impact factor medical journals and extracted all text mentioning the CONSORT Statement or CONSORT extension papers. Any mention of the International Committee of Medical Journal Editors (ICMJE) or clinical trial registration were also sought and extracted. Study 2: We surveyed the editor-in-chief, or editorial office, for each of the 165 journals about their journal's endorsement of CONSORT recommendations and its incorporation into their editorial and peer-review processes.

Results

Study 1: Thirty-eight percent (62/165) of journals mentioned the CONSORT Statement in their online 'Instructions to Authors'; of these 37% (23/62) stated this was a requirement, 63% (39/62) were less clear in their recommendations. Very few journals mentioned the CONSORT extension papers. Journals that referred to CONSORT were more likely to refer to ICMJE guidelines (RR 2.16; 95% CI 1.51 to 3.08) and clinical trial registration (RR 3.67; 95% CI 2.36 to 5.71) than those journals which did not. Study 2: Thirty-nine percent (64/165) of journals responded to the on-line survey, the majority were journal editors. Eighty-eight percent (50/57) of journals recommended authors comply with the CONSORT Statement; 62% (35/56) said they would require this. Forty-one percent (22/53) reported incorporating CONSORT into their peer-review process and 47% (25/53) into their editorial process. Eighty-one percent (47/58) reported including CONSORT in their 'Instructions to Authors' although there was some inconsistency when cross checking information on the journal's website. Sixty-nine percent (31/45) of journals recommended authors comply with the CONSORT extension for cluster trials, 60% (27/45) for harms and 42% (19/45) for non-inferiority and equivalence trials. Few journals mentioned these extensions in their 'Instructions to Authors'.

Conclusion

Journals should be more explicit in their recommendations and expectations of authors regarding the CONSORT Statement and related CONSORT extensions papers.     

The potential for using red claw crayfish and hybrid African catfish as biological control agents for Schistosoma host snails

The potential of red claw crayfish and hybrid African catfish (Clarias gariepinus and Clarias ngamensis) as predators for Schistosoma host snails was evaluated in 2014 by monitoring the consumption of snails by crayfish and catfish in experimental tanks over time under laboratory conditions. After 15 days, both crayfish and catfish had significantly reduced the populations of Bulinus globosus. Crayfish consumed 6.9 snails d^?1, whereas catfish consumed 5.9 snails d^?1. However, when supplied with an alternative prey, Melanoides tuberculata (100 individuals per tank), crayfish clearly preferred M. tuberculata (100% consumed over seven days) to B. globosus (100 individuals per tank) (54% consumed over the same period). Catfish, conversely, did not have a clear preference for either prey species, consuming 77% and 88% of M. tuberculata and B. globosus, respectively. It was also observed that young catfish were more efficient predators than older ones, because of ontogenetic shifts in their diet with age. Hybrid catfish retain the molluscivorous characteristics of their parent stock and red claw crayfish also preys on Schistosoma host snails. However, the effectiveness of both predators is affected by the presence of an alternative prey. Therefore, under suitable conditions, these species can be considered for biological control of schistosomiasis transmission.     

Differential response of stomata to air humidity in the parasitic mistletoe (Phthirusa pyrifolia) and its host,mandarin orange (Citrus resitulata)

Measurements of CO₂ and H₂O exchange rate and the calculated leaf conductance of attached leaves were conducted over a range of leaf-to-air vapour pressure difference (VPD) (1.5 to 5.5 kPa) to compare the response of the parasitic mistletoe, Phthirusa pyrifolia, with that of its host, the mandarin orange, Citrus reticulata. Seedlings of the host infected with the parasite were grown in well-watered and adequately fertilized large pots outdoors at the CIAT headquarters, Palmira, Colombia, South America. Observations of leaf anatomy of the parasite and nutrient analysis of young tissues of both the parasite and host were made. The photosynthetic rate of the host decreased linearly with increased VPD, whereas the parasite showed a constant rate. This trend coincided with similar responses in leaf conductance. Due to the insensitivity of the parasite stomata, the transpiration rate increased linearly with VPD as compared with an initial increase and then a decrease in the host transpiration rate. The higher photosynthetic rate and the closure of stomata of the host resulted in high water use efficiency as compared with that of the parasite. The parasite accumulated in its leaves more N, P, K and less Ca and Mg than the host. The significance of the host-parasite differential response to air humidity is discussed in relation to mechanism underlying stomatal sensitivity and in the context of host-parasite association.Visiting Scientist, Coordinator, and Research Assistant of the Cassava Physiology Program.     

The early interaction of the outer membrane protein phoe with the periplasmic chaperone Skp occurs at the cytoplasmic membrane

Spheroplasts were used to study the early interactions of newly synthesized outer membrane protein PhoE with periplasmic proteins employing a protein cross-linking approach. Newly translocated PhoE protein could be cross-linked to the periplasmic chaperone Skp at the periplasmic side of the inner membrane. To study the timing of this interaction, a PhoE-dihydrofolate reductase hybrid protein was constructed that formed translocation intermediates, which had the PhoE moiety present in the periplasm and the dihydrofolate reductase moiety tightly folded in the cytoplasm. The hybrid protein was found to cross-link to Skp, indicating that PhoE closely interacts with the chaperone when the protein is still in a transmembrane orientation in the translocase. Removal of N-terminal parts of PhoE protein affected Skp binding in a cumulative manner, consistent with the presence of two Skp-binding sites in that region. In contrast, deletion of C-terminal parts resulted in variable interactions with Skp, suggesting that interaction of Skp with the N-terminal region is influenced by parts of the C terminus of PhoE protein. Both the soluble as well as the membrane-associated Skp protein were found to interact with PhoE. The latter form is proposed to be involved in the initial interaction with the N-terminal regions of the outer membrane protein.