Greater temperature sensitivity of plant phenology at colder sites: implications for convergence across northern latitudes

Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance at colder sites. To test this hypothesis, we examined up to 20 years of phenology data for 47 tundra plant species at 18 high‐latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than warmer high‐latitude locations. A similar pattern was seen over time for the flowering phenology of a widespread species, Cassiope tetragona. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence in flowering times and therefore an increase in gene flow across latitudes as the climate warms.     

ON THE IDENTITY OF KARLODINIUM VENEFICUM AND DESCRIPTION OF KARLODINIUM ARMIGER SP. NOV. (DINOPHYCEAE), BASED ON LIGHT AND ELECTRON MICROSCOPY,NUCLEAR‐ENCODED LSU RDNA,AND PIGMENT COMPOSITION1

An undescribed species of the dinoflagellate genus Karlodinium J. Larsen (viz. K. armiger sp. nov.) is described from Alfacs Bay (Spain), using light and electron microscopy, pigment composition, and partial large subunit (LSU) rDNA sequence. The new species differs from the type species of Karlodinium (K. micrum (Leadbeater et Dodge) J. Larsen) by lacking rows of amphiesmal plugs, a feature presently considered to be a characteristic of Karlodinium. In K. armiger, an outer membrane is underlain by a complex system of cisternae and vacuoles. The pigment profile of K. armiger revealed the presence of chlorophylls a and c, with fucoxanthin as the major carotenoid. Phylogenetic analysis confirmed K. armiger to be related to other species of Karlodinium; thus forming a monophyletic genus, which, in the LSU tree, occupies a sister group position to Takayama de Salas, Bolch, Botes et Hallegraeff. The culture used by Ballantine to describe Gymnodinium veneficum Ballantine (Plymouth 103) was examined by light and electron microscopy and by partial LSU rDNA. Ultrastructurally, it proved identical to K. micrum (cultures Plymouth 207 and K. Tangen KT‐77D, the latter also known as K‐0522), and in LSU sequence, differed in only 0.3% of 1438 bp. We consider the two taxa to belong to the same species. This necessitates a change of name for the most widely found species, K. micrum, to K. veneficum. The three genera Karlodinium, Takayama, and Karenia constitute a separate evolutionary lineage, for which the new family Kareniaceae fam. nov. is suggested.     

Socio-demographic determinants and effect of structured personal diabetes care: a 19-year follow-up of the randomized controlled study diabetes Care in General Practice (DCGP)

Background

We investigated how four aspects of socio-demography influence the effectiveness of an intervention with structured personal diabetes care on long-term outcomes.

Methods

The Diabetes Care in General Practice (DCGP) study is a cluster-randomized trial involving a population-based sample of 1381 patients with newly diagnosed type 2-diabetes mellitus. We investigated how education, employment, cohabitation status and residence influenced the effectiveness of 6 years of intervention with structured personal diabetes care, resembling present day recommendations. Outcomes were incidence of any diabetes-related endpoint and death during 19 years after diagnosis, and cardiovascular risk factors, behaviour, attitudes and process-of-care variables 6 years after diagnosis.

Results

Structured personal care reduced the risk of any diabetes-related endpoint and the effect of the intervention was modified by geographical area (interaction p?=?0.034) with HR of 0.71 (95%CI: 0.60–0.85) and of 1.07 (95%CI: 0.77–1.48), for patients in urban and rural areas, respectively. Otherwise, there was no effect modification of education, employment and civil status on the intervention for the final endpoints. There were no noticeable socio-demographic differences in the effect of the intervention on cardiovascular risk factors, behaviour, attitudes, and process-of-care.

Conclusion

Structured personal care reduced the aggregate outcome of any diabetes-related endpoint and independent of socio-demographic factors similar effect on cardiovascular risk factors, behaviour, attitudes and process of care, but the intervention did not change the existing inequity in mortality and morbidity. Residence modified the uptake of the intervention with patients living in urban areas having more to gain of the intervention than rural patients, further investigations is warranted.

Trial registration

ClinicalTrials.gov registration no. NCT01074762 (February 24, 2010).

     

Evaluating the impact of biodiversity offsetting on native vegetation

Biodiversity offsetting is a globally influential policy mechanism for reconciling trade-offs between development and biodiversity loss. However, there is little robust evidence of its effectiveness. We evaluated the outcomes of a jurisdictional offsetting policy (Victoria, Australia). Offsets under Victoria's Native Vegetation Framework (2002–2013) aimed to prevent loss and degradation of remnant vegetation, and generate gains in vegetation extent and quality. We categorised offsets into those with near-complete baseline woody vegetation cover (“avoided loss”, 2702 ha) and with incomplete cover (“regeneration”, 501 ha), and evaluated impacts on woody vegetation extent from 2008 to 2018. We used two approaches to estimate the counterfactual. First, we used statistical matching on biophysical covariates: a common approach in conservation impact evaluation, but which risks ignoring potentially important psychosocial confounders. Second, we compared changes in offsets with changes in sites that were not offsets for the study duration but were later enrolled as offsets, to partially account for self-selection bias (where landholders enrolling land may have shared characteristics affecting how they manage land). Matching on biophysical covariates, we estimated that regeneration offsets increased woody vegetation extent by 1.9%–3.6%/year more than non-offset sites (138–180 ha from 2008 to 2018) but this effect weakened with the second approach (0.3%–1.9%/year more than non-offset sites; 19–97 ha from 2008 to 2018) and disappeared when a single outlier land parcel was removed. Neither approach detected any impact of avoided loss offsets. We cannot conclusively demonstrate whether the policy goal of ‘net gain’ (NG) was achieved because of data limitations. However, given our evidence that the majority of increases in woody vegetation extent were not additional (would have happened without the scheme), a NG outcome seems unlikely. The results highlight the importance of considering self-selection bias in the design and evaluation of regulatory biodiversity offsetting policy, and the challenges of conducting robust impact evaluations of jurisdictional biodiversity offsetting policies.     

In vitro generation of germ cells from murine embryonic stem cells

The demonstration of germ cell and haploid gamete development from embryonic stem cells (ESCs) in vitro has engendered a unique set of possibilities for the study of germ cell development and the associated epigenetic phenomenon. The process of embryoid body (EB) differentiation, like teratoma formation, signifies a spontaneous differentiation of ESCs into cells of all three germ layers, and it is from these differentiating aggregates of cells that putative primordial germ cells (PGCs) and more mature gametes can be identified and isolated. The differentiation system presented here requires the differentiation of murine ESCs into EBs and the subsequent isolation of PGCs as well as haploid male gametes from EBs at various stages of differentiation. It serves as a platform for studying the poorly understood process of germ cell allocation, imprint erasure and gamete formation, with 4-6 weeks being required to isolate PGCs as well as haploid cells.     

Comprehensive gene-expression survey identifies wif1 as a modulator of cardiomyocyte differentiation

During chicken cardiac development the proepicardium (PE) forms the epicardium (Epi), which contributes to several non-myocardial lineages within the heart. In contrast to Epi-explant cultures, PE explants can differentiate into a cardiomyocyte phenotype. By temporal microarray expression profiles of PE-explant cultures and maturing Epi cells, we identified genes specifically associated with differentiation towards either of these lineages and genes that are associated with the Epi-lineage restriction. We found a central role for Wnt signaling in the determination of the different cell lineages. Immunofluorescent staining after recombinant-protein incubation in PE-explant cultures indicated that the early upregulated Wnt inhibitory factor-1 (Wif1), stimulates cardiomyocyte differentiation in a similar manner as Wnt stimulation. Concordingly, in the mouse pluripotent embryogenic carcinoma cell line p19cl6, early and late Wif1 exposure enhances and attenuates differentiation, respectively. In ovo exposure of the HH12 chicken embryonic heart to Wif1 increases the Tbx18-positive cardiac progenitor pool. These data indicate that Wif1 enhances cardiomyogenesis.     

The endocytic receptor megalin binds the iron transporting neutrophil-gelatinase-associated lipocalin with high affinity and mediates its cellular uptake

Neutrophil-gelatinase-associated lipocalin (NGAL) is a prominent protein of specific granules of human neutrophils also synthesized by epithelial cells during inflammation. NGAL binds bacterial siderophores preventing bacteria from retrieving iron from this source. Also, NGAL may be important in delivering iron to cells during formation of the tubular epithelial cells of the primordial kidney. No cellular receptor for NGAL has been described. We show here that megalin, a member of the low-density lipoprotein receptor family expressed in polarized epithelia, binds NGAL with high affinity, as shown by surface plasmon resonance analysis. Furthermore, a rat yolk sac cell line known to express high levels of megalin, endocytosed NGAL by a mechanism completely blocked by an antibody against megalin.     

A soybean coproporphyrinogen oxidase gene is highly expressed in root nodules

In plants the enzyme coproporphyrinogen oxidase catalyzes the oxidative decarboxylation of coproporphyrinogen III to protoporphyrinogen IX in the heme and chlorophyll biosynthesis pathway(s).We have isolated a soybean coproporphyrinogen oxidase cDNA from a cDNA library and determined the primary structure of the corresponding gene. The coproporphyrinogen oxidase gene encodes a polypeptide with a predicted molecular mass of 43 kDa. The derived amino acid sequence shows 50% similarity to the corresponding yeast amino acid sequence. The main difference is an extension of 67 amino acids at the N-terminus of the soybean polypeptide which may function as a transit peptide.A full-length coproporphyrinogen oxidase cDNA clone complements a yeast mutant deleted of the coproporphyrinogen oxidase gene, thus demonstrating the function of the soybean protein.The soybean coproporphyrinogen oxidase gene is highly expressed in nodules at the stage where several late nodulins including leghemoglobin appear. The coproporphyrinogen oxidase mRNA is also detectable in leaves but at a lower level than in nodules while no mRNA is detectable in roots.The high level of coproporphyrinogen oxidase mRNA in soybean nodules implies that the plant increases heme production in the nodules to meet the demand for additional heme required for hemoprotein formation.     

The LORE1 insertion mutant resource

Long terminal repeat (LTR) retrotransposons are closely related to retroviruses, and their activities shape eukaryotic genomes. Here, we present a complete Lotus japonicus insertion mutant collection generated by identification of 640 653 new insertion events following de novo activation of the LTR element Lotus retrotransposon 1 (LORE1) ( http://lotus.au.dk ). Insertion preferences are critical for effective gene targeting, and we exploit our large dataset to analyse LTR element characteristics in this context. We infer the mechanism that generates the consensus palindromes typical of retroviral and LTR retrotransposon insertion sites, identify a short relaxed insertion site motif, and demonstrate selective integration into CHG‐hypomethylated genes. These characteristics result in a steep increase in deleterious mutation rate following activation, and allow LORE1 active gene targeting to approach saturation within a population of 134 682 L. japonicus lines. We suggest that saturation mutagenesis using endogenous LTR retrotransposons with germinal activity can be used as a general and cost‐efficient strategy for generation of non‐transgenic mutant collections for unrestricted use in plant research.     

Variants of CYP46A1 may interact with age and APOE to influence CSF Aβ42 levels in Alzheimer’s disease

Recent studies have suggested that variants of CYP46A1, encoding cholesterol 24-hydroxylase (CYP46), confer risk for Alzheimers disease (AD), a prospect substantiated by evidence of genetic association from several quantitative traits related to AD pathology, including cerebrospinal fluid (CSF) levels of the 42 amino-acid cleavage product of -amyloid (A42) and the tau protein. In the present study, these claims have been explored by the genotyping of previously associated markers in CYP46A1 in three independent northern European case-control series encompassing 1323 individuals and including approximately 400 patients with measurements of CSF A42 and phospho-tau protein levels. Tests of association in case-control models revealed limited evidence that CYP46A1 variants contributed to AD risk across these samples. However, models testing for potential effects upon CSF measures suggested a possible interaction of an intronic marker (rs754203) with age and APOE genotype. In stratified analyses, significant effects were evident that were restricted to elderly APOE 4 carriers for both CSF A42 (P=0.0009) and phospho-tau (P=0.046). Computational analyses indicate that the rs754203 marker probably does not impact the binding of regulatory factors, suggesting that other polymorphic sites underlie the observed associations. Our results provide an important independent replication of previous findings, supporting the existence of CYP46A1 sequence variants that contribute to variability in -amyloid metabolism.