Allele exchange at the EPSPS locus confers glyphosate tolerance in cassava

Effective weed control can protect yields of cassava (Manihot esculenta) storage roots. Farmers could benefit from using herbicide with a tolerant cultivar. We applied traditional transgenesis and gene editing to generate robust glyphosate tolerance in cassava. By comparing promoters regulating expression of transformed 5‐enolpyruvylshikimate‐3‐phosphate synthase (EPSPS) genes with various paired amino acid substitutions, we found that strong constitutive expression is required to achieve glyphosate tolerance during in vitro selection and in whole cassava plants. Using strategies that exploit homologous recombination (HR) and nonhomologous end‐joining (NHEJ) DNA repair pathways, we precisely introduced the best‐performing allele into the cassava genome, simultaneously creating a promoter swap and dual amino acid substitutions at the endogenous EPSPS locus. Primary EPSPS‐edited plants were phenotypically normal, tolerant to high doses of glyphosate, with some free of detectable T‐DNA integrations. Our methods demonstrate an editing strategy for creating glyphosate tolerance in crop plants and demonstrate the potential of gene editing for further improvement of cassava.     

The fluorescence detected guanidine hydrochloride equilibrium denaturation of wild-type staphylococcal nuclease does not fit a three-state unfolding model

A three-state equilibrium unfolding of a protein can be difficult to detect if two of the states fail to differ in some easily measurable way. It has been unclear whether staphylococcal nuclease unfolds in a two-state fashion, with only the native and denatured states significantly populated at equilibrium, or in a three-state manner, with a well-populated intermediate. Since equilibrium unfolding experiments are commonly used to determine protein stability and the course of denaturation are followed by changes in the fluorescence which has difficulty in distinguishing various states, this is a potential problem for many proteins. Over the course of twenty years we have performed more than one hundred guanidine hydrochloride equilibrium denaturations of wild-type staphylococcal nuclease; to our knowledge, a number of denaturations unrivaled in any other protein system. A careful examination of the data from these experiments shows no sign of the behavior predicted by a three-state unfolding model. Specifically, a three-state unfolding should introduce a slight, but characteristic, non-linearity to the plot of stability versus denaturant concentration. The average residuals from this large number of repeated experiments do not show the predicted behavior, casting considerable doubt on the likelihood of a three-state unfolding for the wild-type protein. The methods used for analysis here could be applied to other protein systems to distinguish a two-state from a three-state denaturation.     

Addressing power asymmetries in global health: Imperatives in the wake of the COVID-19 pandemic

Seye Abimbola and co-authors argue for a transformation in global health research and practice in the post-COVID-19 world.

Summary points

• The Coronavirus Disease 2019 (COVID-19) pandemic, the Black Lives Matter and Women in Global Health movements, and ongoing calls to decolonise global health have all created space for uncomfortable but important conversations that reveal serious asymmetries of power and privilege that permeate all aspects of global health.
• In this article, we, a diverse, gender-balanced group of public (global) health researchers and practitioners (most currently living in the so-called global South), outline what we see as imperatives for change in a post-pandemic world.
• At the individual level (including and especially ourselves), we emphasise the need to emancipate and decolonise our own minds (from the colonial conditionings of our education), straddle and use our privilege responsibly (to empower others and avoid elite capture), and build “Southern” networks (to affirm our ownership of global health).
• At the organisational level, we call for global health organisations to practice real diversity and inclusion (in ways that go beyond the cosmetic), to localise their funding decisions (with people on the ground in the driving seat), and to progressively self-decentralise (and so, divest themselves of financial, epistemic, and political power).
• And at both the individual and organisational level, we emphasise the need to hold ourselves, our governments, and global health organisations accountable to these goals, and especially for governance structures and processes that reflect a commitment to real change.
• By putting a spotlight on coloniality and existing inequalities, the COVID-19 pandemic inspires calls for a more equitable world and for a decolonised and decentralised approach to global health research and practice, one that moves beyond tokenistic box ticking about diversity and inclusion into real and accountable commitments to transformative change.

     

Melanotropin as a Potential Regulator of Pigment Pattern Formation in Embryonic Skin

Frozen tissue sections of developing axolotl embryos were labeled by indirect immunofluorescence with anti-alpha-MSH. Anti-MSH immunoreactivity is first detectable in embryos when neural crest cells are migrating from the neural tube. Antibody labeling is visible around the lateral and ventral edges of the neural tube and in the embryonic ectoderm. As development progresses, the amount of labeling increases greatly, particularly in developing ectoderm. Western blots of soluble proteins extracted from various developmental stages of axolotl embryo ectoderm reveal that MSH activity is associated directly with several high molecular weight components that may be part of the embryonic extracellular matrix. Thus, we suggest that melanotropin activity is present in embryonic axolotl skin, is associated with the extracellular matrix, and is thereby in a position to play a supportive and/or directive role in the establishment of embryonic pigment patterns.     

Craterellus indicus sp. nov., a new species associated with Cedrus deodara from the western Himalayas, India

Craterellus indicus is proposed here as a new species, resulting from a morphological and molecular study on the diversity of Cantharellaceae in the western Himalayan region of India. The species is characterized by a pale brownish to creamish pileus and a smooth to folded hymenium that is distinctly detached from the stipe apex. There are no clamp connections. The combination of characters makes this species distinct from other known species of Craterellus. Molecular phylogenetic analysis of partial large subunit (LSU) and the ITS region of the nuclear ribosomal operon supports its position as a new species.     

Genetic Diversity and Population Structure Analysis in Indian Mustard Germplasm Using Phenotypic Traits and SSR Markers

Plant Molecular Biology Reporter - Indian mustard is an economically important oilseed crop in India; therefore, exploring the genetic diversity of various germplasm collections is quite relevant...     

Biomedical potential of green synthesized silver nanoparticles from root extract of Asparagus officinalis

Journal of Plant Biochemistry and Biotechnology - Green synthesis of silver nanoparticles (AgNPs) from medicinal plant extracts has gained importance due to its pharmacological potential. In the...