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The assembly of Tcrband Tcragenes require double negative (DN) thymocytes to undergo multiple rounds of programmed DNA double-strand breaks (DSBs), followed by their efficient repair. However, mechanisms governing cell cycle checkpoints and specific survival pathways during the repair process remain unclear. Here, we report high-resolution scRNA-seq analyses of individually sorted mouse DN3 and DN4 thymocytes, which reveals a G2M cell cycle checkpoint, in addition to the known G1 checkpoint, during Tcrband Tcrarecombination. We also show that inactivation of GSK3β by phosphorylation on Ser389is essential for DN3/DN4 thymocytes to survive while being stalled at the G1 and G2/M checkpoints. GSK3β promotes death by necroptosis, but not by apoptosis, of DN3/DN4 thymocytes during V(D)J recombination. Failure to inactivate GSK3β in DN3 thymocytes alters the Tcrbgene repertoire primarily through Trbvsegment utilization. In addition, preferential recombination of proximal V segments in Tcradepends on GSK3β inactivation. Our study identifies a unique thymocyte survival pathway, enabling them to undergo cell cycle checkpoints for DNA repair during V(D)J recombination of Tcrband Tcragenes. Thymocyte survival during cell cycle checkpoints for V(D)J recombination DNA repair determines TCRα/β repertoire.

AbstractThe COVID-19 pandemic caused by SARS-CoV-2 has reached by February 2022 more than 380 million cases and 5.5 million deaths worldwide since its beginning in late 2019, leading to enhanced concern in the scientific community and the general population. One of the most important pieces of this host-pathogen interaction is the spike protein, which binds to the hACE2 cell receptor, mediates the membrane fusion and is the major target of neutralizing antibodies against SARS-CoV-2. The multiple amino acid substitutions observed in this region, specially in RBD have enhanced the hACE2 binding affinity and led to several modifications in the mechanisms of SARS-CoV-2 pathogenesis, improving the viral fitness and/or promoting immune evasion, with potential impact in the vaccine development. In this work, we identified 48 sites under selective pressures, 17 of them with the strongest evidence by the HyPhy tests, including VOC related mutation sites 138, 142, 222, 262, 484, 681, and 845, among others. The coevolutionary analysis identified 28 sites found not to be conditionally independent, such as E484K-N501Y. The molecular dynamics and free energy estimates showed the structural stabilizing effect and the higher impact of E484K for enhanced binding affinity between the spike RBD and hACE2 in P.1 and P.2 lineages (specially with L452V). Structural changes were also identified in the hACE molecule when interacting with B.1.1.7 RDB. Despite some destabilizing substitutions, a stabilizing effect was identified for the majority of the positively selected mutations.Communicated by Ramaswamy H. Sarma

There are now robust data supporting the Developmental Origins of Health and Disease (DOHaD) paradigm. This includes human and animal data focusing on nutrition or environmental chemicals during development. However, the term DOHaD has not been generally accepted as the official term to be used when one is concerned with understanding the pathophysiological basis for how environmental influences acting during early development influence the risk of later noncommunicable diseases. Similarly, there is no global research or public health program built around the DOHaD paradigm that encompasses all aspects of environment. To better inform the global health efforts aimed at addressing the growing epidemic of chronic noncommunicable diseases of environmental origin, we propose a two-pronged approach: first, to make it clear that the current concept of DOHaD comprehensively includes a range of environmental factors and their relevance to disease occurrence not just throughout the life span but potentially across several generations; and second, to initiate the discussion of how adoption of DOHaD can promote a more realistic, accurate, and integrative approach to understanding environmental disruption of developmental programming and better inform clinical and policy interventions.

The article discusses the cultural history of Wyoming through the personal history of Congregational missionary William Bradford Dodge Gray. It describes the formation of the Congregational Home Missionary Society and the Eastern U.S. impulse to evangelize the western states and settlements, Gray's education at the Moody Bible Institute, and the relationship of Gray to the homesteaders, ranchers, and miners in Wyoming. Other subjects under discussion include the cowboy culture and economy of Wyoming, fundraising efforts by the missionaries, and the construction of the Congregational church building.

Abstract: The family of pathogenesis-related (PR) 5 proteins have diverse functions, and some of them are classified as thaumatins, osmotins, and inhibitors of α-amylase or trypsin. Although the specific function of many PR5 in plants is unknown, they are involved in the acquired systemic resistance and response to biotic stress, causing the inhibition of hyphal growth and reduction of spore germination, probably by a membrane permeabilization mechanism or by interaction with pathogen receptors. We have constructed three-dimensional models of four proteins belonging to the Rosaceae and Fagaceae botanical families by using the technique of comparative molecular modelling by homology. There are four main structural differences between all the PR5, corresponding to regions with replacements of amino acids. Folding and the secondary structures are very similar for all of them. However, the isoelectric point and charge distributions differ for earch protein.

Gel-filtration (Sephadex G-75) analysis of hepatic cytosol reveals both qualitative and quantitative sex differences in oestrogen-binding proteins. The elution profile of [3H]oestradiol-labelled cytosol shows four species of oestrogen-binding proteins (peaks I, II, IV and V) common to both sexes. The amount of [3H]oestradiol binding in peak I is equivalent in both males and females and corresponds quantitatively to the specific oestrogen receptor. The amount of binding in the remaining three peaks is greater in males than females. In addition, an oestrogen-binding protein (peak III) is present that is unique to male cytosol. Proteinase-inhibition studies demonstrate that the observed multiplicity of oestrogen-binding proteins is not an artefact of proteolytic breakdown. Sex differences in oestrogen-binding proteins are absent in immature male and female animals; the oestrogen-binding protein profile in immature rats resembles that of an adult female. Gonadectomy of adult animals does not affect the oestrogen-binding-protein profile. In contrast, neonatal (day 1) castration results in partial feminization of the characteristic oestrogen-binding protein profile seen in the adult male; the appearance of Peak III is suppressed and marked decreases in the amount of oestradiol binding occurs in the remaining peaks. Hypophysectomy of adult animals results in near abolishment of the observed sex differences; the male oestrogen-binding protein profile is partially feminized and the female profile is partially masculinized, as characterized by the appearance of [3H]oestradiol binding in the region of peak III and increased amounts of binding in peaks IV and V. The present studies demonstrate a multiplicity of oestrogen-binding proteins in liver cytosol and raise the possibility that the presence of some of these proteins may be imprinted at birth through the hypothalamic–pituitary axis, by a mechanism requiring neonatal androgen exposure.

To identify sources of discomfort in video display terminal (VDT) work stations, the working postures of WO telephone operators who used VDTs to retrieve directory listings were photographed. Attempts to correlate postural angles and distances derived from the photographs with subjective judgments of physical discomfort reported on a questionnaire were unsuccessful. Possible explanations for the failure of the postural parameters to predict discomfort are discussed, and the absence of other postural data that may be appropriately applied to the specification of VDT work stations is noted. It is concluded that recommendations for VDT work stations that are phrased in terms of static angles and distances are currently unsubstantiated and, thus, are not yet ready to be codified as formal standards.

This study explored the clinical utility of two established linguistic measures with a developmentally delayed preschool child adopted from a Romanian orphanage.