Dispersal patterns and influence of air travel during the global expansion of SARS-CoV-2 variants of concern

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Discovery of ultrapotent broadly neutralizing antibodies from SARS-CoV-2 elite neutralizers

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Mutations in SARS-CoV-2 variants of concern link to increased spike cleavage and virus transmission

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Hormonal regulation of membrane phenotype

Incubation of rat hepatoma cells (HTC) in tissue culture with glucocorticoids alters several membrane properties characteristic of transformed cells, without affecting the growth rate of these cells. Variant cell lines resistant to dexamethasone inhibition of plasminogen activator production have been isolated using an agar-fibrin overlay technique to detect plasminogen activator production by individual colonies of HTC cells. The resistance to dexamethasone is not secondary to abnormal or absent glucocorticoid receptors, but due to a lesion in a later step in hormone action specific for plasminogen activator. These variants should prove useful for the study of the mechanism of steroid action as well as for the analysis of the role of proteases in the hormonal regulation of membrane function.     

Potent cross-reactive antibodies following Omicron breakthrough in vaccinees

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Expression and genetics of caprine haemoglobins

The expression of haemoglobin (Hb) has been studied in 260 Norwegian Dairy goats by the Immobiline technique at pH ranges 6.7-7.7, 6.9-7.6 and 6.9-7.5. The majority of goats exhibited two- or four-band patterns. In two-band types the average ratio between the anodal and cathodal band was 74:26. PAGE with 8M urea distinguished three phenotypes for the beta chains, proving that the Hb variation described is in the beta chain. Segregation data in 106 complete sire-dam-offspring families agreed with the existence of four beta globin alleles--A2, A4, A6 and A8. Twenty-seven animals had reversed ratios (R) of Hb bands. In two-band phenotypes the average ratio was 36:64. In 15 complete families where one of the parents had reversed ratio, eight offspring received the R type, indicating a simple genetic control. After urea PAGE the R animals all showed the same alpha chain phenotype which differed from that of goats having common ratios of bands. An additional polymorphism appeared in nine animals as three- and five-band patterns which is assumed to be the result of heterozygosity for II alpha and for II alpha and beta globin genes respectively.     

SARS-CoV-2 spike L452R variant evades cellular immunity and increases infectivity

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Detection of Marker-Free Precision Genome Editing and Genetic Variation through the Capture of Genomic Signatures

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Ring-Toss: Capping highly exposed tyrosyl or tryptophyl residues in proteins with β-cyclodextrin

We have used UV difference spectroscopy and fluorescence spectroscopy to study the perturbation by β-cyclodextrin of tyrosyl or tryptophyl residues located at each of the 10 variable consensus contact positions in the third domain of turkey ovomucoid. The goal was to monitor the accessibility of the side chain rings of these residues when located at these positions. The results indicated that the tyrosyl or tryptophyl rings are most highly exposed when located in the P₁ position followed by the P₄ position. It was possible to determine the association constants for β-cyclodextrin binding at these positions. When located at the P₂, P₅, P₆ and P₃′ positions, the rings of the tyrosyl or tryptophyl residues were exposed but less so than at the P₁ or P₄ positions. By contrast, when located at the P₁′, P₂′, P₁₄^′ and P₁₈^′ positions, the tyrosyl or tryptophyl residues were insufficiently exposed to be perturbed by β-cyclodextrin, although they reacted positively to dimethyl sulfoxide solvent perturbation. These findings indicate that β-cyclodextrin perturbation provides a convenient way to detect highly exposed tyrosyls or tryptophyls in proteins. Furthermore, we evaluated the ability of β-cyclodextrin to inhibit the interaction of turkey ovomucoid third domain variants with different P₁ residues. The results showed that the presence of β-cyclodextrin had little effect on the association constant when the P₁ residue was a glycyl residue, but greatly decreased the association constant when the P₁ residue was a tyrosyl or tryptophyl residue. Thus, β-cyclodextrin may be used to selectively modulate the interaction between proteinase inhibitors and their cognate enzymes.     

Temporal and spatial distribution of meiotin-1 in anthers of Lilium longiflorum

Meiotin-1 is a chromatin associated, conserved protein found in meiocytes immediately preceding and during meiosis and is thought to have a role in determining the higher order structure of meiotic chromosomes [Riggs and Hasenkampf: Chromosoma 101:92–98, 1991]. In the studies reported here we utilized immunoblotting and immunocytochemical techniques to examine the temporal and spatial distribution of meiotin-1 in the anthers of Lilium longiflorum. The results with the anti-meiotin-1 immune serum were compared with those obtained using an anti-his-tone Hl immune serum. The anti-histone Hl immune serum gave constant immunostaining in all cell types of the anther at all of the stages tested. In contrast, the anti-meiotin-1 immune serum only gave immunostaining with the microsporocytes and to a lesser extent with the nutritive layer, the tapetum. It did not react with the cells of the anther wall. Meiotin-1 immunostaining was first present in significant quantities in the microsporocytes as they accumulated in the G1 phase before the onset of premeiotic S phase and reached peak levels in the time interval between leptotene and pachytene—the same interval when chromosome synapsis occurs and when reciprocal genetic exchange is thought to occur. Immunostaining for both meiotin-1 and histone H1 uniformly decorates the longitudinal axes of the chromosomes. Our data are consistent with the idea that the role of meiotin-1 may be to tag certain sequences or to limit the degree of chromosome condensation that occurs during meiotic prophase. © 1993 Wiley-Liss, Inc.