Imprinted SARS-CoV-2-specific memory lymphocytes define hybrid immunity

Immune memory is tailored by cues that lymphocytes perceive during priming. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic created a situation in which nascent memory could be tracked through additional antigen exposures. Both SARS-CoV-2 infection and vaccination induce multifaceted, functional immune memory, but together they engender improved protection from disease, termed hybrid immunity. We therefore investigated how vaccine-induced memory is shaped by previous infection. We found that following vaccination, previously infected individuals generated more SARS-CoV-2 RBD-specific memory B cells and variant-neutralizing antibodies and a distinct population of IFN-𝛾 and IL-10-expressing memory SARS-CoV-2 spike-specific CD4+ T cells than previously naive individuals. While additional vaccination could increase humoral memory, it did not recapitulate the distinct CD4+ T cell cytokine profile in previously naive individuals. Thus, imprinted features of SARS-CoV-2-specific memory lymphocytes define hybrid immunity.

Genetic diversity and aggressiveness of Fusarium virguliforme isolates across the Midwestern United States

Sudden death syndrome (SDS) of soybean is a damaging disease caused by the fungus Fusarium virguliforme. Since this pathogen was first reported in the southern US state of Arkansas in 1971, it has spread throughout the Midwestern U.S. The SDS pathogen primarily colonizes roots but also produces toxins that translocate to and damage leaves. Previous studies detected little to no genetic differentiation among isolates, suggesting F. virguliforme in North America has limited genetic diversity and a clonal population structure. Yet, isolates vary in virulence to roots and leaves. We characterized a set of F. virguliforme isolates from the Midwestern U.S. representing a south to north latitudinal gradient from Arkansas to Minnesota. Ten previously tested microsatellite loci were used to genotype isolates and plant assays were conducted to assess virulence. Three distinct population clusters were differentiated across isolates. Although isolates ranged in virulence classes from low to very high, little correlation was found between virulence phenotype and cluster membership. Similarly, population structure and geographic location were not highly correlated. However, the earliest diverging cluster had the lowest genetic diversity and was detected only in southern states, while the other two clusters were distributed across the Midwest and were predominant in Minnesota. One of the Midwestern clusters had the greatest genetic diversity and was found along the northern edge of the known distribution. The results support three genetically distinct population clusters of F. virguliforme in the U.S., with two clusters contributing most to spread of this fungus across the Midwest.

A transposon expression burst accompanies the activation of Y-chromosome fertility genes during Drosophila spermatogenesis

Transposable elements (TEs) must replicate in germline cells to pass novel insertions to offspring. In Drosophila melanogaster ovaries, TEs can exploit specific developmental windows of opportunity to evade host silencing and increase their copy numbers. However, TE activity and host silencing in the distinct cell types of Drosophila testis are not well understood. Here, we reanalyze publicly available single-cell RNA-seq datasets to quantify TE expression in the distinct cell types of the Drosophila testis. We develop a method for identification of TE and host gene expression modules and find that a distinct population of early spermatocytes expresses a large number of TEs at much higher levels than other germline and somatic components of the testes. This burst of TE expression coincides with the activation of Y chromosome fertility factors and spermatocyte-specific transcriptional regulators, as well as downregulation of many components of the piRNA pathway. The TEs expressed by this cell population are specifically enriched on the Y chromosome and depleted on the X chromosome, relative to other active TEs. These data suggest that some TEs may achieve high insertional activity in males by exploiting a window of opportunity for mobilization created by the activation of spermatocyte-specific and Y chromosome-specific transcriptional programs.

Genome of a Giant (Trevally): Caranx ignobilis

ABSTRACTCaranx ignobilis, commonly known as the kingfish or giant trevally, is a large, reef-associated apex predator. It is a prized sportfish, targeted heavily throughout its tropical and subtropical range in the Indian and Pacific Oceans, and it has drawn significant interest in aquaculture due to an unusual tolerance for freshwater. In this study, we present a high-quality nuclear genome assembly of a C. ignobilis individual from Hawaiian waters, which have recently been shown to host a genetically distinct population. The assembly has a contig NG50 of 7.3Mbp and scaffold NG50 of 46.3Mbp. Twenty-five of the 203 scaffolds contain 90% of the genome. We also present the raw Pacific Biosciences continuous long-reads from which the assembly was created. A Hi-C dataset (Dovetail Genomics Omni-C) and Illumina-based RNA-seq from eight tissues are also presented; the latter of which can be particularly useful for annotation and studies of freshwater tolerance. Overall, this genome assembly and supporting data is a valuable tool for ecological and comparative genomics studies of kingfish and other carangoid fishes.

Internet Recruitment of a Diverse Population of Lesbian, Gay, and Bisexual Nurses in a Study of Substance Use and Minority Stress

Introduction There is a lack of lesbian, bisexual and gay (LGB)-focused nursing research, in part, because the population is traditionally difficult to access. This article explores the effectiveness, benefits, and limitations of online recruitment of a distinct population of LGB-identified nurses in a study of substance use and minority stress. Methodology A sample of nurses who self-identified as LGB were recruited for an online survey using organic Facebook outreach. A $5 Amazon gift card was offered as an incentive. Facebook insights data and demographic data were analyzed. Results Within 96 hours, 394 participants had completed the 101-question online survey. The majority ( n = 269, 68.6%) reported accessing the survey through Facebook. Email ( n = 79, 20.2%) and word of mouth ( n = 44, 11.2%) also contributed to recruitment. Discussion The effectiveness of this Facebook recruitment protocol speaks to the importance of social media, survey incentives, and the “power of visibility” in recruitment of this population.

Quality of Life of Vegetarians during the COVID-19 Pandemic in Brazil

Health emergencies such as the COVID-19 pandemic can negatively impact quality of life (QoL) due to higher levels of stress, social isolation, and uncertainties. In this scenario, distinct population groups might react differently. Vegetarians, who follow a non-conventional dietary pattern, could be more vulnerable to the abrupt changes in normal life routine and economic instability. Therefore, this study aimed at evaluating if the current pandemic situation somehow affected vegetarians’ QoL. A cross-sectional study was carried out in Brazil between 28 July and 14 September 2020 to evaluate the QoL in vegetarians during the pandemic period. Vegetarian adults replied to an online survey that included the VEGQOL and WHOQOL-BREF instruments to evaluate QoL and questions related to the COVID-19 pandemic. A total of 1282 individuals participated. Only 3.8% had tested positive for COVID-19, but 39.9% affirmed having a family member who tested positive for the disease. Almost half (46.3%) of the sample had an income drop due to the pandemic. Results of QoL scores in the different subcategories of vegetarians were similar to previously published data. Individuals who had already tested positive for COVID-19 had lower QoL scores than those who did not test positive, but only in the VEGQOL. QoL was lower for the participants who declared that Sars-Cov-2 had already infected a family member for almost all the parameters evaluated. On the other hand, an income drop affected QoL only partially. Studying how vegetarians are influenced by such conditions contributes to the generation of relevant data that can be used to support healthcare and public policies in the future.