Pregnancy represents a uniquely vulnerable period during which viral infections can exert profound effects on maternal health, placental function, and fetal development. Over the past 30 years, emerging and re-emerging viruses, including flaviviruses, coronaviruses, poxviruses, orthomyxoviruses, paramyxoviruses, and filoviruses, have repeatedly demonstrated their capacity to disrupt pregnancy through diverse mechanisms that extend far beyond classical teratogenic outcomes. Nearly every major viral outbreak has revealed a critical gap in our understanding of maternal susceptibility during pregnancy. In this review, we will examine how emerging and re-emerging viruses threaten pregnancy across multiple biological scales, ranging from congenital infection, placental dysfunction, maternal immune dysregulation, and infertility, focusing on modern day viruses from a range of families. Understanding the mechanisms by which reproductive health can be impacted by these viruses and integrating this knowledge in developing care, prevention, and intervention strategies tailored to pregnancy and reproduction should be a foundational part of global health and preparedness.
Human endogenous retroviruses (HERVs) provide a direct record of the millions of years of co-evolution between humans and viruses. Yet, due to their repetitive nature and former reputation as "junk DNA," a full characterization of the functional roles and transcriptional regulation of HERVs remains to be achieved. As sequencing technologies improve, better resolution data regarding HERV expression and regulation has become attainable, and there is mounting evidence of aberrant HERV expression in various human diseases, particularly cancer. However, the perturbations to the transcriptional regulatory processes that govern these endogenized retroviral elements in cancer remain unclear. In this review, we will summarize the state of our understanding of the various mechanisms that control HERV expression in cancer, focusing primarily on aberrant methylation and KRAB-domain containing zinc finger proteins (KZFPs), among others. Many of these regulatory mechanisms are employed in stem cells to regulate pluripotency and differentiation and are also deployed in a subpopulation of cancer cells with high self-renewal and proliferation capacity, called cancer stem cells. While the expression of specific HERVs in cancer could be beneficial, deleterious, or neutral, the potential to use HERVs as biomarkers or immune adjuvants to enhance immunotherapies against cancer is promising. The implications of shared transcriptional mechanisms across cancer and stem cells will expose new areas to intervene with cancer treatments, ushering in a new era of HERV-based cancer therapeutics and diagnostics.
The vertical transmission of tomato viruses through seeds and pollen is a significant yet often overlooked pathway for the persistence and global spread of these pathogens. This review provides a comprehensive synthesis of current knowledge on the mechanisms, epidemiological implications, and management strategies of vertically transmitted tomato viruses. While recent advances in diagnostic techniques such as high-throughput sequencing (HTS), have improved virus detection, key research gaps remain in understanding the molecular and ecological dynamics of seed and pollen transmission. The interaction between vertical and horizontal transmission modes complicates virus epidemiology, necessitating an integrated management approach that includes rigorous seed health testing, genetic resistance breeding, and biosecurity measures. Emerging threats, such as resistance-breaking virus strains and the impact of climate change on vector distribution, underscore the need for enhanced surveillance and stronger international regulatory cooperation. This review highlights the need for interdisciplinary research and collaboration to develop sustainable virus mitigation strategies. Future research priorities include optimizing detection methods, exploring next-generation breeding technologies, and strengthening international biosecurity frameworks to safeguard global tomato production against the growing threat of vertically transmitted viruses.
Plant virus emergence is a major threat for agricultural production and for the preservation of biodiversity in wild ecosystems. This process is determined by genetic and ecological factors and, among the latter, one of the most important is the chance for the virus to encounter susceptible plant populations. Seed transmission has a great potential to facilitate such encounters: from allowing plant viruses to persist locally over unfavorable conditions such as the absence of susceptible hosts, to mediate long range dissemination to reach distant plant populations that could not otherwise be invaded. Here, we review current knowledge on the relationship between plant virus seed transmission and emergence, and on its consequences for the epidemiology of these pathogens. We start by setting up a conceptual framework based on mathematical modelling. Then, we summarize experimental and empirical evidence supporting the central role of seed transmission for initiating damaging plant virus-induced disease epidemics, at different geographical scales and in wild and cultivated plant populations. Finaly, we explore current methodologies to limit the emergence of plant viruses associated with seed transmission. Considering these studies, we propose avenues for future research on this subject.
