Trends in Genetics最新文献

The prokaryote world is replete with mobile genetic elements (MGEs) – self-replicating entities that can move within and between their hosts. Many MGEs not only transfer their own DNA to new hosts but also transfer host DNA located elsewhere on the chromosome in the process. This could potentially lead to indirect benefits to the host when the resulting increase in chromosomal variation results in more efficient natural selection. We review the diverse ways in which MGEs promote the transfer of host DNA and explore the benefits and costs to MGEs and hosts. In many cases, MGE-mediated transfer of host DNA might not be selected for because of a sex function, but evidence of MGE domestication suggests that there may be host benefits of MGE-mediated sex.

Transposable elements (TEs) are semiautonomous genetic entities that proliferate in genomes. We recently discovered the Starships, a previously hidden superfamily of giant TEs found in a diverse subphylum of filamentous fungi, the Pezizomycotina. Starships are unlike other eukaryotic TEs because they have evolved mechanisms for both mobilizing entire genes, including those encoding conditionally beneficial phenotypes, and for horizontally transferring between individuals. We argue that Starships have unrivaled capacity to engage their fungal hosts as genetic parasites and mutualists, revealing unexplored terrain for investigating the ecoevolutionary dynamics of TE-eukaryote interactions. We build on existing models of fungal genome evolution by conceptualizing Starships as a distinct genomic compartment whose dynamics profoundly shape fungal biology.

The mitotic inheritability of DNA methylation as an epigenetic marker in higher-order eukaryotes has been established for >40 years. The DNA methylome and mitotic division interplay is now considered bidirectional and highly intertwined. Various epigenetic writers, erasers, and modulators shape the perceived replicative methylation dynamics. This Review surveys the principles and complexity of mitotic transmission of DNA methylation, emphasizing the awareness of mitotic aging in analyzing DNA methylation dynamics in development and disease. We reviewed how DNA methylation changes alter mitotic proliferation capacity, implicating age-related diseases like cancer. We link replicative epimutation to stem cell dysfunction, inflammatory response, cancer risks, and epigenetic clocks, discussing the causative role of DNA methylation in health and disease.

Tandem-repeat DNA sequences appear to be singularly capable of yielding abundant repeat-number mutations with a potentially advantageous distribution of fitness effects. Although knowing the rates and relative proportions of deleterious, neutral and beneficial mutations is fundamental for understanding evolvability, analysis of adaptation routinely overlooks small-effect mutations arising in tandem repeats.

Hydrothermal vents are unique habitats like an oases of life compared with typical deep-sea, soft-sediment environments. Most animals that live in these habitats are invertebrates, and they have adapted to extreme vent environments that include high temperatures, hypoxia, high sulfide, high metal concentration, and darkness. The advent of next-generation sequencing technology, especially the coming of the new era of omics, allowed more studies to focus on the molecular adaptation of these invertebrates to vent habitats. Many genes linked to hydrothermal adaptation have been studied. We summarize the findings related to these genetic adaptations and discuss which new techniques can facilitate studies in the future.

Stem cells are the fundamental drivers of growth during development and adult organ homeostasis. The properties that define stem cells – self-renewal and differentiation – are highly biosynthetically demanding. In order to fuel this demand, stem and progenitor cells engage in hypertranscription, a global amplification of the transcriptome. While standard normalization methods in transcriptomics typically mask hypertranscription, new approaches are beginning to reveal a remarkable range in global transcriptional output in stem and progenitor cells. We discuss technological advancements to probe global transcriptional shifts, review recent findings that contribute to defining hallmarks of stem cell hypertranscription, and propose future directions in this field.

Meiosis is essential for eukaryotic reproduction and provides the basis for Mendel's segregation laws. A recent study by Lacy et al. identified a significant deviation from these laws in a clonal ant, hinting at a potentially overlooked meiotic feature. This discovery may have broader implications for recombination in nonclonal eukaryotes.

How we work affects what we achieve. In this piece, we provide a project management toolkit for students to apply to their research, offering a structure to set goals, manage risks, prioritize work, and make effective decisions. With good planning, students can improve outcomes and make their journey more rewarding.