Topic
Weismann barrier
About: Weismann barrier is a research topic. Over the lifetime, 27 publications have been published within this topic receiving 517 citations.
Papers
TL;DR: It is found that neurons of the worm Caenorhabditis elegans can transmit double-stranded RNA to the germline to initiate transgenerational silencing of a gene of matching sequence in germ cells, demonstrating for the first time that a somatic tissue of an animal can have transGenerational effects on a gene through the transport of double- Stranded RNA.
Abstract: An animal that can transfer gene-regulatory information from somatic cells to germ cells may be able to communicate changes in the soma from one generation to the next. In the worm Caenorhabditis elegans, expression of double-stranded RNA (dsRNA) in neurons can result in the export of dsRNA-derived mobile RNAs to other distant cells. Here, we show that neuronal mobile RNAs can cause transgenerational silencing of a gene of matching sequence in germ cells. Consistent with neuronal mobile RNAs being forms of dsRNA, silencing of target genes that are expressed either in somatic cells or in the germline requires the dsRNA-selective importer SID-1. In contrast to silencing in somatic cells, which requires dsRNA expression in each generation, silencing in the germline is heritable after a single generation of exposure to neuronal mobile RNAs. Although initiation of inherited silencing within the germline requires SID-1, a primary Argonaute RDE-1, a secondary Argonaute HRDE-1, and an RNase D homolog MUT-7, maintenance of inherited silencing is independent of SID-1 and RDE-1, but requires HRDE-1 and MUT-7. Inherited silencing can persist for >25 generations in the absence of the ancestral source of neuronal dsRNA. Therefore, our results suggest that sequence-specific regulatory information in the form of dsRNA can be transferred from neurons to the germline to cause transgenerational silencing.
137 citations
TL;DR: The evidence from a diverse and multidisciplinary literature for senescence in the germline and its consequences is reviewed; the underlying mechanisms responsible are examined, emphasizing changes in mutation rate, telomere loss, and impaired mitochondrial function in gametes.
Abstract: The idea that there is an impenetrable barrier that separates the germline and soma has shaped much thinking in evolutionary biology and in many other disciplines. However, recent research has revealed that the so-called 'Weismann Barrier' is leaky, and that information is transferred from soma to germline. Moreover, the germline itself is now known to age, and to be influenced by an age-related deterioration of the soma that houses and protects it. This could reduce the likelihood of successful reproduction by old individuals, but also lead to long-term deleterious consequences for any offspring that they do produce (including a shortened lifespan). Here, we review the evidence from a diverse and multidisciplinary literature for senescence in the germline and its consequences; we also examine the underlying mechanisms responsible, emphasizing changes in mutation rate, telomere loss, and impaired mitochondrial function in gametes. We consider the effect on life-history evolution, particularly reproductive scheduling and mate choice. Throughout, we draw attention to unresolved issues, new questions to consider, and areas where more research is needed. We also highlight the need for a more comparative approach that would reveal the diversity of processes that organisms have evolved to slow or halt age-related germline deterioration.
96 citations
TL;DR: It is reported that the nematode Caenorhabditis elegans can protect itself from osmotic stress by entering a state of arrested development and can protect its progeny by increasing the expression of the glycerol biosynthetic enzyme GPDH-2 in progeny.
Abstract: In 1893 August Weismann proposed that information about the environment could not pass from somatic cells to germ cells, a hypothesis now known as the Weismann barrier. However, recent studies have indicated that parental exposure to environmental stress can modify progeny physiology and that parental stress can contribute to progeny disorders. The mechanisms regulating these phenomena are poorly understood. We report that the nematode Caenorhabditis elegans can protect itself from osmotic stress by entering a state of arrested development and can protect its progeny from osmotic stress by increasing the expression of the glycerol biosynthetic enzyme GPDH-2 in progeny. Both of these protective mechanisms are regulated by insulin-like signalling: insulin-like signalling to the intestine regulates developmental arrest, while insulin-like signalling to the maternal germline regulates glycerol metabolism in progeny. Thus, there is a heritable link between insulin-like signalling to the maternal germline and progeny metabolism and gene expression. We speculate that analogous modulation of insulin-like signalling to the germline is responsible for effects of the maternal environment on human diseases that involve insulin signalling, such as obesity and type-2 diabetes.
85 citations
TL;DR: It is revealed that the Modern Synthesis is based on four important misinterpretations of what molecular biology had shown, so forming the basis of the four Illusions: 1. Natural Selection; 2. The Weismann Barrier; 3. The Rejection of Darwin’s Gemmules; 4. The Central Dogma.
Abstract: The Modern Synthesis has dominated biology for 80 years It was formulated in 1942, a decade before the major achievements of molecular biology, including the Double Helix and the Central Dogma When first formulated in the 1950s these discoveries and concepts seemed initially to completely justify the central genetic assumptions of the Modern Synthesis The Double Helix provided the basis for highly accurate DNA replication, while the Central Dogma was viewed as supporting the Weismann Barrier, so excluding the inheritance of acquired characteristics This article examines the language of the Modern Synthesis and reveals that it is based on four important misinterpretations of what molecular biology had shown, so forming the basis of the four Illusions: 1 Natural Selection; 2 The Weismann Barrier; 3 The Rejection of Darwin’s Gemmules; 4 The Central Dogma A multi-level organisation view of biology avoids these illusions through the principle of biological relativity Molecular biology does not therefore confirm the assumptions of the Modern Synthesis
75 citations
TL;DR: The capacity of germ cells and somatic cells (soma) to transfer genetic information to the next generation is focused on, and the Weismann theory of heredity is revisited.
58 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2020 | 6 |
| 2019 | 4 |
| 2018 | 2 |
| 2017 | 2 |
| 2016 | 3 |