Background: A common feature of most genetic sex-determination systems studied so far is that sex is determined by nonrecombining genomic regions, which can be of various sizes depending on the species. These regions have evolved independently and repeatedly across diverse groups. A number of such sex-determining regions (SDRs) have been studied in animals, plants, and fungi, but very little is known about the evolution of sexes in other eukaryotic lineages.
Results: We report here the sequencing and genomic analysis of the SDR of Ectocarpus, a brown alga that has been evolving independently from plants, animals, and fungi for over one giga-annum. In Ectocarpus, sex is expressed during the haploid phase of the life cycle, and both the female (U) and the male (V) sex chromosomes contain nonrecombining regions. The U and V of this species have been diverging for more than 70 mega-annum, yet gene degeneration has been modest, and the SDR is relatively small, with no evidence for evolutionary strata. These features may be explained by the occurrence of strong purifying selection during the haploid phase of the life cycle and the low level of sexual dimorphism. V is dominant over U, suggesting that femaleness may be the default state, adopted when the male haplotype is absent.
Conclusions: The Ectocarpus UV system has clearly had a distinct evolutionary trajectory not only to the well-studied XY and ZW systems but also to the UV systems described so far. Nonetheless, some striking similarities exist, indicating remarkable universality of the underlying processes shaping sex chromosome evolution across distant lineages.
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http://dx.doi.org/10.1016/j.cub.2014.07.042 | DOI Listing |
Plants (Basel)
December 2024
Food Technology Division, ceiA3, CIAMBITAL, University of Almeria, 04120 Almeria, Spain.
is an invasive brown macroalga that has recently proliferated in the western Mediterranean Sea, causing significant environmental challenges. This alga, however, contains valuable bioactive compounds-alginate, mannitol, and phlorotannins-that can serve as biofertilizers to promote plant growth and aid in bioremediation of degraded or contaminated soils. This study focused on optimizing the extraction of these compounds from , transforming an ecological issue into a beneficial resource.
View Article and Find Full Text PDFMolecules
December 2024
Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Tokyo 108-8477, Japan.
The brown alga (SF) is historically consumed as a food material in Japan. A steaming process is often required for SF products on the market due to their moderate hardness and astringent taste. This investigation aimed to elucidate the effect of steaming on the anti-diabetic activity of SF and its related chemical components.
View Article and Find Full Text PDFMar Environ Res
December 2024
L3MA UR4_1 UFR STE Universite des Antilles, Campus de Schoelcher, Schoelcher, 97275, France. Electronic address:
Since 2011, massive strandings of Sargassum (brown alga) have significantly affected Caribbean islands causing major health, environmental and economic problems. Amongst them, the degradation of algae releases corrosive gases, hydrogen sulphide (HS) and ammonia (NH) which causes an accelerated corrosion of the metallic structures of these coastal areas. The aim of this study was to quantify the impact of Sargassum strandings on the corrosion of three types of steels (DC01 carbon steel, 304L and 316L stainless steels) immersed for up to 120 days at various sites in Martinique which were gradually impacted by Sargassum.
View Article and Find Full Text PDFSci Rep
January 2025
Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Institute , National Research Centre, Dokki, Cairo, 12622, Egypt.
Cisplatin is a chemotherapeutic drug, which exhibits undesirable side effects. Chitosan nanoparticles are promising for drug delivery. The aim of this study was to determine the effect of the brown alga Turbinaria triquetra ethyl acetate fraction and polysaccharides, either loaded on chitosan nanoparticles or free, against podocyturia and cisplatin nephrotoxicity in rats.
View Article and Find Full Text PDFNature
January 2025
Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA.
Reproduction, development and homeostasis depend on motile cilia, whose rhythmic beating is powered by a microtubule-based molecular machine called the axoneme. Although an atomic model of the axoneme is available for the alga Chlamydomonas reinhardtii, structures of mammalian axonemes are incomplete. Furthermore, we do not fully understand how molecular structures of axonemes vary across motile-ciliated cell types in the body.
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