H2020Индивидуална стипендия2021–2023

SEXY · Selfish Genome Exclusion under Hybridogenesis

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-12-01 → 2023-11-30
Финансиране от ЕС: 191 149 €
Участници: 1
Схема: MSCA-IF

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Накратко на български

Молекулярните механизми на хибридогенезата при някои видове насекоми водят до предаването на единия родителски геном, докато другият се изхвърля. Това помага да се разбере как се променят начините на размножаване и защо някои организми се отказват от сексуалното размножаване.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Selfish Genome Exclusion under Hybridogenesis

The existence of genetic elements which enhance their own inheritance at the expense of others, the infamous “selfish genes”, has fascinated scientists and laymen alike for decades. One extreme case of selfish transmission, called hybridogenesis, can be observed in some hybrid species. Here, one entire haploid genome is transmitted clonally while the other haploid genome is eliminated prior to or during gamete formation. It gets renewed each generation through mating with the corresponding parental species which results in maintaining a first generation hybrid state over time. Unlike the evolutionary dynamics that underlie the spread and maintenance of selfish transmission strategies, the molecular innovations that enable the selfish transmission of one complete genome at the expense of another in hybridogenetic animals still remain elusive. Here, we took advantage of Bacillus stick insects as a model to elucidate the phylogenomic origin of hybridogenesis (and parthenogenesis) and identify the molecular foundation of selfish transmission and genome exclusion. Our phylogenomic analyses suggest that sex was lost in favor of hybridogenesis after a single hybridization event followed by at least one secondary reproductive mode diversification, most likely a transition from hybridogenesis to parthenogenesis. These findings indicate transitions between unorthodox modes of reproduction that were previously not known to occur, suggesting that the loss of sex per se can be a driver of reproductive mode diversification. This conclusion is supported by crossing experiments aimed at revealing the genomic foundation of hybridogenesis, which display an unexpected transition from hybridogenesis to an effectively clonal transmission of both parental genomes.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Selfish genetic elements increase their transmission at the expense of others. The ultimate reasons for their increased transmission are generally well understood. However, the molecular mechanisms driving their transmission above the Mendelian 50/50 ratio are poorly understood, especially in the case of selective exclusion of entire haploid genomes. A prime example for genome exclusion is hybridogenesis: some F1 hybrid species clonally transmit one of their haploid genomes (the selfish one) by selectively eliminating the other (the so-called ‘host genome’) during gamete formation. Here, I propose to use Bacillus stick insects to elucidate the molecular innovations that enable genome exclusion and lead to the evolution of hybridogenesis in Bacillus. The Bacillus system is uniquely suited for the proposed research as it is possible to introgress genome-eliminating elements into the genetic background of a ‘normal’ sexual species. This enables identification of genomic regions associated with genome exclusion by targeted genotyping. The project will answer three key questions: I) Bacillus comprises at least two hybridogenetic species that use different host genomes: how did host genome exclusion originate (independent origin vs host switch)? II) what is the genomic basis of genome exclusion?, and III) are cytoplasmic (maternally derived) components involved in genome exclusion? The methodological repertoire will comprise haplome phasing and phylogenomics using long-read data, experimental introgression and genetic mapping, and an experimental cytoplasm switch. By combining the methodology of different disciplines we will generate a cohesive understanding of the mechanistic basis of genome exclusion in a new model organism. The project addresses general hypotheses and will serve as a blueprint for genome exclusion studies with applicative potential in medicine and agriculture.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITE DE LAUSANNE · LAUSANNEКоординаторШвейцария