Back to search

FRIMEDBIO-Fri prosj.st. med.,helse,biol

Sex determination in a heterochiasmy setting - functional studies in Atlantic halibut and European plaice

Alternative title: Kjønnsbestemmelse og genetisk rekombinasjon - funksjonelle studier i kveite og rødspette

Awarded: NOK 12.0 mill.

Project Manager:

Project Number:

325195

Application Type:

Project Period:

2021 - 2026

Partner countries:

In contrast to the highly conserved mammalian and avian sex determination systems, fish species generally display much more variation when it comes to sex chromosomes and sex determination systems. We have shown that Atlantic halibut recently aquired a new genetic sex determining system, due to a transposable element insertion triggering male development. We also observed that chromosome crossovers during germ cell formation differed greatly between males and females, a phenomenon known as heterochiasmy which makes all chromosomes behave as sex chromosomes. The evolutionary and mechanistic drivers behind heterochiasmy and its potential link to sex chromosome evolution are not yet fully understood and require further study. Our early results highlight flatfishes as promising model species for the study of heterochiasmy since both types of recombination are represented in this family. In this project we will use gene editing technology and DNA/RNA sequencing experiments using Atlantic halibut and European plaice as model species. In this project we aim to extend the current understanding of mechanisms behind sex chromosome turn-over with an ambitious goal to provide more insight into the molecular causes of heterochiasmy.

In contrast to the highly conserved mammalian and avian sex determination systems, fish generally display much more plasticity and turnover when it comes to sex chromosomes and sex determination systems. We have shown that Atlantic halibut recently aquired a new genetic sex determining system, due to a transposable element insertion triggering male development. We also observed that chromosome crossovers during germ cell formation differed greatly between males and females, a phenomenon known as heterochiasmy which makes all chromosomes behave as sex chromosomes in meiotic recombination. The evolutionary and mechanistic drivers behind heterochiasmy and its potential link to sex chromosome evolution are not yet fully understood and require further study, although lack of relevant model organisms have made such studies difficult. Our early results highlight flatfishes as promising model species for the study of heterochiasmy since both types of recombination are represented in this family. In this project we will use gene editing technology and DNA/RNA sequencing experiments using Atlantic halibut and European plaice as model species. Furthermore, we will conduct large-scale bioinformatics screens on genomes and other genetic datasets from many flatfish species. Planned experiments include direct inference of recombination hot-spots in sperm and eggs as well as development of gene editing protocols for flatfishes, both requiring considerable R&D efforts. In this project we aim to extend the current understanding of mechanisms behind sex chromosome turn-over with an ambitious goal to provide more insight into the molecular causes of heterochiasmy. Heterochiasmy could be a major driving force behind sex chromosome evolution in flatfish, but may also extend to other fish species or beyond.

Publications from Cristin

No publications found

No publications found

No publications found

No publications found

Funding scheme:

FRIMEDBIO-Fri prosj.st. med.,helse,biol

Funding Sources