Experimental breeding of the diatom Cylindrotheca sp. and high-throughput phenotyping of F1 offspring
Authors
Chris J Hulatt (presenting author) [1]
Hirono Suzuki [1]
Océane Flet [1]
Alexandre Détain [1]
Noémie Corniaux [1]
Matt C Posewitz [2]
Affiliations
- Nord Universitet, Norway
- Colorado School of Mines, USA
Keywords
diatom; breeding; phenotyping; strain improvement
Abstract
Sexual reprduction is widespread in eukaryotes and has profound impacts on the life histories and adaptive diversification of many protist species. In diatoms, mating and recombination is a key activity contributing to their enormous phenotypic and genetic diversity, with perhaps 100,000 or more species inhabiting oceanic, lentic and diverse terrestrial environments. The aim of this project was to investigate the possibilities of a “full cycle” diatom breeding program in the lab, including detecting mating activity between different diatom strains, identifying promising crosses, isolating F1 offspring, and examining their phenotypic traits. We began by isolating strains of Cylindrotheca sp. from coastal waters near our lab in Arctic Norway, and introduced them pairwise in crossing experiments. We identified positive mating patterns within three distinct clades, including between parental cells of different genotypes and phenotypes. After selecting the most promising crosses we initiated controlled mating and isolated the F1 offspring. We then examined the F1 phenotypic trait variation, including the cellular morphology, growth rates, and plastid features including chlorophyll content and photophysiology, together with other bioenergetic traits. We detected substantial trait variation amongst F1 strains, including between different parental crosses and between individual offspring within specific crosses. The results shape future experimentation into diatom reproductive biology and advance diatom breeding for studies in ocean microbiology and biotechnology.
Funding
Research Council of Norway, ExCell Chris J Hulatt (Nord) Matt C. Posewitz (Colorado School of Mines)