Details
Water Algae – First to Race Sperms!
01-Jul-2019
”
By Meghana
Over 700 million years ago, certain algae (ancestors of present day trees) were the first to produce swimming sperm to increase their chance to fertilize, says a research by an International team of scientists.
“Sperm motility is the ability of sperm to move efficiently” – This is important for fertility since sperm need to move through the female reproductive tract to reach and fertilize eggs. Poor sperm motility is thus associated with infertility.
Scientists working on evolution of life on earth from trees to mammals were battling for long to resolve the issue related to sperm motility in plants. This new study shows the origin of sperm motility through the genetic change in aquatic algae over 700 million years ago.
The researchers also discovered how a gene that controls sperm production inside pollen grains of flowering plants, was used by primitive land plants to produce free-swimming sperm. The findings were published in Nature Communications earlier this month.
The key finding was that the DUO1 gene originated in the aquatic stoneworts, an ancient group of algae, that diverged from land plants over 700 million years ago.
The study was led by Professor Takashi Araki of Kyoto University and Professor Frederic Berger of the Gregor Mendel Institute of Molecular Plant Biology in Vienna and involved an international team of 25 researchers. Professor David Twell, from the University of Leicester’s Department of Genetics and Genome Biology, headed Leicester’s contribution to the project.
Their work suggests that it was a simple change in the DUO1 gene sequence that allowed the algal ancestors of land plants to produce small swimming sperm to increase the chances of fertilisation in an aquatic environment.
The DNA sequences of DUO1 were compared with primitive land plants like liverworts and mosses and those in freshwater algae. This revealed that even small genetic changes allowed the ancestral algal DUO1 protein to recognise a new DNA sequence. This change enabled DUO1 to control a gene network needed to produce swimming sperm. The researchers went on to show that liverworts with a mutated DUO1 gene turned infertile as they were unable to make actively mobile sperm.
Interestingly, the role of DUO1 in plant sperm formation also adapted to the demands of life on land. For example, DUO1 is needed to produce the whiplash flagella used for propulsion of liverwort sperm, but this is not the case in the flowering plant Arabidopsis thaliana.
Instead, the sperm of flowering plants do not swim and are transported to the egg by a tube that grows out from each pollen grain. In these sperm, DUO1 has taken control of the specialised network of genes needed for the union of sperm and egg.
The original research paper “MYB transcription factor neo-functionalization associated with evolution of sperm differentiation in plants” by Higo and his team is available online through the open-access journal Nature Communications.”
“By Meghana
Over 700 million years ago, certain algae (ancestors of present day trees) were the first to produce swimming sperm to increase their chance to fertilize, says a research by an International team of scientists.
“Sperm motility is the ability of sperm to move efficiently” – This is important for fertility since sperm need to move through the female reproductive tract to reach and fertilize eggs. Poor sperm motility is thus associated with infertility.
Scientists working on evolution of life on earth from trees to mammals were battling for long to resolve the issue related to sperm motility in plants. This new study shows the origin of sperm motility through the genetic change in aquatic algae over 700 million years ago.
The researchers also discovered how a gene that controls sperm production inside pollen grains of flowering plants, was used by primitive land plants to produce free-swimming sperm. The findings were published in Nature Communications earlier this month.
The key finding was that the DUO1 gene originated in the aquatic stoneworts, an ancient group of algae, that diverged from land plants over 700 million years ago.
The study was led by Professor Takashi Araki of Kyoto University and Professor Frederic Berger of the Gregor Mendel Institute of Molecular Plant Biology in Vienna and involved an international team of 25 researchers. Professor David Twell, from the University of Leicester’s Department of Genetics and Genome Biology, headed Leicester’s contribution to the project.
Their work suggests that it was a simple change in the DUO1 gene sequence that allowed the algal ancestors of land plants to produce small swimming sperm to increase the chances of fertilisation in an aquatic environment.
The DNA sequences of DUO1 were compared with primitive land plants like liverworts and mosses and those in freshwater algae. This revealed that even small genetic changes allowed the ancestral algal DUO1 protein to recognise a new DNA sequence. This change enabled DUO1 to control a gene network needed to produce swimming sperm. The researchers went on to show that liverworts with a mutated DUO1 gene turned infertile as they were unable to make actively mobile sperm.
Interestingly, the role of DUO1 in plant sperm formation also adapted to the demands of life on land. For example, DUO1 is needed to produce the whiplash flagella used for propulsion of liverwort sperm, but this is not the case in the flowering plant Arabidopsis thaliana.
Instead, the sperm of flowering plants do not swim and are transported to the egg by a tube that grows out from each pollen grain. In these sperm, DUO1 has taken control of the specialised network of genes needed for the union of sperm and egg.
The original research paper “MYB transcription factor neo-functionalization associated with evolution of sperm differentiation in plants” by Higo and his team is available online through the open-access journal Nature Communications.”
