Nav: Home

Scientists revealed how water fleas settled during the Ice Age

December 17, 2018

New study shows that the roots used by three close species of microscopic Daphnia crustaceans to settle across the territory of Northern Eurasia differed greatly. This findings shed light on how the continental freshwater fauna was formed. They are published in PLOS ONE.

Branchcrus crustaceans (Cladocera superorder), living mainly in freshwater bodies, are of interest not only to crustaceans. These microscopic animals are model objects of evolutionary biology, genetics, ecology, and other areas of the biological sciences. Most studies focus on crustaceans of the genus Daphnia. Despite being the most famous and widespread, Daphnia still holds some mysteries for biologists. For example, the distribution pattern of these crustaceans in Eurasia has been unknown so far. One of the reasons for that was lack of studies on the vast territory of Siberia. Recently, Russian scientists first collected several species of crustaceans in Siberian waters and examined them in order to learn more about the history of their settlement in the continent.

Three species of Daphnia found throughout Northern Eurasia were selected for the study: Daphnia galeata, D. longispina and D. dentifera. Samples of crustaceans were collected in 35 ponds of the European part of Russia, Eastern Siberia, the Far East, Austria and Mongolia. All animals were photographed before the study in order to preserve data on their appearance, and then the DNA of some of them was extracted. Genetic comparison of populations from different regions was based on two mitochondrial genes.

Mitochondria are small "energy stations" of a cell. Mitochondrial DNA in all animals is transmitted only through the maternal line, while the DNA of the cell nucleus combines the genetic material of both parents. Therefore, the kinship between different populations is easier traced using the mitochondrial genes rather than the genes from the nucleus. The data gained during the study was finally compared to the GenBank international database.

Scientists identified differences in DNA in different regions of Eurasia and determined the genetic differences between populations and the approximate time of their divergence. It turned out that, despite the proximity of the three species, they were differently settled in northern Eurasia. D. galeata spread in the region very quickly and relatively recently. The species D. longispina and D. dentifera were genetically very heterogeneous. The researchers concluded that during the Ice Age they survived in fragmented populations in the so-called refugiums (shelters) in Eastern Siberia in strong isolation from each other. As a result, each species have a strong genetic diversity.

"In this study, we applied phylogenetic and phylogeographic approaches, based on genetic data from native lines, which reveal the links between them and reconstruct the history of species spread through the whole European Union," emphasizes Alexey Kotov, the leading researcher at the Institute of Ecology and Evolution, Member of the Russian Academy of Sciences. "Although Daphnia genus is the most convenient model object for such works, we plan to study the demographic history of other genera of branch-crustaceans, as well as some other microscopic animals of continental water bodies. All these studies help us to create a single picture of what historical processes shaped the modern biological diversity of Northern Eurasia."
-end-
The study was conducted jointly with scientists from the Institute of Ecology and Evolution named after A.N. Severtsov RAN, Institute of Systematics and Ecology of Animals SB RAS and Limnological Institute SB RAS. It was supported by the Russian Science Foundation.

AKSON Russian Science Communication Association

Related Dna Articles:

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.
In one direction or the other: That is how DNA is unwound
DNA is like a book, it needs to be opened to be read.
DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.
A new spin on DNA
For decades, researchers have chased ways to study biological machines.
From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.
Self-healing DNA nanostructures
DNA assembled into nanostructures such as tubes and origami-inspired shapes could someday find applications ranging from DNA computers to nanomedicine.
DNA design that anyone can do
Researchers at MIT and Arizona State University have designed a computer program that allows users to translate any free-form drawing into a two-dimensional, nanoscale structure made of DNA.
DNA find
A Queensland University of Technology-led collaboration with University of Adelaide reveals that Australia's pint-sized banded hare-wallaby is the closest living relative of the giant short-faced kangaroos which roamed the continent for millions of years, but died out about 40,000 years ago.
DNA structure impacts rate and accuracy of DNA synthesis
DNA sequences with the potential to form unusual conformations, which are frequently associated with cancer and neurological diseases, can in fact slow down or speed up the DNA synthesis process and cause more or fewer sequencing errors.
Changes in mitochondrial DNA control how nuclear DNA mutations are expressed in cardiomyopathy
Differences in the DNA within the mitochondria, the energy-producing structures within cells, can determine the severity and progression of heart disease caused by a nuclear DNA mutation.
More Dna News and Dna Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab