Systematicians usually struggle with numerous undescribed and new species of poorly know organisms during biodiversity surveys and taxonomic studies.

In this recently published PLoS One contribution however, Indian, Czech and Slovak colleagues together with the team of J. Mariaux reached a rather unusual result: Their goal was to assess the diversity of a group of parasitic flatworms infesting freshwater fishes in the Indomalayan region. Their comprehensive study included multiple collecting field trips, as well as a complete morphological, molecular and ultrastructural revision of these worms. Surprisingly it demonstrated that only 4 species were present although… 47 had been previously described! This kind of revision allowed to untangle an extreme case of systematic confusion that was created by erroneous interpretations of the morphological variation in these worms. It also offers practical tools to unambiguously differentiate the existing taxa in this group.

The courtship period in mice displays surprising rituals. Researchers from the group of Prof. Denis Duboule show, indeed, that the female actively solicits the male’s  advances, as well as mating. They also demonstrate that this courtship activity is under genetic control, as evidenced by the aggressive behavior of females issued from a mu- tant line. The latter chase the males and investigate their intimate parts relentlessly, before inflicting them genital bites. This behavior is associated with the deletion of a specific region in a group of genes named HoxD. The anomaly induces in mutant female brain ectopic expression of the Hoxd10 gene. The results, published in the journal Current Biology, open new avenues to explore genetic and molecular bases of normal and pathological mammalian affect. 

• Press release (133 KB)
• Communiqué de presse (79.7 KB)

The major histocompatibility complex or HLA in humans, is a group of several genes responsible for our body's ability to distinguish between self and nonself, and then to defend itself against pathogens.

It is to this complex that we owe the phenomena of rejection in organ transplantation, or the disease called graft-versus-host, a response of the immune system that clinicians try to avoid at all costs during blood stem cell transplants used for the treatment of leukemias.

Studies performed by the group of Prof. Alicia Sanchez-Mazas, published in the journal PLoS ONE, supports the strategy of a geographical diversification of centers of recruitment for volunteer stem cell donors in Switzerland in order to increase the chances of finding compatible donors at the scale of the whole country. 

In addition, this study confirms that the Alps have been a barrier to gene flow during the history of human migrations in Europe. 

This complex is, indeed, also very useful to geneticists-anthropologists because its variability can provide valuable information on the peopling of a region or continent.

• Press release (160 KB)
• PLoS One paper (418 KB)

Studies of evolutionary developmental biology commonly use ‘model organisms’ such as fruit flies or mice, and questions are often functional or epigenetic. Phylogenetic investigations, in contrast, typically use species that are less common and mostly deal with broad scale analyses in the tree of life.

However, important evolutionary transformations have taken place at all taxonomic levels, resulting in such diverse forms as elephants and shrews. To understand the mechanisms underlying morphological diversification, broader sampling and comparative approaches are paramount.

Using unique breeding colonies of new model species, the team from Prof. Milinkovitch describe for the first time the developmental series of two tenrecid afrotherian mammals. The developmental timing is compared with that of other mammals, including mouse, echidna, and the opossum. This work, made possible by a close collaboration between four laboratories in Genev, Zurich, Cambridge (UK) and Tubingen (Germany) has just been published in “Journal of Anatomy”.

• First description of developmental staging in tenrecs (3.57 MB)

The laboratory of Prof Jan Pawlowski is pleased to announce the launch of foramBarcoding, an online database of modern foraminifera.

Foraminifera are a major group of protozoans that successfully colonizes aquatic and terrestrial habitats.

Foraminifera are characterized by a granular pseudopodial network called granuloreticulopodia and most of them feature a test (shell) that is composed of an organic, agglutinated or calcareous wall and has one or multiple chambers.

Some species have developed symbiotic relationships with various groups of algal protists and bacteria.

DNA barcoding refers to a technique that characterizes species using DNA fragments specific to each species.

DNA barcode sequences are very short relative to the entire genome and they can be obtained reasonably quickly and cheaply.

The identification of foraminiferal species is mainly based on the morphology of their tests, which leads to difficulties when dealing with morphologically variable species and impedes the detection of sibling species.

The foramBarcoding website proposes a complementary identification system based on DNA barcodes.

The record of each species in the database comprises its general description, photos, collection data, DNA sequences, and references to related publications.

The database is manually curated and differs from other foraminiferal databases by including only species, for which both molecular and morphological data are available.

Our objective is to provide a complete, high quality and freely accessible resource of information about modern foraminiferal species.

Reptilian species are largely under-represented in comparative genomics despite the fact that they are substantially more diverse than mammals. Given the high divergence of reptiles from classical model species, next-generation sequencing of their transcriptomes is an approach of choice for gene identification and annotation.

In the EvoDevo journal, the group of Prof Michel Milinkovitch is reporting the sequencing and analysis of the transcriptome of four divergent reptilian species: the Nile crocodile, the corn snake, the bearded dragon, and the red-eared turtle.

Their reptilian comparative transcriptomics dataset identifies 20,000 to 31,000 transcripts per species for a cumulated non-redundant sequence length of 250 millions nucleotides.

They have also identified thousands of molecular markers and polymorphisms for future population and quantitative genetic analyses.

Finally, Prof. Milinkovitch and his collaborators built very large alignments of protein sequences (about 2 millions amino-acids per species) and performed extensive phylogenetic analyses showing that turtles are not basal living reptiles but are rather the sister-group to Archosaurians (crocodiles & birds), hence, answering a long-standing question in the evolution of vertebrates.

The “Reptilian Transcriptome v1.0” is freely available at www.reptilian-transcriptomes.org.

It should prove a useful new resource for many researchers as reptiles are becoming important new models for comparative genomics, ecology, and evolutionary developmental genetics.

• Reptilian-transcriptome v1.0 (2.73 MB)

In the last issue of PLoS ONE journal, Dr Juan Montoya presents a scan of two puffer fish genomes aimed at detecting and analyzing genes that are involved in adaptive evolution, that is, which confer an advantageous phenotype to their holders (positive Darwinian selection).

This study reveals that more than half of the biological processes targeted by positive Darwinian selection in mammals are also targeted in puffer fishes, highlighting general patterns for vertebrates.

It also reveals that mammalian-specific processes displaying an excess of positively selected genes are related to sensory perception and neurological processes.

For both mammals and fishes, adaptive evolution occurs more often in the extra-cellular environment rather than inside the cell.

This study is also the first to present a genome-wide characterization of neutrally-evolving regions of protein-coding genes.

This analysis uncovered a strong link between neutral evolution and positive Darwinian selection suggesting that neutrally-evolving regions are a major source of novelties screened by positive Darwinian selection.

• Patterns of Positive Selection (190 KB)

The “Fondation pour Genève” was founded in 1976 and is a private, non-political and non-religious organisation recognised as of public benefit.

It works, in particular, on the international positioning of the region, welcoming internationals and their spouses, developing initiatives that encourage dialogue and the exchange of ideas and finally managing its humanist funds.

The “Fondation pour Genève” initiates, promotes, coordination and supports initiatives that contribute to Geneva's traditions of hospitality and openness to the world.

By presenting its 2011 Award to Professor Denis Duboule, the Foundation for Geneva – joined by the Geneva authorities and Merck Serono – gives a tribute to this internationally renowned researcher, whose work radiates the University of Geneva and the EPFL in the world (via http://fondationpourgeneve.ch).

• flyer (392 KB)
• invitation (376 KB)

Intraspecific brood parasitism (IBP) is a remarkable phenomenon by which parasitic females can increase their reproductive output by laying eggs in conspecific female's nests in addition to incubating eggs in their own nest.

In a recent study published in “Molecular Ecology”, Prof. Michel Milinkovitch has analysed molecular data in two eider duck colonies, showing that genetically related females (young females, their aunts and their grandmas) specialize in their energy allocation: young females produce more eggs than they can incubate and they entrust these to their older relatives.

As older females cannot lay as many eggs as young females can, their ability to accept eggs from their nieces and grand-daughters allows them to indirectly increase their own fitness (as the offspring in the parasitic eggs bear some of their own genes).

Hence, what is generally called ‘intraspecific brood parasitism’ in ducks is likely to constitute a spectacular cooperation among generations of closely related females.

• Alien eggs in duck nests: brood parasitism or a help from Grandma?
• More infos

At murky depths greater than 2,000 meters, ocean floors teem with little explored life.

The size and remoteness of this underwater ecosystem, not to mention the difficulty of growing its fragile denizens outside their habitat, lend an air of mystery to the seemingly lost world of deep sea dwellers.

In a paper recently published in the PNAS journal, Béatrice Lecroq and Franck Lejzerowicz from the laboratory of Pr. Jan Pawlowski, and their collaborators, used the ultra-deep sequencing technology to target a 36 base pair fragment of ribosomal DNA as a genetic barcode to distinguish between species of benthic foraminiferans, common bottom-dwelling deep-sea protozoans.

This microbarcode helped classify nearly all of the more than 800 unique taxonomic entities into distinct orders, about half of them into separate families, and a few into individual species.

The barcoding data revealed that most of the foraminiferal species were of the soft-walled, single-chambered kind, thought to have evolved early.

That finding challenges the long-held view that the multi-chambered species dominate the foraminiferan community.

With further optimization of the technology and expansion of the reference database, ultra-deep sequencing could help speed deep sea research, according to the authors.

• Lecroq_PNAS_2011 (906 KB)

This conference, organized by our Department, will address the creation of a DNA-based identification system for every species living in Switzerland and/or preserved in Swiss collections.

The conference will be held at the University of Geneva, Sciences II, room A150. Participation is open.

Please confirm your attendance to Pascale.Larcher.

Program

Café & croissants (10.00 – 10.30)

10.30 – Introduction

10.40 – Paul Hebert, International Barcode of Life

11.20 – Gerhard Haszprunar, Barcoding Fauna Bavarica

11.50 – Lorenzo Lombard, European Consortium for the Barcode of Life

Lunch break (12.30 – 13.30)

13.30 - Martijn Holterman (ACW) The Role of ACW in QBOL: Coordination of Nematode Barcoding and other Activities

13.50 - Alexandre Aebi (ART) Gut-Content Barcoding and Environmental Risk Assessment

14.10 - Carolina Cornejo (WSL) Applying DNA barcoding to crustose lichens: two or more at one stroke

14.30 – Sophia Caetano (CJB) The use of plant DNA barcodes in herbarium collections.

14.50 - Marco Bernasconi (UniZü) DNA barcoding of flies

15.10 - Enrique Lara (UniNe) Soil eukaryotic diversity: a new world under our shoes

Coffee break (15.30 – 16.00)

16.00 – 17.30 – Round table discussion

Aperitif (17.30 – 18.00)

• program (21.5 KB)
• poster (2.31 MB)