Posts tagged: EvoDevo

Developments in Daphnia

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Daphnia magna at various stages of development.

Recent headlines reporting contaminated floodwaters invading British towns and villages may have left you wondering what’s really lurking in these waters. If the floodwater is contaminated, as has been suggested, with bacteria such as E. coli, campylobacteria (a common cause of food poisoning) and norovirus in Surrey and the Somerset levels, what other microscopic entities could be being transported around the country by the extraordinarily high water levels?

One microscopic organism which is almost certainly present in the floodwater, but less of a threat to our health, is the water flea – the subject of a new paper published in EvoDevo this week. Water fleas are in fact not fleas at all, bearing little resemblance to their distant arthropod …

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Supersense- it’s a snap for crocs!

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Crocodylus niloticus (Nile crocodile)

The ancestral crocodylian evolved multiple, multisensory micro-organs located on their skin which can detect chemical, thermal, and mechanical changes in their environment finds new research published in EvoDevo today. This helps to explain how crocodylians were able to evolve their highly armoured skin whilst retaining sensory capabilities required for survival in the numerous environments in which they live. 

Armoured plating provides protection but usually also carries the drawback of reduced sensory capabilities- which can be a problem if you hunt prey in murky water. However, as researchers from the University of Geneva have discovered, crocodylians (which include true crocodiles, gharials, alligators and caiman) have an ingenious and unique solution to this problem. They have Read more

Proteins programme snails shells to coil

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Lymnaea stagnalis

 It is thanks to the graded concentration of a protein that snails’ shells are coiled according to new research published in EvoDevo today. In coil-shelled snails, this protein concentration gradient originates from a spot on the right or left of the mantle –  corresponding to the dextral or sinistral nature of the coil. In limpets, and other non-coiled gastropods, the protein is expressed symmetrically in the mantle, causing a cone-shaped shell.

Evolutionary mechanisms for the diversification of shell-types amongst the physiologically diverse gastropods have been of considerable interest for many years. However, the molecular mechanism describing the development different shell shapes were previously poorly understood. Shimizu et al investigated the expression of the decapentaplegic

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Marking 25 years in metazoan phylogeny- happy birthday Darwin

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EvoDevo

Twenty-five years ago today, on the 12th February 1988, a landmark article was published in Science describing a phylogenetic tree of the metazoans, derived from molecular data. The article, by Katherine Field and colleagues (widely referred to as ‘Field et al.’), represented the first use of small subunit ribosomal RNA to establish the metazoan phylogeny. To mark the anniversary of its publication, and coincidentally Darwin’s 204th birthday, a new commentary is published today in EvoDevo evaluating the impacts of this article.

In this commentary, Max Telford (UCL) critically assesses the techniques and methods used by Field et al., and reconstitutes their dataset, to establish a metazoan phylogeny roughly in line with that accepted today. Despite …

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The difference between a mole and a shrew is in their SOX

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Moles have specialised morphological features, that are highly adapted for their unusual underground lifestyle. One of the most apparent of these features is their specialised forelimbs, which are larger and more robust than their hind limbs. It has been hypothesized that this may be caused by differences in timing (heterochrony) in developmental mechanisms.

In new research published in EvoDevo today, Bickelmann et al. measure the spatial and temporal distribution of SOX9 expression in the Iberian mole Talpa occidentalis. SOX9 is a transcription factor associated with chondrocyte differentiation and the development of the Os falciforme- an extra digit like structure found in both the hands and feet of talpid moles. They compare this with expression …

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