Open Reading Frame: DNA barcoding fish, vertebrate evolution & viral evolution

Posted by Biome on 30th August 2013 - 0 Comments


Open Reading Frame brings together a selection of recent publication highlights from elsewhere in  the open access ecosystem. This week we take a look at the past few weeks in biology.


Sea squirt genome shines a light on vertebrate evolution

Our closest living invertebrate cousin, the sea squirt Botryllus scholosseri, has had its genome sequenced. Although a rather unassuming creature in the wild, albeit forming luridly coloured colonies, some remarkable features of its biology may provide valuable insights into transplant and regenerative medicine. A comparison of its genome sequence with vertebrate genomes reveals clues to the evolution of the vertebrates, specifically identifying genes that are important in the development of the vertebrate heart, eye and auditory system among others.
Voskoboynik et al. eLife 

 

Wattle it take to make a man?

Male wild turkeys (Meleagris gallopavo) sport a number of elaborate features absent in females, including their distinctive, brightly coloured wattles, caruncles and snood as well as iridescent plumage and beard. However not all males are made equal – subordinate males have much drabber head ornamentation than dominant males, appearing more similar to female turkeys in this regard. It has often been assumed that any differences in expression levels of genes in each sex must indicate that they encode sex-specific traits. However when comparing gene expression in subordinate males to dominant males, researchers found male-biased genes were less masculinised in subordinates and female-biased genes were more feminised. This indicates that evolutionary changes in phenotypic sex differences can be achieved by altering the sex-bias in gene expression across a large proportion of the genome.
Pointer et al. PLoS Genetics

 

You’re getting swarmer

Bacteria of the species Pseudomonas aeruginosa exhibit a co-operative behaviour called swarming that provides a growth advantage to their colonies by allowing them to spread over surfaces. However this relies on individual bacteria secreting costly surfactants for the benefit of the group, laying them open to exploitation by cheaters who take the benefit without this cost. An experimental and theoretical study aimed to identify conditions favouring the evolution of this trait. It’s findings showed that continual expression of swarming genes can only be favourable when bacteria are highly related to their neighbours, but conditions are less stringent if they are only expressed when times are good.
de Vargas Roditi et al. Molecular Systems Biology

 

Fantastic viral voyage:  from mongoose to poultry via malaria

The reticuloendotheliosis virus (REV) is an emerging viral threat in birds but its origins were unclear until now. A careful piece of detective work reveals that the virus was originally mammalian as the genomes of Malagasy mongooses and other mammals contain the remnants of a close retroviral relative. The journey into poultry took an improbable accident. In the 1930s researchers at the Bronx Zoo, New York, USA were looking for a model parasite that could be grown in domestic poultry to study malaria. Screening exotic poultry species kept in the zoo, they found a suitable malarial parasite in the Borneo firebacked pheasant. Unbeknownst to the researchers, the bird had also been infected with REV, probably from another zoo specimen, and it hitched a ride with the isolated malarial parasite. During multiple passages through poultry during their research, REV became adapted to life in birds. At some point it also merged with two other bird viruses, which were being used to make vaccines against other bird diseases. This series of unfortunate events allowed REV to spread around the world.
Niewiadomska and Gifford. PLOS Biology

 

Fish and chips – but which fish?

Skate is a popular fish among consumers in the British Isles. Although it is commonly sold simply as ‘skate’ or ‘ray’ it can come from a number of species, varying in their conservation status. In a new survey of skate samples collected from fishmongers, supermarkets and takeaway ‘fish and chip’ shops across the United Kingdom and Ireland, species were identified using DNA barcoding. None of the species identified were from the most endangered category whose fishing is prohibited. However the authors claim the lack of clarity about the species sold limits consumers’ ability to make an informed decision to avoid those species under threat.
Griffiths et al. PeerJ

 

Written by Simon Harold, Senior Executive Editor for the BMC Series.