Biology

Pseudomonas aeruginosa (Image CDC/ Janice Haney Carr)

0

An article published in the journal “Nature” reports a study concerning bacterial immune defenses of the CRISPR-Cas type, which could turn out to be a disadvantage against some types of viruses. A team of researchers analyzed the immune systems present in the genome of over 170,000 bacteria to try to understand the reactions against bacteriophage viruses. The conclusion that CRISPR antiviral systems are sometimes a disadvantage offers an explanation of why only a minority of bacteria have them in their DNA. It also offers new information on bacteria’s defense strategies viruses’ attack strategies with a sort of arms race between them.

A rare photo of a live giant squid (Photo courtesy Tsunemi Kubodera)

0

An article published in the magazine “GigaScience” reports a DNA sequencing of Architeuthis dux, commonly known as giant squid. A team of researchers led by Rute da Fonseca of the Danish University of Copenhagen employed a number of genetic techniques to obtain the complete genome of this cephalopod, one of the largest in the history of this group of invertebrates. Its DNA is very large with its 2.7 billion base pairs of DNA, approximately 90% of the size of the human genome. Among the interesting results there’s the discovery of over 100 genes that encode proteins of the protocadherin family, important in the correct connectivity of a complex brain.

An Asgard archaeon could provide the key to understanding the birth of the eukaryotic cell

0

An article published in the journal “Nature” reports a study on an archaeon called Candidatus Prometheoarchaeum syntrophicum, part of the proposed phylum Lokiarchaeota. A team of researchers took samples from the bottom of the Pacific Ocean near the Japanese coasts, managing to cultivate these Archaea contained in a special laboratory environment specifically created. Years of studies made it possible to separate various strains and to discover that some have long and branched protrusions, a feature that led the researchers to suggest that in the past a bacterium became entangled in similar protrusions becoming an organelle of what became over time a eukaryotic cell.

A spectacled cobra (Photo Saleem Hameed)

0

An article published in the journal “Nature Genetics” reports the DNA sequencing of the spectacled cobra, one of the so-called “Big Four”, the four most venomous and dangerous snakes in India. A team of researchers employed a number of genetic techniques that led to the identification of 23,248 genes that encode proteins, including 12,346 genes that regulate its venom glands. The knowledge of this snake’s genome will help develop better antidotes for its deadly venom and the proteins contained in that venom could also be useful for developing various types of drugs.

Carbonate-rich lakes as possible places where life on Earth originated

0

An article published in the journal “Proceedings of the National Academy of Science” reports a study on carbonate-rich lakes as possible places where life on Earth originated. Jonathan Toner and David Catling of the University of Washington measured the concentration of phosphorus, an element crucial for various cellular processes, in carbonate-rich lakes, detecting phosphorus concentrations up to 50,000 times higher than those present in seawaters, in river waters and also in those of other lakes. The two researchers found a link between an abundance of carbonates and phosphorus, a discovery that offers a possible solution to the problem of the shortage of phosphorus in other possible places of origin of life.