Genetics & Molecular Biology

Researchers at the Max Planck Institute for Developmental Biology in Tuebingen, Germany, have reported the completion of the first genomes of wild strains of the flowering plant Arabidopsis thaliana as part of the 1001 Genomes Project.

The entire genomes of two individuals of this species, one from Ireland, the other from Japan, have now been compared in great detail. They were found to be astonishingly different from each other, as Detlef Weigel and his colleagues write in Genome Research.

This study marks the starting point of the 1001 Genomes Project, in which a total of thousand and one individuals of the same species will be sequenced. The scientists aim at correlating the genetic differences between the different strains with variation in the speed of plant growth and their resistance against infectious germs. These strategies could then also be applied to crop plants or trees.

The recent announcement that Sergey Brin, the multibillionair co-founder of Google, has discovered that he possesses a genetic mutation that predisposes him to a form of Parkinson's disease has resulted in multiple stories in the news on the "genetic basis" of Parkinson's and the candidate gene LRRK2.
A study in northern China indicates that genetically modified cotton, altered to express the insecticide Bt, not only reduces pest populations among those crops, but also reduces pests among other nearby crops that have not been modified with Bt. These findings could offer promising new ideas for controlling pests and maximizing crop yields in the future.

Bt is an insecticide derived from the spores and toxic crystals of the bacteria Bacillus thuringiensis, and has been sold commercially since 1960. It is considered non-toxic to humans, animals, fish, plants, micro-organisms, and most insects. However, it is highly selective and lethal to caterpillars of moths and butterflies. Bt is currently registered and marketed for use as an insecticide in more than 50 countries worldwide. It does not contaminate groundwater because it degrades so rapidly.

Dr. Kong-Ming Wu from the Chinese Academy of Agricultural Sciences in Beijing and colleagues analyzed data from 1997 to 2007 about the agriculture of Bt cotton in six provinces in northern China, covering 38 million hectares of farmland cultivated by 10 million resource-poor farmers. They compared that information with data on pest populations in the region, focusing on the cotton bollworm, a serious pest for Chinese farmers.

I usually like Nicolas Wade, but this very first sentence of a piece in this week's NY Times science section is not right:
The principal rationale for the $3 billion spent to decode the human genome was that it would enable the discovery of the variant genes that predispose people to common diseases like cancer and Alzheimer’s.

Yeast, the essential microorganism for fermentation in the brewing of beer, converts carbohydrates into alcohol and other products that influence appearance, aroma, and taste. In a study published online today in Genome Research, researchers have identified the genomic origins of the lager yeast Saccharomyces pastorianus, which could help brewers to better control the brewing process.

For thousands of years, ale-type beers have been brewed with Saccharomyces cerevisiae (brewer's or baker's yeast). In contrast, lager beer, which utilizes fermentations carried out at much lower temperature than for ale, is a more recently developed alcoholic beverage, appearing in Bavaria near the end of the Middle Ages.

The genetic code is the metabolic instructions by which the genetic information in the DNA is translated into a protein. The fact that almost all organisms use the same code is prime evidence that all life is related in its evolutionary past. The code is considered to be "conserved" and "universal". Of course, the concept of universality may be challenged by exobiology's explorations of Mars, Europa, and Titan, but the conservative nature of the genetic code, with the exception of a few Archaebacteria, has always been a cornerstone of biological science.

Michael Creighton's latest thriller, Next, presents all sorts of what-if scenarios for the genetic community. While most of us will not have to deal with foul-mouthed orangutans or smart-ass parrots, a recent report published in the Proceedings of the National Academy of Sciences suggests that there may be a genetic factor contributing to fear of commitment in males. As reported today by the BBC ("Commitment phobes can blame genes", Sept 2, 2008), this gene is called AVPR1A.
The hereditary disease ponto cerebellar hypoplasia (PCH) occurs when certain areas of the brain do not develop properly; this results in severe mental and physical developmental disorders. Life expectancy of those affected ranges from a few months to a few years.

Scientists from Cologne and Amsterdam have discovered the mutations in human genetics which cause PCH of the types 2 and 4.

“In the case of PCH, the protein complex – the so-called tRNA-Splicing-Endonuclease, is mutated. This complex in involved in the manufacture of proteins in the human body and was identified in connection with a disease for the first time,” reports Birgit Budde from the Cologne Center for Genomics and Institute for Genetics of the University of Cologne.

Together with colleagues from the Department of Dermatology and Allergy and the Center for Allergy and Environment (ZAUM) of the Technische Universität München, scientists at the Helmholtz Zentrum München have pinpointed a major gene for allergic diseases. The gene was localized using cutting edge technologies for examining the whole human genome at the Helmholtz Zentrum München.

The newly discovered FCER1A gene encodes the alpha chain of high affinity IgE receptor, which plays a major role in controlling allergic responses. The team of scientists led by Dr. Stephan Weidinger from the Technische Universität München and Dr. Thomas Illig from the Helmholtz Zentrum München found that certain variations of the FCER1A gene decisively influence the production of immunoglobulin E (IgE) antibodies. IgE antibodies are a particular type of antibody that is normally used to protect against parasites. In Western lifestyle countries with less contact, however, elevated IgE levels are associated with allergic disorders.

A simple and primitive animal, Trichoplax adhaerens, appears to harbor a far more complex suite of capabilities than meets the eye. The findings, reported Nature, establish a group of organisms as a branching point of animal evolution and identify sets of genes, or a "parts list," employed by organisms that have evolved along particular branches.

Trichoplax adhaerens was first detected in the 1880s clinging to the sides of an aquarium but it just recently got characterized by the U.S. Department of Energy Joint Genome Institute (DOE JGI)and they found that its ancient lineage was matched by its complexity.