Genetics & Molecular Biology

Scientists have sequenced the genome of Belgica antarctica, the Antarctic midge – the smallest in insects described to-date –  and believe it can explained by the midge's adaptation to its deep-freeze extreme living environment.

The midge is a small, wingless fly that spends most of its two-year larval stage frozen in the Antarctic ice. Upon adulthood, the insects spend seven to 10 days mating and laying eggs, and then they die. Its genome contains only 99 million base pairs of nucleotides, making it smaller than other tiny reported genomes for the body louse (105 million base pairs) and the winged parasite Strepsiptera (108 million base pairs), as well as the genomes of three other members of the midge family. 

Researchers have come up with a promising method of treating male infertility; a synthetic version of the sperm-originated protein known as PAWP. PAWP has been shown to be required, they write, and their synthetic version was sufficient to initiate the fertilization process.

According to the Centers for Disease Control and Prevention's 2013 Annual Report on Assisted Reproductive Technologies, only about 37 percent of treatment cycles lead to successful pregnancy. This low success rate may be due to a variety of factors in the male and female including the inability of sperm cell to initiate fertilization and trigger embryo development upon egg entry. 

Hey, heads up Public: game-changing new science means we can probably make insects stop spreading malaria, dengue fever, and Lyme disease.  Or reverse pesticide resistance in agricultural pests.  Or even eliminate invasive (or otherwise undesired) species.  But this has major public policy implications, and scientists want to make sure everybody knows what we’re getting into and we set up safeguards before any of this actually happens.

Spider silk is lightweight and stretchy yet has tensile strength greater than steel.

Its chemistry is just as fascinating. Silk proteins, called spidroins, must convert from a soluble form to solid fibers at ambient temperatures, with water as a solvent, and at high speed. How do spiders achieve this astounding feat? A new paper discusses how the silk formation process is regulated. 

Physicists have identified a mechanism that may help explain Zipf's law – a unique pattern of behavior found in disparate systems, including complex biological ones. Their mathematical models demonstrate how Zipf's law naturally arises when a sufficient number of units react to a hidden variable in a system.

Your stress levels may be another thing you can blame on your mother. Scientists investigating pregnancies in four generations of rats show that inherited epigenetic effects of stress could affect pregnancies for generations. 

The researchers believe that these changes are due to epigenetics - the arrangement and expression of our genes. In most cases this refers to DNA methylation of the nucleotide base pairs. In this study the researchers believe the epigenetic changes are due to microRNA (miRNA) - non-coding RNA molecules that play a role in regulating gene expression.

Tuber melanosporum - black or Périgord truffles - are fungi that grow in symbiosis with the roots of oak and hazelnut trees. In the world of haute cuisine, they are expensive and highly prized.

Epigenetics is the study of changes in gene expression caused by mechanisms other than changes in the DNA sequence.
In the world of epigenetics, black truffles are of major interest because of their unique pattern of DNA methylation, a biochemical process that chemically modifies nucleic acids without changing their sequence. 

A newly published reports on the truffle's unique genetic makeup.

Credit: University of Arizona

Researchers have sequenced the complete genome of Oryza glaberrima (African rice), which will enhance scientists' and agriculturalists' understanding of the growing patterns of African rice, as well as enable the development of new rice varieties that are better able to cope with increasing environmental stressors to help solve global hunger challenges.

About 15% of adults suffer from fertility problems, primarily due to genetic factors.

This is something of an evolutionary paradox; wouldn't natural selection have caused people with infertility to not reproduce?Various theories explain the survival of harmful mutations: A gene that today causes obesity, for example may have once granted an evolutionary advantage; or a disease-causing gene may persist because it is passed on in a small, relatively isolated population.

Using data from over 18,000 patients, scientists have identified more than two dozen genetic risk factors involved in Parkinson's disease, including six that had not been previously reported. 

Affecting millions of people worldwide, Parkinson's disease is a degenerative disorder that causes movement problems, including trembling of the hands, arms, or legs, stiffness of limbs and trunk, slowed movements and problems with posture. Over time, patients may have difficulty walking, talking, or completing other simple tasks. Although nine genes have been shown to cause rare forms of Parkinson's disease, scientists continue to search for genetic risk factors to provide a complete genetic picture of the disorder.