Genetics Society of America’s GENETICS Journal Highlights for January 2013

Newswise — Bethesda, MD—December 28, 2012 – Listed below are the selected highlights for the January 2013 issue of the Genetics Society of America’s journal, GENETICS. The January issue is available online at www.genetics.org/content/current. Please credit GENETICS, Vol. 193, January 2013, Copyright © 2013. Please feel free to forward to colleagues who may be interested in reporting on these articles.

ISSUE HIGHLIGHTS

Dispensable, redundant, complementary, and cooperative roles of dopamine, octopamine, and serotonin in Drosophila melanogaster, pp. 159–176Audrey Chen, Fanny Ng, Tim Lebestky, Anna Grygoruk, Christine Djapri, Hakeem O. Lawal, Harshul A. Zaveri, Filmon Mehanzel, Rod Najibi, Gabriel Seidman, Niall P. Murphy, Rachel L. Kelly, Larry C. Ackerson, Nigel T. Maidment, F. Rob Jackson, and David E. KrantzMonoamines such as dopamine and serotonin are implicated in multiple neuropsychiatric diseases. Previous studies hint at important interactions between these neurotransmitter systems. These authors inactivated the ability of fruit flies to use any monoamine neurotransmitters, and then added back one system at time. This uncovered unexpected relationships between aminergic neurotransmitter pathways that may aid the development of new neuropsychiatric treatment strategies.

Demographic inference reveals African and European admixture in the North American Drosophila melanogaster population, pp. 291–301Pablo Duchen, Daniel Živković, Stephan Hutter, Wolfgang Stephan, and Stefan LaurentDrosophila melanogaster spread from Africa and adapted to new environments. To find signatures of these adaptive events we need to understand the demography, since demography and selection leave similar patterns in the genome. By using an approximate Bayesian computation method the authors modeled the joint demography of three populations of D. melanogaster from DNA sequence data (next-generation sequencing). They conclude that the North American population was founded by an admixture between an African and a European population, and estimated the admixture proportion. They also found that a population bottleneck fits best the demographic history of the African population.  

Extensive divergence between mating type chromosomes of the anther-smut fungus, pp. 309–315Michael E. Hood, Elsa Petit, and Tatiana GiraudWhile fungi are good models for sex chromosome evolution, we know little about how their mating types influence genetic architecture. This study describes the remarkable degree to which recombination has ceased on the mating-type chromosomes of the anther-smut fungus. With relevance to plant and animal systems, this study calls for a reevaluation of theories and empirical support for sex chromosome evolution.

Genetic variants contribute to gene expression variability in humans, pp. 95–108Amanda M. Hulse and James J. CaiIncreasing evidence suggests that the variance (as opposed to the mean) among phenotypes may be genotype-dependent. Conventional expression quantitative trait loci (eQTL) analysis focuses on the mean, instead of the variance, of gene expression. In this study, the authors perform an analysis that identifies what they describe as expression variability QTL (evQTL)—loci associated with the variances of gene expression among three possible genotypes of a biallelic SNP. They discovered evQTL provide orthogonal information, unavailable in existing eQTL literature, on genetic control of gene expression. The evQTL can act in single-SNP and multiple-SNP effects. Detecting evQTL may represent a novel method for effectively screening for genetic interactions.

Genome reduction promotes increase in protein functional complexity in bacteria, pp. 303–307Yogeshwar D. Kelkar and Howard OchmanThis article provides evidence that organisms with small genomes compensate for gene loss with increased protein multitasking. Kelkar and Ochman compared protein interaction networks of six bacteria and found that proteins encoded by small genomes interact with proteins that have a wider range of functions than do their orthologs from larger genomes. Thus, reduced genomes have increasingly complex functional relationships among the proteins they encode.

Defining the epigenetic mechanism of asymmetric cell division of Schizosaccharomyces japonicus yeast, pp. 85–94Chuanhe Yu, Michael J. Bonaduce, and Amar J. S. KlarThe intrinsic chirality of double helical DNA has the potential to carry genetic information. This group previously demonstrated that indeed it does in the fission yeast Schizosaccharomyces pombe, whose cell type is determined by an epigenetic difference between the DNA strands. They now show that this is also the case for the evolutionarily distant fission yeast S. japonicas. The conservation of this mechanism of inheritance over vast evolutionary time makes one think that DNA-strand–specific epigenetic differences might be responsible for asymmetric cell division in larger eukaryotes.  Processing body and stress granule assembly occur by independent and differentially regulated pathways in Saccharomyces cerevisiae, pp. 109–123Khyati H. Shah, Bo Zhang, Vidhya Ramachandran, and Paul K. HermanCertain mRNAs can be organized into discrete granules in eukary¬otic cells to facilitate their translation, decay, and/or localization. This study offers insights into how assembly of two evolutionarily conserved ribonucleoprotein complexes—the processing body and stress granule—is controlled. This work demonstrates that these complexes are assembled through independent path¬ways and that both complexes have an important role in nondividing, quiescent cells.

ABOUT GENETICS: Since 1916, GENETICS (http://www.genetics.org/) has covered high quality, original research on a range of topics bearing on inheritance, including population and evolutionary genetics, complex traits, developmental and behavioral genetics, cellular genetics, gene expression, genome integrity and transmission, and genome and systems biology. GENETICS, a peer-reviewed, peer-edited journal of the Genetics Society of America is one of the world's most cited journals in genetics and heredity.

ABOUT GSA: Founded in 1931, the Genetics Society of America (GSA) is the professional membership organization for scientific researchers, educators, bioengineers, bioinformaticians and others interested in the field of genetics. Its nearly 5,000 members work to advance knowledge in the basic mechanisms of inheritance, from the molecular to the population level. GSA is dedicated to promoting research in genetics and to facilitating communication among geneticists worldwide through its conferences, including the biennial conference on Model Organisms to Human Biology, an interdisciplinary meeting on current and cutting edge topics in genetics research, as well as annual and biennial meetings that focus on the genetics of particular organisms, including C. elegans, Drosophila, fungi, mice, yeast, and zebrafish. GSA publishes GENETICS, a leading journal in the field and an online, open-access journal, G3: Genes|Genomes|Genetics. For more information about GSA, please visit www.genetics-gsa.org. Also follow GSA on Facebook at facebook.com/GeneticsGSA and on Twitter @GeneticsGSA.