Human Y‐chromosome short tandem repeats: A tale of acculturation and migrations as mechanisms for the diffusion of agriculture in the Balkan Peninsula

Southeastern Europe and, particularly, the Balkan Peninsula are especially useful when studying the mechanisms responsible for generating the current distribution of Paleolithic and Neolithic genetic signals observed throughout Europe. In this study, 404 individuals from Montenegro and 179 individuals from Serbia were typed for 17 Y‐STR loci and compared across 9 Y‐STR loci to geographically targeted previously published collections to ascertain the phylogenetic relationships of populations within the Balkan Peninsula and beyond. We aim to provide information on whether groups in the region represent an amalgamation of Paleolithic and Neolithic genetic substrata, or whether acculturation has played a critical role in the spread of agriculture. We have found genetic markers of Middle Eastern, south Asian and European descent in the area, however, admixture analyses indicate that over 80% of the Balkan gene pool is of European descent. Altogether, our data support the view that the diffusion of agriculture into the Balkan region was mostly a cultural phenomenon although some genetic infiltration from Africa, the Levant, the Caucasus, and the Near East has occurred. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Temtamy preaxial brachydactyly syndrome is caused by loss-of-function mutations in chondroitin synthase 1, a potential target of BMP signaling

Altered Bone Morphogenetic Protein (BMP) signaling leads to multiple developmental defects, including brachydactyly and deafness. Here we identify chondroitin synthase 1 (CHSY1) as a potential mediator of BMP effects. We show that loss of human CHSY1 function causes autosomal-recessive Temtamy preaxial brachydactyly syndrome (TPBS), mainly characterized by limb malformations, short stature, and hearing loss. After mapping the TPBS locus to chromosome 15q26-qterm, we identified causative mutations in five consanguineous TPBS families. In zebrafish, antisense-mediated chsy1 knockdown causes defects in multiple developmental processes, some of which are likely to also be causative in the etiology of TPBS. In the inner ears of zebrafish larvae, chsy1 is expressed similarly to the BMP inhibitor dan and in a complementary fashion to bmp2b. Furthermore, unrestricted Bmp2b signaling or loss of Dan activity leads to reduced chsy1 expression and, during epithelial morphogenesis, defects similar to those that occur upon Chsy1 inactivation, indicating that Bmp signaling affects inner-ear development by repressing chsy1. In addition, we obtained strikingly similar zebrafish phenotypes after chsy1 overexpression, which might explain why, in humans, brachydactyly can be caused by mutations leading either to loss or to gain of BMP signaling.     

Low pH dye decolorization with ascomycete Lamprospora wrightii laccase

In a screening of saprotrophic, ectomycorrhizal and plant pathogen ascomycetes a frequent occurrence of laccase was observed. Lamprospora wrightii, the best producing organism, was chosen to elucidate the properties of a laccase from a moss-associated, saprotrophic ascomycete. The expression of laccase by this bryophilic fungus could be increased by the addition of tomato juice or copper sulfate to the medium. The obtained volumetric activity after optimization was 420 U/mL in either shaking flask or bioreactor-based cultivations. The purified laccase has a molecular mass of 68 kDa and an isoelectric point of 3.4. Although of ascomycete origin, its catalytic properties are similar to typical basidiomycte laccases, and an excellent activity and stability was observed at low pH, which makes it suitable for bioremediation in acidic environments. As an example, the decolorization reactions of azo-, anthraquinone-, trimethylmethane- and indigoid dyes at pH 3.0 and 5.0 were investigated. All ten selected dyes were decolorized, five of them very efficiently. Depending on the dye, the decolorization was found to be a combination of two reactions, degradation of the chromophore and formation of polymerized products, which contributed to the overall process in a dye-specific pattern.     

Precipitation magnitude and timing differentially affect species richness and plant density in the sotol grassland of the Chihuahuan Desert

Arid and semi-arid environments are dynamic ecosystems with highly variable precipitation, resulting in diverse plant communities. Changes in the timing and magnitude of precipitation due to global climate change may further alter plant community composition in desert regions. In this study, we assessed changes in species richness and plant density at the community, functional group, and species level in response to variation in the magnitude of natural seasonal precipitation and 25% increases in seasonal precipitation [e.g., supplemental watering in summer, winter, or summer and winter (SW)] over a 5-year period in a sotol grassland in the Chihuahuan Desert. Community species richness was higher with increasing winter precipitation while community plant density increased with greater amounts of winter and summer precipitation, suggesting winter precipitation was important for species recruitment and summer precipitation promoted growth of existing species. Herb and grass density increased with increasing winter and summer precipitation, but only grass density showed a significant response to supplemental watering treatments (SW treatment plots had higher grass density). Shrubs and succulents did not exhibit changes in richness or density in response to natural or supplemental precipitation. In this 5-year study, changes in community species richness and density were driven by responses of herb and grass species that favored more frequent small precipitation events, shorter inter-pulse duration, and higher soil moisture. However, due to the long life spans of the shrub and succulent species within this community, 5 years may be insufficient to accurately evaluate their response to variable timing and magnitude of precipitation in this mid-elevation grassland.     

A genetic map of melon highly enriched with fruit quality QTLs and EST markers, including sugar and carotenoid metabolism genes

A genetic map of melon enriched for fruit traits was constructed, using a recombinant inbred (RI) population developed from a cross between representatives of the two subspecies of Cucumis melo L.: PI 414723 (subspecies agrestis) and ‘Dulce’ (subspecies melo). Phenotyping of 99 RI lines was conducted over three seasons in two locations in Israel and the US. The map includes 668 DNA markers (386 SSRs, 76 SNPs, six INDELs and 200 AFLPs), of which 160 were newly developed from fruit ESTs. These ESTs include candidate genes encoding for enzymes of sugar and carotenoid metabolic pathways that were cloned from melon cDNA or identified through mining of the International Cucurbit Genomics Initiative database (http://www.icugi.org/). The map covers 1,222 cM with an average of 2.672 cM between markers. In addition, a skeleton physical map was initiated and 29 melon BACs harboring fruit ESTs were localized to the 12 linkage groups of the map. Altogether, 44 fruit QTLs were identified: 25 confirming QTLs described using other populations and 19 newly described QTLs. The map includes QTLs for fruit sugar content, particularly sucrose, the major sugar affecting sweetness in melon fruit. Six QTLs interacting in an additive manner account for nearly all the difference in sugar content between the two genotypes. Three QTLs for fruit flesh color and carotenoid content were identified. Interestingly, no clear colocalization of QTLs for either sugar or carotenoid content was observed with over 40 genes encoding for enzymes involved in their metabolism. The RI population described here provides a useful resource for further genomics and metabolomics studies in melon, as well as useful markers for breeding for fruit quality.