Ras-MAPK signaling promotes trophectoderm formation from embryonic stem cells and mouse embryos

In blastocyst chimeras, embryonic stem (ES) cells contribute to embryonic tissues but not extraembryonic trophectoderm. Conditional activation of HRas1(Q61L) in ES cells in vitro induces the trophectoderm marker Cdx2 and enables derivation of trophoblast stem (TS) cell lines that, when injected into blastocysts, chimerize placental tissues. Erk2, the downstream effector of Ras-mitogen-activated protein kinase (MAPK) signaling, is asymmetrically expressed in the apical membranes of the 8-cell-stage embryo just before morula compaction. Inhibition of MAPK signaling in cultured mouse embryos compromises Cdx2 expression, delays blastocyst development and reduces trophectoderm outgrowth from embryo explants. These data show that ectopic Ras activation can divert ES cells toward extraembryonic trophoblastic fates and implicate Ras-MAPK signaling in promoting trophectoderm formation from mouse embryos.     

A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder of skeletal malformations and progressive extraskeletal ossification. We mapped FOP to chromosome 2q23-24 by linkage analysis and identified an identical heterozygous mutation (617G --> A; R206H) in the glycine-serine (GS) activation domain of ACVR1, a BMP type I receptor, in all affected individuals examined. Protein modeling predicts destabilization of the GS domain, consistent with constitutive activation of ACVR1 as the underlying cause of the ectopic chondrogenesis, osteogenesis and joint fusions seen in FOP.     

Long-range polony haplotyping of individual human chromosome molecules

We report a method for multilocus long-range haplotyping on human chromosome molecules in vitro based on the DNA polymerase colony (polony) technology. By immobilizing thousands of intact chromosome molecules within a polyacrylamide gel on a microscope slide and performing multiple amplifications from single molecules, we determined long-range haplotypes spanning a 153-Mb region of human chromosome 7 and found evidence of rare mitotic recombination events in human lymphocytes. Furthermore, the parallel nature of DNA polony technology allows efficient haplotyping on pooled DNAs from a population on one slide, with a throughput three orders of magnitudes higher than current molecular haplotyping methods. Linkage disequilibrium statistics established by our pooled DNA haplotyping method are more accurate than statistically inferred haplotypes. This haplotyping method is well suited for candidate gene-based association studies as well as for investigating the pattern of recombination in mammalian cells.     

Fossil evidence for the escalation and origin of marine mutualisms

Mutualism is an interactive, mutually beneficial relationship between two or rarely more unrelated taxa. It is ubiquitous in most environments. In the marine environment it is most likely to occur in shallow marine, oligotrophic regions, the open marine photic zone and oxygen-limited environments. Whereas the eukaryote cell is of some antiquity, other mutualisms may have been acquired during the Phanerozoic. The fossil record provides inferential evidence for the minimum time of origin and occurrence of mutualisms. This suggests that a variety of mutualisms may have occurred during the Palaeozoic with most apparently being terminated by the Permian mass extinction. Tracing back the origin of extant mutualisms suggests that the majority of these began in the Mesozoic or Cenozoic and indicate an increase to the present day. Whether the increase in mutualisms is a product of increased biodiversity or whether mutualisms may have partly driven biodiversity is unclear.     

New records of rare deep-water fish species in the Eastern Ionian Sea (Mediterranean Sea)

We report new species records and information related to meristic, morphometric, bathymetric and biological characteristics that increase our knowledge of the deep ichthyofauna of the Ionian Sea (E. Mediterranean). The material was collected with long lines from 300 to 800 m deep in the Eastern Ionian Sea in June and October 2010. The fish species Schedophilus ovalis (Cuvier, 1833) (Osteichthyes: Centrolophidae), Sudis hyalina Rafinesque, 1810 (Osteicthyes: Paralepididae), Brama brama (Bonnaterre, 1788) (Osteichthyes: Bramidae) and Trachipterus trachypterus (Gmelin, 1789) (Osteichthyes: Trachipteridae) were recorded for the first time in the Eastern Ionian Sea. The absence of these new or rare species from the ichthyofauna of the study area to date is probably related to the absence of adequate sampling and catching techniques, although environmental factors could also be involved.     

Capacity allocation and coordination issues for the timely processing of outsourced operations

We consider dynamic capacity booking problems faced by multiple manufacturers each outsourcing certain operations to a common third-party firm. Each manufacturer, upon observing the current state of the third-party schedule, books capacity with the objective to jointly minimize holding costs that result from early deliveries, tardiness penalties due to late deliveries, and third-party capacity booking costs. When making a reservation, each manufacturer evaluates two alternative courses of action： （i） reserving capacity not yet utilized by other manufactures who booked earlier; or （ii） forming a coalition with a subset or all of other manufacturers to achieve a schedule minimizing coalition costs, i.e., a centralized schedule for that coalition. The latter practice surely benefits the coalition as a whole; however, some manufacturers may incur higher costs if their operations are either pushed back too much, or delivered too early. For this reason, a cost allocation scheme making each manufacturer no worse than they would be when acting differently （i.e., participating in a smaller coalition or acting on their own behalf,） must accompany centralized scheduling for the coalition. We model this relationship among the manufacturers as a cooperative game with transferable utility, and present optimal and/or heuristic algorithms to attain individually and eoalitionally optimal schedules as well as a linear program formulation to find a core allocation of the manufacturers＇ costs.     

Morphological and molecular separation between Macrocamptoptera grangeri Soyka and M. metotarsa (Girault) (Hymenoptera: Mymaridae)

ABSTRACT

Based on morphological and molecular evidence, the European fairyfly Herulia sundholmi Hedqvist syn. n. (Hymenoptera: Mymaridae) is removed from previous synonymy with the Nearctic Macrocamptoptera metotarsa (Girault), and synonymised with the Palaearctic M. grangeri Soyka, which is newly recorded from Georgia, Slovakia and Spain. Macrocamptoptera bulagarica (Donev) syn. n., known from Bulgaria and Italy, is also synonymised with M. grangeri. An updated key to females of the three currently recognised species of the rarely collected genus Macrocamptoptera Girault is given.