Evidence for reopening of the cranial neural tube in mouse embryos treated with cadmium chloride

Use of the whole-embryo culture technique resulted in experimental evidence that the pathogenesis of exencephaly in mouse embryos after cadmium chloride treatment results from reopening of the cranial neural tube.     

Haploinsufficiency of protamine-1 or -2 causes infertility in mice

Protamines are the major DNA-binding proteins in the nucleus of sperm in most vertebrates and package the DNA in a volume less than 5% of a somatic cell nucleus. Many mammals have one protamine, but a few species, including humans and mice, have two. Here we use gene targeting to determine if the second protamine provides redundancy to an essential process, or if both protamines are necessary. We disrupted the coding sequence of one allele of either Prm1 or Prm2 in embryonic stem (ES) cells derived from 129-strain mice, and injected them into blastocysts from C57BL/6-strain mice. Male chimeras produced 129-genotype sperm with disrupted Prm1 or Prm2 alleles, but failed to sire offspring carrying the 129 genome. We also found that a decrease in the amount of either protamine disrupts nuclear formation, processing of protamine-2 and normal sperm function. Our studies show that both protamines are essential and that haploinsufficiency caused by a mutation in one allele of Prm1 or Prm2 prevents genetic transmission of both mutant and wild-type alleles.     

Binocular vision and image location before Kepler

Archive for History of Exact Sciences - Kepler’s 1604 Optics (Ad Vitellionem Paralipomena) proposed among many other things a new way of locating the place of the image under reflection or...     

IFITM3 restricts the morbidity and mortality associated with influenza

The 2009 H1N1 influenza pandemic showed the speed with which a novel respiratory virus can spread and the ability of a generally mild infection to induce severe morbidity and mortality in a subset of the population. Recent in vitro studies show that the interferon-inducible transmembrane (IFITM) protein family members potently restrict the replication of multiple pathogenic viruses. Both the magnitude and breadth of the IFITM proteins' in vitro effects suggest that they are critical for intrinsic resistance to such viruses, including influenza viruses. Using a knockout mouse model, we now test this hypothesis directly and find that IFITM3 is essential for defending the host against influenza A virus in vivo. Mice lacking Ifitm3 display fulminant viral pneumonia when challenged with a normally low-pathogenicity influenza virus, mirroring the destruction inflicted by the highly pathogenic 1918 'Spanish' influenza. Similar increased viral replication is seen in vitro, with protection rescued by the re-introduction of Ifitm3. To test the role of IFITM3 in human influenza virus infection, we assessed the IFITM3 alleles of individuals hospitalized with seasonal or pandemic influenza H1N1/09 viruses. We find that a statistically significant number of hospitalized subjects show enrichment for a minor IFITM3 allele (SNP rs12252-C) that alters a splice acceptor site, and functional assays show the minor CC genotype IFITM3 has reduced influenza virus restriction in vitro. Together these data reveal that the action of a single intrinsic immune effector, IFITM3, profoundly alters the course of influenza virus infection in mouse and humans.     

A proteome-wide screen identifies valosin-containing protein as an essential regulator of podocyte endoplasmic reticulum stress

To investigate proteins expressed in the renal tissue of the passive Heymann nephritis (pHN) rat model,we prepared pHN rat models with anti-FxA1 serum and analyzed the proteins differentially expressed in the kidney tissue with label-free liquid chromatography-tandem mass spectrometry.We then analyzed in depth the endoplasmic reticulum stress (ERS)-related protein using an online bioinformatics platform.Forty-one differential proteins and their annotations were obtained.Gene Ontology (GO) function analysis showed that 16 proteins were involved in cellular metabolism and 22 were proteins related to catalytic activity,including protein folding or ATPase.Protein-GO networks indicated that VCP could interact with the ERS marker HSPa5,with both involved in a single pathway.On inhibition of podocyte VCP by RNAi under normal conditions,the HSPa5 expression level did not change,but when the cell was subjected to ERS by tunicamycin,HSPa5 expression significantly increased with RNAi of VCP when compared with the tunicamycin-treated group.Our results showed that ERS plays an important role in podocyte injury of membranous nephropathy and is mediated by an HSPa5-VCP signaling pathway,in which the most predominant proteins are those related to cellular metabolism and catalytic activity.     

A new genus and four new species of onchidiid slugs from South-East Asia (Mollusca: Gastropoda: Pulmonata: Onchidiidae)

The taxonomy of the Onchidiidae has remained extremely confusing for decades. As part of an on-going systematic revision of the entire family, a new genus, Melayonchis Dayrat and Goulding gen. nov., and four new species (Melayonchis eloisae Dayrat sp. nov., Melayonchis siongkiati Dayrat and Goulding sp. nov., Melayonchis annae Dayrat sp. nov., and Melayonchis aileenae Dayrat and Goulding sp. nov.) are described. Species are delineated using an integrative approach, based on morphological characters and DNA sequences. First-hand field observations and pictures of live animals are provided in order to help future species identification. All four Melayonchis species live in mangrove forests. The geographic distribution of Melayonchis ranges from the Andaman Sea to the South China Sea through the Strait of Malacca. Records are based on entirely new collections from the Andaman Islands, Peninsular Malaysia, Singapore, Brunei Darussalam and Vietnam. The nomenclature of all existing onchidiid species- and genus-group names from that region is addressed, as well as intraspecific character variation within Melayonchis.

www.zoobank.org/urn:lsid:zoobank.org:pub:671922DB-C6C1-44A5-B2CD-A3A3127CB668     

Thomas Harriot’s optics,between experiment and imagination: the case of Mr Bulkeley’s glass

Some time in the late 1590s, the Welsh amateur mathematician John Bulkeley wrote to Thomas Harriot asking his opinion about the properties of a truly gargantuan (but totally imaginary) plano-spherical convex lens, 48 feet in diameter. While Bulkeley’s original letter is lost, Harriot devoted several pages to the optical properties of “Mr Bulkeley his Glasse” in his optical papers (now in British Library MS Add. 6789), paying particular attention to the place of its burning point. Harriot’s calculational methods in these papers are almost unique in Harriot’s optical remains, in that he uses both the sine law of refraction and interpolation from Witelo’s refraction tables in order to analyze the passage of light through the glass. For this and other reasons, it is very likely that Harriot wrote his papers on Bulkeley’s glass very shortly after his discovery of the law and while still working closely with Witelo’s great Optics; the papers represent, perhaps, his very first application of the law. His and Bulkeley’s interest in this giant glass conform to a long English tradition of curiosity about the optical and burning properties of large glasses, which grew more intense in late sixteenth-century England. In particular, Thomas Digges’s bold and widely known assertions about his father’s glasses that could see things several miles distant and could burn objects a half-mile or further away may have attracted Harriot and Bulkeley’s skeptical attention; for Harriot’s analysis of the burning distance and the intensity of Bulkeley’s fantastic lens, it shows that Digges’s claims could never have been true about any real lens (and this, I propose, was what Bulkeley had asked about in his original letter to Harriot). There was also a deeper, mathematical relevance to the problem that may have caught Harriot’s attention. His most recent source on refraction—Giambattista della Porta’s De refractione of 1593—identified a mathematical flaw in Witelo’s cursory suggestion about the optics of a lens (the only place that lenses appear, however fleetingly, in the writings of the thirteenth-century Perspectivist authors). In his early notes on optics, in a copy of Witelo’s optics, Harriot highlighted Witelo’s remarks on the lens and della Porta’s criticism (which he found unsatisfactory). The most significant problem with Witelo’s theorem would disappear as the radius of curvature of the lens approached infinity. Bulkeley’s gigantic glass, then, may have provided Harriot an opportunity to test out Witelo’s claims about a plano-spherical glass, at a time when he was still intensely concerned with the problems and methods of the Perspectivist school.     

Evidence for reopening of the cranial neural tube in mouse embryos treated with cadmium chloride

Summary Use of the whole-embryo culture technique resulted in experiemtal evidence that the pathogenesis of exencephaly in mouse embryos after cadmium chloride treatment results from reopening of the cranial neural tube.