Phylogenetic evidence for the herbaceous origin of angiosperms

The ancestral angiosperm is commonly interpreted as an arborescent to shrubby magnolialean with large, multiparted, complex flowers. We examined this hypothesis using a phylogenetic analysis of new and reevaluated characters polarizabled with outgroup comparison. Our cladistic analysis of basal angiosperms placed the nonmagnolialeanChloranthaceae andPiperaceae at the bottom of the tree. We further inferred the probable ancestral states of characters not polarizable with outgroup comparison by examining their distribution among taxa at the base of our cladogram. The sum of ancestral character states suggests that the protoangiosperm was a diminutive, rhizomatous to scrambling perennial herb, with small, simple flowers.     

Nullisomic deletion of the mcf.2 transforming gene in two haemophilia B patients.

The mcf.2 transforming gene sequence has been located to the region between 29 and 61 kb 3' of the factor IX gene. Two unrelated haemophilia B patients who raise antibodies to infused factor IX ('inhibitors') have deletions in excess of 273 kb encompassing the factor IX and mcf.2 genes and a CG-rich island. We believe these patients show the first nullisomic deletion of a transforming gene to be reported. No clinical condition can be attributed to the loss of the mcf.2 gene.     

PPCMatrix: a PowerPC dotmatrix program to compare large genomic sequences against protein sequences

Summary : An interactive dotmatrix program for the MacOS was designed that allows comparison of DNA to protein sequences using nested 3-frame translations. Availability : Shareware, available at http://copan.bioz.unibas.ch/software/ Contact : burglin@ubaclu. unibas.ch      

Polymorphism in intron 1 of the interferon-gamma gene influences both serum immunoglobulin E levels and the risk for chronic hepatitis B virus infection in Polynesians

Intron 1 of the interferon-gamma (IFNG) gene contains two polymorphisms. The 12 CA-repeat allele of the +875 IFNGCA microsatellite and the T allele of the +A874T single nucleotide polymorphism (SNP) have been associated with increased in vitro IFNG production and a variety of clinical phenotypes. The purpose of this study was to determine whether these polymorphisms influence total serum IgE levels [tsIgE] and the outcome of a hepatitis B virus (HBV) infection. IFNGCA and +A874T were typed in 186 asthmatics of Niuean ancestry and in Polynesian women with a chronic HBV infection (n = 60) and with natural immunity to the HBV (n = 66). The IFNGCA genotype was associated with [tsIgE] in asthmatic children (n = 51, p = 0.004) but not adults (n = 135, p = 0.87). The data were consistent with a co-dominant influence of the 12 CA-repeat allele on high [tsIgE]. The IFNGCA genotype was also associated with the risk for chronic HBV infection (χ ² = 11.6, p = 0.003) because of a dominant effect of the 12 CA-repeat allele on developing natural immunity in homozygotes (OR = 5.8, p = 0.003) and heterozygotes (OR = 2.7, p = 0.01). Similar associations were found for the T allele of the +A874T SNP. The possibility that these associations were due to linked alleles in the adjacent 783 bp of the promoter and 3′-untranslated region of the IFNG gene was excluded by direct sequencing. In summary, high-IFNG-producing alleles in intron 1 of the IFNG locus are associated with high [tsIgE] in asthmatic children from Niue and with natural immunity to the HBV in Polynesian women. These findings are consistent with a previous report of an association between +875 IFNGCA and [tsIgE] and provide preliminary evidence of a new association with the outcome of an HBV infection.     

A new marsilealean fern species from the Early Cretaceous of Jordan

Leaflets of Marsileaceae are described from the Albian (Early Cretaceous) strata of Jordan. The fossils are from the Jarash Formation (Kurnub Group) and are found in fluvial sediments along with water lily leaves. The small wedge-shaped leaves have dichotomous veins that anastomose and form a marginal vein. Based on comparisons to living genera, Marsileaceaephyllum mahisensis Hu, Taylor, Brenner et Basha, n. sp., is most similar to Marsilea, in particular, with terrestrial leaflet forms; yet, it is distinct from living and fossil species by its small size and the few dichotomously branched middle veins that have a monopodial course. In addition, a single similar-veined smaller leaf with a retuse apex is thought to be a juvenile leaf of the same species. This is the first megafossil evidence of the family from Africa/Arabian Peninsula.