Transient expression of type 2 chain in A-active hexaglycosylceramide of rat small intestine at weaning time. Demonstration by affinity chromatography and ceramide glycanase hydrolysis of A-active glycosphingolipids followed by gas chromatography and mass spectrometry of permethylated hexasaccharides

The small intestine of 15- to 23-day-old rats was cut into four segments from the duodenum to the ileum. Neutral glycosphingolipids were purified from each segment and submitted to thin-layer chromatography and immunostaining with the A005 monoclonal anti-A antibody. This antibody detected an hexaglycosylceramide located mainly in the duodenum during the postnatal development. In order to characterize hexaglycosylceramides, blood group A-active glycolipids were purified by affinity chromatography on immobilized Helix pomatia lectin in organic solvent. Hexaglycosylceramides (A-6) were subsequently isolated by preparative thin-layer chromatography and hydrolyzed with ceramide glycanase. The free hexasaccharides were permethylated and analyzed by gas chromatography. Two peaks were detected in varying ratios during development, corresponding to type 1 and type 2 chain A hexasaccharides. Gas chromatography clearly demonstrated that type 2 A-6 occurred in the duodenum of developing rats, and that a shift from type 2 to type 1 A-6 occurred with growing age. The change from type 2 to type 1 chain was also assessed by methylation analysis, and by the variation of the characteristic fragmentations of type 1 and type 2 chain hexasaccharides upon mass spectometry of the permethylated A-6 oligosaccharides from the duodenum of 19-day-old and adult rats.     

Processing Pollen and Spore Exines for Electron Microscopy

A resin mixture containing Araldite M, 15 ml; Epon 812, 25 ml; dodecenyl succinic anhydride, 55 ml; and dibutyl phthlate, 2 ml, was found to be the optimal embedding resin for both fresh and acetylated pollen exines. Diamond knives greatly facilitated sectioning. Exine fine structure, and stratification patterns in fresh pollen were most clearly revealed by section staining of glutaraldehyde-fixed (2 hr), OsO₄-stained (2 hr) specimens. Acetylated exines (acetic anhydride-H₂SO₄ 9:1; 100 C, 5 min) did not require additional treatment prior to embedding, but section staining of exines so treated greatly enhanced stain differentiation of exine subunits. Successfully used section stains included Reynold's lead hydroxide, Millonig's lead citrate and aqueous KMnO₄. Additional procedures were tried but were found to have serious disadvantages, e. g. exines treated with KMnO₄ before embedding shattered badly during sectioning.     

NADPH-dependent reductase solubilized from microsomes by peroxidation and its activity

Isolated rat liver microsomes were subjected to enzymatic or non-enzymatic lipid peroxidation $\text{in vitro}$. NADPH-dependent cytochrome $\text{c}$ reductase activity was released from the microsomes into the media during peroxidation. This activity could be recovered from the media by DEAE-cellulose chromatography. The recovered enzyme retained high activity for the reduction of cytochrome $\text{c}$ and a lower level of activity for the reduction of cytochrome P-450. The active fractions were capable of enzymatically supporting the peroxidation of isolated mitochondria in the presence of organically complexed Fe⁺³ and NADPH, and in this respect the specific activity was found to be about ten times higher than in microsomes.     

Phylogenetic placement of pelican spiders (Archaeidae,Araneae), with insight into evolution of the “neck” and predatory behaviours of the superfamily Palpimanoidea

Phylogenetic relationships among archaeid spider lineages, as well as the placement of archaeids within the Araneomorphae, present a problem in the systematics of spiders. We investigate these relationships by broadly sampling taxa from the Araneomorphae and superfamily Palpimanoidea, as well as from extant and fossil archaeid lineages. Using parsimony and Bayesian methods we perform a total‐evidence analysis that includes 126 morphological characters and over 4000 bases from one mitochondrial and three nuclear molecular markers. Phylogenetic analysis results in a delimitation of the superfamily Palpimanoidea to contain five families: Archaeidae, Mecysmaucheniidae, Stenochilidae, Palpimanidae and Huttoniidae. We also find the extant archaeids, which are restricted to the southern hemisphere, to be monophyletic, with the fossil archaeids paraphyletic. This phylogenetic framework is then used to interpret a novel morphological character, the highly modified and elevated cephalic area and elongated chelicerae (jaws), coupled with prey choice observations in the field and observations of chelicerae movements during predatory attacks. We conclude that the evolution of the elevated cephalic area, which reoriented the chelicerae muscles, led to highly manoeuvrable chelicerae and associated novel prey capture strategies. All members of Palpimanoidea appear to have modifications to the cephalic area, such as a diastema or sclerotization around the chelicerae bases, and furthermore, members appear to have evolved prey specialization.     

Restriction fragment length polymorphisms at the heat shock protein HSP70 gene(s) in pigs*

Pigs from a population consisting of eight US breeds or strains and three Chinese breeds were examined by restriction fragment length polymorphism (RFLP) analysis of the heat shock protein HSP70 gene(s). Limited polymorphisms with PstI and PvuII restriction enzymes were observed, but there were no polymorphisms with BomIII and BglI.