A molecular genetic linkage map of mouse chromosome 18 reveals extensive linkage conservation with human chromosomes 5 and 18

An interspecific backcross between C57BL/6J and Mus spretus was used to generate a molecular genetic linkage map of mouse chromosome 18 that includes 23 molecular markers and spans approximately 86% of the estimated length of the chromosome. The Apc, Camk2a, D18Fcr1, D18Fcr2, D18Leh1, D18Leh2, Dcc, Emb-rs3, Fgfa, Fim-2/Csfmr, Gnal, Grl-1, Grp, Hk-1rs1, Ii, Kns, Lmnb, Mbp, Mcc, Mtv-38, Palb, Pdgfrb, and Tpl-2 genes were mapped relative to each other in one interspecific backcross. A second interspecific backcross and a centromere-specific DNA satellite probe were used to determine the distance of the most proximal chromosome 18 marker to the centromere. The interspecific map extends the known regions of linkage homology between mouse chromosome 18 and human chromosomes 5 and 18 and identifies a new homology segment with human chromosome 10p. It also provides molecular access to many regions of mouse chromosome 18 for the first time.     

Assignment of a novel protein tyrosine phosphatase gene (Hcph) to mouse chromosome 6.

Hematopoietic cell phosphatase (Hcph) was identified by amplification of conserved protein tyrosine phosphatase sequences from a myeloid cell line and is predominantly expressed in hematopoietic cells. Hcph is unique in containing two, tandemly repeated, src-homology 2 domains in the amino terminal region of the phosphatase. Using a genomic probe in interspecific backcross analysis, the murine Hcph gene maps to mouse Chromosome 6 and is tightly linked to the Tnfr-2 and Ly-4 genes.     

Localization of the human gene allowing infection by gibbon ape leukemia virus to human chromosome region 2q11-q14 and to the homologous region on mouse chromosome 2.

Retrovirus receptors remain a largely unexplored group of proteins. Of the receptors which allow infection of human and murine cells by various retroviruses, only three have been identified at the molecular level. These receptors include CD4 for human immunodeficiency virus, Rec-1 for murine ecotropic virus, and GLVR1 for gibbon ape leukemia virus. These three proteins show no homology to one another at the DNA or protein level. Therefore, work to date has not shown any general relationship or structural theme shared by retroviral receptors. Genes for two of these receptors (CD4 and Rec-1) and several others which have not yet been cloned have been localized to specific chromosomes. In order to assess the relationship between GLVR1 and other retroviral receptors, we mapped the chromosome location of GLVR1 in human and mouse. GLVR1 was found to map to human chromosome 2q11-q14 by in situ hybridization and somatic-cell hybrid analysis. This location is distinct from those known for receptors for retroviruses infecting human cells. Glvr-1 was then mapped in the mouse by interspecies backcrosses and found to map to chromosome 2 in a region of linkage conservation with human chromosome 2. This mouse chromosome carries Rec-2, the likely receptor for M813, a retrovirus derived from a feral Asian mouse. These data raise the interesting possibility that Rec-2 and Glvr-1 are structurally related.     

Effect of treatment with glutaraldehyde-fixed myelin basic protein-liposomes on active induction and passive transfer of experimental allergic encephalomyelitis in Lewis rats

Guinea pig myelin basic protein (MBP)-liposomes were prepared and fixed with 0.2% glutaraldehyde (GA). Lewis rats were treated with glutaraldehyde-fixed MBP-liposomes (MBP-L-GA) or with cytochrome-c-liposomes (CYC-L-GA), 7 days before and 7 days after challenge with MBP in CFA. Rats treated with MBP-L-GA, but not with CYC-L-GA, were very well protected against the clinical manifestations of EAE. The protection was better than that obtained after treatment with conventional MBP-liposomes (without glutaraldehyde). Furthermore, when grown in vitro for 72 hr in the presence of MBP, lymphocytes from rats treated with MBP-L-GA and challenged with MBP in CFA exhibited a marked decrease in their ability to transfer EAE to normal syngeneic recipients.     

Vernonia galamensis,Potential new crop source of epoxy acid

Vernonia galamensis is a good source of seed oil rich in epoxy acid, which can be used to manufacture plastic formulations, protective coatings, and other products. Seed from a natural stand in Ethiopia contained 31% epoxy acid. Under cultivation in Kenya, this unimproved germplasm produced a substantial yield of seed with 32% epoxy acid. This African species has good natural seed retention and is a promising new crop for semiarid tropical areas.     

Pollen flow in Psiguria warscewiczii: a comparison of Heliconius butterflies and hummingbirds

Summary Pollen dispersal by male and female Heliconius butterflies and hermit hummingbirds was examined in a natural population of the tropical vine Psiguria warscewiczii. Fluorescent dyes were used to track flowers visited by individual pollinators. Mean distance of pollen dispersal was significantly higher by males than by female Heliconius. Butterflies dispersed pollen greater distances than did hummingbirds. There were no significant differences in dispersal distance among species of Heliconius. The number of flowers or plants to which dye was dispersed was greater for Heliconius than for hummingbirds.The home range behavior and site specificity exhibited by Heliconius, together with the preference by most Heliconius species in the study site for Psiguria led us to examine the relationship between the butterflies' home range and its daily foraging among Psiguria. A Heliconius mark-recapture program was conducted simultaneously with the dye program. This study showed that individual butterflies, for which extensive recaptures were made, visited an area of Psiguria plants on any one day that corresponded to the area in which those butterflies were caught or observed. The area over which a butterfly moved was termed its home range; within home ranges relative movement by butterflies was estimated as the mean distance between sequential captures. This estimate differed significantly among species of Heliconius; males of all species moving greater distances than females.     

Detection of gonadotrophic hormones on isolated thecal interstitial cells of the domestic hen, Gallus domesticus, by an immunohistochemical method

Summary An immunohistochemical method was used to demonstrate the presence of gonadotrophins in isolated ovarian interstitial cells. The cells were obtained by collagenase digestion of large ovarian follicles after removal of the yolk and the granulosa layer. Using a peroxidase-labelled anti-rabbit serum with anti-chicken follicle stimulating hormone (FSH) serum raised in rabbits, a strong positive reaction was obtained. Anti-human FSH serum also produced a positive result but the reaction was weaker. There was no apparent difference in the staining reaction of cells which had been preincubated with ovine FSH serum. Treatment with anti-ovine luteinizing hormone (LH) resulted in a faintly positive reaction.The viability of the cells was tested by the Trypan Blue method and they were identified as steroid-producing cells by the histochemical demonstration of their 3-hydroxysteroid dehydrogenase activity.     

Influence of δ-Opioid Receptors on Production of Labeled Methionine5-Enkephalin in Murine Neuroblastoma Cells

Synthesis of methionine5-enkephalin by intact cells of murine neuroblastoma clone N1E-115 has been demonstrated both immunocytochemically and biochemically. In addition, N1E-115 cells possess homogeneous enkephalin (delta) receptors which inhibit prostaglandin E1-induced intracellular cyclic AMP formation. An assay was developed for measuring de novo synthesis of methionine5-enkephalin by pulsing cells in culture with radioactive methionine and isolating this pentapeptide to radiochemical purity by a procedure that included immunoaffinity chromatography specific for oxidized methionine5-enkephalin. This assay indicated that production of radiolabeled-methionine5-enkephalin was increased upon lengthy exposure of intact N1E-115 cells in the late logarithmic phase of growth to a nonproteolyzable analog of methionine5-enkephalin. This increase in synthesis of intracellular methionine5-enkephalin relative to control cells was prevented by prior incubation of the clone with naloxone, indicating that the response was mediated by the delta receptor.     

Successful transfer of embryos recovered from a cow with chronic cervicitis of mixed aerobic and anaerobic bacterial aetiology a case report

An imported 13-year-old Simmentaler cow was presented with severe purulent cervicitis and endometritis from which Corynebacterium pyogenes , Fusobacterium necrophorum , Bacteroides melaninogenicus and an untyped Clostridium perfringens were isolated. The endometritis responded to treatment but the cervix did not and remained fibrous, continuously patent and purulent. Natural pregnancy was considered unlikely and the cow was prepared as an embryo transfer donor. Eight embryos were recovered and six transferred, resulting in five confirmed pregnancies and four live births.