Twenty-five loci form a continuous linkage map of markers for human chromosome 7

We have constructed a primary genetic linkage map from DNA markers that define 25 loci on chromosome 7. The markers form a continuous linkage group of 141 cM in males and 340 cM in females; female genetic distances were on average more than twofold higher than those in males throughout the chromosome. The average heterozygosity of the loci was 45%. A subset of the markers can be used for efficient application of this map to studies of human genetic disease.     

Mitochondrial behaviour during the yeast-hypha transition of Candida albicans

Yeast cells of Candida albicans were brought to germ tube formation and hyphal growth in liquid synthetic medium. The behaviour of mitochondria and mitochondrial nucleoids (mt-nucleoids) during morphological conversion was examined by fluorescence staining with 2-(4-dimethylaminostyryl)-1-methylpyridinium iodide (DASPMI) and 4',6-diamidino-2-phenylindole (DAPI). Parent yeast cells possessed one or very few branched giant mitochondria which were stained intensely with DASPMI. When a germ tube emerged from the parent cell, one end of a giant mitochondrion extended into the germ tube and developed into the elongated form. In mycelia, apical hyphal cells contained giant mitochondria, whereas older hyphal compartments near the parent cells were vacuolated and possessed small, peripherally located mitochondria. The vacuolated hyphal compartments resynthesized cytoplasm before producing branches and contained giant mitochondria. The cytological model for germ tube formation and hyphal growth proposed by Gow and Gooday (1984) is discussed.     

Comparative investigation of vitamins and their analogues on terminal differentiation, from preadipocytes to adipocytes, of 3T3-L1 cells

1. The effects of 20 kinds of vitamins or their analogues on the growth rate of preadipocytes and the terminal differentiation of preadipocytes to adipocytes was systematically compared in 3T3-L1 cells. 2. The addition of vitamin C markedly increased the growth rate of preadipocytes at over 50 microM. 3. The addition of vitamin K3 slowed down the growth rate at over 0.1 microM. 4. In water soluble vitamins and their analogues tested, the vitamin B6 group and vitamin C significantly stimulated the differentiation, and consequently increased the glycerophosphate dehydrogenase activity and triglyceride accumulation, to a concentration of over 10 microM. 5. Many fat soluble vitamins and their analogues (the vitamin A group, including beta-carotene, the vitamin D group, vitamin E and the vitamin K group) strongly inhibited the adipose conversion of 3T3-L1 cells at microM level.     

Appearance of parvalbumin-specific immunoreactivity in the cerebral cortex and hippocampus of the developing rat and gerbil brain

Developmental changes in the distribution of parvalbumin-specific immunoreactivity in the brain, in particular in the cerebral cortex and hippocampus, were followed immunohistochemically in two different species, the rat and the Mongolian gerbil (Meriones unguiculatus) using an antibody raised against for rat parvalbumin. The gerbil is known to develop its auditory and visual capacity later than rat. In both the rat and gerbil, parvalbumin-specific immunoreactivity appeared after birth in both the cerebral cortex and hippocampus. The timing of the development of expression of parvalbumin varied among different parts of the cerebral cortex. The parietal cortex showed evidence of the earliest expression of parvalbumin whilst the occipital and temporal cortices expressed parvalbumin at a later stage of a development. This feature was common to both the rat and gerbil but occurred at a relatively later stage in the gerbil. The profile of the distribution of parvalbumin in the brain of the developing and adult gerbil was similar to that of the rat, but there were some differences. The frequency of bead-like structures on the dendrites of the parvalbumin-positive cells in the CA1 region of the hippocampus was markedly lower in the gerbil; instead, straight non-beaded fibers which ran vertically into the pyramidal layer were stained. Parvalbumin-positive fibers were also found in the cerebral cortex of the gerbil.     

Molecular nature of chromosome 5q loss in colorectal tumors and desmoids from patients with familial adenomatous polyposis

Summary Familial adenomatous polyposis (FAP), which includes familial polyposis coli (FPC) and the Gardner syndrome (GS), is a genetically determined premalignant disease of the colon inherited by a locus (APC) mapping within 5q15–q22. To elucidate the role of 5q loss in FAP tumorigenesis, we analysed 51 colorectal tumors and seven desmoids from 19 cases of FPC and five GS patients, as well as 15 sporadic colon cancers. RFLP analysis revealed a high incidence of allelic deletion in hereditary colon cancers as well as in sporadic colon cancers with a peak at the APC locus. APC loss resulted primarily from interstitial deletion or mitotic recombination. Combined tumor and pedigree analysis in a GS family revealed loss of normal 5q alleles in three tumors, including a desmoid tumor, which suggests the involvement of hemizygosity or homozygosity of the defective APC gene in colon carcinogenesis and, possibly, in extracolonic neoplasms associated with FAP.     

Bioconcentration and excretion of diazinon, IBP, malathion and fenitrothion by carp

1. Bioconcentration and excretion of diazinon, IBP, malathion and fenitrothion were studied for carp (Cyprinus carpio L.). 2. The concentrations of these pesticides in muscle and viscera of the carp reached plateaus in 12-48 hr exposure. 3. The average values of bioconcentration factors (BCF) for diazinon were 20.9 in muscle, 60.0 in liver, 111.1 in kidney and 32.2 in gallbladder over the 168 hr exposure period. Similarly, those values were 4.3-26.7 for IBP, 2.7-17.3 for malathion, and 36.0-157.1 for fenitrothion. 4. The excretion rate constants of malathion (hr-1) were 0.13 for muscle, 0.12 for liver, 0.08 for kidney and 0.06 for gallbladder. Those of diazinon, IBP and fenitrothion (g.ng-1.hr-1) were 0.002-0.024 for muscle, 0.001-0.020 for liver, 0.0004-0.004 for kidney and 0.002-0.023 for gallbladder, respectively.     

Urea denaturation of bovine serum albumin at pH 9

The action of 5 m urea on bovine serum albumin has been studied at pH 9.0 and 25°C. Analysis by the acrylamide gel electrophoresis revealed the presence of a few components 1, 1′, 2, 3, 4 and 5. The components 1 and 1′ are monomers, component 2 is a dimer, and components 3, 4 and 5 are aggregates. In presence of SH blocking reagent, bovine serum albumin gave only the zone 1, indicating that the components 1′-5 were formed by the SH to S-S exchange reactions. Component 1′ was formed by the intramolecular SH to S-S exchange reaction, and components 2–5 were formed by the intermolecular exchange reaction. Addition of cysteine either to bovine serum albumin or to the SH-blocked bovine serum albumin increased the percent of zone 1′, indicating that a complex bovine serum albumin-cysteine was formed or that the SH-catalyzed structural alteration occurred in bovine serum albumin. Components 1, 1′, 2 and 3 were isolated separately by the preparative disc gel electrophoresis. The sedimentation coefficients 1 and 1′ differed slightly indicating that they were different monomers, and values were slightly smaller than the normal value of bovine serum albumin, indicating that these components were in slightly expanded state. Isolated component 1 was exposed to 5 m urea again, but no further change occurred. This supports the concept of microheterogeneity of bovine serum albumin.