Southern elephant seal (Mirounga leonina) II. Studies of milk protein fractions by gel electrophoresis

 Milk protein fractions during various stages of lactation in the southern elephant seal Mirounga leonina were analysed. Twelve milk samples were taken from ten females throughout the lactation period during 1990 and 1991 at Stranger Point, King George Island, South Shetland Islands. Milk samples were subjected to polyacrylamide gel electrophoresis (PAGE). Samples from different days of lactation gave similar qualitative electrophoretic patterns. True protein content was significantly higher (P<0.05) at the beginning of lactation, and then remained constant until weaning. Caseins and whey proteins each consisted of several protein entities (four and five distinct bands respectively). Casein constituted only about 30% of the protein nitrogen, the remaining 70% being derived from whey proteins. There was some variation in concentration of casein and whey proteins as a function of time (P<0.0.5). Received: 28 July 1993/Accepted: 25 July 1995     

A microspectrofluorometric approach for the study of Benzo(a)pyrene and Dibenzo(a,h)anthracene metabolization in single living cells

Summary The use of a microspectrofluorometer in conjunction with the microelectrophoretic intracellular injection of glycolytic intermediates, for the study of carcinogen metabolization (i.e. Benzo(a)pyrene (BP) and Dibenzo(a, h)anthracene) by single living EL2 ascites cells, has allowed the detection of fluorescence attributable to the metabolites of BP and DBA.The results obtained are in agreement with those yielded by more conventional methods: i.e. in vivo assay and in vitro reconstitution of intracellular environment. Thus, it is observed that NADPH is more active in the metabolization of BP. Furthermore, in the case of BP the fluorescence attributable to a BP metabolite, exhibits a strong similarity to 3-OH benzo(a) pyrene.     

Effect of immunization of ewes against prostaglandin F-2 alpha on the life-span of corpora lutea and oestrous behaviour during two breeding seasons

Two adjuvants, Freund's complete adjuvant (FCA) and GNE (proprietary product; Intervet Ltd, The Netherlands), were used to immunize cyclic Finnish Landrace ewes (4-6/treatment) against a prostaglandin F-2 alpha-human serum albumin (PGF-HSA) conjugate. Ewes were randomized to the following treatments: (a) control-untreated, (b) control-5 mg HSA in FCA (control-HSA), (c) 5 mg PGF-HSA in FCA (FCA-5 mg), (d) 15 mg PGF-HSA in FCA (FCA-15 mg), (e) 5 mg PGF-HSA in GNE (GNE-5 mg) and (f) 15 mg PGF-HSA in GNE (GNE-15 mg). Ewes were monitored for oestrus (twice daily) and ovarian activity (progesterone concentrations in blood samples taken twice weekly) for 2 consecutive breeding seasons. In the first breeding season, the mean number of oestrous periods detected was 6.0, 5.7, 0.0, 0.2, 1.8 and 0.5 in control, control-HSA, FCA-5 mg, FCA-15 mg, GNE-5 mg and GNE-15 mg-assigned ewes, respectively [pooled standard error of difference (s.e.d.) = 1.2]. A persistent CL formed, on average, 10.0, 10.0, 29.8 and 32.5 days after primary immunization (pooled s.e.d. = 14.6) in 6/6 FCA-5 mg, 6/6 FCA-15 mg, 5/6 GNE-5 mg and 4/4 GNE-15 mg-assigned ewes, respectively; these CL were maintained for, on average, 138.7, 139.0, 127.8 and 129.0 days, respectively (pooled s.e.d. = 15.9).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cytogenetic investigations on Werner's syndrome, Acrogeria and Keratosis Palmo-Plantaris

The frequencies of sister chromatid exchanges and of aspecific chromosome aberrations have been investigated in the lymphocytes from a Werner patient, from an Acrogeria patient and from three members of a family with Keratosis Palmo-Plantaris. These investigations point out that: 1) the SCE frequency is significatively enhanced in Werner as in KPP lymphocytes, 2) the frequency of aspecific chromosome aberrations is increased only in Werner lymphocytes, without evidence of variegated translocation mosaicism. The findings confirm that SCE and chromosome aberrations do not necessarily result from the same genetic damage and that SCE may represent the cytological evidence of unexcised non fatal DNA lesions, which occasionally may be responsible for carcinogenesis.     

SARS-CoV-2 spike variants exhibit differential infectivity and neutralization resistance to convalescent or post-vaccination sera

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The Fragaria vesca Homolog of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 Represses Flowering and Promotes Vegetative Growth

In the annual long-day plant Arabidopsis thaliana, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) integrates endogenous and environmental signals to promote flowering. We analyzed the function and regulation of the SOC1 homolog (Fragaria vesca [Fv] SOC1) in the perennial short-day plant woodland strawberry (Fragaria vesca). We found that Fv SOC1 overexpression represses flower initiation under inductive short days, whereas its silencing causes continuous flowering in both short days and noninductive long days, similar to mutants in the floral repressor Fv TERMINAL FLOWER1 (Fv TFL1). Molecular analysis of these transgenic lines revealed that Fv SOC1 activates Fv TFL1 in the shoot apex, leading to the repression of flowering in strawberry. In parallel, Fv SOC1 regulates the differentiation of axillary buds to runners or axillary leaf rosettes, probably through the activation of gibberellin biosynthetic genes. We also demonstrated that Fv SOC1 is regulated by photoperiod and Fv FLOWERING LOCUS T1, suggesting that it plays a central role in the photoperiodic control of both generative and vegetative growth in strawberry. In conclusion, we propose that Fv SOC1 is a signaling hub that regulates yearly cycles of vegetative and generative development through separate genetic pathways.     

MIC-A allele profiles and HLA class I associations in Behçet's disease

Recently a new family of non-classical MHC molecules, the MHC class I chain-related protein (MIC), encoded by genes located in the major histocompatability complex have been identified. On the basis of the location of MIC genes and the structure and expression of MIC molecules it has been postulated that MIC may be a susceptibility factor in Behçet's disease (BD). We investigated the association of the 16 described external domain alleles and the transmembrane triplet repeats of MIC-A with BD in a Middle Eastern population. DNA from ninety-five patients and 102 age- and sex-matched controls were analyzed by polymerase chain reaction using allele specific primers. Our results show an increase of MIC-A*009 in the BD patient group 44/95 (46%) compared with controls 24/102 (24%) (χ²=11.3, OR=2.8, P=0.00078). MIC-A*009 was also found to be strongly associated with HLA-B51 in the patients 39/44 (88%) when compared with controls 10/24 (42%) (χ²=4, P=0.04). MIC-A*009 was also found in linkage disequilibrium with HLA-B52, but only in controls. The A6 form of a MIC-A transmembrane triplet repeat was found to be significantly raised in the patients (80/95; 84%;) compared with controls (58/102, 57%) (χ²=17.5, OR=4, P=0.000028). Although the MIC-A associations described are highly significant, the association with HLA-B51 independently remains the most significant factor (χ²=56.8, P<10^–6). The data suggests that as both MIC-A*009 and A6 are in strong linkage disequilibrium with HLA-B51, they are unlikely to be the susceptibility gene for BD but may be markers for additional risk factors.     

Microspectrofluorometry of fluorescent photoproducts in photosensitized cells: Relationship to cellular quiescence and senescence in culture

Microspectrofluorometry of L and WI-38 cells reveals chemical/structural changes due to quiescence or senescence, i.e., lipid peroxidation, spontaneous or photosensitized by hematoporphyrin. Cells treated with hematoporphyrin and a lysosomal umbelliferone probe show a fast-rising umbelliferone emission, plus a fluorescent photoproduct. Studies in rapidly growing versus quiescent L, early passage/late passage WI-38 cells, suggest accumulation of fluorescence Schiff bases (i.e., their association with granular regions of cells in stationary phase, spectral properties, fast increase in photosensitized cells) and a possible lysosomal membrane permeabilization in quiescent or senescent cells.