“A cleaner break”: Genetic divergence between geographic groups and sympatric phenotypes revealed in ballan wrasse (Labrus bergylta)

Capture and long‐distance translocation of cleaner fish to control lice infestations on marine salmonid farms has the potential to influence wild populations via overexploitation in source regions, and introgression in recipient regions. Knowledge of population genetic structure is therefore required. We studied the genetic structure of ballan wrasse, a phenotypically diverse and extensively used cleaner fish, from 18 locations in Norway and Sweden, and from Galicia, Spain, using 82 SNP markers. We detected two very distinct genetic groups in Scandinavia, northwestern and southeastern. These groups were split by a stretch of sandy beaches in southwest Norway, representing a habitat discontinuity for this rocky shore associated benthic egg‐laying species. Wrasse from Galicia were highly differentiated from all Scandinavian locations, but more similar to northwestern than southeastern locations. Distinct genetic differences were observed between sympatric spotty and plain phenotypes in Galicia, but not in Scandinavia. The mechanisms underlying the geographic patterns between phenotypes are discussed, but not identified. We conclude that extensive aquaculture‐mediated translocation of ballan wrasse from Sweden and southern Norway to western and middle Norway has the potential to mix genetically distinct populations. These results question the sustainability of the current cleaner fish practice.     

Effect of Yeast Hulls on Stuck and Sluggish Wine Fermentations: Importance of the Lipid Component

The effect of yeast hulls (yeast ghosts) on sluggish or stuck white wine fermentations was studied. The enhancing effect on yeast growth and fermentation rate displayed by the hulls was shown to be similar to the effect provided by lipid extract from the same hulls. Unsaturated fatty acids and sterols were incorporated into the yeast from lipid extracts during fermentation carried out under oxygen-limited conditions. Adsorption of toxic medium-chain fatty acid (decanoic acid) onto the yeast hulls took place through a dialysis membrane. However, when the hulls were placed inside a dialysis bag, the increase in yeast growth and fermentation rate seen when freely suspended hulls were used did not occur. Accordingly, the effect of yeast hulls in preventing stuck fermentations cannot be attributed only to the adsorption and consequent removal of medium-chain fatty acids from the juice.     

The critical region on the human Xq

Summary Adult female carriers of balanced X; autosome translocations (118 cases) and of balanced X inversions (31 cases) have been collected from the literature. Forty-five of the 118 translocation carriers in whom the break was in the critical region (Xq13–q22, Xq22–q26, separated by a narrow region within Xq22) showed gonadal dysgenesis. Seven of the 31 inversion carriers in whom the break was in the same region also had gonadal dysgenesis, whereas the remaining 24 were normal in this respect. The critical region consists mainly of Q-bright material, and is the fifth brightest segment in the human genome. The region contains relatively few genes. It is possible that meiotic crossing-over, rarely, if ever, takes place in it. The critical region may therefore consist of two supergenes whose integrity must be maintained to allow normal ovarian development. The effect exerted by this region differs from other known position effects, in that it is independent of the break-point within the region and of the chromosome bands to which the broken ends are attached. One possible mechanism causing this effect might be a change in the replication order of the chromosome bands, which, in turn, might affect their function.     

Human mitochondrial DNA types in Finland

Summary Variation in mitochondrial DNA (mtDNA) in a sample of 110 Finns was analyzed with six restriction enzymes, AvaII, BamHI, HaeII, HinII, HpaI, and MspI, by using total blood cell DNA probed with mouse mtDNA. Two new enzyme morphs were observed, one for HaeII and one for HindII. Double-digestion experiments indicated that the BamHI morphs 2 and 3 result from base changes leading to AvaII morphs 3 and 9, respectively. Of the ten different mtDNA types observed, defined by restriction fragment patterns, seven have been previously described in Caucasoid populations. The three new Finnish mtDNA types can be derived from Caucasoid lineages by single restriction site changes. The results were used to reconstruct a phylogenetic tree for Caucasoid mtDNA types defined by the enzymes used. The frequencies of mtDNA types were used to compute genetic distances between Finns, Italians, and Israeli Jews. The frequencies of both enzyme morphs and mtDNA types show that the Finnish population is highly homogeneous.     

Lymphoid cell subclasses in rejecting renal allograft in the rat

We have quantitated the frequency of lymphoid cell subsets in rejecting renal allografts and in the spleen of the allograft recipient during drug-unmodified rejection in the rat. The number of inflammatory (white) cells in the graft was approximately similar to the number of white cells responding to the allograft in the recipient spleen. The inflammatory population of the graft consisted of lymphoid cells and mononuclear phagocytes, with increasing numbers of macrophages toward the end of rejection. Analysis of allograft cellular dispersates with monoclonal antibodies directed to the lymphoid cell subsets demonstrated that although the majority of allograft-infiltrating lymphocytes were T cells, a sizable B-cell proliferation and immunoglobulin synthesis was associated with the inflammatory response of rejection. Within the T-cell subset, the T suppressor/killer cells predominated in the graft whereas the predominant lymphoid cell subset responding to the allograft in the recipient spleen was the T helper cell.     

Combined interferon and vinblastine treatment of advanced melanoma: evaluation of the treatment results and the effects of the treatment on immunological functions

Summary Thirteen patients with metastatic malignant melanoma received interferon -2a (Roferon-A) and vinblastine. The interferon dosage was increased from 3×10⁶ IU to 9×10⁶ IU daily in 10 weeks and thereafter 9×10⁶ IU was administered three times weekly intrasmuscularly. Vinblastine (0.075–0.15 mg/kg) was given every third week intravenously. One of the ten evaluable patients had partial remission (PR) (11%) for 10 months. The diseases was stabilized (NC) in three patients (30%) for 3, 6 and 9 months. Progression (PD) occurred in six patients. The treatment time varied from 5 weeks to 44 weeks. The median survial time from the beginning of this combination treatment was 5 months. The most common side-effects were fever, fatigue, loss of taste, weight loss and neutropenia.The mitogen response to phytohemagglutinin and purified protein derivative of tuberculin decreased in all patients. The response to concanavalin A decreased less and began to increase again in the patients with PR and NC. The natural killer cell activity in PD patients decreased more than in the patients with PR and NC. The ratio of T4/T8-positive cells was restored in PR + NC patients but rose in PD patients indicating a difference in the immunomodulatory effect of the combination or of the advanced disease itself on T-cell function in PD patients.This combination of daily interferon and vinblastine did not prove to be effective in melanoma. The depression of immunological functions, which was more marked in patients with PD, might indicate that vinblastine in this combination counteracts the immunostimulatory effect of interferon.     

Mitotic chiasmata in human diplochromosomes

Summary Three placental tissue cultures of spontaneous human abortions showed an unusually high frequency of metaphases with diplochromosomes. In 62 such cells, nine configurations were interpreted as mitotic chiasmata between the two sister chromosomes of a diplochromosome. One U-type exchange between two sister chromosomes was also found. This differs significantly from the 1:1 ratio of adjacent and alternate exchanges in translocations, thus supporting the idea that mitotic chiasmata are in principle different from chromatid translocations. The hypothesis is put forward that the frequency of homologous exchanges is determined by the intimacy of pairing which ranges from meiotic pairing through sister chromatid association, through sister chromosome association in diplochromosomes to accidental pairing of homologous regions in diploid cells.     

Structure and Barr body formation of an Xp + chromosome with two inactivation centers.

A patients with seizures, Von Willebrand disease, and symptoms of Turner syndrome was a chromosomal mosaic. In blood culture (1974), 56% of the cells were 45, X 33% 46, XXp+ and 11% 47,XXp + Xp +; in the skin, no cells with 47 chromosomes were found. Presumably the Xp + chromosome arose through a break in the Q-banded dark region next to the centromere on Xp to which an Xq had been attached. The abnormal X was late-labeling and formed a larger than normal Barr body. Of the chromatin-positive fibroblasts, 18.2% showed bipartite Barr bodies, which agrees with the hypothesis that the X inactivation center lies on the proximal part of the Xq. On the basis of the structure and behavior of the bipartite bodies in the present patient, as compared to those formed by other chromosomes with two presumed inactivation centers, we propose that the dark region next to the centromere of Xp remains active in the inactive X. In cells with 45,X and 46,XY, this region has the same relative size, whereas it is significantly shorter in the active X of three females, including the present patient, with one abnormal X. We propose that this region on the active X reveals different states of activity, as reflected in its length, depending on how many other X chromosomes are in the cell.