A Novel Pair of HMW Glutenin Subunits from Aegilops searsii Improves Quality of Hexaploid Wheat

This study involved screening of wild species of wheat in search of functionally useful seed storage proteins for improvement of breadmaking quality of wheat (Triticum aestivum). After screening of 177 disomic addition lines (DALs) of wheat belonging to different wild species, Aegilops searsii DALs were selected and studied in detail. These DALs of Ae. searsii were from chromosome 1S^s to 7S^s in the background of cultivated wheat cv. Chinese Spring (CS). By analyzing these addition lines, genetic loci of actively expressed genes for the high molecular weight glutenin subunits (HMW‐GS) and gliadin were found on the chromosome 1S^s for the first time and have been designated as Glu‐S^s1 and Gli‐S^s1, respectively. Disomic addition line of chromosome 1S^s (DAL1S^s) showed improved dough strength in different generations compared with CS. SDS sedimentation value and specific sedimentation of DAL1S^s were higher than CS. Mixograph peak height and band width were higher, with no difference in mixing peak time from CS. All these factors indicate a positive effect of quantity as well as quality of gluten proteins of Ae. searsii. This was further supported by increased polymer formation in DAL1S^s because the ratio of unextractable polymeric protein to total polymeric protein (UPP/TPP%) of DAL1S^s was significantly higher than CS. Genes for HMW‐GS (major determinant of end‐product quality in wheat) of Ae. searsii were cloned and sequenced from the DAL1S^s. Phylogenetic analysis of deduced amino acid sequences showed that both x and y HMW‐GS were more similar to that of D genome rather than B genome of wheat. Although S genome is structurally more similar to B genome of wheat, functionally it is more similar to the D genome of wheat and possesses good quality HMW‐GS required for improvement of breadmaking quality of wheat.     

Abundance of sulphate-reducing bacteria in fish farm sediments along the coast of Japan and South Korea

The abundance of sulphate-reducing bacteria (SRB) was investigated in the coastal marine sediments along the coast of Japan and South Korea. Sediment samples were collected from fish and shellfish farms between 2006 and 2008. As non-fish farming reference sites, sediments were also collected from highly eutrophic bays, a highly sulphidogenic saline lake, and the deep sea. A quantitative real-time PCR analysis that targeted the gene coding for a portion of the α-subunit of dissimilatory sulphite reductase (dsrA) was performed to assess the abundance of the SRB in the sediments. Between 2.8 × 10⁷ and 2.5 × 10⁹ copies of the dsrA gene per gram dry sediment were detected. There was no relationship between dsrA gene copy number and total bacterial count in the sediments, whereas organic matter contents (particulate organic carbon and nitrogen, ignition loss and chemical oxygen demand) and acid-volatile sulphide contents were significantly correlated with the dsrA copy number. The data presented demonstrate that organic enrichment of sediment may influence the abundance of SRB communities in coastal marine sediments and that the cell density of SRB may be used as a biological indicator for assessing pollution levels in sediments of marine fish farms.     

Hemolytic suppression roles of taurine in yellowtail Seriola quinqueradiata fed non-fishmeal diet based on soybean protein

ABSTRACT:   To elucidate the hemolytic suppression roles of taurine and the necessity of dietary taurine supplementation in yellowtail Seriola quinqueradiata fed a diet without fishmeal, juvenile fish with an initial body weight of 250 g were fed for 40 weeks in floating net cages on soybean protein diets supplemented with 0, 3.0, 4.5 and 6.0% taurine. Taurine concentration of the experimental diets were 0.03, 33.9, 52.8 and 71.6 mg/g, respectively. On the 21st week, fish fed the taurine unsupplemented diet had inferior growth and feed performances, higher death, and there were incidences of green liver and hemolytic anemia. In this group, hepatic and plasma taurine concentrations, serum osmolality and osmotic tolerance of erythrocytes (EC50 value) were significantly lower, and plasma hydroperoxide concentration was markedly higher than in the taurine supplemented groups. These conditions markedly improved corresponding with the increase of dietary taurine concentration. These results indicate that taurine plays a role in hemolytic suppression through osmoregulation and biomembrane stabilization in fish. In addition, it is suggested that yellowtail requires dietary taurine as an essential nutrition for maintaining physiological condition normally.     

Correction to: Precocious maturation in male tiger pufferfish Takifugu rubripes: genetics and endocrinology

Fisheries Science - A correction to this paper has been published: https://doi.org/10.1007/s12562-021-01505-w     

Alteration of wheat vernalization requirement by alien chromosome-mediated transposition of MITE

Under the changing climate, early flowering is advantageous to escape terminal heat and drought. Previously during evaluation of 14 chromosome introgression lines (ILs), we found three ILs that flowered a month earlier than their wheat background Chinese Spring (CS). This paper describes the cause of the early flowering in the ILs and provides insight into the evolution of spring wheat from the winter wheat. We used specific molecular markers for Vrn genes to determine its allelic composition. Phenotypic evaluations carried out under field conditions and in a growth chamber. Unlike the winter vrn-A1 allele of CS, the spring Vrn-A1 allele of the ILs had insertions of 222 and 131-bp miniature inverted-repeat transposable element (MITE) in the promoter region. Sequence analysis indicated that the 222-bp insertion is similar to an insertion in the spring genotype, Triple Dirk D. Our results ruled out any possibility of outcrossing or contamination. Without vernalization, Vrn-A1 is highly expressed in the ILs compared to CS. We attribute the early flowering of the ILs to the insertion of the MITE in the promoter of Vrn-A1. The alien chromosome might mediate this insertion.     

Permeability of the fish intestinal membrane to bulky chemicals

The ability to predict the environmental behavior of chemicals precisely is important for realizing more rational regulation. In this study, the bioaccumulation of nine chemicals of different molecular weights absorbed via the intestinal tract was evaluated in fish using the everted gut sac method. The amounts of chemicals that passed through the intestinal membrane after a 24-hr exposure were significantly decreased for chemicals with MW≥548 and D_{max min}≥15.8 Å (or D_{max aver}≥17.2 Å). These thresholds are consistent with those previously proposed in terms of MW (>800) and molecular size (D_{max min}>15.6 Å or D_{max aver}>17.1 Å) for the limit of permeable chemicals through the gill membrane. The results show that the same MW and D_max criteria can be used to predict low bioaccumulation through both the gill membrane and the intestinal tract. These findings are helpful in reducing the need to conduct animal tests in environmental safety studies.     

Current status of commercial Calibrachoa cultivars as assessed by morphology and other traits

To study the morphological diversity of the popular ornamental crop Calibrachoa, traded since the 1990s, floral and vegetative characters of 91 commercial cultivars were compared to those of natural species. Floral colours were classified according to the ISCC-NBS system and the CIE LAB system. The numerical data obtained by measuring 19 floral and vegetative characters was tested with principal component (PC) analysis. Floral colour classes of commercial cultivars were divided into 37 groups according the ISCC-NBS system, whereas those of natural species were divided into 9 groups. These tendencies were readily observable in the scatter diagrams of the a* vs. b* values and the C* vs. L* values. As the result of PC analysis, six PCs were obtained. For PC4, which negatively correlated with the degree of nocturnal corolla limb closure, the majority of natural species showed negative scores whereas the majority of cultivars had positive PC4 scores. In terms of PC2 (flower size), PC3 (growth form), PC5 (floral shape) and PC6 (leaf shape), natural species were dispersed in a range wider than the cultivars. These results suggest that Calibrachoa cultivars possess more highly variable floral colour than natural species, and breeding programmes to diversify the floral colour seem to have progressed rapidly. The tendency of natural species to close the corolla limb toward evening has been removed almost completely from the cultivars. The floral size, growth form, floral shape and leaf shape of the cultivars were rather uniform compared to those of natural species.     

Cellular compartmentation and membrane permeability to sugars in relation to early or high temperature-induced watercore in apples

Early watercore was observed in apples (Malus domestica Borkh.) from the outer canopy of ‘Orin’, an early watercore susceptible cultivar, while there was no watercore in ‘Orin’ fruit from the inner canopy and resistant ‘Fuji’. Sorbitol content was higher not only in the free space but also in the vacuole and cytoplasm in watercored ‘Orin’ than in other non-watercored fruit. Comparing watercored apples to non-watercored fruit of ‘Orin’, higher fructose and glucose in the vacuole and no significant difference in the distribution rate of sorbitol to each compartment were observed. Watercored ‘Orin’ apples showed significantly higher permeability of tonoplast to fructose, glucose, and sorbitol than those in other non-watercored apples. The permeability of plasma membrane to each sugar was much higher than that of tonoplast but no marked difference was observed among the treatments. The results suggest that metabolism of sorbitol could be active even in watercored ‘Orin’ apples and the accumulated sorbitol in the intercellular spaces might be primarily due to an active unloading from the phloem and not be brought by increased leakage from the cells.     

Analysis of the 18S rRNA gene sequence of a Hepatozoon detected in two Japanese dogs

Partial sequences of the 18S rRNA gene (625 bp) from a Hepatozoon detected in two canine hepatozoonosis cases, one clinical and one subclinical, in Japan were analyzed. Both sequences were identical to each other and they were closely related to the Hepatozoon canis strain found in Israel with 99% (617/625) nucleotide identity. Both Hepatozoon americanum and Hepatozoon catasbianae were distantly related to the Japanese Hepatozoon with 94% (586/625) and 91% (566/625) identities, respectively. In a phylogenetic tree, the Japanese Hepatozoon was most closely related to H. canis from Israel but was significantly different than H. americanum and H. catasbianae. These results suggest that the Hepatozoon detected in the Japanese dogs might be a strain variant of H. canis, but is apparently a different species than H. americanum.