Enhanced muscle regeneration in freshwater prawn Macrobrachium rosenbergii achieved through in vivo silencing of the myostatin gene

Myostatin (MSTN) is an interesting negative growth‐regulating gene that has been well characterized in vertebrates but scantly described in invertebrates. The current study focuses on the downregulation of the MrMSTN gene and subsequently records any histological changes for giant freshwater prawn, Macrobrachium rosenbergii (Mr). In addition, the study also deals with the MrMSTN gene's influence on other growth‐related genes, which include myosin heavy chain, dystrophin‐dystroglycoprotein complex, tropomyosin, farnesoic acid o‐methyl transferase, arginine kinase, cyclophilin, and acyl CoA desaturase. The preliminary histological analysis following MrMSTN silencing favors muscle regeneration, which supports its functional role as a negative growth regulator and its significant effect on the expression of other growth‐related genes. Overall, our results show that the MrMSTN gene could therefore be a potential target for gene manipulation aimed at enhancing the growth and muscle development of M. rosenbergii, which could be beneficial in increasing the total mass production in the postlarva phase at the hatchery level.     

Effect of Mixing Time and Speed on Experimental Baking and Dough Testing with a 200 g Pin Mixer

Undermixing or overmixing the dough results in varied experimental loaf volumes. Bread preparation requires a trained baker to evaluate dough development and determine the stop points of the mixer. Instrumentation and electronic control of the dough mixer would allow for automatic mixing. This study used a 200 g mixer that provided an output signal during dough mixing to evaluate potential mixing stop points. The effect of varied mixing time on the baked loaf volume was tested by using three flours with protein contents of 10.6, 12.4, and 13.8%. Dough samples were undermixed, mixed to peak, and overmixed. Overmixing by 0.6 min reduced the loaf volume in all flours tested, by 16–50 cm³ at 90 rpm and by 29–68 cm³ at 118 rpm. When the high‐protein flour sample was undermixed, the largest baked loaves were produced, with an average volume of 922 cm³. A second objective studied the similarities and differences between a 200 g mixer and a 35 g mixograph. The same flours were mixed on both units. The mixing peaks for the 200 g mixer were normalized with the 35 g mixograph peaks. When flour and water were used, the mixing times for the 200 g mixer averaged 0.7, 1.2, and 1.6 min shorter than the 35 g mixograph, at 90, 104, and 118 rpm, respectively. Although both the 200 g mixer and the 35 g mixograph system look mechanically similar, they both have unique mechanical motion, speeds, and sample sizes. Their results may show similar trends, but their measured values are usually different. However, when other baking ingredients were included in the 200 g mixer at 90 rpm, the mixing times were within 0.2 min of the 35 g mixograph times for three of four flours.     

Day-to-Day variation of the urine protein: creatinine ratio in female dogs with stable glomerular proteinuria caused by X-linked hereditary nephropathy

BACKGROUND: Interpretation of serial urine protein:creatinine (UPC) values is confounded by a lack of data regarding random biologic variation of UPC values in dogs with stable glomerular proteinuria. HYPOTHESIS: That there is minimal day-to-day variability in the UPC of dogs with unchanging proteinuria and the number of measurements needed to reliably estimate UPC varies with the magnitude of proteinuria. ANIMALS: Forty-eight heterozygous (carrier) female dogs with X-linked hereditary nephropathy (XLHN) causing stable proteinuria. METHODS: Urine samples were obtained daily by cystocentesis for 3 consecutive days on 183 occasions (549 samples). The UPC was measured for each sample with a single dry-film chemistry auto-analyzer. Data were analyzed retrospectively by a power of the mean model because the variance of UPC values within the 3-day evaluation periods increased as the magnitude of proteinuria increased. RESULTS: To demonstrate a significant difference (P < .05) between serial values in these proteinuric dogs, the UPC must change by at least 35% at high UPC values (near 12) and 80% at low UPC values (near 0.5). One measurement is adequate to reliably estimate the UPC when UPC <4, but 2-5 determinations are necessary at higher UPC values. CONCLUSIONS AND CLINICAL IMPORTANCE: These guidelines for interpretation of serial UPC values in female dogs with XLHN may also be helpful for interpretation of UPC values in dogs with other glomerulopathies.     

Outcomes of esophageal and gastric bone foreign bodies in dogs

BackgroundBone foreign bodies are commonly encountered in small animal practice. Esophageal bone foreign bodies (E‐bFBs) warrant removal, whereas gastric bone foreign bodies might not.ObjectivesDescribe management and outcomes for dogs with esophageal or gastric bone foreign bodies.AnimalsOne hundred twenty‐nine dogs with esophageal (n = 45) or gastric (n = 84) bone foreign bodies.MethodsRetrospective review of medical records.ResultsDogs with E‐bFBs were younger than dogs with gastric bone foreign bodies (median age esophageal, 4 years [IQR 2‐8]; median age gastric, 6 years [IQR 3‐10]; P = .03), and had a higher bone cross‐sectional area relative to body weight (median esophageal, 98.21 mm²/kg [IQR 48.25‐142.6]; median gastric, 28.6 mm²/kg [IQR 17.25‐64.28]; P < .001). Forty‐two of 45 esophageal foreign bodies were resolved non‐surgically and 3 by esophagotomy. Esophageal erosions were more likely with distal entrapment (OR 12.88, [95% CI 31.95‐129.29], P = .01) and longer duration (OR 18.82 [95% CI 2.22‐273.97], P = .01). Sixty‐two of 84 bone gastric foreign bodies were left in situ. Endoscopic removal was successful in 20 of 22 (91%; 95% CI 70‐99) attempts.Conclusions and Clinical ImportanceWhile all E‐bFBs were dislodged either by advancement into the stomach, endoscopic removal, or esophagotomy, the majority of gastric bone foreign bodies were left in situ for dissolution, with no reported complications. Gastric advancement of E‐bFBs should be considered when oral removal is not feasible, and dissolution can be considered even with large bones.     

Sap flow in ‘Hass’ avocado trees on two clonal rootstocks in relation to xylem anatomy

The rates of sap flow and xylem vessel features were studied in two-year-old nongrafted and grafted avocado (Persea americana Mill.) trees. Daily sap flow rates were measured with heat and balance stem gauges in clonal Duke 7 (D7) and Toro Canyon (TC) trees and ‘Hass’ clonal scions grafted onto clonal D7 (H/D7) and TC (H/TC) rootstocks. Vessel features as size, number and total vessel area were determined histologically in the stem of the scion and rootstock and the roots of the grafted trees. Significant differences in the sap flow rate were found among the rootstocks, where D7 had a 29% higher sap flow rate than did TC (grafted and nongrafted trees). There were no differences among xylem vessel features in the stems of any of the varieties. However in the roots, D7 had wider and fewer vessels then TC do. Also, D7 had a 19% higher total vessel area than TC. These results suggest that the differences in water consumption of ‘Hass’ on different rootstocks may be associated with differences in the efficiency of the roots to absorb water across conductive tissue which may be linked to differences in the area of xylem vessels in the root.     

Comparative forcing of Hydrangea macrophylla ‘Bailer’ as a florist's hydrangea

‘Bailer’ (Endless Summer™) is a new, pink- or blue-flowered hydrangea that flowers on new wood continuously throughout the growing season. It is also winter-hardy in northern, temperate climates (USDA Z4). Use of Endless Summer as a florist's potted hydrangea would provide consumers with a dual-use product (flowering potted plant, landscape shrub). The objectives were to determine if Endless Summer could be forced as a florist's hydrangea using two forcing regimes (immediate, standard), two soil pH regimes, and two pinching treatments. ‘Merritt Supreme Pink’ (pink), ‘Blue Danube’ (blue), and Endless Summer (blue, pink) were forced under immediate (no cold treatment, short- and long-day photoperiods) and standard (6 weeks cold, 4 °C to overcome dormancy) conditions. Since commercial liners were not yet available, cuttings of Endless Summer were used in the immediate forcing experiment. Days to visible flower bud, first color, full flower were recorded, as well as height, no. of branches, no. of flowers, and flower size. In the immediate forcing experiment, only Endless Summer produced flowers. Cultivars differed significantly (P < 0.001) for days to visible flower bud, days to first color, days to full flower, and height. The number of flowers and flower size were not significantly different among pink cultivars. In the standard forcing experiment, Endless Summer reached days to visible flower bud, days to first color, and days to full flower significantly earlier than either comparison, although it exhibited weaker stems and less intense flower pigmentation. Pinching (blue pH) had a significant effect on all traits except the days to full flower and flower size, although no pinching treatment was significant for pink pH. Photoperiod was significant only for the days to visible flower bud (pink pH), days to full flower (blue pH), and final height (blue pH). Further research is needed before Endless Summer can be grown as a dual-use florist's potted hydrangea with acceptable quality.     

Identification of resistant germplasm containing novel resistance genes at or tightly linked to the <Emphasis Type="Italic">Pi2/9</Emphasis> locus conferring broad-spectrum resistance against rice blast

Background

The rice Pi2/9 locus harbors multiple resistance (R) genes each controlling broad-spectrum resistance against diverse isolates of Magnaporthe oryzae, a fungal pathogen causing devastating blast disease to rice. Identification of more resistance germplasm containing novel R genes at or tightly linked to the Pi2/9 locus would promote breeding of resistance rice cultivars.

Results

In this study, we aim to identify resistant germplasm containing novel R genes at or tightly linked to the Pi2/9 locus using a molecular marker, designated as Pi2/9-RH (Pi2/9 resistant haplotype), developed from the 5′ portion of the Pi2 sequence which was conserved only in the rice lines containing functional Pi2/9 alleles. DNA analysis using Pi2/9-RH identified 24 positive lines in 55 shortlisted landraces which showed resistance to 4 rice blast isolates. Analysis of partial sequences of the full-length cDNAs of Pi2/9 homologues resulted in the clustering of these 24 lines into 5 haplotypes each containing different Pi2/9 homologues which were designated as Pi2/9-A5, ?A15, ?A42, ?A53, and -A54. Interestingly, Pi2/9-A5 and Pi2/9-A54 are identical to Piz-t and Pi2, respectively. To validate the association of other three novel Pi2/9 homologues with the blast resistance, monogenic lines at BC₃F₃ generation were generated by marker assisted backcrossing (MABC). Resistance assessment of the derived monogenic lines in both the greenhouse and the field hotspot indicated that they all controlled broad-spectrum resistance against rice blast. Moreover, genetic analysis revealed that the blast resistance of these three monogenic lines was co-segregated with Pi2/9-RH, suggesting that the Pi2/9 locus or tightly linked loci could be responsible for the resistance.

Conclusion

The newly developed marker Pi2/9-RH could be used as a potentially diagnostic marker for the quick identification of resistant donors containing functional Pi2/9 alleles or unknown linked R genes. The three new monogenic lines containing the Pi2/9 introgression segment could be used as valuable materials for disease assessment and resistance donors in breeding program.