Ancient invasions: from endosymbionts to organelles

The acquisitions of mitochondria and plastids were important events in the evolution of the eukaryotic cell, supplying it with compartmentalized bioenergetic and biosynthetic factories. Ancient invasions by eubacteria through symbiosis more than a billion years ago initiated these processes. Advances in geochemistry, molecular phylogeny, and cell biology have offered insight into complex molecular events that drove the evolution of endosymbionts into contemporary organelles. In losing their autonomy, endosymbionts lost the bulk of their genomes, necessitating the evolution of elaborate mechanisms for organelle biogenesis and metabolite exchange. In the process, symbionts acquired many host-derived properties, lost much of their eubacterial identity, and were transformed into extraordinarily diverse organelles that reveal complex histories that we are only beginning to decipher.     

Environmental factors affecting productivity, indican content, and indigo yield in Polygonum tinctorium Ait., a subtropical crop grown under temperate conditions

Polygonum tinctorium Ait. is a herbaceous subtropical annual plant, belonging to the family Polygonaceae. Within the cells of its leaves P. tinctorium accumulates large amounts of a colorless glycoside, indican (indoxyl beta-d-glucoside), from which the blue dye indigo is synthesized. P. tinctorium is well-known in Japan, where it had been cultivated to produce natural indigo for textile dyeing, whereas it represents a potentially interesting new crop in Europe. To better understand the effects of environmental parameters on P. tinctorium crop production and indigo yield, field experiments were carried out in central Italy under temperate climate. Three lines were tested during the 2001 and 2002 growing seasons, and plant/leaf yields as well as indican contents were evaluated. The results showed that P. tinctorium grown in temperate climate conditions can be harvested three times a year. Yields of 82 and 120 t ha(-1) of fresh plant yield were obtained in 2001 and 2002, respectively. The contrasting weather conditions between the two years significantly affected biomass production, which was higher in the 2002 season, characterized by wet weather conditions. The cycle length from sowing to the last harvest was accomplished in 229-238 days when plants had accumulated 2017-2018 degrees C. Green leaves accounted for 40-45% by weight of fresh plant tissue and contained 11-20 g kg(-1) indican. The three lines did not significantly differ in the main productive parameters or in fresh leaf indican content (14.1 g kg(-1) mean value). Photosynthetic active radiation influences indican leaf production according to the model y = 0.0004x + 8.566 (P < 0.01, correlation coefficient = 0.818). Indican content ranged from 12 to 25 g kg(-1) of fresh leaves with PAR daily values from 10000 to 40000 mEinstein m(-2) (recorded in May and at the end of July-beginning of August, respectively). The results indicate that in nonlimiting rainfall conditions a very high indican content and a potentially high indigo yield can be obtained by cultivating P. tinctorium in this pioneer geographical area.     

Risk factors for insect bite hypersensitivity in Friesian horses and Shetland ponies in The Netherlands

Insect bite hypersensitivity (IBH) is an equine skin allergy caused by bites of Culicoides spp. and impacts on the welfare of affected horses. The aim of this study was to identify and quantify risk factors for IBH. Data from 3453 Friesian horse mares and 7074 Shetland pony mares scored for IBH by inspectors during obligatory foal inspections were analysed using breed-specific multivariable logistic regression models. The combined effect of month and year of scoring, Province and inspector were significantly associated with IBH in both breeds. In Shetland pony mares, withers height and coat colour were also significantly associated with IBH, while body condition had a nearly significant effect. The outcomes from this study on risk factors might contribute to the development of more efficient measures to reduce the prevalence of IBH.     

Arthropathy caused by a lead bullet in a dog

CASE DESCRIPTION: A 3-year-old spayed female Labrador Retriever was evaluated for progressive lameness of the left forelimb 21 months after being shot in the elbow with a lead bullet. CLINICAL FINDINGS: Physical examination findings were consistent with moderate osteoarthritis of the left elbow joint. Orthogonal radiographic views of the elbow revealed multiple metallic fragments in and around the joint space as well as signs of osteoarthritis. TREATMENT AND OUTCOME: The elbow joint was evaluated arthroscopically. A lead-based bullet fragment was seen in the lateral synovial compartment and removed in multiple pieces. Excess fibrin and synovium were removed, and microfractures were created in exposed subchondral bone to stimulate neovascularization and fibrocartilage formation. In a follow-up telephone conversation 4 months after surgery, the owner reported a marked improvement in the lameness. CLINICAL RELEVANCE: Removal of lead intra-articular foreign bodies may be indicated even if the material is not believed to mechanically interfere with joint motion.     

Food resources and cyprinid diet in permanent and temporary Mediterranean rivers with natural and regulated flow

This study addresses the differences in food availability, diet and feeding activity of the Iberian barbel, between permanent and temporary nonregulated rivers, and the effect of flow regulation on feeding parameters. A total of 267 adult barbels were seasonally collected in four nonregulated and regulated rivers from permanent and temporary basins, and their gut content was analysed. Locally available food sources were evaluated across sites and seasons. Barbels from the permanent nonregulated river exhibit a more variable and diversified diet in which invertebrates assumed a large importance, especially during high flows. Barbels from the temporary nonregulated river presented a more uniform diet composed of plant material and detritus, particularly in drought seasons. Flow regulation affected different flow components in both systems, but the effects on food resources and barbels' diet were similar, resulting in an intra‐annual stabilisation of resource availability and fish diet, with a higher consumption of plants and detritus. Changes in fish diet and feeding activity in both nonregulated and regulated rivers were strongly associated with the seasonal variability of streamflow components, particularly between low‐ and high‐flow periods, and with the reduction in flow variability in the case of dam regulation. Results from this study can be used to improve guidelines for flow requirement implementation.     

Use of molasses as a carbon source during the nursery rearing of Farfantepenaeus brasiliensis (Latreille, 1817) in a Biofloc technology system

The present work evaluated the use of molasses as a carbon source during the nursery rearing of Farfantepenaeus brasiliensis in a Biofloc technology system. During a 30 days trial, three replicate tanks were randomly assigned to the following treatments: 1.) molasses (with molasses addition) and 2.) control (without molasses addition). Bacteriological analysis was used to quantify the abundance of presumptive Vibrio spp. between control and molasses treatment. The concentration of this microorganism was lower in molasses compared with control. For the immunological analysis, shrimp haemolymph was collected to determine the total haemocyte count and the total protein concentration. The immunological results were not different between treatments. The performance results of shrimp reared with molasses addition showed that the survival rate (88.87 ± 6.36), the mean final weight (1.22 ± 0.38) and the specific growth rate (0.0309 ± 1.06) were significantly higher compared with control (80.5 ± 2.42; 1.03 ± 0.13; 0.0256 ± 0.97 respectively). Moreover, the addition of molasses contributed to the maintenance of water quality and lower concentration of presumptive Vibrio spp. The control presented an unstable variation of Vibrio spp. reaching values of 80 × 10² CFU/ml, while the highest result of molasses was 20 × 10² CFU/ml, confirming the beneficial effects of molasses addition.