Prioritising sites for pollinators in a fragmented coastal nectar habitat network in Western Europe

Landscape Ecology - Habitat loss and fragmentation contribute significantly to pollinator decline and biodiversity loss globally. Conserving high quality habitats whilst restoring and connecting...     

Characterization of resistance to the wheat stem sawfly in spring wheat landrace accessions from targeted geographic regions of the world

Plant landraces have long been recognized as potential gene pools for biotic and abiotic stress-related genes. This research used spring wheat landrace accessions to identify new sources of resistance to the wheat stem sawfly (WSS) (Cephus cinctus Norton), an important insect pest of wheat in the northern Great Plains of North America. Screening efforts targeted 1409 accessions from six geographical areas of the world where other species of grain sawflies are endemic or where a high frequency of accessions possesses the resistance characteristic of solid stems. Resistance was observed in approximately 14% of accessions. Half of the lines displayed both antixenosis and antibiosis types of resistance. Among the resistant accessions, 41% had solid or semi-solid stems. Molecular genetic screening for haplotypes at the solid stem QTL, Qss.msub.3BL, showed that 15% of lines shared the haplotype derived from ‘S-615’, the original donor of the solid stem trait to North American germplasm. Other haplotypes associated with solid stems were also observed. Haplotype diversity was greater in the center of origin of wheat. Evaluation of a representative set of resistant landrace accessions in replicated field trials at four locations over a three year period identified accessions with potential genes for reduced WSS infestation, increased WSS mortality, and increased indirect defense via parasitoids. Exploitation of distinct types of plant defense will expand the genetic diversity for WSS resistance currently present in elite breeding lines.     

The source of autumn and spring downstream migrating juvenile Atlantic salmon in a small lowland river

Over 3 years, 32,444 age‐0 group Atlantic salmon (Salmo salar) parr tagged with passive integrated transponder tags throughout the River Frome catchment were assigned to one of three groups, nonmigrants, autumn migrants and spring smolts, depending on the detection and the timing of detection at downstream tag readers (situated 8.6 km above the tidal limit). We examined the effect of density at the time of tagging (n·m^?2), distance upstream from the tidal limit (km), fish length (mm), Fulton condition index, habitat type (divided into two types, main river and carrier), days after 1 September that each fish was tagged and year (replication) on the proportions of fish in each of the migration groups. Distance upstream from tidal limit was strongly negatively related to the proportion of autumn migrants and positively related to the proportion of spring smolts. Nonmigrants had a lower average body size than migrants, although there were no differences in the sizes of autumn migrants and spring smolts in September prior to migration. Fish density had no effect on migration strategy. A lower proportion of fish migrated as autumn migrants from the smaller carrier habitats than the main river channel. There is some evidence that those parr destined to become autumn migrants underwent a lower mortality rate during September before tagging than those destined to become spring migrants indicating possible physiological or behavioural differences between these two groups of fish at that time. More research into the factors responsible for initiating the autumn migration is required.     

Differential responses of Equus caballus and Equus asinus to infection with two pathogenic strains of equine infectious anemia virus

Most in vivo studies with equine infectious anemia virus (EIAV) have been performed in horses and ponies (Equus caballus) with little published information available detailing the clinical responses of donkeys (Equus asinus) to infection with this virus. Consequently, donkeys were inoculated with two strains of EIAV (EIAV(PV) and EIAV(WY)) which have been documented to produce disease in E. caballus. Four ponies, 561, 562, 564 and 567 and two donkeys, 3 and 5 were infected with EIAV(PV) and one horse (94-10) and one donkey (4) were infected with EIAV(WY). Although the horse and ponies all experienced clinical signs of disease, which in some cases were severe, the donkeys remained asymptomatic throughout a 365-day observation period, except for mild transient reductions in platelet counts. The results from serological assays, virus isolation from plasma and detection of plasma-associated viral RNA by RT-PCR, indicated that initial replication of EIAV(PV) and EIAV(WY) was lower in donkeys than in horses and ponies. This conclusion was confirmed using competitive RT-PCR, in which viral RNA levels in the plasma of EIAV(PV)-infected ponies was up to 100,000-fold higher than in infected donkeys during the first 20 days post-infection (dpi). Similar results were obtained in the EIAV(WY)-infected animals, in which viral RNA burdens in the donkey at 20 dpi were 1000-fold less than in the horse. However, infection of donkey and horse monocyte-derived macrophage cultures with EIAV(PV) demonstrated that these cells in vitro were equally susceptible to virus-induced cytopathic effects and yielded similar levels of progeny virus. This result suggests that factors other than host cell permissiveness mediate the clinical differences observed between horses and donkeys infected with EIAV(PV) or EIAV(WY).     

In vitro effects of glucosamine and acetylsalicylate on canine chondrocytes in three-dimensional culture

OBJECTIVE: To determine effects of glucosamine and acetylsalicylate on canine chondrocytes in 3-dimensional culture. SAMPLE POPULATION: Chondrocytes isolated from articular cartilage of 2 adult female dogs recently euthanatized for reasons unrelated to orthopedic abnormalities. PROCEDURE: Chondrocytes were cultured in a 3-dimensional agarose-based medium alone (control), with glucosamine (100 microg/ml; GL), or with acetylsalicylate (18 microg/ml; AS). Supernatant and agarose plugs from 4 wells/group/d were collected on days 3, 6, and 12 of culture. Agarose plugs were evaluated for percentage of viable cells, percentage of cells producing pericellular or territorial matrix, glycosaminoglycan (GAG) concentration, and type-II collagen production. Prostaglandin E2 concentration in supernatants was determined. RESULTS: Chondrocytes in all groups had characteristics indicative of viability and differentiation; however, on day 12, a lower percentage of viable cells was detected in the AS group, compared with the other 2 groups. On day 6, GAG concentration in the AS group was significantly greater than concentrations in the other 2 groups. On day 12, GAG concentrations in the GL and AS groups were significantly less than in the control group. Within the GL and AS groups, cell viability was significantly less on day 12, compared with day 3. Significant differences in PGE2 concentration among or within groups and evidence of type II collagen production were not detected. CONCLUSIONS: 3-dimensional culture of canine chondrocytes allows for production of hyaline cartilage matrix constituents and growth of cells with morphologic characteristics similar to those of articular cartilage. Acetylsalicylate and glucosamine, at the single concentration evaluated, had detrimental effects on chondrocyte viability, GAG production, or both.     

Maternal behaviour in sheep (Ovis aries) following administration of opioid agonists

AIMS: As kappa(kappa)-opioids have marked effects on pain threshold in sheep during oestrus, late pregnancy and after birth, a study was undertaken to determine if kappa -opioids also had other roles during these states. METHODS: Opioid agonists (GR89696, DAMAGO) were administered into either the lateral hypothalamus (LH) or amygdala of non-pregnant sheep (n = 5) or pregnant sheep (n = 15) in late pregnancy (n = 5) within 12 h of birth (n = 5) or in the third week after birth (n = 5). Cortisol, behavioural and electrocardiographic responses to an auditory stimulus were assessed with and without drug administration, as was feed consumption and suckling events. RESULTS: In non-pregnant sheep, DAMAGO injected into either the LH or amygdala had little effect on the response to the auditory stimulus but when injected into the LH did decrease food consumption. GR 89696 had no obvious effects. In late pregnancy, cortisol and heart rate responses to the auditory stimulus were significantly reduced compared to the non-pregnant animals irrespective of treatment. This was also the case in the third week after birth. Immediately post-partum cortisol responses were closer to that seen in the non-pregnant animal. In late pregnancy and both post-partum periods, GR 89696 in the LH significantly increased feed consumption while DAMAGO had no significant effects. GR 89696 injected into the amygdala reduced the behavioural response to the auditory stimulus in late pregnancy and both post-partum periods. CONCLUSION: Changes in sensitivity to opioids occur in both the amygdala and LH with pregnancy and after birth. These may influence maternal behaviours and feed intake.