Widespread lateral gene transfer from intracellular bacteria to multicellular eukaryotes

Although common among bacteria, lateral gene transfer-the movement of genes between distantly related organisms-is thought to occur only rarely between bacteria and multicellular eukaryotes. However, the presence of endosymbionts, such as Wolbachia pipientis, within some eukaryotic germlines may facilitate bacterial gene transfers to eukaryotic host genomes. We therefore examined host genomes for evidence of gene transfer events from Wolbachia bacteria to their hosts. We found and confirmed transfers into the genomes of four insect and four nematode species that range from nearly the entire Wolbachia genome (>1 megabase) to short (<500 base pairs) insertions. Potential Wolbachia-to-host transfers were also detected computationally in three additional sequenced insect genomes. We also show that some of these inserted Wolbachia genes are transcribed within eukaryotic cells lacking endosymbionts. Therefore, heritable lateral gene transfer occurs into eukaryotic hosts from their prokaryote symbionts, potentially providing a mechanism for acquisition of new genes and functions.     

A short circuit in thermohaline circulation: A cause for northern hemisphere glaciation?

The cause of Northern Hemisphere glaciation about 3 million years ago remains uncertain. Closing the Panamanian Isthmus increased thermohaline circulation and enhanced moisture supply to high latitudes, but the accompanying heat would have inhibited ice growth. One possible solution is that enhanced moisture transported to Eurasia also enhanced freshwater delivery to the Arctic via Siberian rivers. Freshwater input to the Arctic would facilitate sea ice formation, increase the albedo, and isolate the high heat capacity of the ocean from the atmosphere. It would also act as a negative feedback on the efficiency of the "conveyor belt" heat pump.     

Bioturbation on wildfire-affected southeast Australian hillslopes: Spatial and temporal variation

The importance of bioturbation as an agent of soil and geomorphological change is well known but few observations have been made of spatial and temporal variations in bioturbation rates. We quantified variations in surface bioturbation by ants (particularly Aphaenogaster longiceps) and vertebrates in the sandstone terrain of the Blue Mountains, southeast Australia. Following wildfire during the period late 2001–early 2002, we monitored thirty-three 5 m² plots positioned in six different slope units and in two catchments affected by different wildfire severities. Measurements were made seasonally for six years. Overall, mean rates of ant mounding and surface scraping by vertebrates were similar (246 ± 339 g m^− 2 yr^− 1 and 274 ± 179 g m^− 2 yr^− 1, respectively). However, rates varied substantially according to slope unit, showing a marked maximum for both ant mounding and total bioturbation on footslopes. Possible reasons for this spatial variation are discussed. A complex response to various soil and ecological factors such as soil texture, soil moisture and vegetation patterns is the most likely explanation. Associated estimates of topsoil (0–30 cm depth) turnover times, based on ant mounding rates alone, ranged from 300 to 100,000 years for different slope units. In contrast to previous findings, wildfire severity did not seem to affect bioturbation, possibly because of ant survival in deep nests and spatial patchiness of fire severity. There was likewise no clear link between temporal changes in bioturbation and fire severity; high rates in the first two years after wildfire were followed by lower rates for all burn severity types. There was also seasonal variability that was not directly related to rainfall. The results substantiate the importance of bioturbation in modifying soil characteristics and influencing soil erosion, especially following a major disturbance event like wildfire.     

The Effects of Temperature,Extent of Evaporation,and Restriction of Ventilation on the Storage Life of Tomatoes

The storage life of English glasshouse tomatoes is generally terminated by the onset of rotting which at temperatures above 50° F. (10° C.) generally starts from the calyx. As the temperature of storage is reduced below 50° F. the skins of tomatoes become increasingly susceptible to fungal invasion.

Storage at 59° F. (15° C.), under conditions of restricted ventilation in controlled-atmosphere storage which allow exposure to more than 5% CO₂, , also renders the skins of tomatoes susceptible to fungal infection.

The establishment of infection is also greatly influenced by the extent of evaporation, i.e. by the humidity of the storage atmosphere.

The conditions for the storage of tomatoes and the precautions to be observed in prepackaging are discussed in the light of these effects.     

Lateralization in the domestic dog (Canis familiaris): Relationships between structural,motor, and sensory laterality

Several studies have assessed different components of lateralization. To date, the relationships between the 3 measures of laterality, structural, motor, and sensory, have not widely been assessed. Specifically, the relationships between structural (hair whorl characteristics) and motor or sensory lateralization have largely been overlooked. This study investigated the associations between these measures of lateralization in dogs (n = 114), using hair whorl characteristics (structural), the Kong and First-stepping Tests (motor), and the Sensory Jump Test (sensory). Several associations emerged, revealing the first evidence of a relationship between structural asymmetry (both the presence and direction of a hair whorl in various regions of the body) and sensory lateralization. Specifically, the presence of a whorl on the dog’s left side of the head (cephalic) and thorax was associated with a right visual bias. In addition, right visual bias was probable if the ventral mandibular whorl was present in a counter-clockwise direction (P = 0.008). Our data also demonstrated an association between structural and motor laterality (paw preference). Most notably, dogs with clockwise chest whorls were significantly more right-preferent in the First-stepping Test than those with counter-clockwise whorls (P = 0.010). In addition, an association between measures of motor and sensory lateralization also emerged, representing some of the first evidence of such a relationship in nonhuman animals.     

First-stepping Test as a measure of motor laterality in dogs (Canis familiaris)

Motor laterality in potential guide dogs (n = 113) was determined using two methods: the Kong? Test (the current benchmark test) and our innovation, a First-stepping Test. Kong? studies record paw use during foraging from a rubber cylinder. However, motivation to feed varies markedly among dogs and breeds, and the test comprises 50 observations which for a single dog can take up to 4 hours to collect. The First-stepping Test bypasses hunger, and simply records the first foot advanced after standing with both forelegs level. In contrast to the Kong? Test, it allows 50 observations to be gathered in 20 minutes. The findings of the current study indicate that lateralized behavior in the domestic dog is strongly task-dependent. The First-stepping Test revealed more significant paw preferences (PPs) than the Kong? Test (76.1% vs. 52.2%). A significant right population bias (P = 0.036) was revealed using this novel test, whereas there was no bias in the direction of laterality observed using the Kong? Test (P = 0.30). Instead, there was a significant population bias for the category of ambidextrous PP using the Kong? (P = 0.005). Strength of laterality (regardless of direction) was significantly high in the First-stepping Test (P < 0.001), but only weak PPs were observed for the Kong? Test (P = 0.65). Measures of laterality from the First-stepping Test were not influenced by dog factors, whereas age, breed, and sex of the dog were significantly associated with several laterality measures during the Kong? Test. The occurrence of using both paws simultaneously to either hold the Kong?, or to step-off by means of jumping, was associated with a decrease in lateral strength for both tests. The First-stepping Test was repeatable, and the intraobserver (κ = 0.988) and interobserver (κ = 0.975) reliabilities were high. It offers a simple, quick and, when compared with the Kong? Test, a more discriminative method of determining PP that is less influenced by dog factors.     

Risk factors for Haemobartonella felis infection in cats

A seroepidemiologic survey for Haemobartonella felis infection in cats of Wake County, NC was undertaken. To help assess risk factors, cat owners completed a 10-item questionnaire. Additionally, blood samples were obtained for determination of H felis presence, FeLV infection, and anemia. Prevalence rates for H felis presence were as follows: all cats, 4.9% (6/123); healthy cats, 3.6% (3/83); and ill cats, 7.5% (3/40). The estimated relative risk for haemobartonellosis was also increased in cats with any of the following: anemia, FeLV-positive status, lack of vaccinations, history of catbite abscesses and/or anemia, age less than or equal to 3 years, or outdoor-roaming status. The sex, breed, number of cats in the household, or presence of fleas were not significant factors, although ill male cats had a greater estimated relative risk for haemobartonellosis.     

Haematological values of young male rusa deer (Cervus timorensis)

OBJECTIVE: To measure haematological values of clinical significance for rusa deer and provide reference data for farmed animals. DESIGN: Blood samples were collected regularly from eight male rusa deer from 14 days to 27 months old. PROCEDURE: Blood samples, collected by venipuncture, were analysed within 6 hours of collection for red cell count, haemoglobin, packed cell volume, plasma glucose, white cell count and differentials. RESULTS: Haemoglobin concentrations appeared to increase with age and ranged from 6.0 to 20.9 g/dL. Packed cell volume and plasma glucose concentration did not appear to vary with age. White cell counts ranged from 6.3 to 7.0 x 10(9)/L and differential counts indicated neutrophils > lymphocytes > monocytes > eosinophils > basophils. In general, the values for packed cell volume, red cell count, mean cell volumes and mean cell haemoglobin concentrations were within ranges previously reported for captive or sedated rusa deer. CONCLUSIONS: Physical restraint and resultant stress was sufficient to generate some of the effects previously reported for physically immobilised or agitated deer. The values reported here do not differ greatly from those previously reported for rusa deer and can be used as reference values for clinically healthy young farmed male rusa deer.