Molecular basis for the auxin-independent phenotype of crown gall tumor tissues

The transfer of specific Ti (tumor-inducing) plasmid sequences, the T-DNA, from Agrobacterium tumefaciens to a wide range of plants results in the formation of crown gall tumors. These tissues differ from most plant cells in that they can be grown in vitro in the absence of added phytohormones. Here, data are presented that offer an explanation for the auxin-independent phenotype of crown gall tissues. It is shown that crude cell-free extracts prepared from three bacterial species harboring pTiA6 gene 1 could convert L-tryptophan to indole-3-acetamide; control extracts lacking gene 1 could not carry out the reaction. Other reports indicate that the pTiA6 gene 2 product can convert indole-3-acetamide to indole-3-acetic acid, a naturally occurring auxin of plants. It is concluded that the auxin-independent phenotype of crown gall tissue involves the introduction of Ti plasmid sequences encoding a two-step pathway for auxin synthesis.     

Prevalence of Bartonella species,Rickettsia felis,haemoplasmas and the Ehrlichia group in the blood of cats and fleas in eastern Australia

Objectives To define the prevalence of Bartonella spp., Rickettsia felis, Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ (Mhm) and ‘Candidatus Mycoplasma turicensis’ (Mtc) in cats and their fleas in eastern Australia. Design and procedure Conventional PCR assays that detect Bartonella spp., M. haemofelis, Mhm, Mtc, Rickettsia spp., Ehrlichia spp., Anaplasma spp. and Neorickettsia spp. were performed on DNA extracted from blood and fleas collected from 111 cats. Cat sera were assayed by ELISA for IgG of Bartonella spp. Results DNA of M. haemofelis, Mtc and Mhm was amplified from 1 (0.9%), 1 (0.9%) and 17 cats (15.3%), respectively. Only DNA of Mhm was amplified from the 62 of 111 pooled flea samples (flea sets; 55.9%). Overall, the prevalence rates for Bartonella spp. DNA in the cats and the flea sets was 16.2% (18 cats) and 28.8% (32 flea sets), respectively. Bartonella spp. IgG was detected in 42 cats (37.8%), of which 11 (26.2%) were positive for Bartonella spp. DNA in their blood. R. felis DNA was amplified from 22 flea sets (19.8%), but not from cats. Overall, DNA of one or more of the organisms was amplified from 27% (30) of cats and 67.6% (75) of the flea sets. Conclusions This is the first Australian study to determine the prevalence of R. felis and B. clarridgeiae in both fleas and the cats from which they were collected. Flea-associated infectious agents are common in cats and fleas in eastern Australia and support the recommendation that stringent flea control be maintained on cats.     

Chemotherapy and radiation therapy in 4 dogs with muscle-invasive transitional cell carcinoma of the urinary tract

Four dogs with T₂N₀M₀ transitional cell carcinoma of the lower urinary tract underwent multimodal treatment consisting of neoadjuvant chemotherapy, external-beam radiotherapy, and adjuvant chemotherapy. No significant toxicity was documented. All dogs showed clinical improvement and reduction of tumor volume based on computed tomography (CT).     

Investigating the turkey's 'snood' as a morphological marker of heritable disease resistance

The sexual ornamentation of many wild species, including the ancestors of domestic poultry, are reliable indicators of parasite burden, suggesting that they may serve as morphological markers of heritable disease resistance. Measures of male ornamentation might be a culturally and economically feasible method of identifying conservation‐worthy genotypes from indigenous poultry flocks. Here we investigate the relationship between the sexually selected, parasite‐burden‐indicating ‘snood’ of male game farm turkeys, and their immunocompetence and immunogenetic [major histocompatibility complex (MHC) class II B restriction fragment‐length polymorphism (RFLP)] variation. We find that specific restriction fragments appear to be favourable to both immunocompetence and ornament size, but that turkey snood length is not a valuable predictor of wing web swelling due to phytohemagglutinin (PHA) injection. Immunocompetence increased with composite band sharing, a measure of absolute variation at the MHC. Snood length, however, was greatest in males that showed intermediate measures of relative band sharing. We conclude that tradeoffs among the conflicting demands on the energy reserves of free‐living poultry, might ensure that long‐snooded indigenous turkeys are best adapted to local disease conditions without wasting resources on hyperimmunity.     

Impact of human disturbance on the thermoregulatory behaviour of the endangered ringed sawback turtle (Graptemys oculifera)

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