Optimizing the order of taxon addition in phylogenetic tree construction using genetic algorithm

Abstract. Phylogenetics has gained in public favor for the analysis of DNA sequence data as molecular biology has advanced. Among a number of algorithms for phylogenetics, the fastDNAml is considered to have reasonable computational cost and performance. However, it has a defect that its performance is likely to be significantly affected by the order of taxon addition. In this paper, we propose a genetic algorithm for optimizing the order of taxon addition in the fastDNAml. Experimental results show that the fastDNAml with the optimized order of taxon addition constructs more probable evolutionary trees in terms of the maximum likelihood.

Expression of costimulatory molecules in the bovine corpus luteum

BACKGROUND: Bovine luteal parenchymal cells express class II major histocompatibility complex (MHC) molecules and stimulate class II MHC-dependent activation of T cells in vitro. The ability of a class II MHC-expressing cell type to elicit a response from T cells in vivo is also dependent on expression of costimulatory molecules by the antigen presenting cell and delivery of a costimulatory signal to the T cell. Whether bovine luteal parenchymal cells express costimulatory molecules and can deliver the costimulatory signal is currently unknown. METHODS: Bovine luteal tissue was collected during the early (day 5; day of estrus = day 0), mid (day 11–12), or late (day 18) luteal phase of the estrous cycle, and at 0, 0.5, 1, 4, 12 or 24 hours following administration of PGF2alpha to cows on day 10 of the estrous cycle. Northern analysis was used to measure CD80 or CD86 mRNA concentrations in luteal tissue samples. Mixed luteal parenchymal cell cultures and purified luteal endothelial cell cultures were prepared, and real-time RT-PCR was used to examine the presence of CD80 and CD86 mRNA in each culture type. Monoclonal antibodies to CD80 and CD86 were added to a mixed luteal parenchymal cell-T cell co-culture in vitro T cell proliferation assay to assess the functional significance of costimulatory molecules on activation of T lymphocytes by luteal parenchymal cells. RESULTS: Northern analysis revealed CD80 and CD86 mRNAs in luteal tissue, with greatest steady-state concentrations at midcycle. CD80 and CD86 mRNAs were detected in mixed luteal parenchymal cell cultures, but only slight amounts of CD80 (and not CD86) mRNA were detected in cultures of luteal endothelial cells. Luteinizing hormone, PGF2alpha and TNF-alpha were without effect on concentrations of CD80 or CD86 mRNA in mixed luteal parenchymal cells cultures. Anti-CD80 or anti-CD86 monoclonal antibodies inhibited T cell proliferation in the in vitro T cell proliferation assay. CONCLUSION: It can be concluded from this study that parenchymal cells within the bovine CL express functional costimulatory molecules that facilitate interactions between with T cells, and these components of the antigen presentation pathway are expressed maximally in the midcycle CL

EXPERIMENTAL-INFECTION IN CHICKENS WITH LARVAE OF BAYLISASCARIS-TRANSFUGA (NEMATODA, ASCARIDOIDEA)

The larvae of Baylisascaris transfuga (Rudolphi, 1819) were able to penetrate the liver, lungs, carcass and brain of infected chickens, but a great number of larvae accumulated in the liver. No clinical signs were seen. Birds may serve as paratenic hosts of the parasite, but B. transfuga seems not to be a possible agent of avian cerebrospinal nematodosis

IN-VIVO OVICIDAL EFFECT OF MEBENDAZOLE ON BAYLISASCARIS TRANSFUGA EGGS

Mebenzadole was tested for in vivo effect on the eggs of B. transfuga recovered from polar bears treated with the drug. A marked reduction of the number of eggs that developed to the larval stage was observed. The pre-treatment percentage of incubated eggs that developed to the larval stage was 80 %-92 %. On day 1, after treatment was starting, the percentage was 26 %-70 %, on day 2 the number was 0 %-9 % and on day 3 it was 0 %-1 %. No eggs developed on day 4 and thereafter. Coprological examinations were negative after 4-7 days the treatment was starting

Fibrocartilaginous embolic myelopathy in a lion (Panthera leo)

A 6-yr-old, captive-born male lion (Panthera leo) with a 3-day history of acute and nonprogressive spastic paraplegia of the hind limbs and flaccid paraplegia of the left forelimb, was submitted for postmortem examination. Before and after the onset of the neurologic signs, neither hematologic nor other significant clinical abnormalities were observed. The only remarkable gross lesion was restricted to the C6–C7 segments of the spinal cord, where a focal and asymmetric enlargement of the cord displaced the nerve roots. On the cut surface, a poorly demarcated dark red hemorrhagic lesion involved the lateroventral funiculi and the ventral horn of the gray matter, exclusively on the left half of the cord. Extensive necrosis, hemorrhages, degeneration of the neuroparenchyma, and several fibrocartilaginous emboli occluding the lumina of intraparenchymal arteries were present within histologic sections of spinal cord. Emboli also were detected within the meningeal vessels. This is the first report of fibrocartilaginous embolic myelopathy occurring in a lion