Evolutionary conservation of Trichomonas-mycoplasma symbiosis across the host species barrier.

Introduction: The protozoan parasite Trichomonas vaginalis is the most common cellular sexually transmitted disease in humans, and the closely related species Trichomonas gallinae is an avian parasite of ecological and economic importance. Phylogenetic evidence suggests T. vaginalis arose during bird to human transmission of a T. gallinae-like ancestor. Trichomonas vaginalis shares a strong clinical association with the independent sexually transmitted pathogen Metamycoplasma (formerly Mycoplasma) hominis, and the uncultured bacterium "Candidatus Malacoplasma (formerly Mycoplasma) girerdii," with the latter association being an order of magnitude stronger. Both bacterial species have been shown to profoundly influence T. vaginalis growth, energy production and virulence-associated mechanisms. Methods: Evidence for a novel Malacoplasma sp. was discovered by in vivo Illumina metatranscriptomics sequencing of the T. gallinae-infected pigeon mouth. We leveraged published 16S rDNA profiling data from digestive tract of 12 healthy and 24 T. gallinae-infected pigeons to investigate association between the novel Malacoplasma sp. and T. gallinae. We utilised Illumina metagenomics sequencing targeted to pigeon oral and crop samples infected with the novel Malacoplasma sp. to generate its full-length genome sequence. Sequence similarity network analysis was used to compare annotated proteins from the novel Malacoplasma sp. with a range of other related species. Results: Here we present evidence for a novel Malacoplasma species, related to "Ca. M. girerdii," that is strongly associated with T. gallinae in the upper digestive tract of domestic pigeons. Analysis of the genome sequence revealed gene features apparently specific to a Trichomonas-symbiotic Malacoplasma lineage. Discussion: These data support a model of long-term association between Trichomonas and Malacoplasma spp. that has been conserved across diversification of the Trichomonas lineage and the host species barrier from birds to human.

The Effects of Inorganic Phosphorus Levels on Phosphorus Utilization, Local Bone-Derived Regulators, and BMP/MAPK Pathway in Primary Cultured Osteoblasts of Broiler Chicks.

Understanding the underlying mechanisms that regulate the bone phosphorus (P) utilization would be helpful for developing feasible strategies to improve utilization efficiency of P in poultry. We aimed to investigate the effects of inorganic P levels on P utilization, local bone-derived regulators and bone morphogenetic protein/mitogen-activated protein kinase (BMP/MAPK) pathway in primary cultured osteoblasts of broiler chicks in order to address whether local bone-derived regulators or BMP/MAPK pathway was involved in regulating the bone P utilization of broilers using an in vitro model. The primary cultured tibial osteoblasts of broiler chicks were randomly divided into one of five treatments with six replicates for each treatment. Then, cells were respectively incubated with 0.0, 0.5, 1.0, 1.5, or 2.0 mmol/L of added P as NaH2PO4 for 24 days. The results showed that as added P levels increased, tibial osteoblastic P retention rate, number and area of mineralized nodules, the mRNA expressions of endopeptidases on the X chromosome (PHEX), dentin matrix protein 1 (DMP1), bone morphogenetic protein 2 (BMP2), and the mRNA and protein expressions of matrix extracellular phosphoglycoprotein (MEPE) increased linearly (p < 0.001) or quadratically (p < 0.04), while extracellular signal-regulated kinase 1 (ERK1) mRNA expression and c-Jun N-terminal kinase 1 (JNK1) phosphorylated level decreased linearly (p < 0.02) or quadratically (p < 0.01). Correlation analyses showed that tibial osteoblastic P retention rate was positively correlated (r = 0.452-0.564, p < 0.03) with MEPE and BMP2 mRNA expressions. Furthermore, both number and area of mineralized nodules were positively correlated (r = 0.414-0.612, p < 0.03) with PHEX, DMP1, MEPE, and BMP2 mRNA expressions but negatively correlated (r = -0.566 to -0.414, p < 0.04) with the ERK1 mRNA expression and JNK1 phosphorylated level. These results suggested that P utilization in primary cultured tibial osteoblasts of broiler chicks might be partly regulated by PHEX, DMP1, MEPE, BMP2, ERK1, and JNK1.

Regulation of bone phosphorus retention and bone development possibly by related hormones and local bone-derived regulators in broiler chicks.

BACKGROUND: Phosphorus is essential for bone mineralization in broilers, however, the underlying mechanisms remain unclear. We aimed to investigate whether bone phosphorus retention and bone development might be regulated by related hormones and local bone-derived regulators in broilers. METHODS: Broilers were fed diets containing different levels of non-phytate phosphorus (NPP) 0.15%, 0.25%, 0.35%, 0.45% and 0.55% or 0.15%, 0.22%, 0.29%, 0.36% and 0.43% from 1 to 21 or 22 to 42 days of age. Serum and tibia samples were collected for determinations of bone phosphorus retention and bone development parameters, related hormones and local bone-derived regulators of broiler chickens on d 14, 28 and 42, respectively. RESULTS: Tibia ash phosphorus, total phosphorus accumulation in tibia ash (TPTA), bone mineral concentration (BMC), bone mineral density (BMD), bone breaking strength (BBS), and ash on d 14, 28 or 42, serum 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on d 28 and 42, mRNA expressions of tibia fibroblast growth factor 23 (FGF23) and dentin matrix protein 1 (DMP1) on d 14 and 28 increased linearly or quadratically (P < 0.05), while serum parathyroid hormone (PTH) on d 28, tibia alkaline phosphatase (ALP) on d 14, 28 and 42, bone gal protein (BGP) on d 14, and mRNA expression of tibia phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) on d 14 and 28 decreased linearly or quadratically (P < 0.04) as dietary NPP level increased. TPTA, BMC, BMD, and ash on d 28 and 42, BBS on d 28, and ash phosphorus on d 42 were positively correlated (r = 0.389 to 0.486, P < 0.03) with serum 1,25(OH)2D3. All of the above parameters were positively correlated (r = 0.380 to 0.689, P < 0.05) with tibia DMP1 mRNA expression on d 14, 28 and 42, but negatively correlated (r = - 0.609 to - 0.538, P < 0.02) with serum PTH on d 28, tibia ALP on d 14, 28 and 42, and BGP on d 14. TPTA, BMC and ash on d 14 and BMD on d 28 were negatively correlated (r = - 0.397 to - 0.362, P < 0.03) with tibia PHEX mRNA expression, and BMD on d 28 was positively correlated (r = 0.384, P = 0.04) with tibia FGF23 mRNA expression. CONCLUSIONS: These results suggested that bone phosphorus retention and bone development parameters had moderate to strong correlations with serum PTH and 1,25(OH)2D3 and tibia DMP1, PHEX, FGF23, ALP and BGP in broilers during the whole growth period, and thus they might be partly regulated by these related hormones and local bone-derived regulators.