Positive selection footprints and haplotype distribution in the genome of dromedary camels.

Dromedary camels are a domestic species characterized by various adaptive traits. Limited efforts have been employed toward identifying genetic regions and haplotypes under selection that might be related to such adaptations. These genetic elements are considered valuable sources that should be conserved to maintain the dromedaries' adaptability. Here, we have analyzed whole genome sequences of 40 dromedary camels from different Arabian Peninsula populations to assess their genetic relationship and define regions with signatures of selection. Genetic distinction based on geography was observed, classifying the populations into four groups: (1) North and Central, (2) West, (3) Southwest, and (4) Southeast, with substantial levels of genetic admixture. Using the de-correlated composite of multiple signal approach, which combines four intra-population analyses (Tajima's D index, nucleotide diversity, integrated haplotype score, and number of segregating sites by length), a total of 36 candidate regions harboring 87 genes were identified to be under positive selection. These regions overlapped with 185 haplotype blocks encompassing 1 340 haplotypes, of which 30 (∼2%) were found to be approaching fixation. The defined candidate genes are associated with different biological processes related to the dromedaries' adaptive physiologies, including neurological pathways, musculoskeletal development, fertility, fat distribution, immunity, visual development, and kidney physiology. The results of this study highlight opportunities for further investigations at the whole-genome level to enhance our understanding of the evolutionary pressures shaping the dromedary genome.

Diagnostic accuracy of urinary creatinine concentration in the estimation of differential renal function in patients with obstructive uropathy.

OBJECTIVES: To determine the diagnostic accuracy of spot urine creatinine concentration (UCC) as a new test for the evaluation of differential renal function in obstructed kidneys (DRF(ok)) drained by percutaneous nephrostomy tube (PCNT). METHODS: In patients with obstructed kidneys drained by PCNT, DRF(ok) was derived from UCC by comparing the value of UCC in the obstructed kidney to the value in the contralateral kidney, and was derived from dimercaptosuccinic acid (DMSA) renal scans and creatinine clearance (CCr) using standard methods. Subsequently, the results of UCC were compared to the results of DMSA and CCr. RESULTS: 61 patients were enrolled. Bland-Altman plots to compare DMSA and UCC showed that the upper limit of agreement was 14.8% (95% CI 10.7-18.5) and the lower limit was -19.9% (95% CI -23.8 to -16.1). The sensitivity and specificity of detecting DMSA DRF(ok) < or = 35% using UCC was 85.2 and 91.2%, respectively. When UCC was compared to CCr, Bland-Altman tests gave an upper limit of agreement of 10.4% (95% CI 7.9-12.8) and a lower limit of agreement of -11.3% (95% CI -13.8 to -8.9). CONCLUSIONS: UCC is accurate in the estimation of DRF(ok) drained by PCNT.