Multiomic analysis of the Arabian camel (Camelus dromedarius) kidney reveals a role for cholesterol in water conservation

The Arabian camel (Camelus dromedarius) is the most important livestock animal in arid and semi-arid regions and provides basic necessities to millions of people. In the current context of climate change, there is renewed interest in the mechanisms that enable camelids to survive in arid conditions. Recent investigations described genomic signatures revealing evolutionary adaptations to desert environments. We now present a comprehensive catalogue of the transcriptomes and proteomes of the dromedary kidney and describe how gene expression is modulated as a consequence of chronic dehydration and acute rehydration. Our analyses suggested an enrichment of the cholesterol biosynthetic process and an overrepresentation of categories related to ion transport. Thus, we further validated differentially expressed genes with known roles in water conservation which are affected by changes in cholesterol levels. Our datasets suggest that suppression of cholesterol biosynthesis may facilitate water retention in the kidney by indirectly facilitating the AQP2-mediated water reabsorption.

Meat quality characteristics of the Arabian camel (Camelus dromedarius) at different ages and post-mortem ageing periods

Objective: Meat quality characteristics and sensory attributes were evaluated in three age groups (12, 18, and 24 mo) of one-humped camels of the Saudi Arabian Najdi breed.Methods: Thirty-six male camels (12 for each age group) were used. The <i>Longissimus dorsi</i> muscle from each carcass was divided into three parts and subjected to three ageing periods (1, 5, or 10 d) and evaluated for shear force, myofibril fragmentation index (MFI), expressed juice, cooking loss, and sensory attributes.Results: Age had a significant effect on shear force, MFI, expressed juice quantity, and organoleptic properties. Camels slaughtered at 12 mo exhibited lower shear force and MFI, and higher expressed juice quantity, tenderness, juiciness, and overall acceptability than those slaughtered at 24 mo. Ageing had a significant influence on shear force, MFI, expressed juice quantity, but not on cooking loss. Camel meat aged for 10 d exhibited significantly lower shear force values and expressed juice quantity, and significantly higher MFI compared to that aged for 1 d. However, ageing did not significantly affect sensory attributes, except for tenderness, in camels slaughtered at 18 mo.Conclusion: Both instrumental and sensory evaluations showed that young camel meat has desirable quality characteristics, with superior tenderness and juiciness.

A pilot study on the pharmacokinetics of a single intramuscular injection of cefquinome in Arabian camel calves

This study was conducted to evaluate the pharmacokinetics of cefquinome in camel calves after a single intramuscular injection in a dose of 2 mg/kg body weight (kg b. w.). Cefquinome concentrations were measured by ultra-high performance liquid chromatography–mass spectrometry (UPLC-MS/MS). A non-compartmental pharmacokinetic model was used to fit the time–concentration curve and estimate the pharmacokinetic parameters. The peak serum concentration (Cmax) was 28.4 μg/mL at the time of maximum concentration (Tmax) of 25 min. The elimination half-life (t1/2) was 17.4 h. The area under the concentration–time curve (AUC0–∞) was 103.7 μg/ml−1h and the mean residence time (MRT0–∞) was 21.3 h. In comparison with other animal species, the pharmacokinetics of cefquinome in Arabian camel calves showed faster absorption from the site of injection and slower elimination. Since cefquinome, as other beta-lactams, is a time-dependent antimicrobial agent, a single dose of 2 mg/kg b. w. might be sufficient against the most sensitive organisms in camel calves owing to its prolonged elimination phase. However, dose readjustment is required for cases needing concentrations above 2 µg/mL for 12 h or above 1 µg/mL for 24 h.

Genome-wide characterization and analysis of microsatellite sequences in camelid species

Microsatellites or simple sequence repeats (SSRs) are among the genetic markers most widely utilized in research. This includes applications in numerous fields such as genetic conservation, paternity testing, and molecular breeding. Though ordered draft genome assemblies of camels have been announced, including for the Arabian camel, systemic analysis of camel SSRs is still limited. The identification and development of informative and robust molecular SSR markers are essential for marker assisted breeding programs and paternity testing. Here we searched and compared perfect SSRs with 1–6 bp nucleotide motifs to characterize microsatellites for draft genome sequences of the Camelidae. We analyzed and compared the occurrence, relative abundance, relative density, and guanine-cytosine (GC) content in four taxonomically different camelid species: Camelus dromedarius, C. bactrianus, C. ferus, and Vicugna pacos. A total of 546762, 544494, 547974, and 437815 SSRs were mined, respectively. Mononucleotide SSRs were the most frequent in the four genomes, followed in descending order by di-, tetra-, tri-, penta-, and hexanucleotide SSRs. GC content was highest in dinucleotide SSRs and lowest in mononucleotide SSRs. Our results provide further evidence that SSRs are more abundant in noncoding regions than in coding regions. Similar distributions of microsatellites were found in all four species, which indicates that the pattern of microsatellites is conserved in family Camelidae.

Isolation and Culture of Skin-Derived Differentiated and Stem-Like Cells Obtained from the Arabian Camel (Camelus dromedarius)

Elite camels often suffer from massive injuries. Thus, there is a pivotal need for a cheap and readily available regenerative medicine source. We isolated novel stem-like cells from camel skin and investigated their multipotency and resistance against various stresses. Skin samples were isolated from ears of five camels. Fibroblasts, keratinocytes, and spheroid progenitors were extracted. After separation of different cell lines by trypsinization, all cell lines were exposed to heat shock. Then, fibroblasts and dermal cyst-forming cells were examined under cryopreservation. Dermal cyst-forming cells were evaluated for resistance against osmotic pressure. The results revealed that resistance periods against trypsin were 1.5, 4, and 7 min for fibroblasts, keratinocytes, and spheroid progenitors, respectively. Furthermore, complete recovery of different cell lines after heat shock along with the differentiation of spheroid progenitors into neurons was observed. Fibroblasts and spheroid progenitors retained cell proliferation after cryopreservation. Dermal cyst-forming cells regained their normal structure after collapsing by osmotic pressure. The spheroid progenitors incubated in the adipogenic, osteogenic, and neurogenic media differentiated into adipocyte-, osteoblast-, and neuron-like cells, respectively. To the best of our knowledge, we isolated different unique cellular types and stem-like cells from the camel skin and examined their multipotency for the first time.