Signature MicroRNA expression profile is associated with lipid metabolism in African green monkey.

BACKGROUND: Non-human primates (NHPs) are important models of medical research on obesity and cardiovascular diseases. As two of the most commonly used NHPs, cynomolgus macaque (CM) and African green monkey (AGM) own different capacities in lipid metabolism of which the mechanism is unknown. This study investigated the expression profiles of lipid metabolism-related microRNAs (miRNAs) in CM and AGM and their possible roles in controlling lipid metabolism-related gene expression. METHODS: By small RNA deep sequencing, the plasma miRNA expression patterns of CM and AGM were compared. The lipid metabolism-related miRNAs were validated through quantitative reverse-transcription (RT) polymerase chain reaction (PCR). Related-target genes were predicted by TargetScan and validated in Vero cells. RESULTS: Compared to CM, 85 miRNAs were upregulated with over 1.5-fold change in AGM of which 12 miRNAs were related to lipid metabolism. miR-122, miR-9, miR-185, miR-182 exhibited the greatest fold changes(fold changes are 51.2, 3.8, 3.7, 3.3 respectively; all P < 0.01). And 77 miRNAs were downregulated with over 1.5-fold change in AGM of which 3, miR-370, miR-26, miR-128 (fold changes are 9.3, 1.8, 1.7 respectively; all P < 0.05) were related to lipid metabolism. The lipid metabolism-related gene targets were predicted by TargetScan and confirmed in the Vero cells. CONCLUSION: We report for the first time a circulating lipid metabolism-related miRNA profile for CM and AGM, which may add to knowledge of differences between these two non-human primate species and miRNAs' roles in lipid metabolism.

Metagenomic comparison of the rectal microbiota between rhesus macaques (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis).

Rhesus macaques (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis) are frequently used in establishing animal models for human diseases. To determine the differences in gut microbiota between these species, rectal swabs from 20 rhesus macaques and 21 cynomolgus macaques were collected, and the microbial composition was examined by deep sequencing of the 16S rRNA gene. We found that the rectal microbiota of cynomolgus macaques exhibited significantly higher alpha diversity than that of rhesus macaques, although the observed number of operational taxonomic units (OTUs) was almost the same. The dominant taxa at both the phylum and genus levels were similar between the two species, although the relative abundances of these dominant taxa were significantly different between them. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) showed significant differences in the functional components between the microbiota of the two species, in particular the lipopolysaccharide (LPS) synthesis proteins. The above data indicated significant differences in microbial composition and function between these two closely related macaque species, which should be taken into consideration in the future selection of these animals for disease models.

Genetic diversity of Bartonella quintana in macaques suggests zoonotic origin of trench fever.

Bartonella quintana is a bacterium that causes a broad spectrum of diseases in humans including trench fever. Humans were previously considered to be the primary, if not the only, reservoir hosts for B. quintana. To identify the animal reservoir and extend our understanding of the ecological and evolutionary history of B. quintana, we examined blood samples from macaques and performed multilocus sequence typing (MLST) analysis. We demonstrated the prevalence of B. quintana infection was common in macaques from main primate centres in mainland China. Overall, 18.0% (59/328) of rhesus macaques and 12.7% (39/308) of cynomolgus macaques were found to be infected with B. quintana by blood culture and/or polymerase chain reaction. The infection was more frequently identified in juvenile and young monkeys compared with adult animals. In contrast with the relatively low level of sequence divergence of B. quintana reported in humans, our investigation revealed much higher genetic diversity in nonhuman primates. We identified 44 new nucleotide variable sites and 14 novel sequence types (STs) among the B. quintana isolates by MLST analysis. Some STs were found only in cynomolgus macaques, while some others were detected only in rhesus macaques, suggesting evidence of host-cospeciation, which were further confirmed by phylogenetic analysis and Splits decomposition analysis. Our findings suggest that trench fever may primarily be a zoonotic disease with macaques as the natural hosts.

Characteristics of circle of Willis variations in the mongolian gerbil and a newly established ischemia-prone gerbil group.

Mongolian gerbils (Meriones unguiculatus) have an incomplete circle of Willis (CoW), as a result of which approximately 30-40% of these animals develop focal cerebral ischemia after unilateral carotid occlusion (UCO). There are four types of patterns of the anterior and posterior communicating arteries (ACoAs and PCoAs, respectively) of the CoW and they determine the severity of the ischemic symptoms. We used 398 gerbils from five generations, including a selectively bred ischemia-prone group, to investigate post-UCO ischemic symptoms and possible correlations of ACoA and PCoA patterns between parents and their progeny. We observed that if the parents had complete ACoAs, their progeny also had complete ACoAs, and we found significant differences when the parents' ACoAs were incomplete: in 60.4% of offspring the type of ACoA was consistent with that of the mother and in 48.2% it was consistent with that of the father. The severity of the neurological symptoms after UCO was significantly related to the patterns of the ACoAs when PCoAs were absent. The proportion of UCO ischemia in gerbils with incomplete ACoAs was significantly higher than in those with complete ACoAs. After selectively breeding five generations, the proportion of UCO ischemia increased from 40% in the F1 animals to 75% in the F5 animals. Our results suggest that variations in the CoW are genetic and demonstrate that we successfully established an ischemia-prone group of gerbils.

[Exogenous DNA influencing fertilization of goat sperm cells and expression in early embryos].

Our early study found that goat spermatozoa could spontaneously take up foreign DNA and vary in capabilities of spermatozoa from different donors to bind and internalize exogenous DNA. In this study, three goats with considerable differences of capability were used to investigate the effect of exogenous DNA on goat spermatozoa, and feasibility and efficiency of transgenic embryo production by sperm-mediated gene transfer method. The viability, acrosomal reaction frequencies and cleavages were decreased in the groups co-cultured with exogenous DNA, compared with the control groups, and the range of decrease was correlated with the capability of sperm cells up-take foreign DNA. After fertilizing with co-cultured spermatozoa, GFP gene was introduced into oocytes and expressed in early embryos. However, different efficiencies of transgenic embryos appeared in sperm donors (P<0.05). GFP gene was detected in 16.2% (25/154), 5.3% (4/76), and 0% (0/36) embryos, respectively, when high, middle and low capability of sperm donors were used. But only 6.5% (10/154) embryos from high capability sperm donor expressed GFP. Our results demonstrate that selecting high capability of sperm donor is a key step for improving efficiency of sperm mediated-gene transfer method. However, the adverse influence of foreign DNA on spermatozoa needs to be further studied.

[Characteristics and Influencing factors of Sperm Interaction with Exogenous DNA].

Exogenous DNA localization and the frequency of spermatozoa carrying exogenous DNA after sperm/DNA co-culture are key to a successful sperm mediated-gene transfer (SMGT). In the study, the characteristics and influencing factors of exogenous DNA uptake by spermatozoa were tested using digoxigenin (DIG) labeled DNA as trace. Results showed that goat spermatozoa could spontaneously take up exogenous DNA. The exogenous DNA was initially bound to the outer sperm membrane at postacrosomal region; subsequently party of the bound DNA was internalized into nucleus. There were considerable differences in the capability of spermatozoa from different donors to bind and internalize exogenous DNA. In 35 samples, binding rates (before DNase I digestion) and internalization rates (the positive rate after DNase I digestion) varied between 4.6%-62.4% and 2.1%-53.8%, respectively. For the spermatozoa from the same goat, the binding and internalization capacities were mostly inhibited by the seminal fluid. Compared to ejaculate sperm, the binding rate and internalization rate were increased three and five times in washed sperm cells, respectively. At the same time, capacitated spermatozoa also had lower exogenous DNA uptake (P<0.01). Dead spermatozoa did not complete the internalization process. The highest positive rate (before DNase I digestion) was found in membrane-broken spermatozoa as a result of freeze-thawing and this was independent of the sperm donors. These results suggest that selection of appropriate sperm donors and optimization of sperm processing procedures are the key steps for successful SMGT.