Probiotics could promote animal growth and enhance immune function. This study investigated the effects of Clostridium butyricum (CB) on the growth performance, intestinal immune, and gut microbiota of weaning rex rabbits. A total of 60 healthy female rabbits (5-month-old) were divided equally into four groups and mated on the same day: control group (CTRL, fed with basal feed), low-dose group (LDG, fed with basal feed + 1.0 × 103 CFU/g CB), middle-dose group (MDG, fed with basal feed + 1.0 × 104 CFU/g CB), and high-dose group (HDG, fed with basal feed + 1.0 × 105 CFU/g CB). Then, 30 weaning rex rabbits (35-day-old) were collected from each group for this experiment, and they were offered the same feeds as their mother. The results demonstrated that high-dose CB treatment significantly increased average daily weight gain of weaning rex rabbits. Further studies suggested that CB enhanced small intestinal digestive enzyme activity and improved mucosal morphology and antioxidant status. Supplemented with CB, small intestinal barrier function was maintained with the upregulation of mRNA levels of ZO-1, claudin, and occludin as well as the increase of sIgA production. Moreover, the relative expressions of MyD88, TLR2, and TLR4 were elevated in HDG; simultaneously, pro-inflammatory cytokines including IL-6, INF-γ, and TNF-α were decreased after CB administration. In addition, CB showed beneficial effects in improving weaning rex rabbit intestinal microflora via increasing the abundance of beneficial bacteria. Therefore, our results indicated CB can promote rex rabbit growth, which is likely to the enhancement of immune function and the improvement of intestinal microbiota.
The phylogeography of the European wild boar was mainly determined by postglacial recolonization patterns from Mediterranean refugia after the last ice age. Here we present the first analysis of SNP polymorphism within the complete mtDNA genome of West Russian (n = 8), European (n = 64), and North African (n = 5) wild boar. Our analyses provided evidence of unique lineages in the East‐Caucasian (Dagestan) region and in Central Italy. A phylogenetic analysis revealed that these lineages are basal to the other European mtDNA sequences. We also show close connection between the Western Siberian and Eastern European populations. Also, the North African samples were clustered with the Iberian population. Phylogenetic trees and migration modeling revealed a high proximity of Dagestan sequences to those of Central Italy and suggested possible gene flow between Western Asia and Southern Europe which was not directly related to Northern and Central European lineages. Our results support the presence of old maternal lineages in two Southern glacial refugia (i.e., Caucasus and the Italian peninsula), as a legacy of an ancient wave of colonization of Southern Europe from an Eastern origin. 相似文献
The genus Dioscorea is widely distributed in tropical and subtropical regions, and is economically important in terms of food supply and pharmaceutical applications. However, DNA barcodes are relatively unsuccessful in discriminating between Dioscorea species, with the highest discrimination rate (23.26%) derived from matK sequences. In this study, we compared genic and intergenic regions of three Dioscorea chloroplast genomes and found that the density of SNPs and indels in intergenic sites was about twice and seven times higher than that of SNPs and indels in the genic regions, respectively. A total of 52 primer pairs covering highly variable regions were designed and seven pairs of primers had 80%–100% PCR success rate. PCR amplicons of 73 Dioscorea individuals and assembled sequences of 47 Dioscorea SRAs were used for estimating intraspecific and interspecific divergence for the seven loci: The rpoB‐trnC locus had the highest interspecific divergence. Automatic barcoding gap discovery (ABGD), Poisson tree processes (PTP), and generalized mixed Yule coalescence (GMYC) analysis were applied for species delimitation based on the seven loci and successfully identified the majority of species, except for species in the Enantiophyllum section. Phylogenetic analysis of 51 Dioscorea individuals (28 species) showed that most individuals belonging to the same species tended to cluster in the same group. Our results suggest that the variable loci derived from comparative analysis of plastid genome sequences could be good DNA barcode candidates for taxonomic analysis and species delimitation. 相似文献
The oriental armyworm, Mythimna separata, is a serious agricultural pest in China. Seasonal and roundtrip migration has recently led to sudden, localized outbreaks and crop losses. To evaluate genetic differentiation between populations in eastern and western China and elucidate gene flow, the genetic structure of 20 natural populations from nine provinces was examined using seven microsatellite markers. The results indicated high genetic diversity. However, little to moderate (0 < FST < 0.15) genetic differentiation was detected, and there was no correlation between genetic distance and geographical distance. Bayesian clustering analysis identified three groups whereas discriminant analysis of principal components identified ten clusters that were considered as two clear‐cut clusters and one admixed group. Gene flow occurred frequently in most population pairs, and an asymmetrical migration rate was detected in several pairwise population comparisons. The bottleneck test showed that few populations had experienced recent bottlenecks. Correspondingly, large‐scale and long‐distance migration of M. separata has caused low genetic differentiation and frequent gene exchange. Our findings are important for studying genetic evolution and help to improve predictions of M. separata outbreaks in China. 相似文献