Rex rabbit

Abstract: Antibiotics have been widely used for the prevention and the treatment of diseases to humans and animals, and they have fed additives for agricultural animals to promote growth. However, there is a growing concern over the practice due to its side effects on intestinal microbial communities which plays a vital role in animals’ health. To investigate the effect of antibiotics on the bacterial population of the caecum in rex rabbits, 80 rex rabbits were randomly divided into four groups: control group (B, basal diet), chlortetracycline group (C, 50 mg/kg), colistin sulfate group (S, 20 mg/kg) and zinc bacitracin group (Z, 40 mg/kg). Caecum microbial communities of rex rabbits from the four groups were analyzed through Illumina Miseq platform after being fed 28 days. The results showed that most obtained sequences belongs to Firmicutes followed by Bacteroidetes, and the ratio of Bacteroidetes/Firmicutes in C group (42.31 %) was higher than that in Z group (21.84 %). Zinc bacitracin supplementation caused a significant decreased of the Proteobacteria phylum and Lactobacillus spp. (P < 0.05), while the Lactobacillus spp. significantly increased in S group (P < 0.05). In addition, Ruminococcus spp., especially Ruminococcus albus were the predominant bacterial species found in both S and Z groups. The proportion of Coprococcus spp. significantly increased in Z group (P < 0.05). These findings suggested that the antibiotics used may cause significant changes in the caecum microbiota of rex rabbits, and we also found C group had a similarity caecum bacteria structure with B group which was probably due to the high levels of chlortetracycline resistance.

Abstract: Solute carrier family 7 member 11 (Slc7a11) is a cystine/glutamate xCT transporter that controls the production of pheomelanin pigment to change fur and skin color in animals. Previous studies have found that skin expression levels of Slc7a11 varied significantly with fur color in Rex rabbits. However, the molecular regulation mechanism of Slc7a11 in pigmentation is unknown. Here, rabbit melanocytes were first isolated and identified. The distribution and expression pattern of Slc7a11 was confirmed in skin from rabbits with different fur colors. Slc7a11 affected the expression of pigmentation related genes and thus affected melanogenesis. Meanwhile, Slc7a11 decreased melanocyte apoptosis, but inhibition of Slc7a11 enhanced apoptosis. Furthermore, the POU2F1 protein was found to bind to the −713 to −703 bp region of Slc7a11 promoter to inhibit its activity in a dual-luciferase reporter and site-directed mutagenesis assay. This study reveals the function of the Slc7a11 in melanogenesis and provides in-depth analysis of the mechanism of fur pigmentation.

Abstract: BACKGROUND: Encephalitozoon cuniculi is a microsporidian parasite commonly found in rabbits that can infect humans, causing encephalitozoonosis. Our objective in this study was to evaluate the seroprevalence of this parasite in rabbits and humans in China. METHODS: Overall, 300 serum samples each from clinically healthy rabbit and human were collected from three regions of China (Sichuan Province, Chongqing Municipality and Jilin Province) from January to September 2013 and tested for anti-E. Cuniculi antibodies using an ELISA. RESULTS: An overall seroprevalence of E. cuniculi was recorded as 56/300 (18.76%) and 29/300 (9.76%) in rabbit and human sera, respectively. The seropositivity of rabbit samples collected from Jilin province was 41%, which was significantly higher (P<0.01) than Sichuan Province (9%) and Chongqing Municipality (6%). Three breeds of rabbit were used in the present study and antibody detection in Rex Rabbit was significantly (P<0.01) higher than Japanese White and New Zealand Rabbit. In human, Jilin province was more prevalent (18%) followed by Sichuan Province (6%) and Chongqing Municipality (5%). CONCLUSIONS: The E. cuniculi was present and widespread among healthy rabbits and humans in China.