Paper Title
The Impact of Cytochrome B (MTDNA) on The Viability of Weaned Rabbits

The authors described two new cytochrome b haplotypes of mitochondrial DNA (mtDNA) of rabbit meat lines cyt b 306 and cyt b 430. Haplotype cyt b 306 is presented by nucleotide substitution A571G, i.e. 571G (190Alanine-A) + 877G (292Alanine-A). The haplotype cyt b 430 represents 571A (190Threonine-T) + 877G (292Alanine -A). Haplotype cyt b 306 with polymorphism A571G mtDNA is registered in the BOLD System-The Barcode of Life Data System, Canada: + OC cytb Cyt b 306 haplotype vitality, expressed as mean number of weaned offspring at 42 days, was significantly higher compared to cyt b haplotype b 430 (ẍ = 7.00 vs. ẍ = 5.69, t (0,01) =2,91++). These results are also confirmed by immunogenetic data obtained from flow cytometry. Haplotype cyt b 306 is characterized by a significant increase (P = 0.041+ to P = 0.049+) flow cytometric parameters in the T cell frequency, which is reflected by activation of pT2 and CD4 lymphocytes (pT2 = 22.02 ± 4.45% and CD4 = 17.08 ± 3.43%). Compared to cyt b 430 haplotype, which is represented by significantly lower flow cytometric parameters in pT2 and CD4 lymphocyte activation (pT2=15.32±6.11% and CD4=11.48±4.83%). While there were no differences (8.45, vs. 8.00) in reproductive indicators such as the average number of live-born kits between the haplotypes of interest (cyt b 306, vs. cyt b 430). Also, the production indicators represented by the carcass yield (without head and skin) of both haplotypes (cyt b 306, vs. cyt b 430) were not affected by the directed selection and remained at the same level of 54% (54.41,vs.54.26). Keywords - Rabbit, Viability, Cytochrome B, Cyt b 306 and Cyt b 430 Haplotypes, Flow Cytometry