Biology subjects

Larzul, C.

Publications and source records attributed to Larzul, C..

2 recordsLinked to original sources

bioRxiv2026

Study of holobiont resilience following a break in symbiotic transmission in two rabbit lines selected for feed efficiency

This study was carried out on two rabbit lines, each selected for a feed efficiency criterion (growth on restricted feed for the AlimR line or residual consumption on an adlibitum diet for the ConsR line), introduced into a facility by adoption of newborn kits by SPF (specific pathogen free) females. Following this break in symbiotic transmission, fecal samples from females were used to study the microbiota composition of the two lines over seven generations (17 females per line and per generation). The proportion of Firmicutes was significantly higher in the AlimR line than in the ConsR line (82.22% vs 78.21%, p<0.0001). Conversely, the proportion of Bacteroidota was significantly higher in the ConsR line than in the AlimR line (20.38% vs 16.50%, p<0.0001). The effect of generation was also significant for the abundance of Firmicutes and Bacteroidota (p=0.0009 and p<0.0001, respectively). The Shannon diversity index was significantly higher in the AlimR line than in the ConsR line (5.23 vs 5.14, p=0.02). The effect of generation was also significant for the Shannon index (p=0.003). Finally, a discriminant principal component analysis of the microbiota composition allowed us to distinguish both the two lines and the generations, in particular the 11th selected generation (animals adopted by SPF females) and the 18th generation.

microbiology↗

bioRxiv2021

Comparison of breeding strategies for the creation of a synthetic pig line

Creating a new synthetic line by crossbreeding means complementary traits from pure breeds can be combined in the new population. Although diversity is generated during the crossbreeding stage, in this study, we analyze diversity management before selection starts. Using genomic and phenotypic data from animals belonging to the first generation (G0) of a new line, different simulations were run to evaluate diversity management during the first generations of a new line and to test the effects of starting selection at two alternative times, G3 and G4. Genetic diversity was characterized by allele frequency, inbreeding coefficients based on genomic and pedigree data, and expected heterozygosity. Breeding values were extracted at each generation to evaluate differences in starting selection at G3 or G4. All simulations were run for ten generations. A scenario with genomic data to manage diversity during the first generations of a new line was compared with a random and a selection scenario. As expected, loss of diversity was higher in the selection scenario, while the scenario with diversity control preserved diversity. We also combined the diversity management strategy with different selection scenarios involving different degrees of diversity control. Our simulation results show that a diversity management strategy combining genomic data with selection starting at G4 and a moderate degree of diversity control generates genetic progress and preserves diversity.

genetics↗