Marker-assisted introgression of myostatin from Texel to Ramlıç sheep: Growth and real-time ultrasound carcass traits in F1 and BC1 lambs

Abstract

The aim of the study was to evaluate live weights, body measurements, and real-time ultrasound carcass traits of F1 and BC1 genotypes in a marker assisted introgression (MAI) process. Effects of some factors on live weight and body measurements including ultrasonographic assessments in Musculus longissimus dorsi (MLD) were investigated at the F1 (n=51) and BC1 (n=99) cross lambs born in 2015 -2017 period. Variance analysis showed that genotype had significant (P < 0.001) effect on pre-and post-weaning growth characteristics. The birth type had significant (P < 0.05) effect on pre-and post-weaning growth traits. Live weights at twelve months of age were higher in heavier born lambs. The growth performance of F1 lambs was between Texel and Ramlıç. Myostatin heterozygous BC1 lambs had been potentially heavier than the non-carriers and pure Texel. MLD depth and area were also statistically higher (P < 0.05) in BC1 lambs carrying myostatin than non -carriers. As a result, the beginning phase of introgression processes implemented was found to be successful.

Assessing the performance of Moghani crossbred lambs derived from different mating systems with Texel and Booroola sheep

“…In contrast, Moghani pure lambs were significantly ( P < 0.05) heavier at birth compared to F2 crossbred lambs with the Booroola mutation in the homozygous variant genotype (G/G). This aligns with the findings of Çelikeloglu et al [ 19 ] and Tekerli et al [ 20 ], who conducted studies on the introgression of the MSTN mutation into Turkish Ramlıç sheep. Their findings indicated that Texel sheep with the MSTN mutation in homozygous form (A/A) exhibited significantly lower body weights in comparison to Ramlıç sheep with the wild-type genotype (G/G), as well as to the first-generation backcrosses (BC1, G/G and G/A) and the second-generation backcrosses (BC2, G/G and G/A) lambs [ 19 , 20 ].…”

“…This aligns with the findings of Çelikeloglu et al [ 19 ] and Tekerli et al [ 20 ], who conducted studies on the introgression of the MSTN mutation into Turkish Ramlıç sheep. Their findings indicated that Texel sheep with the MSTN mutation in homozygous form (A/A) exhibited significantly lower body weights in comparison to Ramlıç sheep with the wild-type genotype (G/G), as well as to the first-generation backcrosses (BC1, G/G and G/A) and the second-generation backcrosses (BC2, G/G and G/A) lambs [ 19 , 20 ]. Moreover, the A allele of the MSTN mutation OAR2:g.118150665G>A exerted a non-significant adverse impact on live weight traits in Texel sheep [ 49 ], Norwegian White sheep [ 50 ], Turkish Ramlıç sheep [ 19 ], and New Zealand Romney sheep [ 51 ].…”

“…Their findings indicated that Texel sheep with the MSTN mutation in homozygous form (A/A) exhibited significantly lower body weights in comparison to Ramlıç sheep with the wild-type genotype (G/G), as well as to the first-generation backcrosses (BC1, G/G and G/A) and the second-generation backcrosses (BC2, G/G and G/A) lambs [ 19 , 20 ]. Moreover, the A allele of the MSTN mutation OAR2:g.118150665G>A exerted a non-significant adverse impact on live weight traits in Texel sheep [ 49 ], Norwegian White sheep [ 50 ], Turkish Ramlıç sheep [ 19 ], and New Zealand Romney sheep [ 51 ]. Nevertheless, these studies did report a statistically significant positive effect on carcass and meat quality traits.…”

“…These breeds encompass New Zealand Texel [ 12 , 13 ], Australian Texel [ 14 ], Belgian Texel [ 15 , 16 ], Norwegian White Sheep [ 17 ], and the commercially relevant Charollais sheep [ 18 ]. For instance, the Texel sheep breed’s MSTN g+6223G>A has been successfully introduced into Ramlıç sheep breeds [ 19 , 20 ]. Similarly, the highly prolific Booroola / FecB allele of the bone morphogenetic protein receptor type 1B ( BMPR1B ) gene, initially identified in the Booroola Merino breed, has been effectively incorporated into diverse sheep breeds [ 8 ].…”

Genetic basis of muscle‐related traits in sheep: A review

“…Based on reference SNP ID assigned by dbSNP rs408469734, it is located on OAR2, position 118 150 665 of the genome assembly Oar_v3.1 (Figure 4). Recent studies revealed successful experiences in improving carcass traits after introgression of MSTN g + 6223G>A from Texel into the Ramlıç Turkish sheep (Çelikeloglu et al, 2022; Tekerli et al, 2022).…”