Abstract:Docking the tails of lambs in long-tailed sheep breeds is a common practice worldwide. But this practice is associated with pain. Breeding for a shorter tail could offer an alternative. Therefore, this study aimed to analyze the natural tail length variation in the Merinolandschaf and to identify causal alleles for the short tail phenotype segregating within long-tailed breeds. We used SNP-based association analysis and haplotype-based mapping in 362 genotyped (Illumina OvineSNP50) and phenotyped Merinolandsch… Show more
“…These include the platelet derived growth factor D ( PDGFD ) gene 1 , 11 , 12 and the intergenic region between the bone morphogenetic protein 2 ( BMP2 ) and hydroxyacid oxidase 1 ( HAO1 ) genes, referred to as the IBH region 13 – 15 linked with the fat-tail phenotype, and the T-box transcription factor T ( TBXT ) gene 16 – 18 linked with variations in caudal vertebrae. Recent studies highlighted a new gene, HOXB13 , which is highly associated with the sheep tail length 19 – 23 (Table 1 ). Of these studies, two independent efforts, one recently published in Communications Biology 23 and the other published as a preprint 21 , strongly highlighted a structural variation (SV) in the form of a short insertion associated with the long-tail phenotype, adding a new critical member to the gene repertoire of the sheep tail configuration.…”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…Recent studies highlighted a new gene, HOXB13 , which is highly associated with the sheep tail length 19 – 23 (Table 1 ). Of these studies, two independent efforts, one recently published in Communications Biology 23 and the other published as a preprint 21 , strongly highlighted a structural variation (SV) in the form of a short insertion associated with the long-tail phenotype, adding a new critical member to the gene repertoire of the sheep tail configuration. Fig.…”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…These include two genes linked with the sheep tail length [ HOXB13 (refs. 21 , 23 ) and TBXT (refs. 16 – 18 )] and two genes/regions linked with the fat-tail phenotype [ PDGFD (refs.…”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…Long fat-tailed (Bonga, Gesses, Kido, Doyogena, Shubi-Gemo, and Loya) Ethiopia Paired-end sequencing (Illumina) Oar_v3.1 Long thin-tailed (Hammari and Kabashi) Sudan Long fat-tailed (shorter caudal vertebrae length; Barberine) Libya Lagler et al 2022 (ref. 23 ) Long thin-tailed (Merinolandschaf) German Ovine 50 K SNP BeadChip (Illumina) Oar_v4.0 *In some of the indicated studies, further validations of potential variants were performed using expanded number of individuals from different populations. …”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…In recent studies 21 – 23 , the HOXB13 gene was first highlighted to be significantly associated with the sheep tail phenotype in a genomic comparison that included Ethiopian fat-rumped and short fat-tailed sheep breeds vs . Ethiopian long fat-tailed and Sudanese long thin-tailed sheep breeds 22 .…”
Section: Hoxb13
As a Controller Of Long And Short Tails: Var...mentioning
Understanding the genetic basis of sheep tails is of great importance to improve sheep production and welfare. In this Comment, we discussed recent findings showing that homeobox B13 (HOXB13) is a regulator of the tail length in sheep. The revelation of the HOXB13 gene adds novel insights into the genetic determinism of the sheep tail phenotype. This new genetic highlight will lead to further advances in sheep breeding using selection-based strategies and molecular genetics-based tools.A brief background: piecing together the genetic structure of sheep tail formation The tail phenotype, an obvious body segment, has been described as a significantly divergent trait in sheep 1 , which is due to the wide phenotypic diversity of sheep tails among different breeds located within various geographical and environmental regions 2 . Several factors influence the sheep tail phenotype, including length, fat deposition level, and directionality. The overall tail length is controlled by the number and length of caudal vertebrae. On the other hand, tail fat deposition is controlled by the size and number of adipocytes. Several tail phenotypic patterns have been shown in sheep, including the thin-long tail, thin-short tail, fat-short tail, fat-long tail, and fat-rumped tail (Fig. 1, upper panel). Studies have been performed to understand the mechanistic determinism of sheep tails based on genetic basis, due to the association of sheep tails with several raising-related and welfare issues (see reviews by refs. [3][4][5][6] ). Of these issues, tail docking, as a painful practice, is the most critical 5,6 . Revealing the genetic determinism of sheep tails will help to direct the selection towards the desired phenotypes 7,8 and provide access to new biotechnological tools to directly introduce the desired variant(s) into the targeted breed 9,10 . Recently, three genes/regions were reported to be significantly associated with the sheep tail phenotype. These include the platelet derived growth factor D (PDGFD) gene 1,11,12 and the intergenic region between the bone morphogenetic protein 2 (BMP2) and hydroxyacid oxidase 1 (HAO1) genes, referred to as the IBH region [13][14][15] linked with the fat-tail phenotype, and the T-box transcription factor T (TBXT) gene [16][17][18] linked with variations in caudal vertebrae. Recent studies highlighted a new gene, HOXB13, which is highly associated with the sheep tail length [19][20][21][22][23] (Table 1). Of these studies, two independent efforts, one recently published in Communications Biology 23 and the other published as a preprint 21 , strongly highlighted a structural variation (SV) in the form of a short insertion associated with the longtail phenotype, adding a new critical member to the gene repertoire of the sheep tail configuration.
“…These include the platelet derived growth factor D ( PDGFD ) gene 1 , 11 , 12 and the intergenic region between the bone morphogenetic protein 2 ( BMP2 ) and hydroxyacid oxidase 1 ( HAO1 ) genes, referred to as the IBH region 13 – 15 linked with the fat-tail phenotype, and the T-box transcription factor T ( TBXT ) gene 16 – 18 linked with variations in caudal vertebrae. Recent studies highlighted a new gene, HOXB13 , which is highly associated with the sheep tail length 19 – 23 (Table 1 ). Of these studies, two independent efforts, one recently published in Communications Biology 23 and the other published as a preprint 21 , strongly highlighted a structural variation (SV) in the form of a short insertion associated with the long-tail phenotype, adding a new critical member to the gene repertoire of the sheep tail configuration.…”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…Recent studies highlighted a new gene, HOXB13 , which is highly associated with the sheep tail length 19 – 23 (Table 1 ). Of these studies, two independent efforts, one recently published in Communications Biology 23 and the other published as a preprint 21 , strongly highlighted a structural variation (SV) in the form of a short insertion associated with the long-tail phenotype, adding a new critical member to the gene repertoire of the sheep tail configuration. Fig.…”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…These include two genes linked with the sheep tail length [ HOXB13 (refs. 21 , 23 ) and TBXT (refs. 16 – 18 )] and two genes/regions linked with the fat-tail phenotype [ PDGFD (refs.…”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…Long fat-tailed (Bonga, Gesses, Kido, Doyogena, Shubi-Gemo, and Loya) Ethiopia Paired-end sequencing (Illumina) Oar_v3.1 Long thin-tailed (Hammari and Kabashi) Sudan Long fat-tailed (shorter caudal vertebrae length; Barberine) Libya Lagler et al 2022 (ref. 23 ) Long thin-tailed (Merinolandschaf) German Ovine 50 K SNP BeadChip (Illumina) Oar_v4.0 *In some of the indicated studies, further validations of potential variants were performed using expanded number of individuals from different populations. …”
Section: A Brief Background: Piecing Together the Genetic Structure O...mentioning
confidence: 99%
“…In recent studies 21 – 23 , the HOXB13 gene was first highlighted to be significantly associated with the sheep tail phenotype in a genomic comparison that included Ethiopian fat-rumped and short fat-tailed sheep breeds vs . Ethiopian long fat-tailed and Sudanese long thin-tailed sheep breeds 22 .…”
Section: Hoxb13
As a Controller Of Long And Short Tails: Var...mentioning
Understanding the genetic basis of sheep tails is of great importance to improve sheep production and welfare. In this Comment, we discussed recent findings showing that homeobox B13 (HOXB13) is a regulator of the tail length in sheep. The revelation of the HOXB13 gene adds novel insights into the genetic determinism of the sheep tail phenotype. This new genetic highlight will lead to further advances in sheep breeding using selection-based strategies and molecular genetics-based tools.A brief background: piecing together the genetic structure of sheep tail formation The tail phenotype, an obvious body segment, has been described as a significantly divergent trait in sheep 1 , which is due to the wide phenotypic diversity of sheep tails among different breeds located within various geographical and environmental regions 2 . Several factors influence the sheep tail phenotype, including length, fat deposition level, and directionality. The overall tail length is controlled by the number and length of caudal vertebrae. On the other hand, tail fat deposition is controlled by the size and number of adipocytes. Several tail phenotypic patterns have been shown in sheep, including the thin-long tail, thin-short tail, fat-short tail, fat-long tail, and fat-rumped tail (Fig. 1, upper panel). Studies have been performed to understand the mechanistic determinism of sheep tails based on genetic basis, due to the association of sheep tails with several raising-related and welfare issues (see reviews by refs. [3][4][5][6] ). Of these issues, tail docking, as a painful practice, is the most critical 5,6 . Revealing the genetic determinism of sheep tails will help to direct the selection towards the desired phenotypes 7,8 and provide access to new biotechnological tools to directly introduce the desired variant(s) into the targeted breed 9,10 . Recently, three genes/regions were reported to be significantly associated with the sheep tail phenotype. These include the platelet derived growth factor D (PDGFD) gene 1,11,12 and the intergenic region between the bone morphogenetic protein 2 (BMP2) and hydroxyacid oxidase 1 (HAO1) genes, referred to as the IBH region [13][14][15] linked with the fat-tail phenotype, and the T-box transcription factor T (TBXT) gene [16][17][18] linked with variations in caudal vertebrae. Recent studies highlighted a new gene, HOXB13, which is highly associated with the sheep tail length [19][20][21][22][23] (Table 1). Of these studies, two independent efforts, one recently published in Communications Biology 23 and the other published as a preprint 21 , strongly highlighted a structural variation (SV) in the form of a short insertion associated with the longtail phenotype, adding a new critical member to the gene repertoire of the sheep tail configuration.
Context Breech strike compromises wool production and welfare of Merinos. Long tails contribute to the formation of dags, increasing the risk of sheep attracting gravid blowfly females. Tail-docking is popular globally, as it reduces the incidence of dags. Breeding for a reduced tail length is a more socially accepted measure to replace tail-docking as a management strategy, since stronger legislation for animal welfare is expected. Aim The study used historic data on tail length (TL), birth weight (BW) and bodyweight at docking (DW) to estimate genetic and environmental parameters for these traits in a well known South African resource flock. Methods Merino lambs born from 2016 to 2021 (except for 2020 due to Covid-19) of the Elsenburg Merino flock were recorded for TL, BW and DW. The flock was separated by divergent selection for and against a number of lambs weaned per ewe mated in a High (H) and a Low (L) line. Fixed effects included birth year, sex, selection line, dam age and birth type. ASReml was used to analyse the fixed effects so as to obtain an operational model, before adding the random direct genetic (h2), maternal genetic (m2) and maternal permanent environmental (c2) effects. Results H-line lambs were heavier at birth and tail-docking, with longer tails than those of L-line contemporaries (all P < 0.01). The line difference in TL seemed to be size-dependent, as it was eliminated by adding DW as a covariate to the analysis. The same trend was observed for sex, dam age and birth type. TL was thus affected (P < 0.01) only by birth year in the latter analysis. Regressions of TL on age at tail-docking and DW were highly significant (P < 0.01). Single-trait estimates of h2 were 0.26 for BW, 0.06 for DW, and 0.30 for TL. TL remained heritable at 0.38 in the analysis including DW as a covariate. Including m2 improved the random-effects model for TL (0.08) and DW (0.20). TL and DW were genetically correlated (rG = 0.47 and rM = 0.70). Conclusions TL was moderately heritable, with small m2 and non-significant c2 effects. It will be possible to directly select for TL. However, selection for shorter tails will reduce size if breeding values are not adjusted for DW as a covariate. Implications Further studies on the genetic basis of TL as well as its genetic correlations with other traits of economic importance are warranted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
