QTL affecting conformation traits in Angora goats

https://doi.org/10.1016/j.smallrumres.2006.07.008Get rights and content

Abstract

A genomic screen for quantitative trait loci (QTL) affecting conformation traits was performed by genotyping 288 Angora goats offspring from 8 half-sub families with 76 microsatellite markers. The following traits were recorded: weaning weight (WW, Kg); stature (S, cm); chest depth (CD, cm); shoulder width (SW, cm); rump length (RL, cm); rump width (RW, cm); head length (HL, cm); head width (HW, cm); shin circumference (SC, cm); chest circumference (CC, cm) and body length (BL, cm). Data were analyzed using the QTL Express program. A total of 5 QTL were detected in five chromosomes with chromosome wide significance level. For the 11 analysed traits the results were: evidence of two possible QTL for HL were found in chromosomes 1 and 4, a putative QTL for trait CD was found in chromosome 2, evidence for BL was found in chromosome 8 and a possible QTL was found for trait CC in chromosome 9. The results reported here show the existence of chromosomal regions in Angora goats involved in conformation traits and represent the first in depth search in some specific-genome sections in order to identify and characterize the genetic variability involved in these traits.

Introduction

Body weight or size in general has long been considered as a paradigm for quantitative inheritance. It is normally distributed and seems to be controlled by many genes, each with relatively small additive effects on the phenotype (Falconer and Mackay, 1996).

The development of molecular biology techniques and the application of these techniques to farm animals have progressed rapidly in the last years and have opened new perspectives for gene identification of underlined quantitative traits. Dense marker maps and advanced statistical methods have made it possible to search for quantitative trait loci (QTL) over the whole genome and have allowed the measurement of individual gene effects on complex morphological traits.

Studies aimed at detecting QTL for growth and conformation traits in cattle have been successfully conducted in the last years (Stone et al., 1999, Schrooten et al., 2000, Casas et al., 2003, Kim et al., 2003, Boichard et al., 2003, Hiendleder et al., 2003). In goats a comprehensive genetic linkage map has been developed (Vaiman et al., 1996, Schibler et al., 1998) and due to the high homology with cattle genetic map some QTL could be found to be homologous between both species, cattle and goat.

In Angora goats, putative QTL affecting fleece traits were reported by Cano et al. (2007). Making use of the resource created by the Angora Dispersed Nucleus in Argentina (Abad et al., 2002) an experiment was designed in order to search for QTL affecting conformation traits. We present here the results of an initial genome-wide scan, using 76 microsatellite markers in 8 half-sibs Angora goat families for 11 conformation traits.

Section snippets

Animals and conformation traits

The population analyzed was the same as reported by Cano et al. (2007). At weaning, the following conformation traits were recorded: weaning weight (WW) expressed in kilograms; stature (S); chest depth (CD); shoulder width (SW); rump length (RL); rump width (RW); head length (HL); head width (HW); shin circumference (SC); chest circumference (CC) and body length (BL), all of them measured in centimetres. All conformation traits were taken by the same operator and follow the methodology by

Results

In Table 1 phenotypic measurements (means and standard deviations) for the eight families progenies are shown.

In the first step a panel of 120 microsatellites was run in the 8 bucks. After taking account of the polymorphic information content (PIC) (Botstein et al., 1980), the allele number and heterozygocity by microsatellite, a set of 76 markers were selected to genotype the 288 offspring in 21 autosomes.

Number of markers used, chromosome length, proportion of sire heterozygous and marker

Discussion

No other reports on QTL associated with conformation traits in goats have been previously published. The study reported in this paper is the first genome-wide scan done in order to analyze the genetic basis of conformation traits in Angora goats. The results will be discussed by chromosome.

Conclusion

Five quantitative trait loci influencing weight and body measurements were found with significant evidence for linkage in an experimental QTL mapping population of Angora goats.

The confidence intervals of QTL location estimated by boostrap were extremely large and frequently included the complete chromosome. These results were expected not only for the small numbers of informative families but also for the limited density marker map on the goat. This design should be expanded by adding more

Acknowledgments

The authors acknowledge the staff of the Pilcaniyeu experimental farm who take care of the animals; Jorge Arrigo for the contact with Programa Mohair SAGPyA and private breeders; Philp Sponenberg for the critic reading of the manuscript. This work was funded by BID OC/AR 1201 PICT 3907 and PAV 137 projects and the ECOS–Sud cooperation programme (French-Argentinian governments).

References (29)

  • E. Casas et al.

    A comprehensive search for quantitative trait loci affecting growth and carcass composition of cattle segregating alternative forms of the myostatin gene

    J. Anim. Sci.

    (2001)
  • E. Casas et al.

    Detection of quantitative trait loci for growth and carcass composition in cattle

    J. Anim. Sci.

    (2003)
  • G.A. Churchill et al.

    Empirical threshold values for quantitative trait mapping

    Genetics

    (1994)
  • A.O. Cohen et al.

    Epidemiology and biology of insuline-like growth factor binding protein-3 (IGFBP-3) as an anti-cancer molecule

    Hormone Metab. Res.

    (2003)
  • Cited by (15)

    • QTLs detection for mohair traits in Iranian Angora goats (Markhoz goats)

      2021, Small Ruminant Research
      Citation Excerpt :

      The QTL of the fiber diameter controller was identified at the beginning of CHI 19 at position 1 cM and QTL of weight control at position 16 cM. Several authors investigated QTLs affecting the hair traits of goats (Cano et al., 2007; Marrube et al., 2007; Debenedetti et al., 2010; Roldan et al., 2014; Nazari-Ghadikolaei et al., 2018). On CHI 1, QTLs controlling fiber diameter, fleece weight, and percentage of medullated fibers have been identified at positions 176 and 104 cM, respectively (Cano et al., 2009).

    • Genome-wide association mapping for type and mammary health traits in French dairy goats identifies a pleiotropic region on chromosome 19 in the Saanen breed

      2018, Journal of Dairy Science
      Citation Excerpt :

      However, very little is known about the loci controlling type traits and lactation SCS (LSCS) in this species. To our knowledge, only one study on QTL detection of caprine body conformation traits was published (Marrube et al., 2007), based on a low-density panel of microsatellites in Angora goats. In this paper, we report a genome scan for 12 type and health traits, including udder type traits, SCC, and stature in Saanen and Alpine dairy breeds.

    • Genome-wide association study of conformation and milk yield in mixed-breed dairy goats

      2018, Journal of Dairy Science
      Citation Excerpt :

      Compared with that in cattle and sheep, the number of QTL studies in goats is limited; however, at present, goat QTL are not included in Animal QTLdb database (http://www.animalgenome.org/cgi-bin/QTLdb/index), which makes it difficult to judge the exact number of studies in this species (for review, see Amills, 2014). Quantitative trait loci for traits such as birth and weaning weight (Mohammad Abadi et al., 2009; Visser et al., 2013), hair fiber characteristics (Cano et al., 2007; Visser et al., 2011), growth (Mohammad Abadi et al., 2009), body conformation (Marrube et al., 2007), parasite resistance (Bolormaa et al., 2010; De La Chevrotière et al., 2012), milk traits (Roldán et al., 2008), and αS1-casein (Sacchi et al., 2005; Hayes et al., 2006; Dagnachew et al., 2011) have been identified in goats using microsatellite markers. With the availability of the Illumina Caprine 50K BeadChip (Illumina Inc., San Diego, CA; Tosser-Klopp et al., 2012, 2014), it is now possible to perform genome-wide scans in goats with much greater resolution.

    • Quantitative trait loci associated with pre-weaning growth in South African Angora goats

      2013, Small Ruminant Research
      Citation Excerpt :

      Only two studies have yet aimed to identify QTL for growth traits in goats. Mohammed Abadi et al. (2009) found putative QTL affecting WW on CHI 1, 2 and 5 while Marrube et al. (2007) failed to detect any QTL influencing WW in Argentinean Angora goats. Usually more associations between genotypes and phenotypic traits are detected for traits with higher heritability estimates than for lower heritable traits.

    • A genome scan for quantitative trait loci affecting body conformation traits in Spanish Churra dairy sheep

      2011, Journal of Dairy Science
      Citation Excerpt :

      The bovine chromosomal region orthologous to the region of the rump width QTL identified in OAR2 by our analysis, which corresponds to BTA8, has been found to carry a QTL for body depth (Hiendleder et al., 2003) and stature/size (Schrooten et al., 2000) in dairy cattle. Furthermore, marker HEL4, which maps close to MCM147, one of the flanking markers of the rump width OAR2 QTL reported here, has been associated with body length in an Angora goat population (Marrube et al., 2007). In dairy cattle, a QTL influencing heel depth has been reported to be linked to marker BM7247 (Boichard et al., 2003), which is close to the peak of the foot angle QTL identified in this study on OAR5.

    View all citing articles on Scopus
    View full text