Progress 10/01/03 to 09/30/08
Outputs
OUTPUTS: Molecular technologies were developed within the past decade that can be used to identify polymorphisms in genes that influence performance in cattle. Measures of performance are typically traits of growth, carcass, lactation, and (or) fertility. There are two approaches for generating DNA information that could be utilized in marker assisted selection/breeding in cattle. One is through associations with quantitative trait loci (QTL), which span broad regions of chromosomes, and the other is a candidate gene approach that associates DNA polymorphisms within genes known to regulate production traits. These approaches merge in the discipline of molecular genetics as positional candidate genes underlie QTL. This project evaluates relationships between genetic markers, physiological responses, and performance in populations of beef cattle selected for production systems in semi-arid environments (i.e., predicting phenotype from genotype). The approach/procedures involves re-sequencing candidate genes of economically relevant traits in beef cattle, discover/identify polymorphisms, particularly single nucleotide (SNP), in the coding and conserved regions of these genes, and conduct tag SNP-based association studies for growth, reproduction, and efficiency traits. In the past year, this project discovered 9 SNP that flank a microsatellite in the bovine growth hormone receptor. There is a tag SNP in this group of DNA polymorphisms and this SNP predicts body composition in growing Brangus bulls. Project also reported an association of genotypes from the Eth10 microsatellite located on bovine chromosome 5. This microsatellite is located in the promoter region of the STAT6 gene, which is an important cell signaling gene for growth hormone and leptin receptors. This polymorphism is also a predictor of growth and body composition traits in Brangus cattle. The two DNA polymorphisms herein are within the pathway of genes in the growth hormone/insulin-like growth hormone endocrine axis; thus, the approach of combing QTL information with candidate genes is providing new tools to assist breeding decisions for beef cattle. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Discovery of functional regions of the bovine genome assist with design of DNA-based tools for genetic improvement of domestic ruminants, which enhances efficiency in the beef industry. DNA polymorphisms within genes of the GH-IGF1 axis are predictors of growth and body composition in cattle. This knowledge can be used to further develop marker assisted breeding programs for cattle, which enhances efficiency in the beef industry.
Publications
- A. J. Garrett, G. Rincon, J. F. Medrano, M. A. Elzo, G. A. Silver, and M. G. Thomas. 2008. Promoter region of the bovine growth hormone receptor gene: single nucleotide polymorphism discovery in cattle and association with performance in Brangus bulls. J. Anim Sci. 86:3315-3323.
- Luna-Nevarez, P., D. VanLeeuwen, D. W. Bailey, R. M. Enns, S. A. Soto-Navarro, G. A. Silver, and M. G. Thomas. 2008. Altered growth curve characteristics and pregnancy rate levels in thirty-four years of Brangus cattle production in the Chihuahuan Desert. Proc. West. Sect. Am. Soc. Anim. Sci. 59:57-60.
- DeAtley, K. L., G. Rincon, C. R. Farber, J. F. Medrano, R. M. Enns, G. A. Silver, and M. G. Thomas. 2008. Association of microsatellite ETH10 genotypes with growth and carcass trait levels in Brangus cattle. Proc. West. Sect. Am. Soc. Anim. Sci. 59:69-71.
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Progress 01/01/07 to 12/31/07
Outputs
Somatotroph synthesis and secretion of growth hormone (GH) are essential for growth and fat metabolism. Sequence polymorphisms in GH and its transcriptional regulators, Pit-1 and the prophet of Pit-1 (Prop-1), were analyzed for associations with growth and carcass trait levels in Brangus bulls (3/8 Brahman x 5/8 Angus; n = 434 from 38 sires). Sequence variations included synonymous SNP mutations in intron 4 of GH and exon IV of Pit-1 and non-synonymous SNPs in exon V in GH and exon III in Prop-1. Yearling bulls possessing the Pit-1 GG genotype had greater (P < 0.05) percent fat in longissimus muscle than the AA or AG genotypes. Heterozygous genotypes of SNPs in GH appeared advantageous (P < 0.05) for traits of fat deposition and muscularity. Interactions, suggesting epistasis, were detected (P < 0.05) in mixed model analyses involving genotypes in Pit-1 and Prop-1 with GH. Linkage disequilibrium analyses of haplotypes in GH suggested these SNPs were in phase (r2 = 0.4;
D' = 0.8). Haplotypes were significant sources of variation (P < 0.05) in prediction of carcass traits. Mixed model analyses tested haplotypes as fixed effects as well as the probability of an individual possessing a haplotype as a covariate. Results suggest polymorphisms in GH and its transcriptional regulators were associated with growth and carcass traits in Brangus bulls. Results also suggest gene and allele interactions may be important to the GH endocrine axis in this admixed population of Bos indicus x Bos taurus cattle. Data presented at the International Plant and Animal Genome meeting in San Diego, January 2007.
Impacts
Beef cattle industry is multi-million dollar industry in NM and this research will contribute to its efficiency. More specifically, these data will contribute to the knowledge of needed to improve sire selection for improved growth and carcass characteristics of cattle. Efforts will also lead to improved reproductive efficiency of NM beef herds.
Publications
- M.G. Thomas, J. Hawkes, G. Khumalo, and J.L. Holechek. 2007. Brangus cow-calf performance under two stocking levels on Chihuahuan Desert rangeland. Range Ecol. Mgt.60:110-114.
- A.L. Van Eenennaam, J. Li, R.M. Thallman, R.L. Quaas, M.E. Dikeman, C.A. Gill, D.E. Franke, and M.G. Thomas. 2007. Validation of commercial DNA tests for quantitative beef quality traits. J. Anim. Sci. 85:891-900.
- Garrett, A.J. 2007 Promoter region of the bovine growth hormone receptor (GHR) gene: re-sequencing, SNP detection, and association with performance in Brangus bulls. M.S. Thesis, New Mexico State University.
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Progress 01/01/06 to 12/31/06
Outputs
Progress made in gaining knowledge of how to improve production efficiency of beef cattle with enhanced understanding of physiological genetics was accomplished in two studies. In brief, we developed pathways of genes involved in GH signaling. From this pathway, we selected genes that map to BTA5 as primary candidates for SNP discovery and which may be useful in association studies. Our strategy consists of re-sequencing 1000bp of the 5'UTR, coding regions, and 500bp of 3'UTR in IGF1, IGFBP6, PMCH and STAT2 genes. Vista alignments were used to view extremely conserved exon regions for re-sequencing. Forty-eight cattle without common ancestors in a 3 generation pedigree were used for re-sequencing. Number of cattle and their breed were 8 Holstein, 8 Jersey, and 8 Brown Swiss of dairy cattle and 6 Angus, 6 Simmental, 6 Brahman, and 6 Brangus of beef cattle. This panel of beef breeds included admixture of Bos taurus and Bos indicus as Brangus are 3/8 Brahman and 5/8
Angus. Haploview software was used to identify linkage disequilibrium regions among breeds. In PMCH, IGF1, and STAT2 an average of 5 tag SNPs were identified. These results will be useful in identifying potential haplotype blocks, which can be used to design association studies of haplotypes to measures of cattle performance. Additionally, we queried publication databases for candidate markers in GH. Sequence polymorphisms in GH and its transcriptional regulators, Pit-1 and the prophet of Pit-1 (Prop-1), were analyzed for associations with growth and carcass trait levels in Brangus bulls (3/8 Brahman x 5/8 Angus; n = 434 from 38 sires). Sequence variations included synonymous SNP mutations in intron 4 of GH and exon IV of Pit-1 and non-synonymous SNPs in exon V in GH and exon III in Prop-1. Yearling bulls possessing the Pit-1 GG genotype had greater (P < 0.05) percent fat in longissimus muscle than the AA or AG genotypes. Heterozygous genotypes of SNPs in GH appeared advantageous (P <
0.05) for traits of fat deposition and muscularity. Interactions, suggesting epistasis, were detected (P < 0.05) in mixed model analyses involving genotypes in Pit-1 and Prop-1 with GH. Linkage disequilibrium analyses of haplotypes in GH suggested these SNPs were in phase (r2 = 0.4; D' = 0.8). Haplotypes were significant sources of variation (P < 0.05) in prediction of carcass traits. Results suggest polymorphisms in GH and its transcriptional regulators were associated with growth and carcass traits in Brangus bulls. Results also suggest gene and allele interactions may be important to the GH endocrine axis in this admixed population of Bos indicus x Bos taurus cattle. Together these studies provide evidence to suggest 1) frequencies of DNA polymorphisms in genes of the GH axis or its transcriptional regulators differ among Angus, Brangus, and Brahman cattle and 2) DNA polymorphisms in genes of the GH axis or its transcriptional regulators appear to predict growth and or reproductive
traits in Brangus bulls and heifers.
Impacts
Discovery of genetic markers will enhance the ability of the beef industry to select for more efficient and higher quality product. The GH-IGF-1 axis has a major role in regulating animal growth and reproduction; thus, discovery and implementation of markers in the GH-IGF-1 axis will contribute to genetic improvement programs. This procedure will be called marker assisted selection (MAS). This type of selection will involve panels of DNA markers. The markers evaluated in this project will be on these panels.
Publications
- K.L. Shirley, M.G. Thomas, D.H. Keisler, D.M. Hallford, D.M. Montrose, G.A. Silver, and M.D. Garcia. Case study: 2006. A Chihuahuan Desert Brangus breeding program: feed efficiency, metabolic hormones, and puberty in developing Brangus heifers sired by bulls with differing EPD for growth and scrotal circumference. Prof. Anim. Sci. 22:48-58.
- R. Lopez, M.G. Thomas, D.M Hallford, D.H. Keisler, G.A. Silver, B.S. Obeidat, M.D. Garcia, and C.R. Krehbiel. 2006. Case study: metabolic hormone profiles and evaluation of associations of metabolic hormones with body fat and reproductive characteristics of Angus, Brangus, and Brahman heifers. Prof. Anim. Sci. 22:273-282.
- Beauchemin, V.R., M.G. Thomas, D.E. Franke, and G.A. Silver. 2006. Evaluation of DNA polymorphisms involving growth hormone relative to growth and carcass characteristics in Brahman steers. Genet. Mol. Res. 5:438-447.
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Progress 01/01/05 to 12/31/05
Outputs
Research findings have led us to conclude that: 1) frequencies of DNA polymorphisms in genes of the GH axis or its transcriptional regulators differ among Angus, Brangus, and Brahman cattle, 2) DNA polymorphisms in genes of the GH axis or its transcriptional regulators appear to predict growth and or reproductive traits in Brangus bulls and heifers (CAUTION: Single locus associations), and 3) interaction of polymorphisms within the GH gene account for >10% of variation in prediction models of data from NMSU Brangus bulls, but a much lower level in populations with greater number of sires.
Impacts
Ruminant livestock represent 70% of the gross receipts of the 2 billion dollar agriculture industry in NM and this research will contribute to its efficiency of production of ruminant livestock. More specifically, these data will contribute to the knowledge of needed to improve sire selection for improved growth and carcass characteristics of cattle. Efforts will also lead to improved reproductive efficiency of NM beef herds.
Publications
- D.A. Henderson, M.G. Thomas, and Y. Da. 2005. Conference review: bovine genomics from academia to industry. Cattle and sheep workshop, International Plant and Animal Genome Conference 2005. Comp. Funct. Genom. 6:174-180.
- K.L. Shirley, M.G. Thomas, D.H. Keisler, D.M. Hallford, D.M. Montrose, G.A. Silver, and M.D. Garcia. Case study: A Chihuahuan Desert Brangus breeding program: feed efficiency, metabolic hormones, and puberty in developing Brangus heifers sired by bulls with differing EPD for growth and scrotal circumference. In press: Prof. Anim. Sci. Feb; 2006.
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Progress 01/01/04 to 12/31/04
Outputs
Two efforts have been made to further evaluate relationships of genetic markers and physiologic response to performance of cattle. More specifically, Relationships of GH gene polymorphisms to pituitary responsiveness to GHRH were evaluated in 8 month-old Bos taurus (Angus) and Bos indicus-derivative (Brahman, F1-Brahman x Angus, and Brangus-3/8:5/8) bulls (n = 361). Polymorphisms were an intron 4 Msp-I RFLP (+/+, +/-, -/-) and an exon V L-leucine to V-valine SNP. Pituitary responsiveness was determined by serial blood sampling after intravenous injection of GHRH and calculating area under the response curve (AUC) using trapezoidal summation. F1-Brahman x Angus bulls were hyper-responsive to GHRH relative to Angus and Brangus bulls with an attenuated response in Brahman (AUC units, 2961 > 1963 = 2063 < 972 +/- 340, P < 0.05). Angus had high frequencies (> 0.68) of the homozygous +/+ and LL genotypes. Conversely, Brahman had a high frequency (0.63) of the -/- genotype
for the Msp-I RFLP, but all were homozygous LL for the LV-SNP. F1-Brahman x Angus and Brangus had relative equivalent genotypic frequencies for each polymorphism. Genotype within breed was a significant (P < 0.05) source of variation in prediction of GH-AUC with the interaction of the two polymorphisms accounting for 10.7 % of the variation. The heterozygous (+/-) Msp-I genotype yielded higher GH-AUC relative to homozygous genotypes in Angus whereas the -/- and VV genotype yielded the greatest GH-AUC in Brangus. The +/+ and LV genotypes yielded greatest levels of GH-AUC in F1-Brahman x Angus. Genotypic frequencies of GH polymorphisms differ among Bos taurus (Angus) and Bos indicus-derivative cattle and these polymorphisms appear to differentially influence pituitary responsiveness to GHRH. In regard to performance traits of beef bulls, Relationships of GH gene polymorphisms to ADG and yearling ultrasound carcass measures were evaluated in performance tested Angus and Brangus bulls (n
= 361 from 36 sires). Bi-allelic polymorphisms were an intron 4 Msp-I RFLP (+/+, +/-, -/-) and an exon V L-leucine to V-valine single nucleotide polymorphism (SNP). Bulls were spring-born and fall-weaned and then gain tested for 112-d as they approached 1 yr of age with a ration formulated to yield 1.58 kg gain/d. Mixed model analyses revealed that the Msp-I and LV genotypes within breed were significant (P < 0.05) sources of variation in prediction of ADG and ribfat.
Impacts
Ruminant livestock represent 70% of the gross receipts of the 2 billion dollar agriculture industry in NM and this research will contribute to its efficiency of production of ruminant livestock. More specifically, these data will contribute to the knowledge of needed to improve sire selection for improved growth and carcass characteristics of cattle. Efforts will also lead to improved reproductive efficiency of NM beef herds.
Publications
- K.K. Kane, D.E. Hawkins, GD. Pulsipher, D.J. Denniston, C. R. Krehbiel, M.G. Thomas, M.K. Petersen, D.M. Hallford, M.D. Remmenga, A.J. Roberts, and D.H. Keisler. 2004. Effect of increasing levels of undegradable intake protein on metabolic and endocrine factors in estrous cycling beef heifers. J. Anim. Sci. 82:283-291.
- R. Flores, M.L. Looper, M.G. Thomas, and D.M. Hallford. 2004. Influence of bovine somatotropin on characteristics of estrus and reproduction of Holstein cows during summer months. Prof. Anim. Sci. 20:191-197.
- J. Joseph, J.L. Holechek, R. Valdez, and M. Thomas. 2004. Mourning dove densities on Chihuahuan desert rangelands. J. Range. Mange. 57:243-247.
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Progress 01/01/03 to 12/31/03
Outputs
Two efforts have been made to further evaluate relationships of genetic markers and physiologic response to performance of cattle. More specifically, relationships of GH gene polymorphisms to pituitary responsiveness to GHRH were evaluated in 8 month-old Bos taurus (Angus) and Bos indicus-derivative (Brahman, F1-Brahman x Angus, and Brangus-3/8:5/8) bulls (n = 361). Polymorphisms were an intron 4 Msp-I RFLP (+/+, +/-, -/-) and an exon V L-leucine to V-valine SNP. Pituitary responsiveness was determined by serial blood sampling after intravenous injection of GHRH and calculating area under the response curve (AUC) using trapezoidal summation. F1-Brahman x Angus bulls were hyper-responsive to GHRH relative to Angus and Brangus bulls with an attenuated response in Brahman. Angus had high frequencies (> 0.68) of the homozygous +/+ and LL genotypes. Conversely, Brahman had a high frequency (0.63) of the -/- genotype for the Msp-I RFLP, but all were homozygous LL for the
LV-SNP. F1-Brahman x Angus and Brangus had relative equivalent genotypic frequencies for each polymorphism. Genotype within breed was a significant source of variation in prediction of GH-AUC with the interaction of the two polymorphisms accounting for 10.7 % of the variation. The heterozygous (+/-) Msp-I genotype yielded higher GH-AUC relative to homozygous genotypes in Angus whereas the -/- and VV genotype yielded the greatest GH-AUC in Brangus. The +/+ and LV genotypes yielded greatest levels of GH-AUC in F1-Brahman x Angus. Genotypic frequencies of GH polymorphisms differ among Bos taurus (Angus) and Bos indicus-derivative cattle and these polymorphisms appear to differentially influence pituitary responsiveness to GHRH. Metabolic hormones were also evaluated in spring-born Brangus heifers sired by bulls with differing EPDs for growth and scrotal circumference were evaluated for growth, level of feed intake, serum concentrations of leptin, and puberty from 12.5 to 15.5 months of
age. Individual feed intake was measured daily and body weight was measured every two wk. Blood samples were collected twice weekly to evaluate serum concentrations of leptin and progesterone with RIA, and two consecutive samples of progesterone > 1 ng/mL was considered as day of puberty. Heifers were exposed to breeding for 90-d beginning at 14.3 months of age. Age of puberty was earlier (P < 0.02) in heifers from the Balanced EPD sire relative to heifers from the LG-MSC and MG-LSC EPD sires, however, pregnancy percentage was similar among sire groups (87.5% = 71.4% = 75.0%, X2 = 0.72). Data suggest that Brangus heifers from a sire with balanced EPDs for growth and scrotal circumference achieve reproductive competency earlier than heifers from a sire with EPDs for either large growth moderate scrotal circumference or moderate growth large scrotal circumference. This relationship may be related to differences in mechanisms which influence feed intake, but appears to be independent of
serum concentrations of leptin among the sires groups.
Impacts
Beef cattle industry is multi-million dollar industry in NM and this research will contribute to its efficiency. More specifically, these data will contribute to the knowledge of needed to improve sire selection for improved growth and carcass characteristics of cattle. Efforts will also lead to improved reproductive efficiency of NM beef herds.
Publications
- No publications reported this period
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