S M Galloway

University of Otago, Taieri, Otago Region, New Zealand

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Publications (27)101.77 Total impact

  • M C French · K G Dodds · G H Davis · S M Galloway · S J Edwards
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    ABSTRACT: We have constructed a genetic linkage map of the sheep X chromosome (OARX) containing 22 new gene loci from across the human X chromosome (HSAX). The female OARX linkage map has a total length of 152.6 cM with average gene spacing of 5.5 cM. Comparison with HSAX confirms one previously reported major breakpoint and inversion, and other minor rearrangements between OARX and HSAX. Comparison of the linkage map with sheep sequence data OAR 1.0 reveals a different arrangement of markers on the q arm, which may more accurately reflect the genuine arrangement of this region.
    No preview · Article · Jun 2011 · Animal Genetics
  • S. Banerjee · S.M. Galloway · G.H. Davis
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    ABSTRACT: The Garole is a prolific breed of sheep. High prolificacy in sheep carrying the Booroola gene (FecB) is the result of a mutation in bone morphogenetic protein receptor-IB (BMPR-IB) (Wilson et al., 2001a,b) which had previously been identified in Garole sheep from the Sunderban region of West Bengal (Davis et al., 2002) . There is evidence that the breed has originated from the sheep brought by the Tibetan traders and traded in the plains of Bengal during the seventeenth till the nineteenth century. The present study was carried out to remap the distribution of the Garole sheep within the state of West Bengal (India) using the presence of the BMPR-IB mutation in the sheep flocks reared at different locations within the state of West Bengal. The breeding tract of Garole sheep was initially thought to be in the districts of 24 Parganas, South and North alone. However, the results from the present study indicate that the sheep is also reared in the district of Midnapur (East), besides in Jalpaiguri and Cooch Behar districts situated in northern parts of the state. The results of the present study indicate that the breeding tract of Garole sheep extends up to Jalpaiguri and CoochBehar districts of West Bengal at 26°16′ and 27°0′ North latitude and 88°4′ and 89°53′ East longitude. This study also indicates that the ancestors of the Garole sheep have migrated from China/Tibet, during the trading between West Bengal and Bangladesh during the seventeenth century till the early-twentieth century.
    No preview · Article · Apr 2011
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    ABSTRACT: This work investigated effects of carrying 0, 1, or 2 copies of the A allele resulting from the g+6723G-A transition in growth differentiation factor gene (GDF8) in New Zealand Texel-cross sheep at different lamb ages and carcass weights. Two Texel-cross sires carrying 1 copy of the A allele were mated to approximately 200 ewes carrying 0, 1, or 2 copies of the A allele. A total of 187 progeny were generated and genotyped to determine whether they were carrying 0, 1, or 2 copies of the A allele. The progeny were assigned to 1 of 4 slaughter groups balanced for the 3 genotypes, sex, and sire. The 4 groups were slaughtered commercially when their average BW (across all progeny in the slaughter group) reached 33, 40, 43, and 48 kg, respectively. Measurements of BW, and carcass dimensions and yield were made on all animals using Viascan (a commercial 2-dimensional imaging system that estimates lean content of the carcass as a percentage of total carcass weight). Additional measurements were made on the fourth slaughter group, which was computed tomography scanned at each slaughter time point to obtain 4 serial measures of lean and fat as estimated from the computed tomography images. The A allele did not have an effect on any BW traits. The A allele was associated with increased muscle and decreased fat across the variety of measures of muscling and fat, explaining between 0.2 and 1.1 of a residual SD unit. Estimates for an additive effect were significant and were positive for muscle and negative for fat traits. No dominance effect estimates (positive or negative) were significant. There was no significant interaction between A allele number and carcass weight or slaughter group for any trait. This is the first systematic study of the effect of the A allele copy number over a range of carcass weights (13 to 20 kg) and ages and results suggest the size of the effect across these endpoints is proportionately the same. Testing for the A allele therefore offers breeders the potential to improve rates of genetic gain for lean-meat yield across most production systems.
    Full-text · Article · Mar 2009 · Journal of Animal Science
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    Full-text · Conference Paper · Jun 2008
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    ABSTRACT: Sheep chromosome 2q (OAR2q), which is homologous with human chromosome 2q (HSA2q), and cattle chromosome 2 (BTA2), is known to contain several loci contributing to carcass traits. However, the chromosomal rearrangements differentiating these chromosomes among the three species have not yet been determined and thus precise correspondences between the locations of sheep and human genes are not known. Twenty-six genes from HSA2q (2q21.1-->2q36) have been assigned to OAR2q by genetic linkage mapping to refine this area of the sheep genome. Seventy-six genes were initially selected from HSA2q. Sixty-eight percent of the PCR primer sets designed for these genes amplified successfully in sheep, and 34% amplified polymorphic products. Part of the proximal arm of OAR2q was found to be inverted compared with HSA2q. The breakpoint has been localised near the growth differentiation factor 8 gene (GDF8), spanning 380 kb between the positions of the hypothetical protein (FLJ20160) (HSA2:191008944-191075046) and glutaminase (GLS) (HSA2:191453847-191538510) (Build36.1).
    No preview · Article · Feb 2007 · Cytogenetic and Genome Research
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    ABSTRACT: Ovulation rates were measured in 547 progeny of 24 rams in a Romney flock with a long history of high prolificacy. These sheep were from the same family line and the distribution of ovulation rates suggests the presence of a segregating major gene (FecW) that increases prolificacy. The phenotype differs from those previously described for major genes affecting prolificacy in sheep. The putative gene shows autosomal inheritance and one copy increases ovulation rate by 0.8-1.0 eggs per ewe ovulating. To date, we have found no evidence of infertility among putative homozygous ewes, as described in some autosomal major genes for prolificacy.
    No preview · Article · Apr 2006 · Animal Reproduction Science
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    ABSTRACT: Twenty-one of the world's prolific sheep breeds and strains were tested for the presence of the FecB mutation of BMPR1B and the FecX(I) mutation of BMP15. The breeds studied were Romanov (2 strains), Finn (2 strains), East Friesian, Teeswater, Blueface Leicester, Hu, Han, D'Man, Chios, Mountain Sheep (three breeds), German Whiteheaded Mutton, Lleyn, Loa, Galician, Barbados Blackbelly (pure and crossbred) and St. Croix. The FecB mutation was found in two breeds, Hu and Han from China, but not in any of the other breeds. The 12 Hu sheep sampled were all homozygous carriers of FecB (FecB(B)/FecB(B)) whereas the sample of 12 Han sheep included all three genotypes (FecB(B)/FecB(B), FecB(B)/FecB+, FecB+/FecB+) at frequencies of 0.33, 0.58 and 0.08, respectively. There was no evidence of FecX(I) in any of the breeds sampled.
    Full-text · Article · Apr 2006 · Animal Reproduction Science
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    ABSTRACT: Two related oocyte-derived members of the transforming growth factor-beta (TGF-beta) superfamily, namely growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15, also known as GDF9B), have recently been shown to be essential for ovarian follicular growth. In addition, both proteins have been shown to regulate ovulation rate in sheep, and although it is evident that these growth factors interact both with one another and with other intra- and extra-ovarian factors, the precise mechanisms by which they influence follicular growth and ovulation rate have not been thoroughly elucidated.
    No preview · Article · Aug 2004 · Animal Reproduction Science
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    ABSTRACT: The physiological mechanisms controlling ovulation rate in mammals involve a complex exchange of endocrine signals between the pituitary gland and the ovary, and a localized exchange of intraovarian hormones between the oocyte and its adjacent somatic cells. The discoveries in sheep of mutations in bone morphogenetic protein 15 (BMP15) and bone morphogenetic protein receptor type IB (BMPR-IB) together with recent findings on the physiological effects of growth differentiation factor 9 (GDF9) and BMP15 on follicular development and ovulation rate highlight some important differences in the way in which the oocyte may function in mammals with different ovulation rate phenotypes. In sheep, BMP15 and GDF9 have each been shown to be essential for the early and later stages of follicular development. In addition, ovulation rate is sensitive to changes in the dose of either of these two oocyte-derived growth factors. These findings are in contrast to those reported for mice in which GDF9, but not BMP15, is essential for follicular development. The evidence to date is consistent with the hypothesis that the oocyte plays a central role in regulating key events in the process of follicular development and hence, is important in determining ovulation rate. Moreover, it appears that the mechanisms that the oocyte uses to control these processes differ between species with low and high ovulation rate phenotypes.
    No preview · Article · Feb 2003 · Reproduction (Cambridge, England) Supplement
  • M Sadighi · K J Bodensteiner · AE Beattie · S M Galloway

    No preview · Article · Jul 2002 · Animal Genetics
  • S M Galloway · S M Gregan · T Wilson · K P McNatty · J L Juengel · O Ritvos · G H Davis
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    ABSTRACT: BMP15, also known as growth and differentiation factor 9B (GDF9B), is a member of the transforming growth factor beta superfamily (TGFbeta) which in humans, rodents and sheep is expressed exclusively in the oocyte. BMP15 is closely related to GDF9, another oocyte-specific member of this superfamily which has been shown to be essential for early ovarian folliculogenesis. Inactivation of the BMP15 gene in mice has shown only minor effects on fertility. However, Inverdale and Hanna lines of sheep carry naturally occurring mutations in BMP15 which highlight differences in the action of this gene between mice and other mammals. Sheep which are heterozygous show an increase in ovulation rate whereas homozygotes are infertile. The granulosa cell receptor which mediates the BMP15 response has not yet been identified, but the discovery that a point mutation in the BMP1B receptor in Booroola sheep is responsible for increased ovulation rate highlights the importance of the TGFbeta signalling molecules in early folliculogenesis.
    No preview · Article · Jun 2002 · Molecular and Cellular Endocrinology
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    G W Montgomery · S M Galloway · G H Davis · K P McNatty
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    ABSTRACT: Sheep provide a valuable model for studying the genetic control of ovulation rate. Recent progress includes the identification of mutations in BMP15 (bone morphogenetic protein 15) that increase ovulation rate in heterozygous carriers and block follicular development in homozygous carriers. The genes characterized to date appear to act principally within the ovary and result in earlier maturity of granulosa cells and reduced follicular size. There may also be other sites of action, and increased FSH concentrations appear to be important in the expression of the FecB phenotype. A new locus on the X chromosome in New Zealand Coopworth sheep increases ovulation rate by about 0.4 and is maternally imprinted. Results from studies in the Cambridge and Belclare breeds indicate that further genes remain to be characterized. Finding the first mutations leading directly to variation in ovulation rate is likely to speed up the identification and molecular analysis of these other genes. There is still much to learn about follicular development and the control of litter size from genetic models in sheep.
    Full-text · Article · Jul 2001 · Reproduction (Cambridge, England)
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    ABSTRACT: A medium-density linkage map of the ovine genome has been developed. Marker data for 550 new loci were generated and merged with the previous sheep linkage map. The new map comprises 1093 markers representing 1062 unique loci (941 anonymous loci, 121 genes) and spans 3500 cM (sex-averaged) for the autosomes and 132 cM (female) on the X chromosome. There is an average spacing of 3.4 cM between autosomal loci and 8.3 cM between highly polymorphic [polymorphic information content (PIC) > or = 0.7] autosomal loci. The largest gap between markers is 32.5 cM, and the number of gaps of > 20 cM between loci, or regions where loci are missing from chromosome ends, has been reduced from 40 in the previous map to 6. Five hundred and seventy-three of the loci can be ordered on a framework map with odds of > 1000 : 1. The sheep linkage map contains strong links to both the cattle and goat maps. Five hundred and seventy-two of the loci positioned on the sheep linkage map have also been mapped by linkage analysis in cattle, and 209 of the loci mapped on the sheep linkage map have also been placed on the goat linkage map. Inspection of ruminant linkage maps indicates that the genomic coverage by the current sheep linkage map is comparable to that of the available cattle maps. The sheep map provides a valuable resource to the international sheep, cattle, and goat gene mapping community.
    Full-text · Article · Jul 2001 · Genome Research
  • K P McNatty · J L Juengel · T Wilson · S M Galloway · G H Davis
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    ABSTRACT: Ovulation rate in mammals is determined by a complex exchange of endocrine signals between the pituitary gland and the ovary, and by paracrine signals within ovarian follicles between the oocyte and its adjacent somatic cells. One approach to identifying factors regulating ovulation rate is to find mutations that influence the target phenotype and, in this context, sheep are proving to be remarkable experimental models. Recently, in three sheep families, namely Inverdale, Hanna and Booroola, the inherited mutation was mapped to a specific region of the sheep X chromosome (Inverdale, Hanna) or sheep chromosome 6 (Booroola) and in each, a point mutation was identified in genes from the bone morphogenetic protein (BMP) relatives of the transforming growth factor beta superfamily or their receptors. In Inverdale (I) and Hanna (H) sheep, separate point mutations were identified in the BMP15 gene corresponding to sites in the mature peptide coding region of the BMP15 growth factor (also known as growth differentiation factor 9B; GDF9B). Expression of the BMP15 gene was located exclusively in oocytes from the primary stage of follicular growth. There is a complete block of normal follicular development in females carrying two copies of the Inverdale mutation (II), two copies of the Hanna mutation (HH), or one copy of each mutation (HI). Increased ovulation rates are found in females with only one copy of either mutation (I+ or H+). In Booroola sheep, a point mutation was identified in the highly conserved intracellular serine threonine kinase signalling domain of the BMP-1B receptor. Within the ovary, this gene is expressed in oocytes in primordial and pre-antral follicles and in granulosa cells from the primary stage of growth as well as in corpora lutea. The effect of the Booroola mutation is additive for ovulation rate: animals with one copy of the mutation have an ovulation rate of 3 or 4, whereas those with two copies have an ovulation rate of between 5 and 14. Physiological studies of the above mutations demonstrate that the oocyte plays an active role with respect to its adjacent somatic cells during follicular development and support the hypothesis that the oocyte has a significant influence on the number of follicles that proceed to ovulation.
    No preview · Article · Feb 2001 · Reproduction Fertility and Development
  • L M Cambridge · J M Lumsden · M Sadhigi · S M Galloway

    No preview · Article · Jan 1998 · Animal Genetics
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    ABSTRACT: Three genes--parathyroid hormone-like hormone (PTHLH), insulin-like growth factor 1 (IGF 1), and retinoic acid receptor gamma (RARG)--have been mapped to sheep (Ovis aries) chromosome 3 (OAR 3). The order and genetic distances between loci on OAR 3 are similar to those on cattle (Bos taurus) chromosome 5, as expected from their close evolutionary relationship. The OAR 3 linkage map shows conserved synteny with human chromosome 12, but there are at least two rearrangements in gene order between the species.
    No preview · Article · Feb 1997 · Cytogenetics and cell genetics
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    S M Galloway · V Hanrahan · K G Dodds · M D Potts · A M Crawford · D F Hill
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    ABSTRACT: A genetic linkage map of the ovine X chromosome containing type I and type II markers has been constructed. The map contains 7 known gene markers and 14 microsatellite markers with a recombination length of 141.9 cM. Segregation of polymorphic markers was observed in a three-generation pedigree containing 480 animals. The maximum number of informative meioses was 912. Additional information was obtained for some markers by following segregation in the AgResearch International Mapping Flock, consisting of nine three-generation full-sib pedigrees. A pseudoautosomal region containing two markers has been identified at one end of the linkage map. Comparisons with mouse and human X chromosomes confirms the observation of Ohno (1973) that the gene content of the mammalian X chromosome is retained. In particular, the conserved grouping of the genes PHKA1, ATP7A, and XIST observed in both the human and the mouse X chromosome appears to be conserved in the sheep X chromosome, and XIST has been mapped to near the center of the chromosome. This study provides the first reported genetic linkage map combining both type I and type II markers for any ruminant X chromosome.
    Full-text · Article · Sep 1996 · Genome Research
  • D J Tisdall · L D Quirke · S M Galloway

    No preview · Article · Jul 1996 · Mammalian Genome
  • J M Penty · E A Lord · K G Dodds · S M Galloway · G W Montgomery

    No preview · Article · May 1995 · Mammalian Genome
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    ABSTRACT: The 5' untranslated region (UTR) of beta A inhibin mRNA was compared in a variety of sheep tissues, using primer extension. Considerable variation in the length and number of 5' extended products were noted between tissues. Specific bands were noted in ovarian follicular RNA, which were also present in samples from corpora lutea, stroma, and placental cotyledon RNA. Other extended products were observed in RNA from corpora lutea, stroma, cotyledon, pituitary, bone marrow, frontal cortex, medial basal hypothalamus, adrenal, liver, and kidney, which were not present or weakly represented in follicular RNA. Additional tissue-specific bands were noted in testis and bone marrow RNA. No specific differences in the lengths of the 5' UTR of the beta A inhibin mRNA were observed in sheep homozygous for the Booroola fecundity gene FecB, in any tissue studied. The coding region of ovine beta A inhibin cDNA was sequenced and a genetic polymorphism confirmed within or close to the ovine beta A inhibin gene. We conclude that the beta A inhibin gene is expressed widely in the sheep. Furthermore there is variation in the length of the 5' UTR of beta A inhibin mRNA between male and female gonads and other tissues, implying that expression of this gene is differentially controlled. However, the FecB mutation does not affect mRNA splicing events or the initiation site used in ovarian transcription. The mechanism by which the FecB mutation influences the amounts of beta A inhibin mRNA, follicle-stimulating hormone (FSH) secretion and ovulation rate has still to be elucidated.
    No preview · Article · Jan 1995 · Molecular Reproduction and Development

Publication Stats

833 Citations
101.77 Total Impact Points

Institutions

  • 1993-2008
    • University of Otago
      • • Department of Biochemistry
      • • Centre for Gene Research
      Taieri, Otago Region, New Zealand
  • 2001
    • University of Queensland
      • Queensland Children’s Medical Research Institute (QCMRI)
      Brisbane, Queensland, Australia