Heterozygous Inverdale ewes show increased ovulation rate sensitivity to pre-mating nutrition

2011 ◽  
Vol 23 (7) ◽  
pp. 866 ◽  
Author(s):  
K. J. Demmers ◽  
B. Smaill ◽  
G. H. Davis ◽  
K. G. Dodds ◽  
J. L. Juengel

This study aimed to determine whether ewes heterozygous (I+) for the Inverdale mutation of the bone morphogenetic protein-15 (BMP15) gene with high natural ovulation rate (OR) show similar sensitivity to nutritional manipulation as non-carriers (++). Increasing pre-mating nutrition results in OR increases in sheep, but whether this effect occurs in ewes with naturally high OR is unknown. Over 2 years, I+ or ++ ewes were given high (ad libitum) or control (maintenance) pasture allowances for 6 weeks prior to mating at a synchronised oestrus, with OR measured 8 days later. The high group increased in weight compared with controls (+5.84 kg; P < 0.01), accompanied by increased OR (+19%; P < 0.01). As well as having higher OR (+45%; P < 0.01), I+ ewes responded to increased feed with a larger proportional increase in OR (+27%; P < 0.01) compared with the response in ++ ewes (+11%; P < 0.05), suggesting an interaction between BMP15 levels and nutritional signals in the follicle to control OR. Although litter size increases only tended to significance (+12%; P = 0.06), extra feed resulted in over 50% of I+ ewes giving birth to more than three lambs, compared with 20–31% of I+ ewes on maintenance rations. This information can guide feed management of prolific Inverdale ewes prior to breeding.

Reproduction ◽  
2009 ◽  
Vol 138 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Jennifer L Juengel ◽  
Norma L Hudson ◽  
Martin Berg ◽  
Keith Hamel ◽  
Peter Smith ◽  
...  

Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are essential for ovarian follicular growth in sheep, whereas only GDF9 is essential in mice suggesting that the roles of these oocyte-derived growth factors differ among species. At present, however, there is only limited information on the action of BMP15 and GDF9 in other species. Thus, the aim of this experiment was to determine the effect of neutralizing GDF9 and/or BMP15in vivoon ovarian follicular development and ovulation rate in cattle through active immunization using the mature regions of the proteins or peptides from the N-terminal area of mature regions. Immunization with the BMP15 peptide, with or without GDF9 peptide, significantly altered (increased or decreased) ovulation rate. In some animals, there were no functional corpora lutea (CL), whereas in others up to four CL were observed. From morphometric examination of the ovaries, immunization with GDF9 and/or BMP15 reduced the level of ovarian follicular development as assessed by a reduced proportion of the ovarian section occupied by antral follicles. In addition, immunization against GDF9 and/or BMP15 peptides reduced follicular size to <25% of that in the controls. In conclusion, immunization against GDF9 and BMP15, alone or together, altered follicular development and ovulation rate in cattle. Thus, as has been observed in sheep, both GDF9 and BMP15 appear to be key regulators of normal follicular development and ovulation rate in cattle.


2020 ◽  
Author(s):  
Gabriele Flossmann ◽  
Christine Wurmser ◽  
Hubert Pausch ◽  
Amabel Tenghe ◽  
Jörg Dodenhoff ◽  
...  

Abstract Background: Atypical external genitalia are often a sign of reproductive organ pathologies and infertility with both environmental or genetic causes, including karyotypic abnormalities. Genome-wide association studies (GWAS) provide a means for identifying chromosomal regions harboring deleterious DNA-variants causing such phenotypes. We performed a GWAS to unravel the causes of incidental cases of atypically small vulvae in German Landrace gilts. Results: A case-control GWAS involving Illumina porcine SNP60 BeadChip-called genotypes of 17 gilts with atypically small vulvae and 1,818 control animals (fertile German Landrace sows) identified a significantly associated region on the X-chromosome (P = 8.81 × 10 -43 ). Inspection of whole-genome sequencing data in the critical area allowed us to pinpoint a likely causal variant in the form of a nonsense mutation of bone morphogenetic protein-15 ( BMP15 , Sscrofa11.1_X:g.44618787C>T, BMP15:p.R212X). The mutant allele occurs at a frequency of 6.2% in the German Landrace breeding population. Homozygous gilts exhibit underdeveloped, most likely not functional ovaries and are not fertile. Male carriers do not seem to manifest defects. Heterozygous sows produce 0.41±0.02 (P=4.5 × 10 -83 ) piglets more than wildtype animals. However, the mutant allele’s positive effect on litter size accompanies a negative impact on lean meat growth. Conclusion: Our results provide an example for the power of GWAS in identifying the genetic causes of a fuzzy phenotype and add to the list of natural deleterious BMP15 mutations that affect fertility in a dosage-dependent manner, the first time in a poly-ovulatory species. We advise eradicating the mutant allele from the German Landrace breeding population since the adverse effects on the lean meat growth outweigh the larger litter size in heterozygous sows.


Endocrinology ◽  
2007 ◽  
Vol 148 (1) ◽  
pp. 393-400 ◽  
Author(s):  
Loys Bodin ◽  
Elisa Di Pasquale ◽  
Stéphane Fabre ◽  
Martine Bontoux ◽  
Philippe Monget ◽  
...  

Genetic mutations with major effects on ovulation rate and litter size in sheep were recently identified in three genes belonging to the TGFβ superfamily pathway: the bone morphogenetic protein 15 (BMP15, also known as GDF9b), growth differentiation factor 9 (GDF9), and BMP receptor type IB (also known as activin-like kinase 6). Homozygous BMP15 or GDF9 mutations raise female sterility due to a failure of normal ovarian follicle development, whereas heterozygous animals for BMP15 or GDF9 as well as heterozygous and homozygous animals for BMP receptor type IB show increased ovulation rates. In the present work, a new naturally occurring mutation in the BMP15 gene in the high prolific Lacaune sheep breed is described. The identified variant is a C53Y missense nonconservative substitution leading to the aminoacidic change of a cysteine with a tyrosine in the mature peptide of the protein. As for other mutations found in the same gene, this is associated with an increased ovulation rate and sterility in heterozygous and homozygous animals, respectively. Further in vitro studies showed that the C53Y mutation was responsible for the impairment of the maturation process of the BMP15 protein, resulting in a defective secretion of both the precursor and mature peptide. Overall, our findings confirm the essential role of the BMP15 factor in the ovarian folliculogenesis and control of ovulation rate in sheep.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gabriele Flossmann ◽  
Christine Wurmser ◽  
Hubert Pausch ◽  
Amabel Tenghe ◽  
Jörg Dodenhoff ◽  
...  

Abstract Background Atypical external genitalia are often a sign of reproductive organ pathologies and infertility with both environmental or genetic causes, including karyotypic abnormalities. Genome-wide association studies (GWAS) provide a means for identifying chromosomal regions harboring deleterious DNA-variants causing such phenotypes. We performed a GWAS to unravel the causes of incidental cases of atypically small vulvae in German Landrace gilts. Results A case-control GWAS involving Illumina porcine SNP60 BeadChip-called genotypes of 17 gilts with atypically small vulvae and 1818 control animals (fertile German Landrace sows) identified a significantly associated region on the X-chromosome (P = 8.81 × 10− 43). Inspection of whole-genome sequencing data in the critical area allowed us to pinpoint a likely causal variant in the form of a nonsense mutation of bone morphogenetic protein-15 (BMP15; Sscrofa11.1_X:g.44618787C>T, BMP15:p.R212X). The mutant allele occurs at a frequency of 6.2% in the German Landrace breeding population. Homozygous gilts exhibit underdeveloped, most likely not functional ovaries and are not fertile. Male carriers do not seem to manifest defects. Heterozygous sows produce 0.41±0.02 (P=4.5 × 10-83) piglets more than wildtype animals. However, the mutant allele’s positive effect on litter size accompanies a negative impact on lean meat growth. Conclusion Our results provide an example for the power of GWAS in identifying the genetic causes of a fuzzy phenotype and add to the list of natural deleterious BMP15 mutations that affect fertility in a dosage-dependent manner, the first time in a poly-ovulatory species. We advise eradicating the mutant allele from the German Landrace breeding population since the adverse effects on the lean meat growth outweigh the larger litter size in heterozygous sows.


Reproduction ◽  
2011 ◽  
Vol 142 (4) ◽  
pp. 565-572 ◽  
Author(s):  
Jennifer L Juengel ◽  
Laurel D Quirke ◽  
Stan Lun ◽  
Derek A Heath ◽  
Peter D Johnstone ◽  
...  

Sheep with a heterozygous inactivating mutation in the bone morphogenetic protein 15 (BMP15) gene experience an increased ovulation rate during either a natural oestrous cycle or a cycle in which exogenous FSH and eCG (gonadotrophins) are given to induce multiple ovulations. The primary aim of these studies was to determine whether ewes immunised against BMP15 would also show an improved superovulation rate following exogenous gonadotrophin treatment. A secondary aim was to determine the effects of BMP15 immunisation on ovarian follicular characteristics. In most ewes (i.e. >75%) immunised with a BMP15-keyhole limpet haemocyanin peptide in an oil-based adjuvant in order to completely neutralise BMP15 bioactivity, there was no superovulation response to exogenous gonadotrophins. In ewes treated with exogenous gonadotrophins following a BMP15-BSA peptide immunisation in a water-based adjuvant to partially neutralise BMP15 bioactivity, the ovulation rate response was similar to the control superovulation treatment groups. Characterisation of follicular function revealed that the water-based BMP15-immunised animals had fewer non-atretic follicles 2.5–3.5 or >4.5 mm in diameter compared with controls. Basal concentrations of cAMP were higher in granulosa cells from animals immunised against BMP15 than control animals. There were no significant differences in the concentrations of cAMP between granulosa cells from BMP15- and control-immunised animals when given FSH or hCG, although there were differences in the proportions of follicles in different size classes that responded to FSH or hCG. Thus, immunisation against BMP15 may have been causing premature luteinisation and thereby limiting the numbers of follicles recruited for ovulation following treatment with exogenous gonadotrophins.


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