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DNA methylation and transcription in a distal region upstream from the bovine AlphaS1 casein gene after once or twice daily milking.

Nguyen M, Boutinaud M, Pétridou B, Gabory A, Pannetier M, Chat S, Bouet S, Jouneau L, Jaffrezic F, Laloë D, Klopp C, Brun N, Kress C, Jammes H, Charlier M, Devinoy E - PLoS ONE (2014)

Bottom Line: Once daily milking (ODM) induces a reduction in milk production when compared to twice daily milking (TDM).Our results therefore shed light on mechanisms that help to explain how milk production is almost, but not fully, restored when TDM is resumed (15.1 ± 0.2 kg/day instead of 16.2 ± 0.2 kg/day, p<0.01).We now need to clarify whether the transcription of this novel RNA is a consequence of STAT5 interacting with the CSN1S1 distal region, or whether it plays a role in the chromatin structure of this region.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR1313 Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France.

ABSTRACT
Once daily milking (ODM) induces a reduction in milk production when compared to twice daily milking (TDM). Unilateral ODM of one udder half and TDM of the other half, enables the study of underlying mechanisms independently of inter-individual variability (same genetic background) and of environmental factors. Our results show that in first-calf heifers three CpG, located 10 kb upstream from the CSN1S1 gene were methylated to 33, 34 and 28%, respectively, after TDM but these levels were higher after ODM, 38, 38 and 33%, respectively. These methylation levels were much lower than those observed in the mammary gland during pregnancy (57, 59 and 50%, respectively) or in the liver (74, 78 and 61%, respectively). The methylation level of a fourth CpG (CpG4), located close by (29% during TDM) was not altered after ODM. CpG4 methylation reached 39.7% and 59.5%, during pregnancy or in the liver, respectively. CpG4 is located within a weak STAT5 binding element, arranged in tandem with a second high affinity STAT5 element. STAT5 binding is only marginally modulated by CpG4 methylation, but it may be altered by the methylation levels of the three other CpG nearby. Our results therefore shed light on mechanisms that help to explain how milk production is almost, but not fully, restored when TDM is resumed (15.1 ± 0.2 kg/day instead of 16.2 ± 0.2 kg/day, p<0.01). The STAT5 elements are 100 bp away from a region transcribed in the antisense orientation, in the mammary gland during lactation, but not during pregnancy or in other reproductive organs (ovary or testes). We now need to clarify whether the transcription of this novel RNA is a consequence of STAT5 interacting with the CSN1S1 distal region, or whether it plays a role in the chromatin structure of this region.

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Related in: MedlinePlus

Average milk yield for each udder half of the eight cows during the three periods.Milk yield from the left right udder is indicated by black squares, whereas that of the left one is indicated by grey diamonds. The three periods are: P1, twice daily milking of both udder halves; P2, twice daily milking of the right udder half and once daily milking of the left one; P3, twice daily milking of both udder halves. Significant differences between the amounts of milk produced by the two udder halves are indicated by stars: *** P<0.001; * P<0.05.
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pone-0111556-g002: Average milk yield for each udder half of the eight cows during the three periods.Milk yield from the left right udder is indicated by black squares, whereas that of the left one is indicated by grey diamonds. The three periods are: P1, twice daily milking of both udder halves; P2, twice daily milking of the right udder half and once daily milking of the left one; P3, twice daily milking of both udder halves. Significant differences between the amounts of milk produced by the two udder halves are indicated by stars: *** P<0.001; * P<0.05.

Mentions: During P1, the average milk yield did not differ between udder halves (16.3±0.17 kg/day, p-value  = 0.97) (Table 4). During the first 24 hours of P2, unilateral ODM of the left udder halves induced a sharp decrease in milk yield to an average value for the eight cows of 9.4 kg/day (Figure 2). The average milk yield during P2 (9.8 kg/day) remained lower than that of the contralateral udder (15.8 kg/day), exhibiting a significant decrease (P<0.001) which varied from 4.8 to 7.6 kg/day depending on the animal (Table 5).


DNA methylation and transcription in a distal region upstream from the bovine AlphaS1 casein gene after once or twice daily milking.

Nguyen M, Boutinaud M, Pétridou B, Gabory A, Pannetier M, Chat S, Bouet S, Jouneau L, Jaffrezic F, Laloë D, Klopp C, Brun N, Kress C, Jammes H, Charlier M, Devinoy E - PLoS ONE (2014)

Average milk yield for each udder half of the eight cows during the three periods.Milk yield from the left right udder is indicated by black squares, whereas that of the left one is indicated by grey diamonds. The three periods are: P1, twice daily milking of both udder halves; P2, twice daily milking of the right udder half and once daily milking of the left one; P3, twice daily milking of both udder halves. Significant differences between the amounts of milk produced by the two udder halves are indicated by stars: *** P<0.001; * P<0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4219721&req=5

pone-0111556-g002: Average milk yield for each udder half of the eight cows during the three periods.Milk yield from the left right udder is indicated by black squares, whereas that of the left one is indicated by grey diamonds. The three periods are: P1, twice daily milking of both udder halves; P2, twice daily milking of the right udder half and once daily milking of the left one; P3, twice daily milking of both udder halves. Significant differences between the amounts of milk produced by the two udder halves are indicated by stars: *** P<0.001; * P<0.05.
Mentions: During P1, the average milk yield did not differ between udder halves (16.3±0.17 kg/day, p-value  = 0.97) (Table 4). During the first 24 hours of P2, unilateral ODM of the left udder halves induced a sharp decrease in milk yield to an average value for the eight cows of 9.4 kg/day (Figure 2). The average milk yield during P2 (9.8 kg/day) remained lower than that of the contralateral udder (15.8 kg/day), exhibiting a significant decrease (P<0.001) which varied from 4.8 to 7.6 kg/day depending on the animal (Table 5).

Bottom Line: Once daily milking (ODM) induces a reduction in milk production when compared to twice daily milking (TDM).Our results therefore shed light on mechanisms that help to explain how milk production is almost, but not fully, restored when TDM is resumed (15.1 ± 0.2 kg/day instead of 16.2 ± 0.2 kg/day, p<0.01).We now need to clarify whether the transcription of this novel RNA is a consequence of STAT5 interacting with the CSN1S1 distal region, or whether it plays a role in the chromatin structure of this region.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR1313 Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France.

ABSTRACT
Once daily milking (ODM) induces a reduction in milk production when compared to twice daily milking (TDM). Unilateral ODM of one udder half and TDM of the other half, enables the study of underlying mechanisms independently of inter-individual variability (same genetic background) and of environmental factors. Our results show that in first-calf heifers three CpG, located 10 kb upstream from the CSN1S1 gene were methylated to 33, 34 and 28%, respectively, after TDM but these levels were higher after ODM, 38, 38 and 33%, respectively. These methylation levels were much lower than those observed in the mammary gland during pregnancy (57, 59 and 50%, respectively) or in the liver (74, 78 and 61%, respectively). The methylation level of a fourth CpG (CpG4), located close by (29% during TDM) was not altered after ODM. CpG4 methylation reached 39.7% and 59.5%, during pregnancy or in the liver, respectively. CpG4 is located within a weak STAT5 binding element, arranged in tandem with a second high affinity STAT5 element. STAT5 binding is only marginally modulated by CpG4 methylation, but it may be altered by the methylation levels of the three other CpG nearby. Our results therefore shed light on mechanisms that help to explain how milk production is almost, but not fully, restored when TDM is resumed (15.1 ± 0.2 kg/day instead of 16.2 ± 0.2 kg/day, p<0.01). The STAT5 elements are 100 bp away from a region transcribed in the antisense orientation, in the mammary gland during lactation, but not during pregnancy or in other reproductive organs (ovary or testes). We now need to clarify whether the transcription of this novel RNA is a consequence of STAT5 interacting with the CSN1S1 distal region, or whether it plays a role in the chromatin structure of this region.

Show MeSH
Related in: MedlinePlus