PMID- 22266997
OWN - NLM
STAT- MEDLINE
DCOM- 20121220
LR  - 20120706
IS  - 1525-3163 (Electronic)
IS  - 0021-8812 (Linking)
VI  - 90
IP  - 7
DP  - 2012 Jul
TI  - Increased abundance of aromatase and follicle stimulating hormone receptor mRNA 
      and decreased insulin-like growth factor-2 receptor mRNA in small ovarian 
      follicles of cattle selected for twin births.
PG  - 2193-200
LID - 10.2527/jas.2011-4735 [doi]
AB  - Cattle genetically selected for twin ovulations and births (Twinner) exhibit 
      increased ovarian follicular development, increased ovulation rate, and greater 
      blood and follicular fluid IGF-1 concentrations compared with contemporary cattle 
      not selected for twins (Control). Experimental objectives were to 1) assess 
      relationships among aromatase (CYP19A1), IGF-1 (IGF1), IGF-2 receptor (IGF2R), 
      and FSH receptor (FSHR) mRNA expression in small (</=5 mm) antral follicles and 2) 
      determine their association with increased numbers of developing follicles in 
      ovaries of Twinner females. Ovaries were collected from mature, cyclic (d 3 to 6) 
      Twinner (n = 11), and Control (n = 12) cows at slaughter and pieces of cortical 
      tissue were fixed and embedded in paraffin. Expression of mRNA was evaluated by 
      in situ hybridization using (35)S-UTP-labeled antisense and sense probes for 
      CYP19A1, FSHR, IGF1, and IGF2R mRNA. Silver grain density was quantified within 
      the granulosa and theca cells of individual follicles (2 to 7 follicles/cow) by 
      Bioquant image analysis. Follicles of Twinners tended to be smaller in diameter 
      than Controls (1.9 +/- 0.1 vs. 2.3 +/- 0.1 mm; P = 0.08), but thickness of granulosa 
      layer did not differ (P > 0.1) by genotype. Relative abundance of CYP19A1 (P < 
      0.01) and FSHR (P < 0.05) mRNA was greater in granulosa cells of Twinners vs. 
      Controls, respectively, whereas IGF2R mRNA expression was less in both granulosa 
      (P < 0.01) and theca (P < 0.05) cells in follicles of Twinners vs. Controls, 
      respectively. Abundance of CYP19A1 mRNA in granulosa cells was correlated 
      negatively with IGF2R mRNA expression in both granulosa (r = -0.33; P < 0.01) and 
      theca (r = -0.21; P = 0.05) cells. Expression of IGF1 mRNA was primarily in 
      granulosa cells, including cumulus cells, and its expression did not differ 
      between Twinners vs. Controls (P > 0.10). Detected increases in CYP19A1 and FSHR, 
      but not IGF1, mRNA expression along with decreases in IGF2R mRNA expression in 
      individual follicles of Twinners support the hypothesis that increased follicular 
      development and steroidogenesis in Twinner females result from increased 
      extra-ovarian IGF-1 production. Furthermore, a reduction in follicular IGF2R mRNA 
      expression accompanied by a reduction in receptor numbers would increase 
      availability of free IGF-2 and its stimulation of follicular development in 
      Twinners.
FAU - Echternkamp, S E
AU  - Echternkamp SE
AD  - USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE 68933, USA. 
      Sherrill.Echternkamp@ars.usda.gov
FAU - Aad, P Y
AU  - Aad PY
FAU - Eborn, D R
AU  - Eborn DR
FAU - Spicer, L J
AU  - Spicer LJ
LA  - eng
PT  - Journal Article
DEP - 20120120
PL  - United States
TA  - J Anim Sci
JT  - Journal of animal science
JID - 8003002
RN  - 0 (RNA, Messenger)
RN  - 0 (Receptor, IGF Type 2)
RN  - 9002-68-0 (Follicle Stimulating Hormone)
RN  - EC 1.14.14.1 (Aromatase)
SB  - IM
MH  - Animals
MH  - Aromatase/genetics/*metabolism
MH  - Cattle/genetics/*metabolism
MH  - Female
MH  - Follicle Stimulating Hormone/genetics/*metabolism
MH  - Gene Expression Regulation/physiology
MH  - Ovarian Follicle/*metabolism
MH  - Pregnancy
MH  - RNA, Messenger/genetics/*metabolism
MH  - Receptor, IGF Type 2/genetics/*metabolism
MH  - Twins
EDAT- 2012/01/24 06:00
MHDA- 2012/12/21 06:00
CRDT- 2012/01/24 06:00
PHST- 2012/01/24 06:00 [entrez]
PHST- 2012/01/24 06:00 [pubmed]
PHST- 2012/12/21 06:00 [medline]
AID - jas.2011-4735 [pii]
AID - 10.2527/jas.2011-4735 [doi]
PST - ppublish
SO  - J Anim Sci. 2012 Jul;90(7):2193-200. doi: 10.2527/jas.2011-4735. Epub 2012 Jan 
      20.