Type

Journal Article

Authors

A.C.O. Evans
M Mihm
M Diskin
D Matthews
M A Crowe
B Loftus
F J Mulligan
R M Alibrahim
N Forde
J A Browne
and 3 others

Subjects

Biochemistry

Topics
estradiol cellular microenvironment insulin like growth factor i luteinization metabolism real time polymerase chain reaction insulin gene expression regulation reverse transcriptase polymerase chain reaction female cattle progesterone genetics ovarian follicle caloric restriction blood biosynthesis estrous cycle 3 hydroxybutyric acid phosphoproteins steroidogenic acute regulatory protein time factors cell differentiation follicular fluid animals lactation ultrasonography blood glucose

Effect of the metabolic environment at key stages of follicle development in cattle: focus on steroid biosynthesis. (2012)

Abstract Cellular mechanisms that contribute to low estradiol concentrations produced by the preovulatory ovarian follicle in cattle with a compromised metabolic status are largely unknown. To gain insight into the main metabolic mechanisms affecting preovulatory follicle function, two different animal models were used. Experiment 1 compared Holstein-Friesian nonlactating heifers (n = 17) and lactating cows (n = 16) at three stages of preovulatory follicle development: 1) newly selected dominant follicle in the luteal phase (Selection), 2) follicular phase before the LH surge (Differentiation), and 3) preovulatory phase after the LH surge (Luteinization). Experiment 2 compared newly selected dominant follicles in the luteal phase in beef heifers fed a diet of 1.2 times maintenance (M, n = 8) or 0.4 M (n = 11). Lactating cows and 0.4 M beef heifers had higher concentrations of β-hydroxybutyrate, and lower concentrations of glucose, insulin, and IGF-I compared with dairy heifers and 1.2 M beef heifers, respectively. In lactating cows this altered metabolic environment was associated with reduced dominant follicle estradiol and progesterone synthesis during Differentiation and Luteinization, respectively, and in 0.4 M beef heifers with reduced dominant follicle estradiol synthesis. Using a combination of RNA sequencing, Ingenuity Pathway Analysis, and qRT-PCR validation, we identified several important molecular markers involved in steroid biosynthesis, such as the expression of steroidogenic acute regulatory protein (STAR) within developing dominant follicles, to be downregulated by the catabolic state. Based on this, we propose that the adverse metabolic environment caused by lactation or nutritional restriction decreases preovulatory follicle function mainly by affecting cholesterol transport into the mitochondria to initiate steroidogenesis.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

A.C.O. Evans, M Mihm, M Diskin, D Matthews, M A Crowe, B Loftus, F J Mulligan, R M Alibrahim, N Forde, J A Browne and 3 others

Experts in our system

1
A.C.O. Evans
University College Dublin
Total Publications: 93
 
2
M G Diskin
Teagasc
Total Publications: 94
 
3
M A Crowe
Teagasc
Total Publications: 102
 
4
Brendan Loftus
University College Dublin
Total Publications: 21
 
5
F J Mulligan
University College Dublin
Total Publications: 18
 
6
N Forde
University College Dublin
Total Publications: 55
 
7
John A Browne
University College Dublin
Total Publications: 73