Submitted November 20, 2006
Returned for revision December 19, 2006
Accepted March 23, 2007
Mechanisms of Hormone Action
Gene Expression Profiles Linked to the Hormonal Induction
of Male-Effect Pheromone Synthesis in Goats (Capra
hircus)
Yukihide Momozawa ,
Yukari Takeuchi *,
Masaru Kitago ,
Koji Masuda ,
Yoshie Kakuma ,
Chie Hashizume ,
Toru Ichimaru ,
Kazutaka Mogi ,
Hiroaki Okamura ,
Tomohiro Yonezawa ,
Takefumi Kikusui ,
and
Yuji Mori
* To whom correspondence should be addressed. E-mail: aytake{at}mail.ecc.u-tokyo.ac.jp.
Abstract
The male effect is a well-known phenomenon in female
sheep and goats whereby a pheromone-induced activation of
reproductive function occurs. However, the molecule(s)
involved in this phenomenon are unknown. We investigated
gene expression profiles for the induction of male effect
pheromone synthesis using a PCR-based cDNA subtraction
strategy. We constructed two subtracted cDNA libraries
using mRNA from the skin of the head or rump region of
orchidectomized male goats with or without pheromone
induction using testosterone or dihydrotestosterone (DHT).
Both libraries were assumed to contain genes whose
expression increases with pheromone induction. Clones (n =
480) from each library were sequenced and identified using
BLAST to reveal 115 and 239 types of sequences in the
libraries of the head and rump region, respectively. Among
these, 12 genes were expressed in both libraries. We
conducted real-time PCR to further analyze their
expression using cDNA samples derived from
pheromone-producing or nonproducing skin from the head of
an ovariectomized female goat with or without DHT
implantation, respectively. For nine genes, we observed
significantly increased expression in samples following
DHT implantation. Among these, stearoyl-CoA desaturase 1
(SCD1) and elongation of long chain fatty acid
family member 5 (ELOVL5) genes showed more than
100-fold higher expression levels in pheromone-positive
samples, suggesting that the products of these genes may
be important in pheromone synthesis.
Key words:
Gene regulation •
Implantation •
Pheromones •
Seasonal reproduction •
Testosterone
