Identification of the sexually dimorphic gastrin-releasing peptide system in the lumbosacral spinal cord that controls male reproductive function in the mouse and Asian house musk shrew (Suncus murinus).
Several regions of the brain and spinal cord control male reproductive function. We previously demonstrated that the gastrin-releasing peptide (GRP) system, located in the lumbosacral spinal cord of rats, controls spinal centers to promote penile reflexes during male copulatory behavior. However, little information exists on the male-specific spinal GRP system in animals other than rats. The objective of this study was to examine the functional generality of the spinal GRP system in mammals using the Asian house musk shrew (Suncus murinus; suncus named as the laboratory strain), a specialized placental mammal model. Mice are also used for a representative model of small laboratory animals. We first isolated complementary DNA encoding GRP in suncus. Phylogenetic analysis revealed that suncus preproGRP was clustered to an independent branch. Reverse transcription-PCR showed that GRP and its receptor mRNAs were both expressed in the lumbar spinal cord of suncus and mice. Immunohistochemistry for GRP demonstrated that the sexually dimorphic GRP system and male-specific expression/distribution patterns of GRP in the lumbosacral spinal cord in suncus are similar to those of mice. In suncus, we further found that most GRP-expressing neurons in males also express androgen receptors, suggesting that this male-dominant system in suncus is also androgen-dependent. Taken together, these results indicate that the sexually dimorphic spinal GRP system exists not only in mice but also in suncus, suggesting that this system is a conserved property in mammals. J. Comp. Neurol. 525:1586-1598, 2017. © 2016 Wiley Periodicals, Inc.
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.
Kei
K
Tamura
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.|Laboratory for Aquatic Biology, Department of Fisheries, Graduate School of Agriculture, Kindai University, Nara, 631-0052, Japan.
Yasuhisa
Y
Kobayashi
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.
Asuka
A
Hirooka
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.
Keiko
K
Takanami
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.
Takumi
T
Oti
Laboratory of Animal Management and Resources, Department of Zoology, Okayama University of Science, Okayama, 700-0005, Japan.|Division of Bio-Resources, Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, Miyazaki, 889-1692, Japan.
Takamichi
T
Jogahara
Laboratory of Animal Management and Resources, Department of Zoology, Okayama University of Science, Okayama, 700-0005, Japan.
Sen-Ichi
SI
Oda
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.
Tatsuya
T
Sakamoto
Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama, 701-4303, Japan.
Hirotaka
H
Sakamoto
D000595:Amino Acid Sequence; D000818:Animals; D005260:Female; D005455:Fluorescent Antibody Technique; D019886:Gastrin-Releasing Peptide / Q000378:metabolism*; D007150:Immunohistochemistry; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D051379:Mice; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012098:Reproduction; D012727:Sex Characteristics; D012788:Shrews / Q000502:physiology*; D013116:Spinal Cord / Q000378:metabolism*
D019886:Gastrin-Releasing Peptide
RRID: AB_2060157; RRID: AB_2571636; RRID: AB_626757; Suncus murinus (suncus); gastrin-releasing peptide; male reproductive function; sexual dimorphism; spinal cord