title: Development of multidrug resistance type I Cmdr1 expression in chicken embryonic gonads.
abstract: A primary role of P-glycoprotein (P-gp), encoded by the multidrug resistance type I gene, is to protect against naturally occurring xenotoxics. Recently, the preferential expression of chicken multidrug resistance type I (Cmdr1) was identified in the embryonic gonads during the early periods of development. Here we investigated the expression of Cmdr1 and P-gp in the gonads during embryogenesis, and compared to that in the ovarian follicles of domestic hens (Gallus gallus). As revealed by immunohistochemistry, P-gp was highly expressed in theca cells of mature follicles, whereas the expression was low in immature follicles. Immunohistochemical analysis showed that expression of Cmdr1-type P-gp was very low in embryonic gonads. Cmdr1 mRNA was undetectable in the gonads of 5-day embryos (E5) by RT-PCR, whereas Cmdr1 mRNA was significantly detectable in the developing gonads at E9 and E21. In the testicular tissues, germ cells were distributed along developing seminiferous cords as identified by a specific marker gene, whereas Cmdr1-type P-gp positive cells were observed evenly on testicular tissues. Collectively, it is concluded that Cmdr1 expression is initiated in the chicken ovary and testis after sexual differentiation, but expression of Cmdr1-type P-gp is very low through embryogenesis.
authors: Laboratory of Reproductive Physiology and Biotechnology, Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.
authors: K
authors: K
authors: Yamada
authors: N
authors: N
authors: Shibuya
authors: S
authors: S
authors: Aramaki
authors: S
authors: S
authors: Okuno
authors: T
authors: T
authors: Soh
authors: N
authors: N
authors: Yamauchi
authors: M-A
authors: MA
authors: Hattori
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002645:Chickens / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006066:Gonads / Q000196:embryology* / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D013799:Theca Cells / Q000166:cytology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012333:RNA, Messenger