Evidence of H beta 58, a gene involved in mammalian placental development, in the three-toed skink, Chalcides chalcides (Squamata: Scincidae), a viviparous placentotrophic reptile.
The H beta 58 gene, whose disruption in mice causes reabsorption of the embryo at 9.5 days post-conception, is believed to be essential for development of the placenta. Although the H beta 58 gene is well conserved in some Amniota, nothing is known about its presence in reptiles, some species of which have developed a chorioallantoic placenta. In this work, we investigated the expression of H beta 58 mRNA and protein in the three-toed skink, Chalcides chalcides. H beta 58 protein expression was found in the uterine epithelium beginning from the peri-ovulatory stage. However, it increased strongly at the moment of placental formation, when a high level of expression of mRNA and protein was also observed in the extra-embryonic membranes. The expression of H beta 58 mRNA and protein was maintained, although to a lesser degree, in the placenta during late pregnancy. It was also present in the early embryo. Finally, cloning and sequencing of a gene fragment revealed strong homology of the reptile gene with that of mammals. The high degree of conservation of the gene in amniote vertebrates and its presence in a viviparous squamate reptile (as in mammals) indicates an important role of this gene in the chorioallantoic placenta formation and development.
Paulesu
L
L
Institute of General Physiology, University of Siena, Siena, Italy. paulesu@unisi.it
Cateni
C
C
Romagnoli
R
R
Chellini
F
F
Angelini
F
F
Guarino
F M
FM
Rider
V
V
Imakawa
K
K
Bigliardi
E
E
D000482:Allantois / Q000737:chemistry; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics*; D002823:Chorion / Q000737:chemistry; D003001:Cloning, Molecular; D004848:Epithelium / Q000737:chemistry; D005260:Female; D015870:Gene Expression; D008969:Molecular Sequence Data; D010060:Ovulation; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D012104:Reptiles / Q000235:genetics*; D030162:Reptilian Proteins / Q000032:analysis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014599:Uterus / Q000737:chemistry; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; C498295:H beta 58 protein, Chalcides chalcides; D012333:RNA, Messenger; D030162:Reptilian Proteins; D033921:Vesicular Transport Proteins