Cytokines in the viviparous reproduction of squamate reptiles: interleukin-1 alpha (IL-1 alpha) and IL-1 beta in placental structures of a skink.
Placental viviparity is known in many species of squamate reptiles. Among these, some scincids have developed an epithelio-chorial chorio-allantoic placenta which in the structure of its central ridged zone is similar to those of certain therian mammalian species. A broad range of immunoregulatory peptides, cytokines, has been identified at the maternofetal interface of several species of mammals, either with invasive or non-invasive types of placenta. Thus we began to study whether interleukin-1, which is considered to play a crucial role in mammalian pregnancy, might also be involved in the viviparity of reptilian species. Placentae of Chalcides chalcides L. were processed by immunohistochemistry and incubated in a culture medium for different times. A very strong immunoreactivity for interleukin-1 alpha (IL-1 alpha) and for interleukin-1 beta (IL-1 beta) was present in the chorial epiblast and in uterine epithelial cells, with varying degree and localization in different periods of pregnancy. IL-1 beta was also released into the medium at different amounts during incubation. In light of the mammalian data, our results suggest that the role of cytokines in pregnancy may represent a significant event in the evolution of placental viviparity.
Paulesu
L
L
Institute of General Physiology, University of Siena, Italy.
Romagnoli
R
R
Marchetti
M
M
Cintorino
M
M
Ghiara
P
P
Guarino
F M
FM
Ghiara
G
G
D000818:Animals; D000911:Antibodies, Monoclonal; D003470:Culture Media; D005260:Female; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000032:analysis*; D008116:Lizards / Q000378:metabolism*; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D012098:Reproduction / Q000502:physiology*
D000911:Antibodies, Monoclonal; D003470:Culture Media; D007375:Interleukin-1