INVESTIGADORES
DA CUÑA Rodrigo Hernan
artículos
Título:
Early expression of zona pellucida proteins under octylphenol exposure in Cichlasoma dimerus (Perciformes, Cichlidae)
Autor/es:
GENOVESE, GRISELDA; DA CUÑA, RODRIGO; TOWLE, DAVID; MAGGESE, MARIA CRISTINA; LO NOSTRO, FABIANA
Revista:
AQUATIC TOXICOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2011 vol. 101 p. 175 - 185
ISSN:
0166-445X
Resumen:
An increasing number of widely used industrial and agricultural chemicals are being found to cause
endocrine disruption. In fishes, xenoestrogens can induce female proteins, and in some cases, the development
of testis-ova, demonstrating feminization of males. In this study we analyzed the effect of an
acute exposure of adult male Cichlasoma dimerus fish to estradiol (E2) and octylphenol (OP). E2 and OP
were injected at 10 and 50g/g body weight doses, respectively. After a single OP dose, liver was processed
for RNA extraction at 1, 3, 12, 24, and 72 h. PCR was performed using cDNA and primers for egg coat
or zona pellucida proteins (ZP). Genes encoding ZPB and ZPC isoforms were sequenced. E2-induced fish
were sacrificed at 72 h. Using multiple OP or E2 injections, blood and surface mucus were sampled on days
0, 3, 6, 9, and 13. On day 13 fish were sacrificed for liver and testis dissection. Histological examination of
E2 and OP-treated fish livers showed cellular disarray and intense cytoplasmatic basophilia within hepatocytes,
probably due to increased mRNA synthesis, as well as hypertrophied euchromatic nuclei, and
conspicuous nucleoli, indicative of augmented cell activity. An abnormal amount of sperm and immature
germ cells within the testis lumen were seen in treated fish, suggesting reproductive impairment. Both
plasma and mucus revealed the presence of ZP (and vitellogenin) at day 3 and thereafter with E2 treatment,
using Western and Dot blot techniques; OP effects were delayed in time. These results validate
the analysis of mucus by Dot blot as an easy and rapid technique to address endocrine disruption caused
by OP. Quantitative gene expression showed induction of liver ZPB and ZPC upon OP injection; muscle,
brain, and intestine did not express any ZP. Both ZPs were induced at 1 h post injection, but only ZPB
expression was statistically significant. At 12 h, both ZPs increased significantly, reaching the same levels
of E2-challenged males after 72 h. Therefore, OP mimicked the action of E2 with a prompt and strong
xenoestrogenic effect, evidenced by the early response through mRNA and protein expression of ZP and
the concomitant histological liver and testis alterations.