Reproductive and developmental effects of transovarian exposure to o,p'-DDT in Japanese quails.
Avian species have the possible risk of embryonic exposure to persistent, lipophilic environmental contaminants, such as dichlorodiphenyltrichloroethane (DDT), by transfer of chemicals accumulated in mother birds to eggs. To model developmental and reproductive disorders of wild birds living in contaminated areas, we exposed Japanese quails in ovo to o,p'-DDT prior to incubation. A positive estrogenic substance diethylstilbestrol (DES; 1 and 10 ng/g of egg) and o,p'-DDT (1-100 microg/g of egg) were injected into the yolk before incubation. Treatment with o,p'-DDT (10 or 100 microg/g) but not with DES significantly reduced the hatchability of eggs. After sexual maturation, o,p'-DDT affected eggshell formation in female quails but had little influence on laying; high doses of o,p'-DDT significantly reduced eggshell strength, shell weight, and shell thickness, and several females treated with 100 microg o,p'-DDT/g laid eggs lacking shells. Diethylstilbestrol decreased egg production itself but had little effect on the eggshell. Both o,p'-DDT and DES caused dose-dependent shortening of the left oviduct and abnormal development of the right oviduct in females, while testis asymmetry was observed in males treated with a high dose of DES. In the uterus of the oviduct, the mRNAs for calcium-regulating factors osteopontin and calbindin D28K were reduced by both treatments, particularly that with o,p'-DDT. The results indicated that transovarian exposure to o,p'-DDT could bring about population declines in avian species through loss of fecundity caused by depression of hatchability and dysfunction of the reproductive tract.
Kamata
Ryo
R
Research Centre for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. kamata.ryo@nies.go.jp
Shiraishi
Fujio
F
Takahashi
Shinji
S
Shimizu
Akira
A
Shiraishi
Hiroaki
H
D000818:Animals; D064026:Calbindins; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000187:drug effects / Q000235:genetics; D052284:Clutch Size / Q000187:drug effects; D003370:Coturnix / Q000196:embryology* / Q000502:physiology*; D003634:DDT / Q000008:administration & dosage* / Q000633:toxicity*; D004054:Diethylstilbestrol / Q000008:administration & dosage / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004528:Egg Shell / Q000002:abnormalities / Q000187:drug effects / Q000254:growth & development; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D048788:Growth and Development / Q000187:drug effects*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D053495:Osteopontin / Q000187:drug effects / Q000235:genetics; D010057:Oviducts / Q000002:abnormalities / Q000187:drug effects; D011374:Progesterone / Q000097:blood; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D015203:Reproducibility of Results; D012098:Reproduction / Q000187:drug effects* / Q000502:physiology; D064030:S100 Calcium Binding Protein G / Q000187:drug effects / Q000235:genetics; D013737:Testis / Q000002:abnormalities / Q000187:drug effects; D018675:Toxicity Tests
D064026:Calbindins; D012333:RNA, Messenger; D064030:S100 Calcium Binding Protein G; D053495:Osteopontin; D011374:Progesterone; D004054:Diethylstilbestrol; D003634:DDT; C016340:o,p'-DDT; D002786:Cholesterol Side-Chain Cleavage Enzyme