J~IFF
EFFECT OF ANTI ANDROGENS ON EARLY DEVELOPMENT OF TESTIS IN CHIC[( EMBRYOS. M O H A M E D A. SHAHI N Biology Dept., Faculty of Ldueation Ain S ham s Uni ve rsi ty, CAI RO-EG YPT. The role of androgens in sexual development and differentiation in avian embryos has been the subject of numerous investigations. Cyproterone acetate, a potent antiandrogen, was employed to study this problem. It was injected in a dosage of 0.5 mg into the yolk sac of 48 hours chick embryos. On the 2Oth day of incubation, the embryos were examined. A significant decrease in most of testicular parameters (testicular w e i g h t , s e m i n i f e r o u s tubule diameter,mean number of s~ermatogonia and Sertoli ceils) was observed when compared to control embryos. These results indicated that tkc~ antiandrogen cyproterone acetate exerted highly retardation effect on testicu]ar develop~Jent. This effect may be due to the inhibiting effect of the drug on the activity of androgens secreted by the embryo during earl2 embryogenesis.
The present study aims to investigate the h i s t o m o r p h o m e t r i c changes induced by the antiestrogen Clomiphe1~e citrate in the testis of newly born rats. Newly born rats were treated once daily for ~ days with 5ug Zlomilhene citrate(ClostJlbegyt,]
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THE ROLE OF FOLLICLE CELL NUCLEI IN AMPHIBIAN OOCYTE MATU TION M.N.Skobl~na~l, O.T.Kondratieva | and E.V.Orlov 2 Institute of Developmental Biology, Institute of Immunology, Moscow Actinomycin D (AD) inhibits gonadotropininduced oocyte maturation but sometimes AD is ineffective. The effects of AD on follicle maturation (1.5-2h pretreatment) were studied in Rana temporaria. Oocytes of all females remained at the GV stage in Ringer solution but matured (98-I00%) in response to pituitary extract (PE)(I/25-I/200 ml). Data on oocyte maturation after AD (25 gg/ml) treatment are given below (per cent for 100 oocytes): N/PE ]/25 1/50 I/;00 1/200 1-2 I-4 9-]2 74-88 I00 3-5 0-3 0-8 37-50 9]-99
XENOPUS
6-8
-
23-35
77-97
D7,
A TRANSLATIONALLY
CONTROLLED mRNA INVOLVED IN OOCYTE MATURATION R.C. Smith, M.B. Dworkin, and E. Dworkin-Rastl, Ernst Boehringer Institut, Vienna, Austria. XenoDus D7 RNA is a moderately abundant message whose expression is restricted to o o g e n e s i s a n d e a r l y embryogenesis. D7 mRNA is translationally repressed in oocytes and becomes recruited for t r a n s l a t i o n during maturation. D7 protein is detectable in the unfertilised egg and the early embryo. Sequencing of D7 cDNA clones predicts the D7 protein to be a 31kD polypeptide with no known homologies. Destruction of D7 mRNA in oocytes was performed by antisense DNA oligomer-mediated degradation. D7 protein failed to accumulate during progesterone-induced m a t u r a t i o n of t h e s e o o c y t e s . The loss of D7 protein affects the maturation process itself, significantly delaying the timecourse of germinal vesicle breakdown• Injection of SP6 D7 RNA transcripts into D7 mRNA-depleted oocytes substantially rescued this phenotype. D7 appears to be a novel gene involved in maturation of the oocyte.
98-]00
Similar results were obtained with Xenopus laevis follicles. Preliminary estimates (RIA) suggest that, before GVBD, progesterone content of all AD-treated follicles is reduced to a few per cent of the control. Hence, follicle cell nuclei appear to be involved in the control of progesterone synthesis and do not affect gonadotropininduced oocyte maturation.